HK1141909A

HK1141909A - Ciphering sequence number for an adjacent layer protocol in data packet communications

Info

Publication number: HK1141909A
Application number: HK10108201.6A
Authority: HK
Inventors: A‧梅朗; E‧F‧沙蓬尼尔
Original assignee: 高通股份有限公司
Priority date: 2007-05-01
Filing date: 2008-05-01
Publication date: 2010-11-19

Description

Encrypted sequence number for adjacent layer protocols in data packet communications

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

[001] This patent application claims priority from U.S. provisional patent application entitled "provisional patent NUMBER IN LTE" No. 60/915,404, filed on day 5/1 of 2007, and from U.S. provisional patent application entitled "CIPHERING SEQUENCENUMBER IN LTE", No. 60/916,261, filed on day 5/4 of 2007, both of which have been assigned to the assignee of the present application and are hereby expressly incorporated by reference.

Technical Field

[002] The present disclosure relates to data packet communication systems, and more particularly, to such systems in which adjacent layers in a protocol stack all need to use different sequence numbers for their respective Packet Data Units (PDUs).

Background

[003] Evolved communication systems, such as 3GPP Long Term Evolution (LTE), achieve greater economic benefits and reduced latency in a flat architecture through a co-location function (e.g., combining two sub-layers that are considered part of layer 2 of a transceiver). For example, the Packet Data Convergence Protocol (PDCP), previously in the core entity, and the Radio Link Control (RLC), previously in the radio network controller, are both today in an enhanced base station (a so-called "evolved base node (eNodeB)" according to the 3GPP standard) with the physical layer. Such enhanced Base Transceiver Stations (BTSs) provide the LTE air interface and perform radio resource management for the evolved access system.

[004] With this protocol concatenation, there is an opportunity to allocate specific communication procedures that were all previously handled by lower layers such as the RLC. For example, it has been proposed that ciphering and data compression can be performed in the PDCP upper layer, rather than the RLC, in order to handle operations such as retransmission. This allocation function, while achieving certain advantages, can result in increased overhead. Such an allocation function in an upper layer (e.g., PDCP) requires that a sequence number be allocated to a PDU by the transmitting upper layer. The sequence number is used by the receiving upper layer after the PDU is used for purposes such as decryption. In addition, the respective lower layers (e.g., RLC) of the involved transmitter and receiver require their unique sequence numbers for reordering, retransmission, gap detection, and the like. In addition, the RLC concatenates or segments PDUs from upper layers, adding additional complexity in acquiring the PDUs at the receiver.

Disclosure of Invention

[005] The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed aspects. This summary is provided to introduce a selection of elements that are not critical or essential to the claimed subject matter, nor is it intended to delineate the scope of such aspects. Its sole purpose is to present some concepts described in a simplified form as a prelude to the more detailed description that is presented later.

[006] In accordance with one or more aspects and corresponding disclosure thereof, various aspects are described in connection with reconstructing one of two Packet Data Unit (PDU) sequence numbers without transmission (e.g., over the air) between a transmitter device and a receiver device. The Packet Data Convergence Protocol (PDCP) uses a ciphering sequence number associated with each PDCP PDU. The same ciphering sequence number is used to decipher the PDU. For a given encryption key, it is advantageous that the same serial number is used only once to avoid security degradation. By using the same sequence twice, the same keystream is generated which is xored with the data to encrypt the data. Knowing a set of data encrypted by the keystream means that it is possible to derive a second set of data. The Radio Link Control (RLC) service reliably indicates whether each RLC Service Data Unit (SDU) submitted to the transmitter was successfully received. The receiving PDCP entity calculates a ciphering sequence number from the ordering information provided by the RLC service.

[007] In one aspect, a method of data packet communication with reduced overhead is provided. A first sequence number is signaled from a transmitter to a receiver. Processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number. A plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs are generated by a transmitter lower protocol and transmitted to the receiver, wherein each PDU is associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs. The transmitted sequence difference value is equal to a number of upper layer PDUs transmitted from the transmitter to the receiver signaled from the first sequence number.

[008] In another aspect, at least one processor for data packet communication with reduced overhead is provided. A first module signals a first sequence number from a transmitter to a receiver. A second module processes a plurality of Service Data Units (SDUs) in a transmitter upper protocol using a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number. A third module generates, via a transmitter lower protocol, a plurality of Packet Data Units (PDUs) containing a plurality of transmitter upper protocol SDUs each associated with a transmitted sequence difference value used to reconstruct, at the receiver, a respective one of the plurality of transmitter sequence numbers to retrieve a plurality of SDUs, and transmits the plurality of PDUs to the receiver.

[009] In another aspect, a computer program product for data packet communication with reduced overhead is provided. The computer-readable medium includes sets of codes for causing a computer to: a first sequence number is signaled from a transmitter to a receiver. Processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number. A plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs are generated by a transmitter lower protocol and transmitted to the receiver, wherein each PDU is associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs.

[010] In another aspect, an apparatus for data packet communication with reduced overhead is provided. Means are provided for signaling a first sequence number from a transmitter to a receiver. Means are provided for processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers ordered starting with the first sequence number. Means are provided for generating, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) containing a plurality of transmitter upper protocol SDUs each associated with a transmitted sequence difference value for reconstructing at the receiver a respective one of the plurality of transmitter sequence numbers for retrieving the plurality of SDUs, and transmitting the plurality of PDUs to the receiver.

[011] In another aspect, an apparatus for data packet communication with reduced overhead is provided. The local transmitter signals the first sequence number to the remote receiver. The data packet processor is to: processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number; generating, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs, wherein each PDU is associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs, wherein the local transmitter transmits the PDU to the remote receiver.

[012] In another aspect, a method of data packet communication with reduced overhead is provided. A first sequence number sent from a transmitter to a receiver is received. A plurality of Packet Data Units (PDUs) received in a receiver lower protocol are generated and transmitted by a transmitter lower protocol of a remote transmitter and comprise a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU being associated with a transmitted sequence difference value. Retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

[013] In another aspect, at least one processor for data packet communication with reduced overhead is provided. A first module receives a first sequence number transmitted from a transmitter to a receiver. A second module receives a plurality of Packet Data Units (PDUs) in a receiver lower protocol generated and transmitted by a transmitter lower protocol of a remote transmitter and containing a plurality of transmitter upper protocol Service Data Units (SDUs) each associated with a transmitted sequence difference value. A third module retrieves each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

[014] In another aspect, a computer program product for data packet communication with reduced overhead is provided. A computer-readable medium comprising sets of codes for causing a computer to: receiving a first sequence number transmitted from a transmitter to a receiver; receiving a plurality of Packet Data Units (PDUs) in a receiver lower protocol, wherein the PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value; retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

[015] In another aspect, an apparatus for data packet communication with reduced overhead is provided. Means are provided for receiving a first sequence number transmitted from a transmitter to a receiver. Means are provided for receiving a plurality of Packet Data Units (PDUs) in a receiver lower protocol generated and transmitted by a transmitter lower protocol of a remote transmitter and containing a plurality of transmitter upper protocol Service Data Units (SDUs) each associated with a transmitted sequence difference value. Means are provided for retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

[016] In another aspect, an apparatus for data packet communication with reduced overhead is provided. The local receiver receives a first sequence number from the remote transmitter. The data packet processor is to: processing a plurality of Packet Data Units (PDUs) received in a receiver lower protocol, wherein the PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value; retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

[017] 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 aspects and are indicative of but a few of the various ways in which the principles of these aspects may be employed. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings and the disclosed aspects are intended to include all such aspects and their equivalents.

Drawings

[018] The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:

[019] fig. 1 shows a block diagram of a reduced overhead data packet communication system in which two layers of a protocol stack requiring different packet sequence numbers transmit only one sequence number;

[020] FIG. 2 shows a flow diagram of a method of avoiding transmission of an encrypted sequence number reconstructed at a receiver for decryption;

[021] FIG. 3 shows a timing diagram between two transmitter layer protocols and two receiver layer protocols using lower layer sequence numbers without loss;

[022] FIG. 4 shows a timing diagram between two transmitter layer and two receiver layer protocols in the case of a Packet Data Unit (PDU) with transmission loss;

[023] FIG. 5 shows a timing diagram between two transmitter layer protocols and two receiver layer protocols alternately using upper layer sequence numbers;

[024] FIG. 6 shows a block diagram of a transmitter with a module to send a polling command to a receiver;

[025] FIG. 7 shows a block diagram of a receiver with modules that receive polls and respond with status PDUs;

[026] FIG. 8 illustrates a transmitter of a communication system including a module for reducing overhead packet transmission;

[027] fig. 9 illustrates a receiver of a communication system including a module for reducing overhead packet reception.

Detailed Description

[028] In a Packet Data Convergence Protocol (PDCP) and a Radio Link Control (RLC) in layer 2 for transmission between a Transmitter (TX) and a Receiver (RX), a data packet communication system employs data ciphering. A single sequence number is used for both PDCP and RLC to reduce overhead by signaling the TX PDCP first ciphering sequence number to the RX prior to ciphered data packet communication. Each RLC PDU, which may include concatenated or segmented Service Data Units (SDUs) from the higher layer PDCP, is accompanied by a sequence number. The sequence number is sufficient for the RLC to perform reordering, gap detection, retransmission, etc., while also enabling the RX upper layer PDCP to reconstruct a sequence value used to cipher the content.

[029] 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 the various aspects may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing these aspects.

[030] As used in this application, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, 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 server and the server 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.

[031] The word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs.

[032] Furthermore, one or more versions may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof to control a computer to implement the disclosed aspects. The term "article of manufacture" (or alternatively, "computer program product") as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., card, stick, etc.). It should be further appreciated that a carrier wave can be employed to carry computer-readable electronic data such as those used in transmitting and receiving electronic mail or in accessing a network such as the internet or a Local Area Network (LAN). Of course, those skilled in the art will recognize many modifications may be made to this configuration without departing from the scope of the disclosed aspects.

[033] Various aspects will be described in terms of systems that may include a number of components, modules, and the like. It is to be understood and appreciated that the various systems may include additional components, modules, etc. and/or may not include all of the components, modules etc. discussed, for example, in connection with the figures. Combinations of these methods may also be used. Various aspects disclosed herein may be performed on an electronic device, including devices utilizing touch screen display technology and/or mouse-and-keyboard type interfaces. Examples of such devices include computers (desktop or mobile), smart phones, Personal Digital Assistants (PDAs), wireless phones, wireless smart phones, wireless data cards, and other wired and wireless electronic devices.

[034] Turning to the drawings, in fig. 1, a communication system 100 for communicating data packets between a transmitter 102 and a receiver 104 reduces overhead by avoiding the transmission of one of two sequence numbers. Higher layer protocols or applications 106 in the transmitter 102 have content for communication, shown as IP packets 108, 110, where they are delivered as Service Data Units (SDUs) 112 to an upper layer protocol, shown as Packet Data Convergence Protocol (PDCP) 114. In an exemplary embodiment, the PDCP 114 may include: an encryption component 115 that requires a sequence key for encryption at the transmitter and decryption at the receiver 104. This is illustrated by a first PDU 116, where the first PDU 116 is ciphered with a Transmitter Ciphering Sequence Number (TCSN), illustrated as sequence number "U" 118. PDU 116 encapsulates first IP packet 108. The second PDU 120 is encrypted with another TCSN, shown as an incremented sequence number "U" 122, and encapsulates the second IP packet 110. The PDCP 114 transmits the PDUs 116, 120 as SDUs 124 to a serving access point of a lower layer protocol (lower protocol), shown as a radio link layer (RLC) 126.

[035] RLC 126 uses an RLC sequence number, shown as "L" 128, to track reception, retransmission, and other operations. In an exemplary illustration, the RLC 126 may use the sequence number "N" 130 to create concatenated PDUs 126 to perform RLC functions. Concatenated PDU 126 sends more than one SDU 124 from the upper protocol PDCP 114, shown as PDUs 116, 120. The boundary data 132 is designated to at least partially identify the two PDUs 116, 120. Alternatively or in addition, the RLC 126 can generate and transmit a segmented PDU 134 identified by a sequence number "N" 136 to send a partial SDU 138 from the PDCP 114. Alternatively or in addition, the RLC 126 can send a PDU (not shown) that directly corresponds to one SDU 124 received from the PDCP 114, wherein the PDU has a directly mapped sequence number (e.g., a sequence number from the PDCP with the front portion omitted). Alternatively or in addition, the RLC 126 can send a composite PDU (not shown) from the PDCP 114 with both concatenated SDUs 124 and partial SDUs 124 to achieve a desired transmission size.

[036] The PDUs 126, 134 are passed to a media access layer (MAC)140 and then to a physical layer (PHY)142 for transmission to the data packet receiver 104. Advantageously, the transmission from the transmitter 102 to the receiver 104 includes only one sequence number, thereby reducing overhead, wherein two sequence numbers required for the PDCP 114 and RLC 126 can be derived from the one sequence number, shown as: (a) u ═ N and L ═ f (N), or (b) U ═ f (N) and L ═ N. This reduced overhead is sufficient for the receiver 146 to employ the first sequence number 144 signaled from the transmitter 102 prior to exchanging encrypted data. Thus, the synchronization component 146 can identify the appropriate sequence number required by the deciphering component 148 to retrieve each PDU 116, 120 from the transmitter upper layer protocol (i.e., PDCP 114).

[037]It should be appreciated that in accordance with the present disclosure, in "layer 2" of a telecommunications system, the PDCP 114 and RLC 126 are adjacent protocols that enable ARQ (automatic repeat request) as, for example, RLC under LTE and RLC under HSPA in 3GPP, among others. Moreover, 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 radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and so on. UTRA includes wideband CDMA (W-CDMA) and other variants of CDMA. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. TDMA systems may implement wireless technologies such as global system for mobile communications (GSM). OFDMA systems 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-OFDMAnd so on. UTRA is part of the Universal Mobile Telecommunications System (UMTS). E-UTRA is part of the 3GPP Long term evolution, 3GPPUpcoming releases that use 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). CDMA2000 and UMB are described in a document entitled "third generation partnership project 2" (3GPP 2). These various wireless technologies and standards are known in the art.

[038] Fig. 2 illustrates a method and/or flow diagram in accordance with the present invention. For purposes of explanation, the methodologies are shown and described as a series of acts. It is to be understood and appreciated that the subject innovation is not limited by the acts illustrated and/or by the order of acts. For example, acts may occur in different orders and/or concurrently with other acts from that shown and described herein. Moreover, not all illustrated acts may be required to implement a methodology in accordance with the subject invention. In addition, those skilled in the art will understand and appreciate that the methodologies could alternatively be represented as a series of interrelated states via a state diagram or events. Moreover, it should be further appreciated that the methodologies disclosed hereinafter and throughout this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring such methodologies to computers. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media.

[039] Fig. 2 is a flow diagram of one example of a method 200 for reducing overhead for data packet communications. The Transmitter (TX) PDCP sends a First Ciphering Sequence Number (FCSN) to the Receiver (RX) PDCP before using the FCSN based on the FCSN (block 202) or through a separate signaling channel while the cipher is already in use. The TX PDCP sets a local Transmitter Ciphering Sequence Number (TCSN) to the FCSN (block 204). The RX PDCP sets a local Receiver Ciphering Sequence Number (RCSN) to the FCSN (block 206). After processing Service Data Units (SDUs), the TX PDCP encrypts each SDU received from a higher layer (e.g., application) by repeatedly incrementing the TSCN (block 208). The TX PDCP conveys ciphered PDCP Packet Data Units (PDUs) as SDUs to a Service Access Point (SAP) of the RLC (block 210). Note that although the TSCN is not included as part of the PDCP PDU header, it may be directed to the RLC SAP. The RLC generates or encapsulates SDUs for transmission and retransmission as needed. Such encapsulation may be a one-to-one relationship, concatenation of received SDUs, segmentation of received SDUs, or concatenation of SDUs and segmented portions of SDUs, based on various considerations. The RLC associates each PDCP PDU with an RLC sequence number. Causing the RLC to perform its operations including retransmission of lost PDUs, in-order delivery. In addition, the PDCP sequence number may be maintained by a difference between sequence numbers. The RLC PDUs are then processed by the MAC layer and the PHY layer for transmission from the transmitter to the receiver (block 214). The RX RLC provides the RX PDCP with the difference in sequence numbers (block 216) to ensure that synchronization is maintained even if RLC PDUs are lost. The RCSN is calculated using the difference between the sequence numbers of the first crypto sequence numbers sent by the transmitter to the receiver and using the first crypto sequence numbers (block 218). The RX PDCP uses the RCSN to decrypt the PDCP SDUs (block 220).

[040] It should be appreciated that the foregoing synchronization method 200 allows the receiver to know the RLC sequence number (RLC _ SN _0) and ciphering sequence number (Count-c) used to carry that ciphered unit in accordance with the present disclosure. Accordingly, the RLC delivers SDUs, which have used an RLC sequence number RLC _ SN _ Z, to the PDCP. The encryption sequence number may be calculated as follows: the currently calculated ciphering sequence number ═ Count-c + (RLC _ SN _ Z-RLC _ SN _ 0). In fig. 3, a method 400 is shown as an exemplary timing diagram using lower layer sequence numbers without loss from an upper layer protocol 402 from a Transmitter (TX)406 to a lower layer protocol 404 to a lower layer protocol 408 to a Receiver (RX)412 and then to an upper layer protocol 410. The TX upper layer protocol 402 synchronizes the RX upper layer protocol 408 (to N) by signaling the sequence number of the higher layer protocol, as shown at 420. The TX upper layer protocol 402 processes the PDU using sequence number N, as indicated at 422, and then transmits the PDU, which does not include a sequence number, to the TX lower layer protocol 404, as indicated at 424. The TX lower layer protocol 404 then causes the transmission of the lower layer PDU, including the sequence number and the upper layer PDU, from the transmitter 408 to the RX lower layer protocol 406 of the receiver 412, as shown at 426. The RX lower layer protocol 408 uses its sequence number to determine that an upper layer PDU was received to report to the RX upper layer protocol 408, as shown at 428. The RX upper layer protocol 408 uses the sequence number N to reconstruct the sequence number used to process (e.g., decrypt) the PDU sent by the TX upper layer protocol 402, where the sequence number is the same number N in this first transmission.

[041] In fig. 4, to illustrate the data loss scenario, the method 400 then presents: another situation that occurs when synchronization of sequence numbers is required as before is shown at 450. The TX upper layer protocol 402 processes the PDU using sequence number N, as shown at 452, and then transmits the PDU, which does not include a sequence number, to the TX lower layer protocol 404, as shown at 454. The TX lower layer protocol 404 then causes a lower layer PDU, including an RLC lower layer sequence number, an upper layer PDU, to be transmitted from the transmitter 408 to the RX lower layer protocol 406 of the receiver 412, as shown at 456. In transmission, the upper layer PDU is erased (erase), as shown at 458. The TX upper protocol 402 processes the PDU with the incremented sequence number N +1, as indicated at 462, and then transmits the PDU without the sequence number to the TX lower protocol 404, as indicated at 464. In turn, the TX lower layer protocol 404 causes a lower layer PDU including an RLC sequence number and an upper layer PDU to be transmitted from the transmitter 408 to the RX lower layer protocol 406 of the receiver 412, as shown at 466. The RX lower layer protocol 408 uses the sequence numbers of the subsequently received PDUs to determine that no upper layer PDUs have been received, reporting to the RX upper layer protocol 408 as shown at 460. The RX lower layer protocol 408 uses its sequence number to determine that an upper layer PDU was received to report to the RX upper layer protocol 408, as shown at 468. The RX upper layer protocol 408 uses the provided delta information to reconstruct the sequence number N +1 based on the RLC sequence number for processing (e.g., ciphering) the PDU sent by the TX upper layer protocol 402.

[042] In fig. 5, a method 500 is shown as an exemplary timing diagram for communication using an upper layer sequence number from an upper layer protocol 502 of a Transmitter (TX)506 to a lower layer protocol 504 to a lower layer protocol 508 of a Receiver (RX)512 and then to an upper layer protocol 510. The TX upper layer protocol 502 synchronizes the RX upper layer protocol 508 (to N) by signaling the full sequence number of the higher layer protocol, as shown at 520. The TX upper layer protocol 502 processes the PDU using the sequence number N, as shown at 522, and then transmits the PDU, including some or all of the least significant bits of the sequence number, to the TX lower layer protocol 504, as shown at 524. The TX lower layer protocol 504 then causes the transmission of the upper layer PDU and the lower layer PDU including some or all of the least significant bits of the upper layer sequence number from the transmitter 508 to the RX lower layer protocol 506 of the receiver 512, as shown at 526. Therefore, relatively low overhead is required to do the following: the full encryption sequence number is used first for synchronization and then the partial least significant bits of the encryption sequence number are signaled over the air with each encrypted packet. This part of the bits of the ciphering sequence number may be carried in, for example, a PDCP PDU, an RLC header, or a MAC header. If these bits are added to the PDCP PDU, 8 bits may be added to maintain PDU byte alignment. Alternatively, by transmitting several of these bits (e.g., 3 bits), the bits may be placed in the RLC header or MAC header, enabling the RLC to be reset as needed at any time, without the need to calculate differences, i.e., "deltas". The upper layer sequence number is used to perform RLC functions such as reordering, gap detection, retransmission, etc. In addition, the RLC protocol requires segmentation processing of the upper layer PDU when first transmission and retransmission are performed. The RX lower layer protocol 508 uses the upper layer sequence number to determine that an upper layer PDU was received to report to the RX upper layer protocol 508, as shown at 528. The RX upper layer protocol 508 uses the sequence number to reconstruct the full sequence number for processing (e.g., decrypting) the PDU sent by the TX upper layer protocol 502.

[043] It should be appreciated that 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 that support communication for 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, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.

[044] Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and 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. Such communication links may be established via single-input single-output (SISO), multiple-input single-output (MISO), or multiple-input (MIMO) systems.

[045]MIMO system using multi-pair (N)_TSub) transmitting antenna and multi-pair (N)_RAnd) a receive antenna for data transmission. From N_TA secondary transmitting antenna and N_RThe MIMO channel formed by the sub-receiving antennas can be decomposed into N_SIndividual channels (also referred to as spatial channels), where N_S≤min{N_T，N_R}。N_SEach of the individual channels corresponds to a dimension. In addition, MIMO systems may provide improved performance (e.g., higher throughput and/or higher reliability) if the more dimensionalities created by the multiple transmit and receive antennas are utilized.

[046] MIMO systems support Time Division Duplex (TDD) and Frequency Division Duplex (FDD) systems. In a TDD system, forward and reverse link transmissions are on the same frequency region, and thus, the reciprocity principle enables estimation of the forward link channel from the reverse link channel. This enables the access point to extract transmit beamforming gain on the forward link when there are multiple antennas at the access node.

[047] Referring to fig. 6, a multiple access wireless communication system in accordance with an aspect is illustrated. An access point 600(AP) includes multiple sets of antennas, one including 604 and 606, another including 608 and 610, and an additional including 612 and 614. In fig. 6, only two antennas are shown for each group of antennas, however, fewer or more than two antennas may be used for each group of antennas. Access terminal 616(AT) is in communication with antennas 612 and 614, where antennas 612 and 614 transmit information to access terminal 616 over forward link 620 and receive information from access terminal 616 over reverse link 618. Access terminal 622 is in communication with antennas 606 and 608, where antennas 606 and 608 transmit information to access terminal 622 over forward link 626 and receive information from access terminal 622 over reverse link 624. In a FDD system, communication links 618, 620, 624 and 626 may use different frequency for communication. For example, forward link 620 may use a different frequency than that used by reverse link 618.

[048] Each group of antennas and/or the area in which they are designed to communicate is often referred to as a sector of the access point. In an aspect, antenna groups each are configured to communicate to access terminals in a sector, of the areas covered by access point 600.

[049] In communication over forward links 620 and 626, the transmitting antennas of access point 600 utilize beamforming in order to improve signal-to-noise ratio of forward links for the different access terminals 616 and 622. 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 if the access point were transmitting through a single antenna to all its access terminals.

[050] 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, and/or some other terminology.

[051] Fig. 7 is a block diagram of aspects of a transmitter system 710 (also known as an access point) and a receiver system 750 (also known as an access terminal) in a MIMO system 700. At the transmitter system 710, traffic data for a number of data streams is provided from a data source 712 to a Transmitter (TX) data processor 714.

[052] In one aspect, each data stream is transmitted via a respective transmit antenna. TX data processor 714 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.

[053] 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 the channel response may be estimated at the receiver system. 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 730.

[054]The modulation symbols for all data streams are then provided to a TX MIMO processor 720, which further processes the modulation symbols (e.g., for OFDM). TX MIMO processor 720 then forwards N_TA number of transmitters (TMTR)722a through 722t provide N_TA stream of modulation symbols. In particular embodiments, TX MIMO processor 720 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

[055]Each transmitter 722 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. N from transmitters 722a through 722t may then be transmitted_TEach modulated signal being from N_TThe secondary antennas 724a through 724t transmit.

[056]At receiver system 750, the transmitted modulated signal consists of N_RAntennas 752a through 752r receive and provide received signals from each antenna 752 to a respective receiver (RCVR)754a through 754 r. Each receiver 754 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.

[057]RX data processor 760 then starts at N_RN is received by a receiver 754_RA received symbol stream and processing the symbol stream according to a particular receiver processing techniqueTo provide N_TA stream of "detected" symbols. RX data processor 760 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 760 is complementary to that performed by TX MIMO processor 720 and TX data processor 714 at transmitter system 710.

[058] A processor 770 periodically determines which pre-coding matrix to use (as described below). Processor 770 generates a reverse link message comprising a matrix index portion and a rank value portion.

[059] 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 738, modulated by a modulator 780, conditioned by transmitters 754a through 754r, and transmitted back to transmitter system 710, the TX data processor 738 also receives traffic data for a number of data streams from a data source 736.

[060] At transmitter system 710, the modulated signals from receiver system 750 are received by antennas 724, conditioned by receivers 722, demodulated by a demodulator 740, and processed by a RX data processor 742 to extract the reverse link message transmitted by receiver system 750. Processor 730 then determines which pre-coding matrix to use for determining the beamforming weights then processes the extracted message.

[061] In one aspect, logical channels are divided into control signals and traffic channels. The logical control channels include: a Broadcast Control Channel (BCCH), which is a DL channel for broadcasting system control information; a Paging Control Channel (PCCH), which is a DL channel transmitting paging information; multicast Control Channel (MCCH), which is a point-to-multipoint DL channel, is used for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several MTCHs. Typically, after establishing the RRC connection, the multicast control channel is only used by UEs receiving MBMS (note: conventional MCCH + MSCH). Dedicated Control Channel (DCCH) is a point-to-point bi-directional channel that transmits dedicated control information and is used by UEs having an RRC connection. In one aspect, the logical traffic channels include a Dedicated Traffic Channel (DTCH), which is a point-to-point bi-directional channel dedicated to one UE for transmitting user information. In addition, a Multicast Traffic Channel (MTCH) is a point-to-multipoint DL channel for transmitting traffic data.

[062] In one aspect, the transport channels are divided into DL and UL. DL transport channels include a Broadcast Channel (BCH), downlink shared data channel (DL-SDCH) and a Paging Channel (PCH), the PCH for support of UE power saving (DRX cycle is indicated by the network to the UE), broadcast over the entire cell, and mapped to PHY resources that may be used for other control/traffic channels. The UL transport channels include a Random Access Channel (RACH), a request channel (REQCH), an uplink shared data channel (UL-SDCH), and a plurality of PHY channels. The PHY channels include a set of DL channels and UL channels.

[063] The DL PHY channels include: common pilot channel (CPICH); a Synchronization Channel (SCH); common Control Channel (CCCH); shared DL Control Channel (SDCCH); multicast Control Channel (MCCH); shared UL Allocation Channel (SUACH); acknowledgement channel (ACKCH); DL physical shared data channel (DL-PSDCH); UL Power Control Channel (UPCCH); a Paging Indicator Channel (PICH); load Indicator Channel (LICH). The UL PHY channels include: physical Random Access Channel (PRACH); a Channel Quality Indicator Channel (CQICH); acknowledgement channel (ACKCH); an Antenna Subset Indicator Channel (ASICH); shared request channel (SREQCH); UL physical shared data channel (UL-PSDCH); broadcast pilot channel (BPICH).

[064] In fig. 8, a transmitter 800 includes means, shown as a module 802, for signaling a first sequence number from a transmitter to a receiver. The transmitter 800 includes means, depicted as a module 804, for processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number. The transmitter 800 includes means, depicted as a module 806, for generating, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) containing a plurality of transmitter upper protocol SDUs, each PDU associated with a transmitted sequence delta value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs, and transmitting the plurality of PDUs to the receiver.

[065] In fig. 9, a receiver 900 includes means, shown as a module 902, for receiving a first sequence number transmitted from a transmitter to a receiver. The receiver 900 includes means, depicted as a module 904, for receiving a plurality of Packet Data Units (PDUs) generated and transmitted by a transmitter lower protocol of a remote transmitter and containing a plurality of transmitter upper protocol Service Data Units (SDUs) each associated with a transmitted sequence delta value in a receiver lower protocol. Receiver 900 includes means, depicted as a module 906, for retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by a respective transmitted sequence delta value.

[066] The above description includes examples of various aspects. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art may recognize that many further combinations and permutations of various aspects are possible. Accordingly, the specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.

[067] In particular regard to the various functions performed by the above described components, devices, circuits, systems and the like, the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary aspects. In this regard, it will also be recognized that the various aspects include a system as well as a computer-readable medium having computer-executable instructions for performing the acts and/or events of the various methods.

[068] In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. With respect to the terms "comprises" and "comprising," and variations thereof, used in the detailed description and claims, these terms are intended to be inclusive in a manner similar to the term "comprising. Furthermore, the term "or" as used in the detailed description of the claims means a non-exclusive "or".

[069] Moreover, it is to be appreciated that portions of the disclosed systems and methods can include artificial intelligence, machine learning or knowledge or rule based components, sub-components, processes, modules, methods or mechanisms (e.g., support vector machines, neural networks, expert systems, bayesian belief networks, fuzzy logic, data fusion engines, classifiers, and the like). These components, among other things, may cause particular mechanisms or processes to be performed automatically, thereby making various portions of the systems and methods more adaptive and efficient and intelligent.

[070] In accordance with the exemplary systems described above, methodologies that may be implemented in accordance with the disclosed invention have been described with reference to a number of flow diagrams. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of blocks, it is to be understood and appreciated that the present invention is not limited by the order of the blocks, as some blocks may occur in different orders and/or concurrently with other blocks from what is depicted and described herein. Moreover, not all illustrated blocks may be required to implement the methodologies described herein. Additionally, it should be further appreciated that the methodologies disclosed herein are capable of being stored on an article of manufacture to facilitate transporting and transferring such methodologies to computers. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media.

[071] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. Thus, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference for the purpose of achieving the desired objectives. The incorporation of any material, or portion thereof, that is incorporated by reference herein, in such an application is limited to the extent that no conflict arises between that incorporated material and the existing disclosure material.

Claims

1. A method for data packet communication with reduced overhead, comprising:

signaling a first sequence number from a transmitter to a receiver;

processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number;

a plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs are generated by a transmitter lower protocol and transmitted to the receiver, wherein each PDU is associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs.

2. The method of claim 1, further comprising:

generating a PDU directly corresponding to the SDU and transmitting the PDU to the receiver, wherein a transmitted sequence difference value included in the transmitter lower layer protocol is sequentially mapped to the plurality of transmitter sequence numbers.

3. The method of claim 2, further comprising:

the transmit sequence values are generated by omitting a front portion of each transmitter sequence number.

4. The method of claim 1, wherein the sequence difference value is equal to a number of upper layer PDUs signaled from a transmitter to a receiver of the first sequence number.

5. The method of claim 1, further comprising:

each upper layer PDU is assigned one of a plurality of different sequence numbers.

6. The method of claim 5, further comprising:

a PDU including the segmented SDU is generated and transmitted.

7. The method of claim 5, further comprising:

a concatenated PDU comprising at least two SDUs is generated and transmitted.

8. The method of claim 7, further comprising: a PDU comprising a concatenation of at least two SDUs and a segmented SDU is generated and transmitted.

9. The method of claim 1, further comprising:

encrypting the SDU in the upper protocol with a corresponding one of the plurality of transmitter sequence numbers ordered starting with the first sequence number.

10. The method of claim 1, wherein the upper layer protocol comprises a packet data convergence protocol and the lower layer protocol comprises a radio link control.

11. The method of claim 1, wherein the transmitter comprises one selected from a group consisting of an enhanced base node and a user equipment, and the receiver comprises another one of the group.

12. The method of claim 1, further comprising:

and receiving a request for retransmission according to detection of a missing part corresponding to the SDU related to the transmission sequence difference value in the PDU by a receiver lower layer protocol.

13. The method of claim 1, wherein the receiver lower protocol provides an indication to the receiver upper protocol of a sequence difference value between an initial value and a value of a delivered upper layer SDU.

14. At least one processor for communicating data packets with reduced overhead, comprising:

a first module that signals a first sequence number from a transmitter to a receiver;

a second module for processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number;

a third module generates, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) including a plurality of transmitter upper protocol SDUs each associated with a transmitted sequence difference value used to reconstruct, at the receiver, a respective one of the plurality of transmitter sequence numbers to retrieve a plurality of SDUs, and transmits the plurality of PDUs to the receiver.

15. A computer program product for data packet communication with reduced overhead, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to signal a first sequence number from a transmitter to a receiver;

a second set of codes for causing the computer to process a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number;

a third set of codes for causing the computer to generate, via a transmitter lower protocol, a plurality of Packet Data Units (PDUs) including a plurality of transmitter upper protocol SDUs each associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs, and transmit the plurality of PDUs to the receiver.

16. An apparatus for data packet communication with reduced overhead, comprising:

means for signaling a first sequence number from a transmitter to a receiver;

means for processing a plurality of Service Data Units (SDUs) in a transmitter upper protocol with a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number;

means for generating, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs, each PDU associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs, and transmitting the plurality of PDUs to the receiver.

17. An apparatus for data packet communication with reduced overhead, comprising:

a local transmitter signaling the first sequence number to the remote receiver;

a data packet processor for:

generating, by a transmitter lower protocol, a plurality of Packet Data Units (PDUs) comprising a plurality of transmitter upper protocol SDUs, wherein each PDU is associated with a transmitted sequence difference value for reconstructing a respective one of the plurality of transmitter sequence numbers at the receiver for retrieving the plurality of SDUs, wherein the local transmitter transmits the PDU to the remote receiver.

18. The apparatus of claim 17, further comprising a transmitter lower protocol of the data packet processor for generating a PDU directly corresponding to the SDU by including a transmitted sequence difference value sequentially mapped to the plurality of transmitter sequence numbers.

19. The apparatus of claim 18, further comprising a lower layer protocol of the data packet processor for generating a transmit sequence number difference by omitting a front end portion of each transmitter sequence number.

20. The apparatus of claim 17, wherein the sequence difference value is equal to a number of upper layer PDUs signaled from a transmitter to a receiver starting with the first sequence number.

21. The apparatus of claim 17, further comprising a lower layer protocol of the data packet processor for assigning one of a plurality of different sequence numbers to each PDU.

22. The apparatus of claim 21, further comprising a lower protocol of the data packet processor for generating and transmitting a PDU comprising a segmented SDU.

23. The apparatus of claim 21, further comprising a lower protocol of the data packet processor for generating and transmitting a PDU comprising a concatenation of at least two SDUs.

24. The apparatus of claim 23, further comprising a lower protocol of the data packet processor for generating and transmitting a PDU comprising a concatenation of at least two SDUs and a segmented SDU.

25. The apparatus of claim 17, further comprising an upper layer protocol of the data packet processor for encrypting the SDU in the upper layer protocol with a corresponding one of the plurality of transmitter sequence numbers sequenced from the first sequence number.

26. The apparatus of claim 17, wherein the upper layer protocol of the data packet processor comprises a packet data convergence protocol and the lower layer protocol of the data packet processor comprises a radio link control of an enhanced base node.

27. The apparatus of claim 17, wherein the transmitter comprises one selected from a group consisting of an enhanced base node and a user equipment, and the receiver comprises another one of the group.

28. The apparatus of claim 17, further comprising: and the local receiver is used for detecting a lost part corresponding to the SDU related to the transmission sequence difference value in the PDU according to the lower-layer protocol of the receiver and receiving a request for retransmission.

29. The apparatus of claim 17, wherein the receiver lower protocol provides an indication to the receiver upper protocol of a sequence difference value between an initial value and a value of a delivered upper layer SDU.

30. A method for data packet communication with reduced overhead, comprising:

receiving a first sequence number transmitted from a transmitter to a receiver;

receiving a plurality of Packet Data Units (PDUs) in a receiver lower protocol, wherein the PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value;

retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

31. The method of claim 30, further comprising: obtaining a PDU directly corresponding to the SDU, wherein a transmitted sequence difference value included in the transmitter lower layer protocol is sequentially mapped to the plurality of transmitter sequence numbers.

32. The method of claim 31, further comprising: the transmitted sequence difference value is obtained by recovering the omitted front-end portion of each transmitter sequence number from the first sequence number.

33. The method of claim 30, wherein the sequence difference value is equal to a number of upper layer PDUs signaled from a transmitter to a receiver of the first sequence number.

34. The method of claim 30, further comprising: the sequence number assigned for each PDU is obtained among a plurality of different sequence numbers.

35. The method of claim 34, further comprising: a PDU including a segmented SDU is received.

36. The method of claim 34, further comprising: a concatenated PDU comprising at least two SDUs is received.

37. The method of claim 36, further comprising: a PDU comprising a concatenation of at least two SDUs and a segmented SDU is received.

38. The method of claim 30, further comprising: decrypting said SDU in a receiver upper protocol using a respective one of said plurality of transmitter sequence numbers sequenced from said first sequence number.

39. The method of claim 30, wherein the receiver upper layer protocol comprises a packet data convergence protocol and the lower layer protocol comprises a radio link control.

40. The method of claim 30, wherein the transmitter comprises one selected from a group consisting of an enhanced base node and a user equipment, and the receiver comprises another one of the group.

41. The method of claim 30, further comprising: and transmitting a request for retransmission according to the detection of the missing part corresponding to the SDU related to the transmission sequence difference value in the PDU by the receiver lower layer protocol.

42. The method of claim 30, wherein the receiver lower protocol provides an indication to the receiver upper protocol of a sequence difference value between an initial value and a value of a delivered upper layer SDU.

43. At least one processor for communicating data packets with reduced overhead, comprising:

a first module for receiving a first sequence number transmitted from a transmitter to a receiver;

a second module for receiving a plurality of Packet Data Units (PDUs) in a receiver lower protocol, wherein the PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value;

a third module for reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by a respective transmitted sequence difference value to retrieve each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol.

44. A computer program product for data packet communication with reduced overhead, comprising:

a computer-readable medium comprising:

a first set of codes for causing a computer to receive a first sequence number transmitted from a transmitter to a receiver;

a second set of codes for causing the computer to receive a plurality of Packet Data Units (PDUs) in a receiver lower protocol generated and transmitted by a transmitter lower protocol of a remote transmitter and containing a plurality of transmitter upper protocol Service Data Units (SDUs) each associated with a transmitted sequence difference value;

a third set of codes for causing the computer to reconstruct a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by a respective transmitted sequence difference value to retrieve each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol.

45. An apparatus for data packet communication with reduced overhead, comprising:

means for receiving a first sequence number sent from a transmitter to a receiver;

means for receiving a plurality of Packet Data Units (PDUs) in a receiver lower protocol, wherein the plurality of PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value;

means for retrieving each of the plurality of SDUs from the plurality of PDUs in a receiver upper protocol by reconstructing a respective one of a plurality of transmitter sequence numbers sequenced from the first sequence number by the respective transmitted sequence difference value.

46. An apparatus for data packet communication with reduced overhead, comprising:

a local receiver for receiving a first sequence number from a remote transmitter;

a data packet processor for:

processing a plurality of Packet Data Units (PDUs) received in a receiver lower protocol, wherein the PDUs were generated and transmitted by a transmitter lower protocol of a remote transmitter and contain a plurality of transmitter upper protocol Service Data Units (SDUs), each PDU associated with a transmitted sequence difference value;

47. The apparatus of claim 46, further comprising a receiver lower protocol of the data packet processor for retrieving the PDU directly corresponding to the SDU by including a transmitted sequence difference value sequentially mapped to the plurality of transmitter sequence numbers.

48. The apparatus of claim 47, further comprising a receiver lower protocol of the data packet processor for receiving transmission sequence values by omitting a front-end portion of each transmitter sequence number.

49. The apparatus of claim 46, wherein the sequence difference value is equal to a number of upper layer PDUs transmitted from a transmitter to a receiver signaled from the first sequence number.

50. The apparatus of claim 46, further comprising a receiver lower protocol of the data packet processor for receiving one of a plurality of different sequence numbers assigned to each PDU by the transmitter lower protocol.

51. The apparatus of claim 50, further comprising a receiver lower protocol of the data packet processor for receiving a PDU comprising a fragmented SDU.

52. The apparatus of claim 50, further comprising a receiver lower protocol of the data packet processor for receiving a PDU comprising a concatenation of at least two SDUs.

53. The apparatus of claim 52, further comprising a receiver lower protocol of the data packet processor for receiving a PDU comprising a concatenation of at least two SDUs and a fragmented SDU.

54. The apparatus of claim 46, further comprising a receiver upper protocol of the data packet processor for decrypting the SDU with a respective one of the plurality of transmitter sequence numbers sequenced from the first sequence number.

55. The apparatus of claim 46, wherein the receiver upper layer protocol of the data packet processor comprises a packet data convergence protocol and the receiver lower layer protocol of the data packet processor comprises a radio link control.

56. The apparatus of claim 55, wherein the transmitter comprises one selected from a group consisting of an enhanced base node and a user equipment, and the receiver comprises another one of the group.

57. The apparatus of claim 46, further comprising: a local transmitter for transmitting a request for retransmission in response to detection of a missing part of a PDU corresponding to an SDU to which the transmitted sequence difference value relates by the receiver lower protocol.

58. The apparatus of claim 46, wherein the receiver lower protocol provides an indication to the receiver upper protocol of a sequence difference value between an initial value and a value of a delivered upper layer SDU.