HK1144738A - Methods and apparatus for in-order delivery of data packets during handoff - Google Patents

Description

Method and apparatus for in-order delivery of data packets during handoff

Claiming priority based on 35U.S.C. § 119

This patent application claims priority from provisional application No.60/951,176 entitled "METHOD, APPATUSAND SYSTEM FOR PRESERVING PACKET ORDER DURINGHAND-OFF" filed on 20.7.2007, provisional application No.60/971,500 entitled "IN-ORDER DELIVERY ALGORITHMS FOR FLSA/DAP SWITCH INUMB" filed on 11.9.2007, provisional application No.60/972,722 entitled "IN-ORDER DELIVERY ALGORITHMS FOR FLSA/DAP SWITCH IN UMB" filed on 14.9.2007, and provisional application No.60/973,095 entitled "METHOD AND PPAR FOR IN-ORDER DELIVERY OF PACKETS AT REVERSELINK HANDOFF" filed on 17.9.2007. All of these provisional applications have been assigned to the assignee of the present application and are expressly incorporated herein by reference.

Technical Field

The described aspects relate to wireless communication networks, and more particularly, to an apparatus, method, and system for providing in-order delivery of data packets in a wireless communication network.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, 3GPP LTE systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.

In general, a wireless multiple-access communication system may simultaneously support communication for multiple wireless terminals (alternatively referred to as access terminals). Each terminal communicates with one or more base stations via transmissions on the forward or reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-input single-output system, a multiple-input single-output system, or a multiple-input multiple-output (MIMO) system.

The term "handover" refers to the process of transferring an ongoing call or data session from one node of the core network to another node of the core network. In a wireless communication network, there may be a number of reasons why a handover may occur. These reasons include, but are not limited to: when an access terminal moves away from the area covered by one cell and into an area covered by another cell, the call is transferred (i.e., handed off) to the second cell in order to avoid call termination when the access terminal moves out of range of the first cell. In addition, when capacity for connecting new calls on a given cell is exhausted, existing or new calls from access terminals located in an area overlapping another cell are transferred to the other cell in order to free up some capacity in the first cell for other users.

The most basic form of handover is to redirect an ongoing call from its current cell (called the source cell) and the used channels in that cell to a new cell (called the target cell) and new channels. In a terrestrial network, the source cell and the target cell may be served by two different cell sites or by the same cell site (in the latter case, these two cells are often referred to as two sectors on the cell site). This handover where the source cell and the target cell are different cells (even if they are on the same cell site) is called an inter-cell handover. The purpose of inter-cell handover is to maintain a call while a user is moving out of the area covered by the source cell and entering the area of the target cell. A special case is possible where the source cell and the target cell are the same cell and only the channel used is changed during handover. Such a handover without cell change is called an intra-cell handover. The purpose of intra-cell handover is to change a channel that is experiencing interference or fading to a new, cleaner or less fading channel.

Conventional wireless communications include two types of data packets: a layer 2 (L2) data packet and a layer 3 (L3) data packet. The L3 data packets include application layer protocol data, such as Internet Protocol (IP) data packets. The L2 data packets are constructed using link layer protocols to make the packets more suitable for transmission over a wireless link. Therefore, the L2 data packets need to be processed again using the peer-to-peer link layer protocol to reconstruct the L3 packets. The L2 data packet may be constructed by a first network entity and tunneled to a second network entity for transmission to an Access Terminal (AT) via the second network entity. The L2 layer carries, for example, Radio Link Protocol (RLP) data packets and Routing Protocol (RP) packets.

One problem associated with handover is: l2 data packets may be delivered and/or received out of order at the application layer. For an L2 handover to a different access point in the physical layer, out-of-order packets are due to a new or different Radio Link Protocol (RLP) in the new route. In a network such as an ultra mobile broadband network, on the forward link, packets typically pass through an Access Gateway (AGW) to a Data Attachment Point (DAP) and then to an evolved base station (eBS), which then wirelessly transmits the packets to an access terminal via RLP. When the access terminal performs an L2 handoff, RLP packets are tunneled from the source eBS to the target eBS and sent to the access terminal. Thus, the target eBS and the AT must manage two competing RLP packet flows, one transmitted from the source eBS and the other generated locally by the local RLP. If the handoff is not well managed, packets from the source eBS may be delayed or dropped, causing communication to stop or failing to reassemble all-IP packets separately, thereby causing IP packet loss.

Another problem associated with handover is: l3 data packets may be delivered and/or received out of order at the application layer. For L3 handoff, Internet Protocol (IP) data packets flow from an Access Gateway (AGW) to a source DAP and then to a target eBS on one path, and from the AGW to the target DAP and then to the target eBS on another path. The target DAP and the target eBS are typically co-located or closer to each other so that the packet undergoes fewer network hops after handoff. Thus, in a UMB or like network, on the forward link, when an L3 handoff is performed, the AGW will be caused to send packets directly to the target DAP/eBS. Because direct packets from the AGW to the target eBS take a shorter path than packets that are still being transferred from the source DAP to the target eBS, this path switch may cause Transmission Control Protocol (TCP) data packets to arrive out of order AT the target eBS and then to the AT and the associated application being executed on the AT. At the application layer, out-of-order delivery of packets adversely affects a particular application. For example, applications implementing TCP may be negatively impacted because out-of-order packet delivery may cause the TCP receiver to generate duplicate Acknowledgement (ACK) messages and cause TCP to react by reducing its congestion window.

Therefore, there is a need to develop a scheme for preventing out-of-order delivery of data packets during handoff. A desired method, apparatus, system, etc., should increase the overall performance of AT-based applications that are adversely affected by out-of-order delivery of data packets. In addition, a desired solution should address forward link serving eBS network and/or DAP handoffs and reverse link serving eBS and/or DAP handoffs that occur over a network such as UMB.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

Methods, apparatuses, systems, and computer program products are provided for in-order delivery of data packets during handoff. The aspects provide for in-order delivery at forward link serving eBS/data attachment point (FLSE/DAP) handover and reverse link serving eBS/data attachment point (RLSE/DAP) handover. As such, the presented aspects provide significant improvements in throughput for Access Terminal (AT) -based applications, e.g., applications that rely on Transmission Control Protocol (TCP) during handoff in networks such as UMB.

According to one aspect, a method for providing in-order delivery of data packets during handover in a communication network is defined. The method is directed to forward link handover and occurs at a target network entity, such as a target base station. The method comprises the following steps: preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; and prioritizing (prioritizing) a transmission order of data packets AT the target network entity, wherein the prioritizing comprises AT least one of a first prioritization or a second prioritization, wherein the first prioritization comprises prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization comprises prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT. The method also includes transmitting the received data packet at the target network entity according to at least one of the first prioritization or the second prioritization.

At least one processor configured to provide in-order delivery of data packets during handoff in a communication network defines a related aspect. The processor includes: a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; a second module for prioritizing a transmission order of data packets AT the target network entity, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT. Further, the method includes a third module for receiving a data packet. Additionally, the processor includes a fourth module for transmitting the received data packet according to at least one of the first prioritization or the second prioritization.

Another related aspect is provided by a computer program product comprising a computer readable medium. The medium includes: a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity; a second set of codes for causing the computer to prioritize a transmission order of data packets AT the target network entity, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing layer 2 (L2) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer 3 (L3) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT. Moreover, the medium includes a third set of codes for causing the computer to receive a data packet at the target network entity. Additionally, the medium includes a fourth set of codes for causing the computer to transmit the received data packet according to at least one of the first prioritization or the second prioritization.

An apparatus defines yet another aspect. The device comprises: means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; means for prioritizing a transmission order of data packets AT the target network entity, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT. Further, the apparatus includes means for receiving a data packet. Additionally, the apparatus includes means for transmitting the received data packet according to at least one of the first prioritization or the second prioritization.

A target network device such as a target base station or the like provides yet another related aspect. The target network device includes a computer platform including a processor and a memory in communication with the processor. The device also includes a switching module stored in the memory and in communication with the processor. The handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity. The apparatus also includes a transceiver in communication with the processor. The transceiver is operable to receive data packets for transmission to the AT. The device also includes a data packet prioritization module stored in the memory and in communication with the processor. The prioritization module is operative to prioritize an order of transmission of data packets, wherein the prioritization includes at least one of a first prioritization or a second prioritization, wherein the first prioritization comprises prioritizing layer 2 (L2) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer 3 (L3) data packets to be transmitted to the AT, wherein the second prioritization comprises prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT, and the prioritization module transmits the received data packet according to at least one of the first prioritization or the second prioritization.

A further aspect is defined by a method for providing in-order delivery of data packets during handover in a communication network. The method is directed to forward link handover and occurs at a source network entity, such as a source base station. The method comprises the following steps: preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; forwarding layer 2 (L2) data packets destined for the AT from the source network entity to the target network entity; and forwarding a layer 3 (L3) data packet intended for the AT from the source network entity to the target network entity. The method also requires prioritizing forwarding the L2 data packets over forwarding the L3 data packets.

Related aspects are defined by at least one processor configured to provide in-order delivery of data packets during handoff in a communication network. The processor includes: a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; and a second module for forwarding a layer 2 (L2) data packet intended for the AT to the target network entity. The processor also includes a third module for forwarding a layer 3 (L3) data packet intended for the AT to the target network entity. Additionally, forwarding of the L2 data packet is prioritized over forwarding of the L3 data packet.

Another related aspect is provided by a computer program product comprising a computer readable medium. The medium includes: a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity; and a second set of codes for causing the computer to forward a layer 2 (L2) data packet destined for the AT to the target network entity. The medium further includes a third set of codes for causing the computer to forward a layer 3 (L3) data packet intended for the AT to the target network entity. Additionally, forwarding of the L2 data packet is prioritized over forwarding of the L3 data packet.

Yet another related aspect includes: means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; means for forwarding a layer 2 (L2) data packet intended for the AT to the target network entity; and means for forwarding a layer 3 (L3) data packet destined for the AT to the target network entity. Additionally, forwarding of the L2 data packet is prioritized over forwarding of the L3 data packet.

A source network device provides yet another aspect. The apparatus includes a computer platform including a processor and a memory in communication with the processor. The device also includes a switching module stored in the memory and in communication with the processor. The handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity. The apparatus also includes a transceiver in communication with the processor. The transceiver is operable to forward a layer 2 (L2) data packet destined for the AT to the target network entity; and forwarding a layer 3 (L3) data packet destined for the AT to the target network entity. In addition, the apparatus includes a data packet prioritization module stored in the memory and in communication with the processor. The prioritization module is operative to prioritize forwarding of the L2 data packets over forwarding of the L3 data packets.

A further method for providing in-order delivery of data packets during handover in a communication network is defined. The method is directed to forward link handoff and occurs at an access terminal, such as a wireless communication device. The method includes preparing for a handover of an Access Terminal (AT) from a source network entity to a target network entity. The method also includes receiving, AT the AT, the L2 data packets sent from the source network entity, and receiving, AT the AT, the data packets sent from the target network entity. Additionally, the method includes delivering the data packet to AT least one corresponding application on the AT such that L2 data packets sent from the source network entity are prioritized over data packets sent from the target network entity.

At least one processor configured to provide in-order delivery of data packets during handoff in a communication network provides a related aspect. The processor includes: a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; a second module for receiving an L2 data packet sent from the source network entity; and a third module for receiving a data packet sent from the target network entity. Additionally, the processor includes a fourth module for delivering the data packet to AT least one application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

The computer program product defines yet another related aspect. The computer program product includes a computer-readable medium. The medium includes a first set of codes for causing a computer to prepare a handover of an Access Terminal (AT) from a source network entity to a target network entity. The medium further includes a second set of codes for causing the computer to receive an L2 data packet sent from the source network entity; and a third set of codes for causing the computer to receive a data packet sent from the target network entity. Additionally, the medium includes a fourth set of codes for causing the computer to deliver the data packet to AT least one application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

An apparatus provides yet another related aspect. The device comprises: means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; means for receiving an L2 data packet sent from the source network entity; and means for receiving a data packet sent from the target network entity. Additionally, the apparatus includes means for delivering the data packet to AT least one application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

Yet another related aspect is provided by an access terminal device. The apparatus includes a computer platform including a processor and a memory in communication with the processor. The apparatus also includes a switching module stored in the memory and in communication with the processor. The handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity. Further, the device includes a transceiver in communication with the processor. The transceiver is operable to receive L2 data packets transmitted from a source network entity and to receive data packets transmitted from a target network entity. Additionally, the transceiver is further used to deliver the data packets to AT least one application on the AT such that L2 data packets from the source network entity are prioritized over data packets sent from the target network entity.

Another aspect is provided by another method for providing in-order delivery of data packets during handoff in a communication network. The method is directed to reverse link handover and occurs at a target network entity, such as a target base station. The method comprises the following steps: preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; and receiving, AT the target network entity, the L2 packet sent from the Access Terminal (AT) and partially processed prior to handover. The method further comprises the following steps: forwarding, at the target network entity, the received L2 packet to the target network entity; and receiving, at the target network entity, the indication signal transmitted from the source network entity. The indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

At least one processor configured to provide in-order delivery of data packets during handoff in a communication network provides yet another related aspect. The processor includes: a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; and a second module for receiving, AT the target network entity, the L2 packet sent from an Access Terminal (AT) and partially processed prior to handover. The processor further comprises: a third module for forwarding, at the target network entity, the received L2 packet to the target network entity; and a fourth module for receiving, at the target network entity, the indication signal transmitted from the source network entity. The indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

A computer program product comprising a computer readable medium defines yet another aspect. The computer readable medium includes: a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity; and a second set of codes for causing a computer to receive, AT the target network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to a handover. The computer readable medium further comprises: a third set of codes for causing a computer to forward the received L2 packet at the target network entity to the target network entity; and a fourth set of codes for receiving, at the target network entity, the indication signal transmitted from the source network entity. The indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

An apparatus provides yet another aspect. The device comprises: means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity; means for receiving, AT the target network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to handover; means for forwarding, at the target network entity, the received L2 packet to the target network entity; and means for receiving, at the target network entity, an indication signal transmitted from the source network entity. The indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

Yet another aspect is provided by a target network device comprising a computer platform including a processor and a memory in communication with the processor. The device also includes a switching module stored in the memory and in communication with the processor. The handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity. The apparatus also includes a transceiver in communication with the processor. The transceiver is operative to receive L2 packets transmitted from an Access Terminal (AT), forward the received L2 packets to the target network entity, and receive an indication signal transmitted from the source network entity. The indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

A method for providing in-order delivery of data packets during handoff in a communication network provides yet another aspect. The method is directed to reverse link handover and occurs at an access terminal, such as a wireless communication device. The method comprises the following steps: preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity; sending, via the target network entity, the partially processed L2 data packet prior to handover to the source network entity; and sending the new data packet to the target network entity. In addition, the target network entity forwards the IP data packets constructed from L2 data packets to the target network entity, and the target network entity sends all L2 data packets to an Access Gateway (AGW) before sending the new data packets.

At least one processor configured to provide in-order delivery of data packets during handoff in a communication network provides yet another related aspect. The processor includes: a first module for preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity; a second module for sending, via the target network entity, the partially processed L2 data packets prior to handover to the source network entity; and a third module for sending a new data packet to the target network entity. In addition, the target network entity forwards the L2 data packet to the source network entity, and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

Yet another aspect is provided by a computer program product comprising a computer readable medium. The medium includes: a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity; a second set of codes for causing the computer to send, via the target network entity, a partially processed L2 data packet prior to handover to the source network entity; and a third set of codes for causing the computer to transmit a new data packet to the target network entity. In addition, the target network entity forwards the L2 data packet to the source network entity, and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

An apparatus defines yet another aspect. The device comprises: means for preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity; means for sending, via the target network entity, the partially processed L2 data packet prior to handover to the source network entity; and means for sending the new data packet to the target network entity. In addition, the target network entity forwards the L2 data packet to the source network entity, and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

An access terminal device provides yet another aspect. The access terminal includes a computer platform including a processor and a memory in communication with the processor. The access terminal also includes a handoff module stored in the memory and in communication with the processor. The handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity. The device also includes a transceiver in communication with the processor. The transceiver is operable to send, via the target network entity, a partially processed L2 data packet prior to handover to the source network entity; and sending the new data packet to the target network entity. In addition, the target network entity forwards the L2 data packet to the source network entity, and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

Accordingly, aspects described and claimed herein provide for in-order delivery of data packets during handoff. The aspects provide for in-order delivery at forward link serving eBS/data attachment point (FLSE/DAP) handover and reverse link serving eBS/data attachment point (RLSE/DAP) handover. As such, the presented aspects provide significant improvements in throughput of applications, e.g., applications that rely on Transmission Control Protocol (TCP) during handover in networks such as UMB and the like.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the present description is intended to include all such aspects and their equivalents.

Drawings

The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements. In the drawings:

fig. 1 is a schematic diagram of a multiple access wireless communication system in accordance with an aspect;

FIG. 2 is a schematic diagram of a system for in-order delivery of data packets during forward link handoff in accordance with an aspect of the present invention;

fig. 3 is a schematic diagram of a system for in-order delivery of data packets during reverse link handoff in accordance with an aspect of the present invention;

FIG. 4 is a schematic diagram of a system for in-order delivery of data packets during a forward link handoff between access service networks, in accordance with an aspect of the present invention;

fig. 5 is a schematic diagram of a system for in-order delivery of data packets during a forward link handoff between data attachment points, in accordance with an aspect of the present invention;

fig. 6 is a schematic diagram of a system for in-order delivery of data packets during reverse link handoff between access service networks, in accordance with various aspects;

fig. 7 is a schematic diagram of a system for in-order delivery of data packets during reverse link handoff between data attachment points, in accordance with an aspect of the present invention;

fig. 8 is a block diagram of an example access terminal device, in accordance with aspects disclosed herein;

FIG. 9 is a block diagram of an exemplary base station in accordance with another aspect of the present invention;

FIG. 10 is a call flow diagram for in-order packet delivery during a forward link handoff between Forward Link Serving EBS (FLSE) networks, according to an aspect of the present invention;

fig. 11 is a call flow diagram for in-order packet delivery during a forward link handoff between data attachment points, according to another aspect;

FIG. 12 is a call flow diagram for in-order packet delivery during a reverse link handoff between Forward Link Serving EBS (FLSE) networks, according to an aspect of the present invention;

fig. 13 is a call flow diagram for in-order packet delivery during reverse link handoff between data connection points, according to another aspect; and

fig. 14 is a block diagram of a transmitter system and a receiver system according to another aspect.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details.

Additionally, various aspects of the disclosure are described below. It should be appreciated that the teachings herein may be embodied in a wide variety of forms and that any specific structure and/or function disclosed herein is merely exemplary. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure and/or functionality in addition to or other than one or more of the aspects set forth herein. As an example, various methods, devices, systems, and apparatus described herein are described in the context of determining characteristics of one or more wireless channels and providing a handover determination based in part on a magnitude of the determined characteristics. Those skilled in the art will appreciate that similar techniques may be applied to other communication environments.

As used in this application, the terms "component," "module," "system," and the like are intended to include a computer-related entity, such as but not limited to hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to: a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal.

Moreover, various aspects are described herein in connection with an access terminal, which can be a wired terminal or a wireless terminal. A terminal can also be called a system, device, subscriber unit, subscriber station, mobile device, remote station, remote terminal, access terminal, user terminal, communication device, user agent, user device, or User Equipment (UE). A wireless terminal may be a cellular telephone, a satellite telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless connection capability, a computing device, or other processing device connected to a wireless modem. Moreover, various aspects are described herein in connection with a base station. A base station may be utilized for communicating with wireless terminal(s) and may also be referred to as an access point, Node B, or some other terminology.

Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise indicated or clearly contradicted by context, the phrase "X employs A or B" is intended to mean any of the actual inclusive permutations. That is, any of the following examples satisfy the phrase "X employs a or B": x is A; b is used as X; or X employs A and B. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other systems. The terms "system" and "network" are often used interchangeably. A CDMA system may implement a wireless technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes wideband CDMA (W-CDMA) and other variants of CDMA. Further, cdma2000 covers IS-2000, IS-95 and IS-856 standards. TDMA systems may implement wireless technologies such as global system for mobile communications (GSM). The OFDMA system may implement wireless technologies such as evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE, and GSM are described in documents of the organization entitled "third Generation partnership project" (3 GPP). In addition, cdma2000 and UMB are described in documents of the organization entitled "third generation partnership project 2" (3GPP 2). In addition, these wireless communication systems may also include peer-to-peer (e.g., mobile node to mobile node) ad hoc network systems that typically use unpaired unlicensed spectrum, 802.xx wireless LANs, bluetooth, and any other short-range or long-range wireless communication technologies.

Various aspects or features will be presented in terms of systems that may include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems may include other devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. Combinations of these schemes may also be used.

In accordance with the presented aspects, a method, apparatus, system, and computer program product are defined for in-order delivery of data packets during handoff. The aspects provide for in-order delivery at forward link serving eBS/data attachment point (FLSE/DAP) handover and reverse link serving eBS/data attachment point (RLSE/DAP) handover. As such, the presented aspects provide significant improvements in throughput of applications, such as applications that rely on Transmission Control Protocol (TCP) during handover in networks such as UMB and the like.

Referring to fig. 1, a multiple access wireless communication system in accordance with one embodiment is illustrated. An access point 100(AP) includes multiple antenna groups, one including 104 and 106, another including 108 and 110, and an additional including 112 and 114. In fig. 1, only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal 116(AT) is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to access terminal 116 over forward link 120 and receive information from access terminal 116 over reverse link 118. Access terminal 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to access terminal 122 over forward link 126 and receive information from access terminal 122 over reverse link 124. In a FDD system, communication links 118, 120, 124 and 126 may use different frequency for communication. For example, forward link 120 may use a different frequency than that used by reverse link 118.

Each group of antennas and/or the area in which each group of antennas is designed to communicate is often referred to as a sector of the access point. In the depicted embodiment, antenna groups each are designed to communicate to access terminals in a sector, of the areas covered by access point 100.

In communication over forward links 120 and 126, the transmitting antennas of access point 100 use beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals 116 and 122. Moreover, an access point using beamforming to transmit to access terminals scattered randomly through its coverage causes less interference to access terminals in neighboring cells than an access point transmitting through a single antenna to all its access terminals.

An access point may be a fixed station used for communicating with the terminals and may also be referred to as an access point, a node B, or some other terminology. An access terminal may also be called an access terminal, User Equipment (UE), a wireless communication device, terminal, access terminal, or some other terminology.

Fig. 2 is a schematic diagram of a system 200 for providing in-order delivery of data packets during a forward link handoff in a communication network, according to one aspect. The system includes an Access Terminal (AT)210, the access terminal 210 being in a forward link handoff from a source network to a target network. Accordingly, the system 200 also includes a source network entity 220, such as a source base station, e.g., a forward link serving eBS and/or a source data attachment point located at an access node or the like; and a target network entity 230, such as a target base station, e.g., a forward link serving eBS and/or a target data attachment point located at an access node or the like. The system also includes an Access Gateway (AGW)240, the AGW240 receiving data packets from a core network (not shown in fig. 2) over a forward link. Prior to the L2 handover, the AT210 communicates over-the-air, i.e., directly with the source network entity 220, and after the L2 handover, the AT210 communicates over-the-air, i.e., directly with the target network entity.

Typically, the source network entity 220 forwards layer 2 (L2) or layer 3 (L3) data packets being processed during the handover to the target network entity 230. The L2 data packet may be in the form of a partial data packet that has begun transmission over the air but has not yet completed transmission, and/or the L2 data packet may be in the form of any packet that has been processed using a link layer protocol in a source network having a corresponding peer-to-peer protocol in AT 210. The L3 data packets may be in the form of Internet Protocol (IP) data packets that have not yet begun transmission over the air. The source network entity 220 prioritizes forwarding of data packets to the target network entity 230 such that L2 data packets are given a first priority and L3 packets are given a second priority.

If during the handover the target network entity 230 is also receiving new data packets from the AGW240, the target network entity 230 prioritizes the received data packets such that data packets from the source network entity 230 are given a first priority and data packets from the AGW240 are given a second priority. In this regard, the target network entity 230 buffers the new data packets until an indication is received from the source network entity 220 that the source network entity 230 has sent all remaining L2 data packets and L3 data packets destined for the AT 210.

AT210 provides prioritization such that L2 data packets forwarded from source network entity 220 during handoff are given priority over any data packets sent from target network entity 230 while the data packets are being delivered to an application resident on AT 210. In addition, when source network entity 220 has exhausted all data packets destined for AT210, source network entity 220 sends a refresh (flush) signal or message, such as a refresh packet, i.e., no data packets, to AT 210. The AT210 only delivers data packets constructed from source L2 data packets until a refresh packet is received, and then the AT210 begins delivering packets constructed from target L2 packets. The target network entity 230 buffers any data packets destined for the AT210 until an indication is received from the source network entity 220 that all L2 data packets and L3 data packets have been forwarded to the target network. Target network entity 230 then begins sending packets to AT210 that are received from sources other than the source network entity only after target network entity 230 has sent all packets from the source network to AT 210. Thus, in other words, the target network entity 230 prioritizes the transmission order of data packets according to AT least one of a first prioritization comprising prioritizing layer 2 (L2) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer 3 (L3) data packets to be transmitted to the AT, or a second prioritization comprising prioritizing L3 data packets received from a source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) (or data connection point (DAP)) and to be transmitted to the AT.

Referring to fig. 3, a schematic diagram is provided of a system 300 for providing in-order delivery of data packets during reverse link handoff in a communication network in accordance with yet another aspect. The system includes an Access Terminal (AT)210, the access terminal 210 being in a reverse link handover from a source network to a target network. Accordingly, the system 200 also includes a source network entity 220, such as a source base station located at a reverse link serving eBS network and/or a source data connection point located at an access node or the like; and a target network entity 230 such as a target base station located on the reverse link serving eBS network and/or a target data attachment point located at an access node or the like. The system also includes an AGW240 for transmitting the data packets over a reverse link to a core network (not shown in fig. 3).

In the reverse link scenario, the data packet originates from a single source, i.e., AT 210. The purpose of in-order delivery on the reverse link is to provide packets AT AGW240 from applications requiring in-order delivery in the order in which the packets were generated in AT 210. Thus, according to one aspect, AT210 may send an L2 data packet that is partially sent to source network entity 220 but has not yet completed over-the-air transmission to source network entity 220. These partial data packets are referred to herein as fragments. AT210 sends these partial data packets to source network entity 220 via a previously established protocol tunnel, or source network entity 220 may establish a tunnel if no tunnel currently exists.

In addition, AT 240 forwards the new data packet to target network entity 230, which target network entity 230 buffers the new data packet and does not send the new data packet to AGW240 until target network entity 230 receives an indication from source network entity 220 that the source network entity has completed forwarding all of the partial data packets to AGW240 or a predetermined period of time has elapsed after the handover.

Referring to fig. 4, a diagram of a particular system 400 that provides in-order delivery of data packets during a forward link handoff in accordance with an aspect is provided. In the illustrated example, the handover occurs at the serving access network level. The system 400 includes an Access Terminal (AT)210, the access terminal 210 being in a forward link handoff from a source Forward Link Serving Ebs (FLSE) network 410 to a target forward link serving access (FLSE) network 420. The system also includes a Data Attachment Point (DAP) access node 430 and AGW240 for forwarding data packets sent by the core network (not shown in fig. 4) on the forward link. Fig. 4 will be discussed in connection with actions taken by a particular node comprising system 400. Target FLSE

Upon detecting the AT210, the target FLSE420 sends AN Internet Protocol Tunnel (IPT) notification to all ANs in the route set (not shown in FIG. 4) indicating that the FLSE is the target FLSE. After sending the IPT notification, the target FLSE420 starts a timer indicating the maximum allowable wait period for pending (pending) L3 data to be received. The timer is reset each time the target FLSE420 receives a tunneled IP packet from the source FLSE 410. This timer is used to prevent situations where signaling messages sent from the source FLSE410 to the target FLSE indicating no subsequent transmissions of pending data are lost or not properly received by the target FLSE 420.

Upon receiving tunneled L2 data packets from the source FLSE410, the target FLSE420 begins forwarding these packets encapsulated in inter-route tunneling protocol (IRTP) or the like to the AT210 on a Radio Link Protocol (RLP) flow. Upon receiving the tunneled IP packets from the source FLSE410, the target FLSE420 begins forwarding these data packets to the AT210 on its own RLP flow. The target FLSE420 provides the tunneled partial L2 packet with a priority for scheduling compared to the tunneled all IP packet. In this regard, in one aspect, the target FLSE420 begins forwarding the tunneled partial L2 data packets before beginning forwarding the tunneled all IP data packets, but the target FLSE420 may begin forwarding the tunneled all IP data packets while some partial L2 data packets are still being transmitted or retransmitted. Also, it is not necessary that in each case the tunneled all-IP data packet arrive AT210 after the tunneled L2 data packet.

The target FLSE420 may not forward tunneled IP packets received directly from the DAP430 (if the DAP430 is a separate entity from the FLSE 420) or the AGW240 until an acknowledgement message is received indicating that there is no data to process and the previous FLSE, or the previously described timer defining the waiting period for the L3 data to process expires. Upon receipt of the acknowledgement message or expiration of the timer, the target FLSE420 can begin sending IP packets received directly from the DAP430 after forwarding tunneled packets received from the source FLSE 410. This process ensures that received packets tunneled from the source FLSE410 and tunneled from the DAP430 are forwarded to the AT210 in order.

Source FLSE

Upon receiving an IPT notification from the target FLSE420 indicating a change in the target FLSE, the source FLSE410 starts a timer indicating a waiting period for receiving IP packets from the DAP 430. The timer is typically set to approximately twice the duration of the backhaul delay. In addition, upon receiving the IPT notification, the source FLSE410 sends an acknowledgement message acknowledging receipt of the IPT notification and indicating the pending data and the previous FLSE status. According to a particular aspect, this acknowledgement message may be sent before waiting for the portion of the L2 data packet currently in transmission to complete transmission.

The source FLSE410 tunnels the L2 packets to the target FLSE420 according to a priority order described below. The first priority is provided to the partial packets that have begun transmission over the air AT the source FLSE410 but have not completed transmission, and/or any packets that have been processed using a link layer protocol in the source network with the corresponding peer-to-peer protocol in the AT. The second priority is provided to IP packets that have not yet begun transmission over the air at the source FLSE 410. After all partial packets and IP packets have been tunneled, a refresh signal or message, such as a refresh packet, is sent to AT210 via the target network entity. In one aspect, for example, the refresh packet does not carry any data and may have an RLP sequence number equal to the sequence number of the last byte sent at the source FLSE according to the RLP.

In most cases, the source FLSE410 is not required to send to the AT210 either a partial packet currently being transmitted or an IP data packet that has not yet begun transmission. This is because these data packets are already being tunneled to the target FLSE420, so sending them on the source FLSE410 does not add significant benefit. However, in some delay sensitive applications (such as voice over IP (voip), etc.), the benefit of less delay may be realized by sending the partial packets and/or IP packets at the source FLSE 410.

Once a handoff to the target FLSE420 occurs, the source FLSE410 does not withdraw (pull out) any IP data packets or any new packets from the IP queue to send over the air.

After the timer indicating the wait period for the IP packet expires, which means that no data packets are queued to be tunneled to the target FLSE420 at the source FLSE410, the source FLSE410 sends an acknowledgement message to the target FLSE420 indicating no data pending and the previous FLSE status.

DAP

It should be noted that the processing discussed with respect to the DAP430 is only required if the DAP is a separate entity from the FLSE 420.

Upon receiving an IPT notification indicating that the FLSE420 is the target FLSE, the DAP430 sends an acknowledgement message indicating receipt of the IPT notification. Once the DAP430 sends the acknowledgement message, the DAP430 begins sending all IP packets tunneled to the target FLSE420 according to the packet's priority. As described, upon receiving the PT notification, the other access nodes send an acknowledgement message indicating the reception of the PT notification.

AT

The AT will forward the data packets in-order to the corresponding application based on the following scheme. If a timer indicating a waiting period for receiving a refresh signal or message, such as a refresh packet, expires or a refresh packet is received for the RLP flow receiving the tunneled L2 packet and there are no unacknowledged or lost packets, AT210 sends all data packets to the application. Upon occurrence of the FLSE handoff, a timer indicating a waiting period for receipt of the refresh packet is started, typically immediately by AT210, on the RLP flow receiving the tunneled L2 data packet. This timer should be reset for each received packet. The AT210 forwards data packets from the RLP flow receiving IP packets to the application only after all data packets from the RLP flow receiving the tunneled L2 packets from the source FLSE410 have been forwarded to the application. It should be noted that the priority rules used AT210 are implemented only for flows requiring in-order delivery. For flows that can tolerate out-of-order delivery, such as VoIP, data packets can be forwarded out-of-order.

Referring to fig. 5, a schematic diagram of a particular system 500 for providing in-order delivery of data packets during a DAP handoff in accordance with an aspect is provided. In the illustrated example, the switching occurs at the data connection point level. The system 500 includes an Access Terminal (AT)210 that assumes a forward link handoff from a source DAP 520 to a target DAP 530. The system also includes a forward link serving eBS 510 network and an AGW240 for forwarding data packets sent by the core network (not shown in fig. 5) on the forward link. Fig. 5 will be discussed with respect to actions taken by a particular node comprising system 500. Target DAP

Upon receiving a DAP move request sent from AT210 or target DAP530, if the target DAP determines to become the target DAP, target DAP530 sends a registration request, such as a Mobile Internet Protocol (MIP) or proxy MIP registration request, to AGW 240.

Once the DAP530 receives a response to the registration request from the AGW240, the target DAP530 sends a DAP notification to the source DAP 520 and the FLSE510, as well as to other ANs in the route set (not shown in FIG. 5). After sending the DAP notification, the target DAP530 starts a timer indicating a waiting period for receiving pending L3 data packets. This timer is reset each time a tunneled IP data packet is received from source DAP 520. This timer is used to prevent situations where signaling messages sent from the source DAP 520 to the target DAP530 to confirm that no subsequent transmissions of pending data are lost or not properly received by the target DAP 530.

The target DAP530 does not forward direct IP data packets received from the AGW240 to the FLSE510 until all IP packets from the source DAP 520 have been forwarded to the FLSE 510. Receipt of an acknowledgement message indicating no pending data and no previous DAP is used by target DAP530 to know when the last packet from source DAP 520 has been received so that target DAP530 can begin forwarding direct IP packets.

Source DAP

Upon receiving the DAP notification sent from the target DAP530, the source DAP 520 starts a timer indicating a waiting period for IP packets. The value of the timer may be approximately equal to the one-way delay between the AGW240 and the base station at the FLSE510 via the source DAP 520. In other words, in one aspect, the timer is set to a value such that the old source/path of the data packet is allowed to be completely exhausted before resuming communication at the target. In addition, upon receiving the DAP notification sent from the target DAP530, the source DAP 520 sends an acknowledgement message indicating receipt of the DAP notification and indicating pending data and previous DAP status.

Upon expiration of the timer indicating the waiting period for receipt of the IP data packet, meaning that no data packets are queued to be tunneled to the target DAP530, the source DAP 520 sends an IPT notification acknowledgement to the target DAP530 indicating no pending data and the previous DAP.

FLSE

It should be noted that the processing discussed with respect to the FLSE430 is only required if the FLSE is a separate entity from the DAP.

Upon receiving an IPT notification acknowledgement sent from the source DAP 520 and indicating that there is no pending data, the FLSE510 can begin forwarding data packets received directly from the AGW240 or through the target DAP530 after having forwarded tunneled data packets received from the source DAP 520. AGW

Upon receiving the registration request sent from the target DAP530, AGW240 sends a registration response to the target DAP 530. Once the response has been sent, the AGW can begin forwarding the data packet directly to the target DAP 530.

Referring to fig. 6, a diagram of a particular system 600 that provides in-order delivery of data packets during reverse link handoff in accordance with an aspect is provided. In the illustrated example, the handover occurs at the serving access network level. The system 600 includes an Access Terminal (AT)210 that assumes a forward link handoff from a source reverse link serving ebs (rlse) network 610 to a target reverse link serving ebs (rlse) network 620. The system also includes a Data Attachment Point (DAP) access node 430 and an AGW240 for forwarding data packets over a reverse link to a core network (not shown in FIG. 6). Fig. 6 will be discussed with respect to actions taken by a particular node comprising system 600.

Target RLSE

Upon detection of AT210, the target RLSE620 sends IPT notifications to the source RLSE 610 and DAP430, as well as to other ANs in the route set (not shown in FIG. 6). The IPT notification is used to advertise that the RLSE620 is a target RLSE.

Upon receiving an acknowledgement message indicating receipt of the IPT notification and indicating pending data and previous RLSE status, the target RLSE620 starts a timer indicating a waiting period for receipt of an L3 data packet. This timer is used to prevent situations where IPT notifications sent from the source RLSE 610 to the target RLSE620 indicating that there is no data to process are lost or not correctly received by the target RLSE 620. In addition, target RLSE620 assigns a Reverse Link Assignment Block (RLAB) to AT 210.

For an in-order delivery flow, the target RLSE620 may not forward IP packets received from AT210 to AGW240 or DAP430 over the target route until an IPT notification is received from the source RLSE 610 indicating no data to process or a timer expires indicating a waiting period for receiving pending L3 data packets. For flows that can tolerate out-of-order delivery, such as VoIP, etc., buffering of data packets on the target RLSE620 may not be required and data packets may be forwarded at any time.

Source RLSE

Upon receiving the IPT notification sent from the target RLSE620, the source RLSE 610 sends an acknowledgement message indicating receipt of the IPT notification and indicating the pending data and the previous RLSE status. The source RLSE 610 also starts a timer indicating a wait period corresponding to a refresh signal or message (e.g., a refresh packet) for each flow requiring in-order delivery. This timer is reset each time a packet is received on the flow with a sequence number greater than the sequence number of any previously received packet.

For all flows requiring in-order delivery, if a timer indicating a wait period for receiving a refresh signal or message (e.g., a refresh packet) expires or a refresh packet corresponding to the RLP receiving the tunneled L2 data packet is received and there are no unacknowledged or lost packets, the source RLSE 610 sends an IPT notification to the target RLSE620 indicating that there is no data pending and a previous RLSE status.

DAP

Upon receiving the IPT notification from the target RLSE620, the DAP430 sends an acknowledgement message to the target RLSE620 indicating receipt of the IPT notification. All other nodes in the route set may also send an acknowledgement message after receiving an acknowledgement message indicating receipt of the IPT notification.

AT

After switching to the target RLSE620, the AT210 sends the L2 data packets on the source RLSE route to the target RLSE620 in the following order. The first priority is provided to the partial packets that have begun transmission over the air AT the source RLSE 610 but have not completed transmission, and/or any packets that have been processed using a link layer protocol in the source network that have a corresponding peer-to-peer protocol in the AT. After all partial packets and IP packets have been tunneled to the source RLSE 610, a refresh signal or message, such as a refresh packet, is sent. The refresh packet does not carry any data and it may have an RLP sequence number equal to the sequence number of the last byte sent at the source RLSE 610 according to the RLP. After transmitting the L2 partial packet on the source route, AT210 begins sending new packets to the target RLSE620 on the target route.

Referring to fig. 7, a schematic diagram of a particular system 700 for providing in-order delivery of data packets during a DAP handoff in accordance with an aspect is provided. In the illustrated example, the switching occurs at the data connection point level. The system 700 includes an Access Terminal (AT)210 that assumes a reverse link handoff from a source DAP 520 to a target DAP 530. The system also includes a reverse link serving eBS 710 network and an AGW240 for forwarding data packets transmitted over the forward link from a core network (not shown in fig. 7). Fig. 7 will be discussed with respect to actions taken by a particular node comprising system 700.

Target DAP

Upon receiving a DAP move request sent from AT210, the target DAP530 sends a registration request, such as a Mobile Internet Protocol (MIP) or proxy MIP registration request, to AGW 240.

Once the target DAP530 receives a response to the registration request from the AGW240, the target DAP530 sends a DAP notification to the source DAP 520 and FLSE 710, as well as other ANs in the route set (not shown in FIG. 7). After sending the DAP notification, the target DAP530 starts a timer indicating a waiting period for receiving pending L3 data packets from the source DAP 520. This timer is reset each time a tunneled IP data packet is received from source DAP 520. This timer is used to prevent situations where acknowledgements sent from source DAP 520 to target DAP530 have not been lost or correctly received by target DAP530 for subsequent transmissions of pending data.

Source DAP

Upon receiving the DAP notification sent from the target DAP530, the source DAP 520 sends an acknowledgement message indicating receipt of the DAP notification and indicating pending data and previous DAP status.

RLSE

Upon receiving the DAP notification acknowledgement sent from the target DAP530, the RLSE 510 starts a timer indicating a waiting period for receiving pending L3 data. The value of the timer may be equal to approximately twice the backhaul delay between the AGW240 and the base station at the RLSE 710.

After expiration of the timer indicating the wait period for receiving the L3 packet, RLSE 710 may begin tunneling data packets to the target DAP 530.

AGW

Upon receiving the registration request sent from the target DAP530, AGW240 sends a registration response to the target DAP 530.

Referring to fig. 8, in one aspect, an access terminal 210 comprises a mobile communication device, such as a mobile telephone or the like, operating in a wireless communication system. As can be appreciated, in addition to UMB networks, there are a variety of wireless communication systems that typically use different spectrum bandwidths and/or different air interface technologies. Example systems include CDMA (CDMA2000, EV DO, WCDMA) systems, OFDM or OFDMA (Flash-OFDM, 802.20, WiMAX) systems, FDMA/tdma (gsm) systems using FDD or TDD licensed spectrum, peer-to-peer (mobile node to mobile node) ad hoc network systems typically using unpaired unlicensed spectrum, 802.xx wireless LAN or bluetooth technologies.

Access terminal 210 includes a processor component 810 that performs processing functions associated with one or more components and functions described herein. Processor component 810 may include a single or multiple sets of processors or multi-core processors. Further, the processing component 810 can be implemented as an integrated processing system and/or a distributed processing system. Additionally, processing component 810 can include one or more processing subsystems, such as a processing subsystem capable of determining link quality or establishing link bindings in accordance with the presented aspects, or a processing subsystem required to execute the presented aspects.

The access terminal 210 also includes a memory 820, such as for storing a local version of the application/module being executed by the processor component 810. Memory 820 may include Random Access Memory (RAM), Read Only Memory (ROM), and combinations thereof. Additionally, in some aspects (not shown in fig. 8), the memory 820 includes a switching module, a data packet prioritization module, and/or the like.

In addition, access terminal 210 includes a communication module 830 for establishing and maintaining communication with one or more participants using hardware, software, and services as described herein. The communication module 830 may communicate between components on the access terminal 210 and between the access terminal 210 and external network devices (e.g., base stations 900 located on a communication network and/or devices connected serially or locally to the access terminal 210). Additionally, the communication module 830 may include a transceiver 832 for transmitting data packets.

Additionally, access terminal 210 may include a data storage device 840 for providing mass storage of information, databases, and programs used in connection with aspects described herein, and data storage device 840 may be any suitable combination of hardware and/or software.

Access terminal 210 may also include a user interface component 850 for receiving input from a user of access terminal 210 and generating output for presentation to the user. User interface component 850 may include one or more input devices including, but not limited to, a keyboard, a numeric keypad, a mouse, a touch-sensitive display screen, navigation keys, function keys, a microphone, a voice recognition component, any other mechanism capable of receiving input from a user, or any combination of the preceding. Further, user interface component 850 may include one or more output devices including, but not limited to, a display, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination of the preceding.

Referring to fig. 9, in one aspect, a network entity, such as a Base Station (BS)900, is configured to receive forward or reverse link data packets and provide in-order delivery of the forward or reverse link data packets. BS 900 comprises any type of network-based communication device, such as a network server operating on a communication network. The communication network may be a wired or wireless communication system or a combination of both and includes a wireless network over which the access terminal 210 operates.

BS 900 includes a processor component 910 for performing processing functions associated with one or more components and functions described herein. Processor component 910 may include a single or multiple sets of processors or multi-core processors. Further, the processor component 910 can be implemented as an integrated processing system and/or a distributed processing system.

BS 900 also includes a memory 920, such as for storing a local version of an application being executed by processor component 910. The memory 920 may include Random Access Memory (RAM), Read Only Memory (ROM), and combinations thereof.

In addition, BS 900 includes a communication module 930 for establishing and maintaining communications with one or more participants using hardware, software, and services as described herein. Communications module 930 may communicate between components at BS 900 and between BS 900 and external devices such as access terminal 210, including devices located on a communications network and/or devices connected serially or locally to BS 900. In one aspect, the communication module 930 is configured to prioritize data packets for providing in-order delivery of data packets during handoff.

Additionally, BS 900 may include data storage 940 for providing mass storage of information, databases, and programs used in connection with aspects described herein, and data storage 940 may be any suitable combination of hardware and/or software.

BS 900 may also include a user interface component 950 for receiving input from a user of BS 900 and generating output for presentation to the user. The user interface component 950 may include one or more input devices including, but not limited to, a keyboard, a numeric keypad, a mouse, a touch-sensitive display screen, navigation keys, function keys, a microphone, a voice recognition component, any other mechanism capable of receiving input from a user, or any combination of the preceding. Further, user interface component 950 may include one or more output devices including, but not limited to, a display, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination of the preceding.

FIG. 10 depicts a call flow diagram for in-order delivery of packets during a forward link handoff between forward link serving eBS networks in accordance with an aspect of the invention. It should be noted that although the in-order delivery packet scheme illustrated in fig. 10 is described with respect to an Ultra Mobile Broadband (UMB) network, the scheme described herein is not limited to UMB networks and may be implemented in other networks that rely on Mobile Internet Protocol (MIP), etc.

At event 1010, prior to the handoff, a layer 3 (L3) Internet Protocol (IP) data packet is being sent from the Access Gateway (AGW)240 to the Data Attachment Point (DAP)430 and then to the source Forward Link Serving EBS (FLSE) network 410. The FLSE network 410 processes the L3IP data packets into encapsulated layer 2 (L2) data packets, which the FLSE network 410 sends over the air to an Access Terminal (AT)210 via a reverse link protocol tunnel, referred to herein as route 2. AT event 1012, the AT210 selects the target Forward Link Serving EBS (FLSE) network 420 as the serving Base Station (BS) on the forward link due to signal strength factors and/or other factors that may affect service performance, network congestion, etc. As described, in the UMB architecture, the serving BS may be an evolved base station (eBS).

At event 1014, the target FLSE420 sends an IPT notification to the source FLSE410, and at event 1020, the target FLSE420 sends the same IPT notification to the Data Attachment Point (DAP) 430. The IPT notifications sent AT events 1014 and 1020 serve to inform the receiving entity that the target FLSE420 has been selected by the AT210 as the serving base station, in other words, that the FLSE420 has become the target FLSE. In addition, the IPT notification is communicated to other Access Nodes (ANs) in the route set (not shown in the call flow of fig. 10). In one aspect, after sending the IPT notification, AT event 1018, the target FLSE420 starts a timer indicating a waiting period for receiving pending L3 data designated for sending to the AT 210. This timer should be reset each time the target FLSE420 receives a tunneled IP packet sent from the source FLSE 410. This timer is used to address the situation where the Acknowledgement (ACK) sent from the source FLSE410 to the target FLSE420 in the subsequent event 1040 is lost or not properly received by the target FLSE 240.

At event 1016, once the source FLSE410 receives the IPT notification from the target FLSE420 (event 1014), the source FLSE410 starts a timer indicating a waiting period for receiving IP packets. In one aspect, this timer may be set to approximately twice the backhaul delay. Once this timer expires, an ACK indicating "no data pending" and "previous FLSE" is sent to the target FLSE420 (event 1040).

At event 1022, the source FLSE sends an IPT Notification Acknowledgement (ACK) to the target FLSE 420. The IPT Notification ACK may also include indicators indicating "pending data" and "previous FLSE", such as a set flag, etc. In most cases, the IPT Notification ACK is sent without the source FLSE waiting for the segment currently in transmission (i.e., the partially processed data packet) to complete the transmission.

Once the target FLSE420 receives the IPT Notification ACK with indicators indicating "pending data" and "previous FLSE", the target FLSE420 assigns a Forward Link Assignment Block (FLAB) to the AT210 AT event 1024. At event 1026, the DAP430 sends an IPT Notification ACK to the target FLSE420, where event 1026 may occur before event 1022 and/or event 1024.

After the source FLSE sends the IPT Notification ACK, at event 1028 the source FLSE410 tunnels the L2 data packet to the target FLSE420 according to the following sequence. First, segments that have begun transmission over the air but have not completed transmission AT the source FLSE410, in other words, partial packets that have not been acknowledged as being fully received by the source FLSE410, and/or any data packets that have been processed using the link layer protocol in the source network with the corresponding peer-to-peer protocol in the AT. Second, fragments of IP packets or IP packets that have not yet begun to be transmitted over the air at the source FLSE410 are not yet delivered. Third, after the last segment is sent, a refresh signal or message, such as a refresh packet, is sent. The refresh packet carries no data and is characterized by having the same Radio Link Protocol (RLP) sequence number as the sequence number of the last byte sent at the source FLSE according to the RLP. AT event 1030, the target FLSE420 sends an L2 packet (i.e., route 2 data packet encapsulated in route 1) to the AT 210.

Once the FLSE handoff has occurred, AT210 starts a timer indicating a waiting period for receiving refresh packets on the RLP flow that receives tunneled L2 packets AT event 1032. This timer allows AT210 to deliver in-order by passing packets from the RLP flow receiving IP packets only after passing (pass up) packets from the RLP flow receiving L2 packets transmitted through the tunnel. In addition, this timer is reset after each data packet is received.

While the IPT Notification ACK is in the process of being forwarded from the source FLSE410 to the target FLSE420 and the AT is still listening to the source FLSE410, the source FLSE may or may not serve the AT210 in the case of fragments with a currently being transmitted or fragments that have not yet begun transmission. Since these fragments are being tunneled to the target FLSE420 (event 1028), in most cases, there is no great advantage in serving these fragments at the source FLSE 410. However, in certain delay sensitive applications, such as voice over ip (voip), etc., the advantage in reducing delay may be achieved by additionally serving the fragments on the source FLSE 410. Fragments may be replicated with the L2 score forwarded through the tunnel, but AT210 is able to detect the replication with RLP. For example, in a VoIP application, the experienced jitter may be reduced by additionally serving the segments on the source FLSE 410.

At event 1034, the source FLSE sends the all-IP data packets to the target FLSE through the protocol tunnel in a layer 2 tunneling protocol (L2TP) according to the priority of the all-IP data packets. According to one aspect, the target FLSE420 provides a scheduling priority for tunneled L2 packets over tunneled all IP packets. Also in these aspects, the target FLSE420 begins servicing the tunneled L2 packets before beginning servicing the tunneled all IP packets. However, the target FLSE may start serving all IP packets that are tunneled while some fragments are still in transit. Thus, tunneled all-IP packets are not required to reach AT210 after receiving tunneled L2 packets. AT event 1036, the target FLSE420 sends the all-IP data packet to the AT210 over RLP route 1.

AT210 delivers the packet to the application according to the scheme described below. If the target FLSE420 receives a refresh signal or message, such as a refresh packet, for the RLP flow receiving the tunneled L2 packets, or a timer associated with a wait period for receiving the refresh signal or message has expired AT the AT210 and there are no unacknowledged or lost packets, then all data packets are sent to the application.

In addition, the data packet is delivered from the RLP flow (destination route) that receives the IP packet to the application only after the data packet has been delivered from the RLP flow (source route) that receives the L2 packet that was tunneled.

At event 1038, the DAP430 initiates sending of the all-IP packet to the target FLSE420 via the L3 tunnel according to the priority of the packet. However, the target FLSE420 will not service these all IP packets until an IPT Notification ACK is received with an indicator indicating "no pending data" and "previous FLSE" or a timer has expired indicating a wait period for receiving pending L3 data packets at the target FLSE 420.

At event 1040, after the timer indicating that the source FLSE410 is waiting for IP packets expires and no data packets are queued to be tunneled to the target FLSE420, the source FLSE410 sends an ACK to the target FLSE420 indicating "no data pending" and "previous FLSE". Upon receiving this ACK, the target FLSE420 can service data packets received directly from the DAP430 after the data packets received from the source FLSE have been serviced.

In certain aspects where the source FLSE410 includes the DAP430, the source FLSE410 may send an IPT Notification ACK indicating "no data pending" and "previous FLSE" immediately upon receiving the IPT Notification (event 1020). In these aspects, the source FLSE410 is not required to send ACKs indicating "pending data" and "previous FLSE".

FIG. 11 depicts a call flow diagram for in-order delivery of packets during a DAP handoff between data attachment point access networks, in accordance with an aspect of the present invention. It should be noted that although the in-order delivery packet scheme illustrated in fig. 11 is described with respect to an Ultra Mobile Broadband (UMB) network, the scheme described herein is not limited to UMB networks and may be implemented in other networks that rely on Mobile Internet Protocol (MIP), etc.

At event 1102, IP data packets are sent from the access network (AGW)240 to a source Data Attachment Point (DAP) Access Node (AN)520, the DAP access node 520 sends the IP data packets to a Forward Link Serving EBS (FLSE) network 510 via a layer 2 tunneling protocol (L2TP) tunnel. The FLSE network 510 sends IP data packets to the Access Terminal (AT) 210. AT event 1104, AT210 sends a DAP move request to the target DAPAN 530. The move request may be initiated based on a reduction in signal strength, network capacity, or any other performance characteristic that warrants a DAP handoff.

At event 1106, the target DAP AN530 sends a registration request, such as a Proxy Mobile IP (PMIP) or Mobile IP (MIP) registration request, to the AGW 240. Once the AGW240 has registered with the target DAP AN530, at event 1108, the AGW240 sends a registration response, such as a corresponding PMIP or MIP registration response, to the target DAP AN 530. Once the AGW240 has transmitted the registration response, the AGW240 begins forwarding the data packet directly to the target DAPAN 530. AT event 1110, the target DAP AN530 sends a DAP assignment to the FLSE510, which the FLSE510 then sends to the AT 210.

At event 1112, the AGW240 sends the all-IP data packet to the target DAP AN 530. While the target DAPAN 530 receives the all-IP data packet, at event 1114, the target DAPAN 530 is receiving the tunneled IP packet from the source DAP 520. The target DAP530 will not service the direct IP data packets from the AGW240 until all IP data packets from the source DAPAN 520 have been serviced. Receipt of AN ACK (event 1124 described earlier) by the target DAPAN 530 indicating "no pending data" and "previous DAP" informs the target DAP AN530 that the last data packet from the source DAP AN 520 has been received. Further, in some aspects of DAP handoff, the transmission by the target DAP AN530 to forward the data packets to AT210 can omit the L2 packets from the transmission.

At event 1116, the target DAP AN530 sends a DAP notification to the source DAP AN 520 and the FLSE 510. In addition, the DAP notification can be sent to other ANs in the route set (not shown in FIG. 11). Once the DAP notification has been sent, at event 1120, the target DAP AN530 starts a timer indicating a waiting period for pending layer three (L3) data. This timer is reset each time a tunneled IP data packet is received from the source DAP AN 520. A timer indicating a waiting period for pending L3 data is implemented to handle the situation where the ACK sent at event 1124 is lost or not received. In one aspect, the value of this timer may be approximately 50 milliseconds. Upon receiving the DAP notification, at event 1118, the source DAP AN 520 starts a timer indicating a waiting period for the IP data packet. In one aspect, the value of this timer may be approximately equal to the one-way delay between the AGW240 and the Base Station (BS) associated with the FLSE 510.

At event 1122, the source DAP 520 sends an ACK to the FLSE510 acknowledging receipt of the DAP notification and indicating "pending data" and "previous DAP". After expiration of the timer at the DAP AN 510 indicating the waiting period for the IP data packet, and when no data packets are queued up to the target DAP AN530, at event 1124, the source DAP AN 520 sends AN IPT Notification ACK to the target DAP AN530 indicating "no data pending" and "previous DAP". Once the target DAP AN530 receives the IPT Notification ACK indicating "no pending data" and "previous DAP", the target DAP AN530 can begin servicing data packets arriving AT the AT210 directly from the AGW240 or, in some aspects, through the FLSE510 after servicing the tunneled data packets received from the source DAP AN 520.

Fig. 12 depicts a call flow diagram for in-order delivery of packets during a reverse link handoff between reverse link serving eBS networks in accordance with an aspect of the invention. It should be noted that although the in-order delivery packet scheme illustrated in fig. 12 is described for an Ultra Mobile Broadband (UMB) network, the scheme described herein is not limited to UMB networks and may be implemented in other networks that rely on Mobile Internet Protocol (MIP) or the like.

AT event 1202, prior to the handoff, data packets are being sent from the Access Terminal (AT)210 to the source Reverse Link Serving Ebs (RLSE)610 network, which source RLSE 610 forwards the data packets to the access network (AGW) 240. In an alternative aspect, AT event 1204, a data packet is sent from AT210 to a source RLSE 610, the source RLSE 610 forwards the data packet to a Data Attachment Point (DAP)430, and the DAP430 forwards the data packet to the AGW 240.

AT event 1206, the AT210 selects a target reverse link serving ebs (rlse)620 network as the serving Base Station (BS) on the reverse link due to signal strength factors and/or other factors that may affect service performance, network congestion, etc. As described, in the UMB architecture, the serving BS may be an evolved base station (eBS).

At event 1208, the target RLSE620 sends an IPT notification to the source RLSE 610, and at event 1210, the target RLSE620 sends the same IPT notification to the Data Attachment Point (DAP) 430. The IPT notifications sent AT events 1208 and 1210 serve to inform the receiving entity that the target RLSE620 has been selected by the AT210 as the serving base station, in other words, that the RLSE620 has become the target RLSE. In addition, the IPT notification is transmitted to other Access Nodes (ANs) in the route set (not shown in the call flow of fig. 12).

At event 1214, once the source RLSE 610 receives an IPT notification from the target RLSE620 (event 1208), the source RLSE 610 sends an IPT notification Acknowledgement (ACK) to the target RLSE 620. The IPT notification ACK may also include indicators, such as a set flag, indicating "pending data" and "previous RLSE". At event 1218, concurrently with sending the IPT notification ACK, the source RLSE 610 starts a timer indicating a wait period for receiving a refresh signal or message (e.g., a refresh packet) at the source RLSE 610 corresponding to each RLP flow that receives L2 data packets (i.e., data requiring in-order delivery) tunneled. This timer allows the source RLSE 610 to complete delivery of the L2 packet on the source route before sending an IPT notification indicating "pending data" and "previous RLSE". This timer is typically reset each time a changed packet is received on the corresponding flow.

Once the target RLSE620 has received the IPT notification ACK indicating the "pending data" and the "previous RLSE", at event 1216, a timer is started indicating a wait period for receiving pending layer 3 (L3) data at the target RLSE 620. This timer is implemented to address the situation where the IPT notification sent from the source RLSE 610 to the target RLSE620 in a subsequent event 1230 is lost or not properly received by the target RLSE 620.

Once the target RLSE620 receives the IPT notification ACK with indicators indicating "pending data" and "previous FLSE," the target RLSE620 allocates a Reverse Link Allocation Block (RLAB) to the AT210 AT event 1220. At event 1222, DAP430 sends an IPT Notification ACK to target RLSE620, where event 1222 can occur before event 1220 and/or event 1214.

After switching to the target RLSE620, AT 1224, the AT210 sends the data packet to the target RLSE620 on the source route, and AT 1226, the target RLSE620 tunnels the data packet to the source RLSE 610. AT210 transmits the data packets in the following order. First, segments on the source RLSE 610 that have begun transmission over the air but have not completed transmission, in other words, partial packets that have not been acknowledged as being fully received by the source RLSE 610, and/or any data packets that have been processed using the link layer protocol in the source network with the corresponding peer-to-peer protocol in the AT. Second, fragments of the IP packet that have not yet begun to be transmitted over the air on the source RLSE 610. Third, after the last segment is sent, a refresh signal or message, such as a refresh packet, is sent. The refresh packet carries no data and is characterized by having the same Radio Link Protocol (RLP) sequence number as the sequence number of the last byte sent at the source RLSE 610 according to the RLP.

AT event 1228, AT210 begins sending new data packets to the target RLSE620 on the target route. For an in-order delivery flow, the target RLSE620 should not forward these data packets until an IPT notification indicating "no pending data" and "previous RLSE" is received from the source RLSE 610 (event 1230) or a timer indicating a wait period for receiving pending L3 data expires (event 1216). This includes forwarding the data packet to AGW240 or DAP430, depending on whether the IP data packet is sent directly to AGW240 or through DAP430 to AGW 240. For flows that can tolerate out-of-order delivery, such as VoIP, etc., the packet does not have to be buffered on the target RLSE620 and can be forwarded immediately.

Once the timer (event 1218) indicating the period for waiting for a refresh signal or message (e.g., refresh packet) expires or a refresh signal/message/packet is received for the RLP route receiving the tunneled L2 packet and there are no unacknowledged or lost packets, the source RLSE 610 sends an IPT notification to the target RLSE620 indicating "no data pending" and "previous RLSE" at event 1230 for all flows requiring in-order delivery.

Upon receiving an IPT notification indicating "no pending data" and "previous RLSE" or expiration of a timer indicating a wait period for receiving pending L3 data at the target RLSE620, the target RLSE620 begins forwarding the buffered IP data packets received on the target RLP route to the AGW240 at event 1232. Alternatively, in other aspects, upon receiving an IPT notification indicating "no pending data" and "previous RLSE" or expiration of a timer indicating a wait period for receiving pending L3 data at target RLSE620, at event 1234, target RLSE620 may begin forwarding buffered IP data packets received on the target RLP route to DAP430, which DAP430 forwards the data packets to AGW 240.

Fig. 13 depicts a call flow diagram for in-order delivery of packets during a reverse link handoff between a Data Attachment Point (DAP) Access Network (AN), in accordance with AN aspect of the subject invention. It should be noted that the DAP handoff aspect generally involves only the RLSE forwarding data packets to the DAP, which then forwards the data packets to the AGW, but is not applicable to the RLSE forwarding data packets directly to the AGW 240. It should also be noted that although the in-order delivery packet scheme illustrated in fig. 13 is described with respect to an Ultra Mobile Broadband (UMB) network, the scheme described herein is not limited to UMB networks and may be implemented in other networks that rely on Mobile Internet Protocol (MIP), etc.

AT event 1302, a data packet is sent from an Access Terminal (AT)210 to the reverse link serving eBS 710 network, and the reverse link serving eBS 710 then forwards the data packet to a source Data Attachment Point (DAP)520 via a protocol tunnel. DAP 520 then forwards the data packet to Access Gateway (AGW) 240. As previously described, in instances where RLSE 710 forwards data packets directly to AGW240, DAP switching need not be configured for in-order delivery of data packets.

AT event 1304, AT210 sends a DAP move request to the target DAP AN 530. The move request may be initiated based on a reduction in signal strength, network capacity, or any other performance characteristic that warrants a DAP handoff.

At event 1306, the target DAP AN530 sends a registration request, such as a Proxy Mobile IP (PMIP) or Mobile IP (MIP) registration request, to the AGW 240. Once the AGW240 has registered with the target DAP AN530, at event 1308, the AGW240 sends a registration response, such as a corresponding PMIP or MIP registration response, to the target DAP AN 530. AT event 1310, the target DAP AN530 sends the DAP assignment to RLSE 710, which RLSE 710 then sends the DAP assignment to AT 210.

At event 1312, the target DAPAN 530 sends a DAP notification to the source DAPAN 520 and RLSE 710. In addition, the DAP notification can be sent to other ANs in the route set (not shown in FIG. 13). Upon receipt of the DAP notification, at event 1314, RLSE 710 starts a timer indicating a wait period for pending L3 data packets. This timer is implemented by RLSE 710 to ensure that data packets sent to the target DAP530 are not sent before packets sent to the source DAP 530. In an aspect, the value of this timer may be approximately equal to twice the backhaul delay between AGW240 and the Base Station (BS) associated with RLSE 710.

After the source DAP 520 and RLSE 710 receive the DAP notification, at event 1316, the source DAP 520 and RLSE 710 send a DAP notification Acknowledgement (ACK) to the target DAP AN530, which acknowledges receipt of the DAP notification.

Once the timer indicating the waiting period for pending L3 data packets has expired AT RLSE 710, AT event 1318, the RLSE can begin tunneling buffered data packets received from AT210 to target DAP530, which target DAP530 then forwards to AGW 240. It should be noted that in some aspects of DAP handoff, the transmission by the target DAP AN530 to forward the data packet to the AGW240 can omit the L2 packet from the transmission.

Fig. 14 is a block diagram of an embodiment of a transmitter system 1410 (also referred to herein as a serving access network, base station, or data connection point) and a receiver system 1450 (also known as an access terminal) in a MIMO system 1400. At transmitter system 1410, traffic data for a number of data streams is provided from a data source 1412 to a Transmit (TX) data processor 1414.

In one embodiment, each data stream is transmitted over a respective transmit antenna. TX data processor 1414 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream is multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream can be determined by instructions performed by processor 1430.

The modulation symbols for all data streams are then provided to a TX MIMO processor 1420, and the TX MIMO processor 1420 can (e.g., for pins)For OFDM) further processes the modulation symbols. The TXMIMO processor 1420 then combines N_TOne modulation symbol stream is provided to N_TAnd Transmitters (TMTR)1422a through 1422 t. In a particular embodiment, TX MIMO processor 1420 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transmitter 1422 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. Then, respectively from N_TN transmitted from transmitters 1422a through 1422t by antennas 1424a through 1424t_TA modulated signal.

At receiver system 1450, the transmitted modulated signal is composed of N_REach antenna 1452a through 1452r receives a received signal from each antenna 1452 and provides a received signal to a respective receiver (RCVR)1454a through 1454 r. Each receiver 1454 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

RX data processor 1460 then receives and processes data from N based on a particular receiver processing technique_RN of receiver 1454_RA stream of received symbols to provide N_TA stream of "detected" symbols. RX data processor 1460 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1460 is complementary to that performed by TX MIMO processor 1420 and TX data processor 1414 at transmitter system 1410.

A processor 1470 periodically determines which precoding matrix to use (discussed below). Processor 1470 formulates a reverse link message comprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is then processed by a TX data processor 1438, modulated by a modulator 1480, conditioned by transmitters 1454a through 1454r, and transmitted back to transmitter system 1410, where TX data processor 1438 also receives traffic data for a number of data streams from a data source 1436.

At transmitter system 1410, the modulated signals from receiver system 1450 are received by antennas 1424, conditioned by receivers 1422, demodulated by a demodulator 1440, and processed by a RX data processor 1442 to extract the reverse link message transmitted by receiver system 1450. Processor 1430 then determines which pre-coding matrix to use for determining the beamforming weights then processes the extracted message.

It is to be understood that the specific order or hierarchy of steps in any disclosed process is an example of exemplary approaches. It should be understood that the particular order or hierarchy of steps in the processes may be rearranged based on design preferences, while remaining within the scope of the present disclosure. The accompanying method claims present various step elements in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logics, logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with the following components: a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Additionally, at least one processor may include one or more modules operable to perform one or more of the above-described steps and/or actions.

Further, the steps and/or actions of a method or algorithm described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An example storage medium may be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. Further, in some aspects, the processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a user device. In the alternative, the processor and the storage medium may reside as discrete components in a user device. Further, in some aspects, the steps and/or actions of a method or algorithm may reside as any combination or set of codes and/or instructions on a machine readable medium and/or computer readable medium, which may be incorporated into a computer program product.

In one or more aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk, blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Accordingly, aspects described and claimed herein provide for in-order delivery of data packets during handoff. The aspects provide for in-order delivery at forward link serving eBS/data attachment point (FLSE/DAP) handover and reverse link serving eBS/data attachment point (RLSE/DAP) handover. Also, the aspects provide significant improvements in the throughput of applications, for example applications that rely on the Transmission Control Protocol (TCP) during handover in networks such as UMB and the like.

While the foregoing disclosure discussion illustrates aspects and/or embodiments, it should be noted that various changes and modifications could be made herein without departing from the scope of the aspects and/or embodiments as defined by the appended claims. Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise.

Claims (56)

1. A method for providing in-order delivery of data packets during handoff in a communication network, comprising:

preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

prioritizing, AT the target network entity, a transmission order of data packets, wherein the prioritizing comprises AT least one of a first prioritization or a second prioritization, wherein the first prioritization comprises prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization comprises prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT;

receiving a data packet at the target network entity; and

transmitting the received data packet at the target network entity according to at least one of the first prioritization or the second prioritization.

2. The method of claim 1, wherein the prioritization comprises the first prioritization, wherein the transmitting step further comprises selectively transmitting data packets received as L2 data packets at the target network entity prior to transmitting data packets received as L3 data packets, wherein the selectively transmitting step is based on an application associated with data packets requiring in-order delivery.

3. The method of claim 1, wherein the L2 data packets include partial data packets that have begun transmission but have not completed transmission over the air or any packets that have been processed using a link layer protocol in the source network entity having a corresponding peer-to-peer protocol in the AT.

4. The method of claim 1, wherein the prioritization comprises the second prioritization, wherein the second prioritization further comprises prioritizing L3 packets received from a source Data Attachment Point (DAP) over L3 packets received from at least one of the AGW or a target DAP.

5. The method of claim 1, wherein receiving the data packet further comprises: receiving the buffered and sent data packets from the AGW or from a target Data Attachment Point (DAP) after the target network entity receives a refresh signal or message from the source network entity indicating that the source network entity has completed transmitting L2 and L3 data packets.

6. The method of claim 1, wherein the transmitting step further comprises: when the target network entity comprises a Data Attachment Point (DAP), L2 packets are omitted from the transmission.

7. The method of claim 1, wherein receiving data packets further comprises receiving L2 data packets transmitted from the source network entity, wherein the source network entity comprises a source forward link service evolved base station (FLSE).

8. At least one processor configured to provide in-order delivery of data packets during handoff in a communication network, the at least one processor comprising:

a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second module for prioritizing an order of transmission of data packets AT the target network entity, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT;

a third module for receiving a data packet at the target network entity; and

a fourth module for transmitting the received data packet at the target network entity according to at least one of the first prioritization or the second prioritization.

9. A computer program product, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second set of codes for causing the computer to prioritize a transmission order of data packets AT the target network entity, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing layer 2 (L2) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer 3 (L3) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT;

a third set of codes for causing the computer to receive a data packet at the target network entity; and

a fourth set of codes for causing the computer to divide or the computer to perform according to the first priority

At least one of a second prioritization, sending the received data packet at the target network entity.

10. An apparatus, comprising:

means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

means for prioritizing, AT the target network entity, a transmission order of data packets, wherein the prioritization includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing any received layer-3 (L3) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer-2 (L2) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT;

means for receiving a data packet at the target network entity; and

means for transmitting, at the target network entity, the received data packet according to at least one of the first prioritization or the second prioritization.

11. A target network apparatus, comprising:

a computer platform comprising a processor and a memory in communication with the processor;

a handover module stored in the memory and in communication with the processor, wherein the handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity;

a transceiver in communication with the processor, wherein the transceiver is operative to receive data packets for transmission to the AT; and

a data packet prioritization module stored in the memory and in communication with the processor, wherein the prioritization module is operative to prioritize an order of transmission of data packets, wherein the prioritization module includes AT least one of a first prioritization or a second prioritization, wherein the first prioritization includes prioritizing layer 2 (L2) data packets received from a source network entity and to be transmitted to an Access Terminal (AT) over any received layer 3 (L3) data packets to be transmitted to the AT, wherein the second prioritization includes prioritizing L3 data packets received from the source network entity and to be transmitted to the AT over L3 data packets received from an Access Gateway (AGW) and to be transmitted to the AT, and the prioritization module transmits the received data packet according to at least one of the first prioritization or the second prioritization.

12. The target network apparatus of claim 11, wherein the L2 data packets include partial data packets that have begun transmission but have not completed transmission over the air or any packets that have been processed using a link layer protocol in the source network entity having a corresponding peer-to-peer protocol in the AT.

13. The target network apparatus of claim 11, wherein the prioritization module comprises the second prioritization, wherein the second prioritization further comprises prioritizing L3 packets received from a source Data Attachment Point (DAP) over L3 packets received from at least one of the AGW or a target DAP.

14. The target network apparatus of claim 11, wherein the transceiver is further operative to receive the buffered and transmitted data packets from the AGW or from a target Data Attachment Point (DAP) after the target network entity receives a signal from the source network entity indicating that the source network entity has completed transmitting L2 and L3 data packets.

15. The target network apparatus of claim 11, wherein the transceiver is further operative to omit L2 packets from the transmission when the target network entity comprises a Data Attachment Point (DAP).

16. The target network apparatus of claim 11, wherein the transceiver is further operative to receive an L2 data packet transmitted from a source forward link serving ebs (flse).

17. The target network apparatus of claim 11, wherein the prioritization module comprises the first prioritization, wherein the data packet prioritization module is further operative to selectively transmit data packets received as L2 data packets prior to transmitting data packets received as L3 data packets, wherein the selectively transmitting data packets is based on an application associated with data packets requiring in-order delivery.

18. The target network apparatus of claim 11, wherein the transceiver is further operative to receive a refresh signal or message sent from the source network entity after transmission of L2 and L3 data packets destined for the AT, wherein the refresh signal or message provides an indication that no more L2 and L3 data packets will arrive from the source network entity.

19. A method for providing in-order delivery of data packets during handoff in a communication network, comprising:

preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

forwarding layer 2 (L2) data packets destined for the AT from the source network entity to the target network entity; and

forwarding layer 3 (L3) data packets destined for the AT from the source network entity to the target network entity,

wherein forwarding the L2 data packet is prioritized over forwarding the L3 data packet.

20. The method of claim 19, wherein forwarding L2 data packets from the source network entity further comprises forwarding partial data packets from the source network entity that have begun transmission but have not completed transmission over the air, and forwarding L3 data packets from the source network entity further comprises forwarding Internet Protocol (IP) data packets from the source network entity that have not begun transmission over the air.

21. The method of claim 19, further comprising: sending a signal from the source network entity to the target network entity indicating completion of the forwarding of L2 and L3 data packets.

22. The method of claim 19, further comprising: after forwarding the L2 and L3 data packets, sending a refresh signal or message from the source network entity, wherein the refresh signal or message provides an indication that no more L2 and L3 data packets will arrive.

23. At least one processor configured to provide in-order delivery of data packets during handoff in a communication network, the at least one processor comprising:

a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second module for forwarding a layer 2 (L2) data packet intended for the AT to the target network entity; and

a third module for forwarding layer 3 (L3) data packets destined for the AT to the target network entity,

wherein forwarding the L2 data packet is prioritized over forwarding the L3 data packet.

24. A computer program product, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second set of codes for causing a computer to forward a layer 2 (L2) data packet intended for the AT to the target network entity; and

a third set of codes for causing the computer to forward a layer 3 (L3) data packet intended for the AT to the target network entity,

wherein forwarding the L2 data packet is prioritized over forwarding the L3 data packet.

25. An apparatus, comprising:

means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

means for forwarding a layer 2 (L2) data packet intended for the AT to the target network entity; and

means for forwarding a layer 3 (L3) data packet intended for the AT to the target network entity,

wherein forwarding the L2 data packet is prioritized over forwarding the L3 data packet.

26. A source network apparatus, comprising:

a computer platform comprising a processor and a memory in communication with the processor;

a handover module stored in the memory and in communication with the processor, wherein the handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity;

a transceiver in communication with the processor, wherein the transceiver is operative to forward layer 2 (L2) data packets destined for the AT to the target network entity and layer 3 (L3) data packets destined for the AT to the target network entity; and

a data packet prioritization module stored in the memory and in communication with the processor, wherein the prioritization module is operative to prioritize forwarding of the L2 data packets over the L3 data packets.

27. The source network apparatus of claim 26, wherein the transceiver is further operative to forward L2 data packets in the form of partial data packets that have begun transmission but have not completed transmission over the air, and to forward L3 data packets in the form of Internet Protocol (IP) data packets that have not begun transmission over the air.

28. The source network apparatus of claim 26, wherein the transceiver is further operative to transmit a signal data packet to the target network entity indicating completion of the forwarding of L2 and L3 data packets.

29. The source network apparatus of claim 26, wherein the transceiver is further operative to send a refresh signal or message after forwarding the L2 and L3 data packets, wherein the refresh signal or message provides an indication that no more L2 and L3 data packets will come in.

30. A method for providing in-order delivery of data packets during handoff in a communication network, comprising:

preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

receiving, AT the AT, an L2 data packet sent from the source network entity;

receiving, AT the AT, a data packet transmitted from the target network entity; and

delivering the data packets to AT least one corresponding application on the AT such that L2 data packets sent from the source network entity are prioritized over data packets sent from the target network entity.

31. The method of claim 30, further comprising: receiving, AT the AT from the source network entity, an indication that all of the L2 data packets have been sent from the source network entity.

32. The method of claim 31, further comprising: receiving, AT the AT, a data packet sent from the target network entity only after receiving the indication from the source network entity.

33. The method of claim 31, further comprising: upon receiving the indication from the source network entity, sending a signal from the AT to the target network entity, wherein the signal provides for transmission of the data packet from the target network entity.

34. The method of claim 31, wherein the data packet is buffered at the target network entity until a signal is received that provides for transmission of the data packet from the target network entity.

35. At least one processor configured to provide in-order delivery of data packets during handoff in a communication network, the at least one processor comprising:

a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second module for receiving an L2 data packet sent from a source network entity;

a third module for receiving a data packet sent from a target network entity; and

a fourth module for delivering the data packet to AT least one corresponding application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

36. A computer program product, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second set of codes for causing a computer to receive an L2 data packet sent from the source network entity;

a third set of codes for causing the computer to receive a data packet sent from the target network entity; and

a fourth set of codes for causing the computer to deliver the data packet to AT least one corresponding application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

37. An apparatus, comprising:

means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

means for receiving an L2 data packet sent from the source network entity;

means for receiving a data packet sent from the target network entity; and

means for delivering the data packet to AT least one corresponding application on the AT such that the L2 data packet takes precedence over a data packet sent from the target network entity.

38. An access terminal, comprising:

a computer platform comprising a processor and a memory in communication with the processor;

a handover module stored in the memory and in communication with the processor, wherein the handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity;

a transceiver in communication with the processor, wherein the transceiver is operative to receive L2 data packets sent from a source network entity and to receive data packets sent from a target network entity, and wherein the transceiver is further operative to deliver the data packets to at least one corresponding application on the access terminal such that L2 data packets from the source network entity take precedence over data packets sent from the target network entity.

39. The access terminal of claim 38, wherein the transceiver is further operative to receive an indication from the source network entity that all of the L2 data packets have been transmitted from the source network entity.

40. The access terminal of claim 39, wherein the transceiver is further operative to receive data packets transmitted from the target network entity only after receiving the indication from the source network entity.

41. The access terminal of claim 39, wherein the transceiver is further operative to transmit a signal to the target network entity upon receiving the indication from the source network entity, wherein the signal provides for transmission of the data packet from the target network entity.

42. The access terminal of claim 41, wherein the data packet is buffered at the target network entity until a signal is received providing for transmission of the data packet from the target network entity.

43. A method for providing in-order delivery of data packets during handoff in a communication network, comprising:

preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

receiving, AT the target network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to handover;

forwarding, at the target network entity, the received L2 packet to the target network entity; and

receiving, at the target network entity, an indication signal transmitted from the source network entity,

wherein the indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

44. The method of claim 43, wherein receiving the indication signal further comprises receiving the indication signal at the target network entity, wherein the target network entity buffers all new data packets received from the access terminal until the indication signal is received.

45. The method of claim 43, wherein receiving L2 packets at the target network entity further comprises receiving L2 packets sent through an L2 protocol tunnel.

46. At least one processor configured to provide in-order delivery of data packets during handoff in a communication network, the at least one processor comprising:

a first module for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second module for receiving, AT the target network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to handover;

a third module for forwarding, at the target network entity, the received L2 packet to the target network entity; and

a fourth module for receiving, at the target network entity, an indication signal transmitted from the source network entity,

wherein the indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

47. A computer program product, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second set of codes for causing a computer to receive, AT the target network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to a handover;

a third set of codes for causing a computer to forward the received L2 packet at the target network entity to the target network entity; and

a fourth set of codes for causing the computer to receive, at the target network entity, an indication signal transmitted from the source network entity,

wherein the indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

48. An apparatus, comprising:

means for preparing a handover of an Access Terminal (AT) from a source network entity to a target network entity;

means for receiving, AT the source network entity, an L2 packet sent from an Access Terminal (AT) and partially processed prior to handover;

means for forwarding, at the source network entity, the received L2 packet to the target network entity; and

means for transmitting, at the source network entity, an indication signal to the target network entity,

wherein the indication signal indicates that all L2 packets from the AT have been forwarded to the target network entity.

49. A target network entity, comprising:

a computer platform comprising a processor and a memory in communication with the processor;

a handover module stored in the memory and in communication with the processor, wherein the handover module is operable to facilitate handover of an Access Terminal (AT) from a source network entity to a target network entity;

a transceiver in communication with the processor, wherein the transceiver is operative to receive L2 packets sent from an Access Terminal (AT), forward the received L2 packets to the target network entity, and receive an indication signal from the target network entity, wherein the indication signal indicates that all L2 packets from the AT have been forwarded to the source network entity.

50. The source network entity of claim 49, wherein the transceiver is further operable to transmit the indication signal to the target network entity, wherein the target network entity buffers all new data packets received from the access terminal until the first indication signal is received.

51. The source network entity of claim 49, wherein the transceiver is further operative to receive L2 packets sent over an L2 protocol tunnel.

52. A method for providing in-order delivery of data packets during handoff in a communication network, comprising:

preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity;

sending, via the target network entity, the partially processed L2 data packet prior to handover to the source network entity; and

sending a new data packet to the target network entity,

wherein the target network entity forwards the L2 data packet to the target network entity and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

53. At least one processor configured to provide in-order delivery of data packets during handoff in a communication network, the at least one processor comprising:

a first module for preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity;

a second module for sending, via the target network entity, the partially processed L2 data packets prior to handover to the source network entity; and

a third module for sending a new data packet to the target network entity,

wherein the target network entity forwards the L2 data packet to the target network entity and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

54. A computer program product, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to prepare for a handover of an Access Terminal (AT) from a source network entity to a target network entity;

a second set of codes for causing the computer to send, via the target network entity, a partially processed L2 data packet prior to handover to the source network entity; and

a third set of codes for causing the computer to transmit a new data packet to the target network entity,

wherein the target network entity forwards the L2 data packet to the target network entity and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

55. An apparatus, comprising:

means for preparing a handover of an Access Terminal (AT) between a source network entity and a target network entity;

means for sending, via the target network entity, the partially processed L2 data packet prior to handover to the source network entity; and

means for transmitting a new data packet to the target network entity,

wherein the target network entity forwards the L2 data packet to the target network entity and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.

56. An access terminal, comprising:

a computer platform comprising a processor and a memory in communication with the processor;

a handover module stored in the memory and in communication with the processor, wherein the handover module is operable to facilitate handover of the Access Terminal (AT) from a source network entity to a target network entity;

a transceiver in communication with the processor, wherein the transceiver is operative to send, via the target network entity, a partially processed L2 data packet prior to handover to the source network entity; and sending a new data packet to the target network entity, wherein the target network entity forwards the L2 data packet to the target network entity, and the source network entity sends all IP data packets constructed from L2 data packets to an Access Gateway (AGW) before sending the new data packet.