WO2011042869A1

WO2011042869A1 - Preventing mac activation with incorrect parameters during handover

Info

Publication number: WO2011042869A1
Application number: PCT/IB2010/054509
Authority: WO
Inventors: Antti-Eemeli Suronen; Mika Petteri Kaukoranta
Original assignee: Nokia Inc
Current assignee: Nokia Inc
Priority date: 2009-10-05
Filing date: 2010-10-05
Publication date: 2011-04-14
Anticipated expiration: 2012-04-05

Abstract

A method for controlling MAC protocol layer functionality during a handover procedure is disclosed. The method includes receiving a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset and wireless network access related activities at the MAC protocol layer are halted. The method also includes receiving a first message at the MAC protocol layer. In response to receiving the first message, access related activities at the MAC protocol layer are resumed. Apparatus and computer readable media are also disclosed.

Description

PREVENTING MAC ACTIVATION WITH INCORRECT PARAMETERS DURING

HANDOVER

TECHNICAL FIELD:

The exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs and, more specifically, relate to controlling MAC protocol layer functionality during a handover procedure.

BACKGROUND:

This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

3 GPP third generation partnership project

CDM code division multiplexing

C-RNTI common radio network temporary identifier

DL downlink (eNB towards UE)

eNB E-UTRAN Node B (evolved Node B)

EPC evolved packet core

E-UTRAN evolved UTRAN (LTE)

HARQ hybrid automatic repeat request

HO handover

LTE long term evolution of UTRAN (E-UTRAN)

MAC medium access control (layer 2, L2)

MM MME mobility management/mobility management entity

Node B base station

NW network

O&M operations and maintenance

OFDMA orthogonal frequency division multiple access

PDCP packet data convergence protocol PHY physical (layer 1, LI)

RACH random access channel

RLC radio link control

RRC radio resource control

RRM radio resource management

S-GW serving gateway

SC-FDMA single carrier, frequency division multiple access

SDU service data unit

SRB signaling radio bearer

UE user equipment, such as a mobile station or mobile terminal

UL uplink (UE towards eNB)

UTRAN universal terrestrial radio access network

A communication system known as evolved UTRAN (E-UTRAN, also referred to as UTRAN-LTE or as E-UTRA) has been specified within 3 GPP. The DL access technique is OFDMA, and the UL access technique is SC-FDMA.

One specification of interest is 3 GPP TS 36.300, V9.0.0 (2009-06), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Access Network (E-UTRAN); Overall description; Stage 2 (Release 9)".

Figure 1 reproduces Figure 4-1 of 3GPP TS 36.300, and shows the overall architecture of the E- UTRAN system. The E-UTRAN system includes eNBs, providing the E-UTRA user plane (PDCPRLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE (not shown). The eNBs are interconnected with each other by means of an X2 interface. The eNBs are also connected by means of an S 1 interface to an EPC, more specifically to a MME (Mobility Management Entity) by means of a SI MME interface and to a Serving Gateway (SGW) by means of a SI interface. The S I interface supports a many-to-many relationship between MMEs/S-GW and eNBs.

The eNB hosts the following functions:

• functions for RRM: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both UL and DL (scheduling);

• IP header compression and encryption of the user data stream;

• selection of a MME at UE attachment;

• routing of User Plane data towards the Serving Gateway; • scheduling and transmission of paging messages (originated from the MME);

• scheduling and transmission of broadcast information (originated from the MME or O&M); and

• a measurement and measurement reporting configuration for mobility and scheduling. During a handover procedure, the network (NW) issues commands to a user equipment (LIE) instructing it to change operation from a first cell in which the UE is currently operating (the source cell), to a second cell (the target cell). Ideally the NW should maintaining a capability to transfer user plane data (e.g., a PDCP SDU carrying IP-packets) with minimized caps.

A handover procedure may be controlled by the RRC protocol layer in the UE (e. g. , after receiving a command from the NW, such as a RRCConnectionReconfiguration command including a mobilityControlInfo RRC PDU). The RRC may control the operation of the packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC) and the L 1 (physical layer etc.) layers. See further: 3 GPP TS 36.331 V8.6.0 (2009-06), chapters 5.1-5.4, chapter 9 and chapter 11.

During the handover procedure the RRC layer resets the MAC layer. See further: 3GPP TS 36.321 V8.6.0 (2009-06), chapters 1-5.

The MAC reset procedure causes cancellation of ongoing MAC procedures but the MAC protocol layer reacts immediately to incoming triggers after the MAC layer is reset. This means that MAC procedures may be started again. For example, a buffer status reporting procedure may be triggered after the MAC reset if user data is received on a high priority logical channel (see 3 GPP T S 36.321 , chapter 5.4.5).

Buffer status reporting then triggers a scheduling request procedure (see TS 36.321, chapter 5.4.4) which causes the MAC layer to start a random access procedure (see 3GPP TS 36.321, chapter 5.1).

For further details on Handover procedures, see TS 36.331, chapter 5.3.5.4.

After the MAC is reset, the MAC protocol layer may then resume operations using the previously configured parameters (excluding those MAC parameters that were removed during the MAC reset). This means that in case of a handover (HO) it is possible that the MAC layer resumes its operations in the target cell, except using the wrong parameters (e.g., the previously configured LI and MAC parameters).

What is needed is a technique to avoid this potential error during a handover.

SUMMARY:

The below summary section is intended to be merely exemplary and non-limiting.

The foregoing and other problems are overcome, and other advantages are realized, by the use of the exemplary embodiments of this invention.

In a first aspect thereof an exemplary embodiment of this invention provides a method for controlling MAC protocol layer functionality during a handover procedure. The method includes receiving a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset and wireless network access related activities at the MAC protocol layer are halted. The method also includes receiving a first message at the MAC protocol layer. In response to receiving the first message, access related activities at the MAC protocol layer are resumed.

In another aspect thereof an exemplary embodiment of this invention provides an apparatus for controlling MAC protocol layer functionality during a handover procedure. The apparatus includes one or more processors; and one or more memories including computer program code, the one or more memories and the computer program code configured to, with the one or more processors, cause the apparatus to perform operations. The operations include to receive a reset command at a MAC protocol layer. The operations also include, in response to receiving the reset command, to reset the MAC protocol layer and to prevent wireless network access related activities at the MAC protocol layer. The operations also include to receive a first message at the MAC protocol layer. The operations also include, in response to receiving the first message, to resume access related activities at the MAC protocol layer.

In a further aspect thereof an exemplary embodiment of this invention provides a computer readable medium for controlling MAC protocol layer functionality during a handover procedure. The computer readable medium is tangibly encoded with a computer program executable by a processor to perform actions. The actions include receiving a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset and wireless network access related activities at the MAC protocol layer are prevented. The actions also include receiving a first message at the MAC protocol layer. In response to receiving the first message, access related activities at the MAC protocol layer are resumed.

In another aspect thereof an exemplary embodiment of this invention provides an apparatus for controlling MAC protocol layer functionality during a handover procedure. The apparatus includes means for receiving a reset command at a MAC protocol layer. The apparatus further includes means responsive to receiving the reset command, for resetting the MAC protocol layer and preventing wireless network access related activities at the MAC protocol layer. The apparatus also includes means for receiving a first message at the MAC protocol layer and means responsive to receiving the first message, for resuming access related activities at the MAC protocol layer. BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of exemplary embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein:

Figure 1 reproduces Figure 4-1 of 3GPP TS 36.300, and shows the overall architecture of the E-

UTRAN system.

Figure 2 shows a simplified block diagram of exemplary electronic devices that are suitable for use in practicing various exemplary embodiments of this invention.

Figure 3 shows a more particularized block diagram of an exemplary user equipment such as that shown at Figure 2.

Figure 4 demonstrates a simplified diagram of an example of a MAC protocol layer erroneously resuming operations in a target cell using the wrong, previously configured parameters.

Figure 5 demonstrates a simplified diagram of an exemplary method for a handover procedure in accordance with this invention.

Figure 6 is a logic flow diagram that illustrates the operation of an exemplary method, and a result of execution of computer program instructions embodied on a computer readable memory, in accordance with the exemplary embodiments of this invention.

DETAILED DESCRIPTION:

Various exemplary embodiments in accordance with this invention may be used to prevent (or seize)

MAC operation during a handover and before parameters are configured according to a handover command (e.g., a RRCConnectionReconfiguration command mcludingmobiUtyControunfo). Operating accordingly, the MAC protocol layer is assured to begin operations in the target cell using correctly configured parameters.

Before describing in further detail exemplary embodiments of this invention, reference is made to Figure 2 for illustrating a simplified block diagram of various electronic devices and apparatus that are suitable for use in practicing exemplary embodiments of this invention.

In the wireless system 230 of Figure 2, a wireless network 235 is adapted for communication over a wireless link 232 with an apparatus, such as a mobile communication device which maybe referred to as a UE 210, via a network access node, such as a Node B (base station), and more specifically an eNB 220. The network 235 may include a network control element (NCE) 240 that may include the MME/S-GW functionality shown in Figure 1, and which provides connectivity with a network, such as a telephone network and/or a data communications network (e.g., the internet 238).

The UE 210 includes a controller, such as a computer or a data processor (DP) 214, a computer- readable memory medium embodied as a memory (MEM) 216 that stores a program of computer instructions (PROG) 218, and a suitable wireless interface, such as radio frequency (RF) transceiver 212, for bidirectional wireless communications with the eNB 220 via one or more antennas.

The eNB 220 also includes a controller, such as a computer or a data processor (DP) 224, a computer-readable memory medium embodied as a memory (MEM) 226 that stores a program of computer instructions (PROG) 228, and a suitable wireless interface, such as RF transceiver 222, for communication with the UE 210 via one or more antennas. The eNB 220 is coupled via a data/control path 234 to the NCE 240. The path 234 may be implemented as the S 1 interface shown in Figure 1. The eNB 220 may also be coupled to other eNBs via data/control path 236, which may be implemented as the X2 interface shown in Figure 1.

The NCE 240 includes a controller, such as a computer or a data processor (DP) 244, a computer- readable memory medium embodied as a memory (MEM) 246 that stores a program of computer instructions (PROG) 248.

At least one of the PROGs 218, 228 and 248 is assumed to include program instructions that, when executed by the associated DP, enable the device to operate in accordance with exemplary embodiments of this invention, discussed below in greater detail.

That is, various exemplary embodiments of this invention may be implemented at least in part by computer s oftwar e executable by the DP 214 of the UE 210 ; by the DP 224 of the eNB 220 ; and/ or by the DP 244 of the NCE 240, or by hardware, or by a combination of software and hardware (and firmware).

The UE 210 and the eNB 220 may also include dedicated processors, for example MAC controller 21 and RRC controller 225.

In general, the various embodiments of the UE 210 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.

The computer readable MEMs 216, 226 and 246 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 214, 224 and 244 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multicore processor architecture, as non4imiting examples. The wireless interfaces (e.g., RF transceivers 212 and 222) may be of any type suitable to the local technical environment and may be implemented using any suitable communication technology such as individual transmitters, receivers, transceivers or a combination of such components.

Figure 3 illustrates further detail of an exemplary UE in both plan view (left) and sectional view (right), and the invention may be embodied in one or some combination of those more function-specific components. At Figure 3 the UE 210 has a graphical display interface 320 and a user interface 322 illustrated as a keypad but understood as also encompassing touch-screen technology at the graphical display interface 320 and voice-recognition technology received at the microphone 324. A power actuator 326 controls the device being turned on and offby the user. The exemplary UE 210 may have a camera 328 which is shown as being forward facing (e.g., for video calls) but may alternatively or additionally be rearward facing (e.g., for capturing images and video for local storage). Thecamera328 is controlled by a shutter actuator 330 and optionally by a zoom actuator 332 which may alternatively function as a volume adjustment for the speaker(s) 334 when the camera 328 is not in an active mode.

Within the sectional view of Fig. 3 are seen multiple transmit/ receive antennas 336 that are typically used for cellular communication. The antennas 336 may be multi-band for use with other radios in the UE. The operable ground plane for the antennas 336 is shown by shading as spanning the entire space enclosed by the UE housing though in some embodiments the ground plane may be limited to a smaller area, such as disposed on a printed wiring board on which the power chip 338 is formed. The power chip 338 controls power amplification on the channels being transmitted and/or across the antennas that transmit simultaneously where spatial diversity is used, and amplifies the received signals. The power chip 338 outputs the amplified received signal to the radio-frequency (RF) chip 340 which demodulates and downconverts the signal for baseband processing. The baseband (BB) chip 342 detects the signal which is then converted to a bit-stream and finally decoded. Similar processing occurs in reverse for signals generated in the apparatus 210 and transmitted from it.

Signals to and from the camera 328 pass through an image/video processor 344 which encodes and decodes the various image frames. A separate audio processor 346 may also be present controlling signals to and from the speakers 334 and the microphone 324. The graphical display interface 320 is refreshed from a frame memory 348 as controlled by a user interface chip 350 which may process signals to and from the display interface 320 and/or additionally process user inputs from the keypad 322 and elsewhere.

Certain embodiments of the UE 210 may also include one or more secondary radios such as a wireless local area network radio WLAN 337 and a Bluetooth® radio 339, which may incorporate an antenna on-chip or be coupled to an off-chip antenna. Throughout the apparatus are various memories such as random access memory RAM 343, read only memory ROM 345, and in some embodiments removable memory such as the illustrated memory card 347. The various programs 218 are stored in one or more of these memories . All of these components within the UE 210 are normally powered by a portable power supply such as a battery 349.

Processors 338, 340, 342, 344, 346, 350, if embodied as separate entities in a UE 210 or eNB 220, may operate in a slave relationship to the main processor 214, 224, which may then be in a master relationship to them. Embodiments of this invention are most relevant to the main processor 214, though it is noted that other embodiments need not be disposed there but may be disposed across various chips and memories as shown or disposed within another processor that combines some of the functions described above for Figure 3. Any or all of these various processors of Fig. 3 access one or more of the various memories, which may be on-chip with the processor or separate therefrom. Similar function- specific components that are directed toward communications over a network broader than a piconet (e.g., components 336, 338, 340, 342-345 and 347) may also be disposed in exemplary embodiments of the access node 220, which may have an array of tower-mounted antennas rather than the two shown at Fig. 3.

Note that the various chips (e.g., 338, 340, 342, etc.) that were described above may be combined into a fewer number than described and, in a most compact case, may all be embodied physically within a single chip.

Figure 4 demonstrates a simplified diagram of an example of a MAC protocol layer erroneously resuming operations in a target cell using the wrong, previously configured parameters. In this example, the UE 210 is performing a handover process.

As shown, the RRC starts to synchronize with the target eNB. At the LI (physical) layer, no download data is expected due to the eNB waiting until the completion of the HO . At A, the RRC sends a signal in order to reset the MAC. This causes cancellation of any ongoing MAC procedures (e.g., all UL grants and DL assignments are removed) and the MAC protocol layer is placed in a reset state.

At B, user data is generated (e.g., by a high level layer) and a random channel (RACH) is initiated. This may occur, for example, when the RLC has data in its buffers which is forwarded to the MAC. Since the MAC has not yet been reconfigured, the MAC begins operation using the current configuration (e.g., that of the source cell) in the target cell.

The RRC re-establishes the PDCP layer. The PDCP layer waits for the security configuration of the target cell, which may include halting uplink transmissions until the configuration is provided. Next the RRC re-establishes the RLC layer. The RLC layer discards uplink data.

The RRC performs defined actions, for example applying parameters for the new C-RNTI and dedicated RACH and deriving new security keys. The RRC provides the new security configuration to the PDCP layer.

Once the PDCP layer receives the new security configuration it is possible for random access to be initiated by user data, for example at C. Such random access is acceptable since it uses the proper configuration for the target cell.

In various exemplary embodiments in accordance with this invention, a handover is indicated (e.g., by signaling) to the MAC layer when a MAC reset is requested by the RRC. Then, the MAC halts activities until either when data from SRBO/SRBl is received or optionally when the PDCP re- establishment has been completed. This ensures that the RRC has applied the correct configuration to the MAC (and other layers) prior to the MAC resuming activities

In another exemplary embodiment in accordance with this invention, the handover is indicated to the MAC when a MAC reset is requested by the RRC as above. MAC activity is then halted until further notification is received. This notification may come directly from the RRC and/or via another layer. As an example, a message (e.g., a "RRCConnectionReconfigurationComplete" massage) may be sent on the SRB 1 from the RRC to the PDCP, then the message is sent in a RLC SDU from the PDCP to the RLC where the message is sent to the MAC in an MAC SDU on the SRB1.

In another exemplary embodiment in accordance with this invention, the MAC is halted as shown above (alternatively, access activities are prevented from occurring) and data radio bearers in the RLC are also suspended (e.g., via a RRC command) so that buffer status reports by the MAC are not triggered. The RLC is suspended prior to the MAC reset operation and may be continued when the RLC is re-established. Figure 5 demonstrates a simplified diagram of an exemplary method for a handover procedure in accordance with this invention.

At A, the R C resets the MAC layer indicating that a handover is being performed. The MAC performs the reset actions and seizes any further actions. At B, user data is generated (e.g., by a high level layer) and sent to the MAC. Since the MAC is seized, the MAC does not accept the user data and no further actions are performed at the MAC layer based on the data.

At C (after the PDCP is provided the security configuration for the target cell), random access is initiated by data being received at the PDCP.

In one embodiment, as shown in D, the PDCP informs the MAC that the MAC may continue operation. The MAC layer then resumes activities. When the MAC receives data it may initiate random access. Since the PDCP is configured with the configuration of the target cell, this random access uses the proper configuration for the target cell. Therefore, the MAC layer does not require explicit command from upper layers in order to resume operations.

In another embodiment, as shown in E, the MAC resumes activity in response to receiving a MAC SDU on the SRB1. The MAC SDU shown includes a "RRCConnectionReconfigurationComplete" message. This message is sent by the UE to confirm the handover after the UE has successfully accessed the target cell.

Based on the foregoing it should be apparent that the exemplary embodiments of this invention provide a method, apparatus and computer program(s) to control MAC protocol layer functionality during a handover procedure.

Figure 6 is a logic flow diagram that illustrates the operation of a method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention. In accordance with these exemplary embodiments a method performs, at Block 610, a step of receiving a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset and wireless network access related activities in the MAC protocol layer are prevented, at Block620. AtBlock 630, a step ofreceiving a first message at the MAC protocol layer is performed. In response to receiving the first message, access related activities are resumed at the MAC protocol layer, at Block 640.

The various blocks shown in Figure 6 may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function(s).

An exemplary embodiment in accordance with this invention is a method for controlling MAC protocol layer functionality during a handover procedure. The method includes receiving (e.g., at a processor) a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset (e.g., by a processor) and wireless network access related activities at the MAC protocol layer are prevented. The method also includes receiving (e.g., at a processor) a first message at the MAC protocol layer. In response to receiving the first message, access related activities at the MAC protocol layer are resumed (e.g., by a processor).

In a further exemplary embodiment of the method above, the first message includes an indication that a PDCP re-establishment has been completed.

In an additional exemplary embodiment of any one of the methods above, receiving data at the MAC protocol layer; the method also includes determining whether access related activities are prevented; in response to a determination that access related activities are prevented, preventing sending the data to the LI layer; and in response to a determination that access related activities are not prevented, initiating random access procedures.

In a further exemplary embodiment of any one of the methods above, the first message is a handover command message. The handover command message may include a RRCConnectionReconfiguration message and/or a mobilityControlInfo information element.

In an additional exemplary embodiment of any one of the methods above, the first message includes user data, and the method also includes initiating a random access channel; and transmitting the user data using the random access channel.

In a further exemplary embodiment of any one of the methods above, the method is performed during a handover procedure.

In an additional exemplary embodiment of any one of the methods above, the first message is received via SRB 1.

In a further exemplary embodiment of any one of the methods above, the method also includes receiving new access related parameters, where resuming access related activities uses the new access related parameters.

In an additional exemplary embodiment of any one of the methods above, the first message is a control/configuration message.

In a further exemplary embodiment of any one of the methods above, the first message is received from a higher protocol layer.

An additional exemplary embodiment in accordance with this invention is an apparatus for controlling MAC protocol layer functionality during a handover procedure. The apparatus includes a receiver configured to receive a reset command at a MAC protocol layer. The apparatus also includes a controller configured, in response to receiving the reset command, to reset the MAC protocol layer and to prevent wireless network access related activities at the MAC protocol layer. The receiver is also configured to receive a first message at the MAC protocol layer. The controller is also configured to, in response to receiving the first message, resume access related activities at the MAC protocol layer.

In a further exemplary embodiment of the apparatus above, the first message includes an indication that a PDCP re-establishment has been completed.

In an additional exemplary embodiment of any one of the apparatus above, the receiver is configured to receive data at the MAC protocol layer; the controller is also configured to determine whether access related activities are prevented; in response to a determination that access related activities are prevented, to prevent sending the data to the LI layer; and, in response to a determination that access related activities are not prevented, to initiate random access procedures.

In a further exemplary embodiment of any one of the apparatus above, the first message is a handover command message. The handover command message may include a RRCConnectionReconfiguration message and/or a mobilityControlInfo information element.

In an additional exemplary embodiment of any one of the apparatus above, the first message includes user data, and the controller is also configured to initiate a random access channel; and to cause the user data to be transmitted using the random access channel.

In a further exemplary embodiment of any one of the apparatus above, the receiver is configured to receiver new access related parameters, where resuming access related activities uses the new access related parameters.

In an additional exemplary embodiment of any one of the apparatus above, the first message is received via SRB 1.

In a further exemplary embodiment of any one of the apparatus above, the first message is a control/configuration message.

In an additional exemplary embodiment of any one of the apparatus above, the first message is received from a higher protocol layer.

A further exemplary embodiment in accordance with this invention is an apparatus for controlling MAC protocol layer functionality during a handover procedure. The apparatus includes one or more processors; and one or more memories including computer program code, the one or more memories and the computer program code configured to, with the one or more processors, cause the apparatus to perform operations. The operations include to receive a reset command at a MAC protocol layer. The operations also include, in response to receiving the reset command, to reset the MAC protocol layer and to prevent wireless network access related activities at the MAC protocol layer. The operations also include to receive a first message at the MAC protocol layer. The operations also include, in response to receiving the first message, to resume access related activities at the MAC protocol layer.

In an additional exemplary embodiment of the apparatus above, the first message includes an indication that a PDCP re-establishment has been completed.

In a further exemplary embodiment of any one of the apparatus above, the one or more memories and the computer program code are further configured to cause the apparatus to receive data at the MAC protocol layer; to determine whether access related activities are prevented; in response to a determination that access related activities are prevented, to prevent sending the data to the LI layer; and, in response to a determination that access related activities are not prevented, to initiate random access procedures.

In an additional exemplary embodiment of any one of the apparatus above, the first message is a handover command message. The handover command message may include a RRCConnectionReconfiguration message and/or a mobilityControlInfo information element.

In a further exemplary embodiment of any one of the apparatus above, the first message includes user data, and the one or more memories and the computer program code are further configured to cause the apparatus to initiate a random access channel; and to cause the user data to be transmitted using the random access channel.

In an additional exemplary embodiment of any one of the apparatus above, the one or more memories and the computer program code are further configured to cause the apparatus to receiver new access related parameters, where resuming access related activities uses the new access related parameters.

In a further exemplary embodiment of any one of the apparatus above, the first message is received via SRB l.

In an additional exemplary embodiment of any one of the apparatus above, the first message is a control/configuration message.

In a further exemplary embodiment of any one of the apparatus above, the first message is received from a higher protocol layer.

An additional exemplary embodiment in accordance with this invention is a computer readable medium for controlling MAC protocol layer functionality during a handover procedure. The computer readable medium is tangibly encoded with a computer program executable by a processor to perform actions. The actions include receiving a reset command at a MAC protocol layer. In response to receiving the reset command, the MAC protocol layer is reset and wireless network access related activities at the MAC protocol layer are prevented. The actions also include receiving a first message at the MAC protocol layer. In response to receiving the first message, access related activities at the MAC protocol layer are resumed.

In a further exemplary embodiment of the computer readable medium above, the first message includes an indication that a PDCP re-establishment has been completed.

In an additional exemplary embodiment of any one of the computer readable media above, the actions also include receiving data at the MAC protocol layer; determining whether access related activities are prevented; in response to a determination that access related activities are prevented, preventing sending the data to the LI layer; and in response to a determination that access related activities are not prevented, initiating random access procedures.

In a further exemplary embodiment of any one of the computer readable media above, the first message is a handover command message. The handover command message may include a RRCConnectionReconfiguration message and/or a mobilityControlInfo information element.

In an additional exemplary embodiment of any one of the computer readable media above, the first message includes user data, and the actions also include initiating a random access channel; and transmitting the user data using the random access channel.

In a further exemplary embodiment of any one of the computer readable media above, the actions are performed during a handover procedure.

In an additional exemplary embodiment of any one of the computer readable media above, the first message is received via SRB1.

In a further exemplary embodiment of any one of the computer readable media above, the actions also include receiving new access related parameters, where resuming access related activities uses the new access related parameters.

In an additional exemplary embodiment of any one of the computer readable media above, the first message is a control/configuration message.

In a further exemplary embodiment of any one of the computer readable media above, the first message is received from a higher protocol layer.

In an additional exemplary embodiment of any one of the computer readable media above, the computer readable medium is a non-transitory computer readable medium.

A further exemplary embodiment in accordance with this invention is an apparatus for controlling MAC protocol layer functionality during a handover procedure. The apparatus includes means for receiving a reset command at a MAC protocol layer (e.g., a receiver). The apparatus further includes means responsive to receiving the reset command, for resetting the MAC protocol layer and preventing wireless network access related activities at the MAC protocol layer. The apparatus also includes means for receiving a first message at the MAC protocol layer (e.g., a receiver) and means responsive to receiving the first message, for resuming access related activities at the MAC protocol layer.

In an additional exemplary embodiment of any one of the apparatus above, the apparatus also includes means for receiving data at the MAC protocol layer (e.g., a receiver); means for determining whether access related activities are prevented (e.g., a processor); means responsive to a determination that access related activities are prevented, for preventing sending the data to an LI layer(e.g., a processor); and, means responsive to a determination that access related activities are not prevented, for initiating random access procedures (e.g., a processor).

In an additional exemplary embodiment of any one of the apparatus above, the first message includes user data, and the apparatus also includes means for initiating a random access channel (e.g., a processor); and means for transmitting the user data using the random access channel (e.g., a transmitter).

In a further exemplary embodiment of any one of the apparatus above, the apparatus also includes means for receiving new access related parameters (e.g., a receiver), where resuming access related activities uses the new access related parameters.

In a further exemplary embodiment of any one of the apparatus above, the reset command receiving means is a receiver; the resetting and preventing means is a processor; the first message receiving means is a receiver; and the resuming means is a processor.

In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as nonlimiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof

It should thus be appreciated that at least some aspects of the exemplary embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules, and that the exemplary embodiments of this invention may be realized in an apparatus that is embodied as an integrated circuit. The integrated circuit, or circuits, may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this invention.

Various modifications and adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, whenread in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention.

For example, while the exemplary embodiments have been described above in the context of the E- UTRAN (UTRAN-LTE) system, it should be appreciated that the exemplary embodiments of this invention are not limited for use with only this one particular type of wireless communication system, and that they may be used to advantage in other transmission systems where a RLC forwards data to the MAC.

It should be noted that the terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

It should be noted that the terms "non-transitory medium", "non-transitory memory" or any variant thereof, describes any medium which may be used to store data. Such media include ROM, RAM, flash memory, and any other suitable data storage technology.

Further, the various names used for the described parameters and messages (e.g., RRCConnectionReconfigurationComplete, mobilityControlInfo, etc.) are not intended to be limiting in any respect, as these parameters may be identified by any suitable names. Further, the various names assigned to different channels (e.g., RACH, etc.) are not intended to be limiting in anyrespect, as these various channels may be identified by any suitable names.

Furthermore, some of the features of the various non-limiting and exemplary embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.

Claims

CLAIMS What is claimed is:

1. A method comprising:

receiving a reset command at a medium access control protocol layer;

in response to receiving the reset command, resetting the medium access control protocol layer and halting wireless network access related activities at the medium access control protocol layer;

receiving a first message at the medium access control protocol layer; and

in response to receiving the first message, resuming access related activities at the medium access control protocol layer.

2. The method of claim 1, where the first message comprises an indication that a packet data convergence protocol re-establishment has been completed.

3. The method of any one of claims 1-2, further comprising:

receiving data at the medium access control protocol layer;

determining whether access related activities are halted;

in response to a determination that access related activities are halted, preventing sending of the data to a physical layer; and

in response to a determination that access related activities are not halted, initiating random access procedures.

4. The method of any one of claims 1-3, where the first message is a RRCConnectionReconfiguration message.

5. The method of any one of claims 1-4, where the method is performed during a handover procedure.

6. The method of any one of claims 1-5, where the first message is received via a signaling radio bearer.

7. The method of any one of claims 1-6, further comprising: receiving new access related parameters, where resuming access related activities uses the new access related parameters.

8. An apparatus (210, 220), comprising at least one processor (214, 215, 224, 225); and at least one memory (216, 226) including computer program code (218, 228), the at least one memory (216, 226) and the computer program code (218, 228) configured to, with the at least one processor (214, 215, 224, 225), cause the apparatus (210, 220)to perform at least the following:

to receive a reset command at a medium access control protocol layer;

in response to receiving the reset command, to reset the medium access control protocol layer and to halt wireless network access related activities at the medium access control protocol layer;

to receive a first message at the medium access control protocol layer; and

in response to receiving the first message, to resume access related activities at the medium access control protocol layer.

9. The apparatus (210, 220) of claim 8, where the first message comprises an indication that a packet data convergence protocol re-establishment has been completed.

10. The apparatus (210, 220) of any one of claims 8-9, where the at least one memory (216, 226) and the computer program code (218, 228) are further configured to cause the apparatus (210, 220): to receive data at the medium access control protocol layer;

to determine whether access related activities are halted;

in response to a determination that access related activities are halted, to prevent sending of the data to a physical layer; and

in response to a determination that access related activities are not halted, to initiate random access procedures.

11. The apparatus (210, 220) of any one of claims 8-10, where the first message is a R CConnectionReconfiguration message.

12. The apparatus (210, 220) of any one of claims 8-11, where receiving the reset command is performed during a handover procedure.

13. The apparatus (210, 220) of any one of claims 8-12, where the first message is received via a signaling radio bearer.

14. The apparatus (210, 220) of any one of claims 8-13, where the at least one memory (216, 226) and the computer program code (218, 228) are further configured to cause the apparatus (210, 220) to receive new access related parameters, where resuming access related activities uses the new access related parameters.

15. A computer readable medium (216, 226) tangibly encoded with a computer program (218, 228) executable by a processor (214, 215, 224, 225) to perform actions comprising:

receiving a reset command at a medium access control protocol layer;

receiving a first message at the medium access control protocol layer; and

16. The computer readable medium (216, 226) of claim 15, where the first message comprises an indication that a packet data convergence protocol re-establishment has been completed.

17. The computer readable medium (216, 226) of any one of claims 15-16, where the actions further comprise:

receiving data at the medium access control protocol layer;

determining whether access related activities are halted;

18. The computer readable medium (216, 226) of any one of claims 15-17, where the first message is a RRCConnectionReconfiguration message.

19. The computer readable medium (216, 226) of any one of claims 15-18, where the actions are performed during a handover procedure.

20. The computer readable medium (216, 226) of any one of claims 15-19, where the first message is received via a signaling radio bearer.

21. The computer readable medium (216, 226) of any one of claims 15-20, where the actions further comprise receiving new access related parameters, where resuming access related activities uses the new access related parameters.

22. An apparatus (210, 220) comprising:

means for receiving a reset command at a medium access control protocol layer;

means for resetting the medium access control protocol layer and halting wireless network access related activities at the medium access control protocol layer in response to receiving the reset command;

means for receiving a first message at the medium access control protocol layer; and

means for resuming access related activities at the medium access control protocol layer in response to receiving the first message.

23. The apparatus (210, 220) of claim 22, where the first message comprises an indication that a packet data convergence protocol re-establishment has been completed.

24. The apparatus (210, 220) of any one of claims 22-23, further comprising:

means for receiving (212, 222) data at the medium access control protocol layer;

means for determining (214, 215, 224, 225) whether access related activities are halted;

means for preventing (214, 21 , 224, 22 ) sending of the data to a physical layer in response to a determination that access related activities are halted; and

means for initiating (214, 21 , 224, 225) random access procedures in response to a determination that access related activities are not halted.

25. The apparatus (210, 220) of any one of claims 22-24, where the first message is a RRCConnectionReconfiguration message.

26. The apparatus (210, 220) of any one of claims 22-25, where the means for receiving (212, 222) the reset command is configured to receive the reset command during a handover procedure.

27. The apparatus (210, 220) of any one of claims 22-26, where the first message is received via a signaling radio bearer.

28. The apparatus (210, 220) of any one of claims 22-27, further comprising means for receiving (212, 222) new access related parameters, where the means for resuming (214, 215, 224, 225) uses the new access related parameters when resuming the access related activities.