Wireless communication method and wireless communication apparatus for supporting reconfiguration of radio link control parameters

This application relates to wireless communication.

Some of the key goals of the development of High Speed Packet Access (HSPA) are higher data rates, higher system capacity and coverage, better packet service support, lower latency, lower operator costs, and backward compatibility. Is included. Meeting these goals requires the evolution of wireless interface protocols and network architectures. More specifically, meeting these goals required a set of L2 (Layer 2) (ie, RLC (Wireless Link Control) and MAC (Media Access Control)) functional enhancements and architectural changes.

Some of the L2 enhancements include flexible sized RLC PDUs (protocol data units) (ie, flexible sized RLC PDUs), MAC-hs (fast MAC) segmentation / concatenation and multiplexing. In UTRA (Universal Terrestrial Radio Access) R6 (Releasure 6), AM (confirmation mode) RLC entities can only use fixed size RLC PDUs (ie, RLC PDUs with fixed sizes). Further, the MAC-hs sublayer at node B can only support the concatenation of MAC-d (dedicated MAC) PDUs. The L2 extension of UTRA R7 (Release 7) results in significant RLC / MAC changes for R6 features.

Currently, when an RB (radio bearer) is set up or reconfigured via RRC (radio resource control) signaling, there is an IE (information element) called "RB mapping information". "RB mapping information" includes information about RLC instances and transport channels corresponding to RB.

The MAC-hs configuration must be the same across all RBs mapped to HS-DSCH (High Speed Downlink Shared Channel), otherwise an invalid configuration will result.

In HSPA, the high speed shared channel is monitored by WTRU (Radio Transmit / Receive Unit) within a single cell (ie, serving HS-DSCH cell). Due to mobility, when the WTRU moves from one cell to the other, the WTRU changes the serving cell by switching to the new serving HS-DSCH cell and terminating communication with the old serving HS-DSCH cell. Need to do. In the node B transfer procedure, a handover between nodes B is performed from the old node B (that is, the source node B) to the new node B (that is, the target node B).

At the time of changing the serving node B, the target node B needs to start transmitting data via the new configuration. Handovers can be performed between evolved HSPA nodes B that support L2 enhancement, or to / from cells with or without L2 enhancement. In either case, the WTRU must be able to perform a handover, adjust for the new configuration, and minimize data loss.

<p num="0008"> With the introduction of new L2 enhancements, new procedures are defined to optimize handovers between cells R7 or between cells R7 and R6 and minimize data loss during such handovers. There is a need. Specifically, the procedure for handling the reconfiguration of MAC-hs entities needs to be modified to take into account the new L2 enhancements.</p><p num="0009"> Furthermore, it cannot be assumed that all of R6 node B will be upgraded to R7 node B at the same time. Therefore, the handover between the R6 cell and the R7 cell may occur frequently. Due to the functional changes of RLC and MAC, a method of performing a handover between these cells with minimal loss of quality and data must be defined. Specifically, on the WTRU side, MAC-hs and RLC must execute the function change during handover.</p>

<p num="0010"> Various wireless communication methods and devices for supporting the reconstruction of RLC parameters are disclosed. Flexible because the RLC unit in WTRU or UTRAN (Universal Terrestrial Radio Access Network) supports flexible size RLC PDUs to support fixed size RLC PDUs, or from supporting fixed size RLC PDUs. An RRC reconfiguration message is generated stating that it must be reconfigured to support RLC PDUs of size. If IE (one-sided RLC reestablishment) is present in the RRC reconfiguration message, only the receiving or transmitting subassembly in the RLC unit will be reestablished. If it does not exist, both the receiving and transmitting subassemblies in the RLC unit are reestablished. It is possible to discard the flexible size RLC PDU and send a message indicating the discarded flexible size RLC PDU. Flexible size RLC The PDUs can be modified so that they correspond to a predefined set of sizes.</p><p num="0011"> A more detailed understanding of the present invention can be obtained from the following description in connection with the accompanying drawings.</p>

<figref num="1">An example showing a WTRU configured to move between cells R6 and R7 and operate with a new RLC sublayer and MAC-hs sublayer when a handover message is received during the serving cell change procedure. Block diagram.</figref><figref num="2">FIG. 5 is an exemplary block diagram showing a UTRAN transmitting an RRC reconstruction message to the WTRU of FIG.</figref>

When referred to below, the term "WTRU (wireless transmit / receive unit)" refers to UEs (user equipment), mobile stations, fixed or mobile subscriber units, pagers, cellular telephones, PDAs (personals). It includes, but is not limited to, digital assistants), computers, or any other type of user device that can operate in a wireless environment. As referred to below, the term "base station" includes node B, site controllers, APs (access points), or any other type of interface device that can operate in a wireless environment. , Not limited to that.

Various wireless communication methods for optimizing handover scenarios, reconfiguration procedures, and reconfiguration procedures for RLC entities are disclosed herein. Further disclosed are various wireless communication methods for handover between cells in which one or both of the cells support L2 enhancement. Both UL (uplink) and DL (downlink) are applicable to these wireless communication methods.

The following terms are used throughout the description below and are briefly defined. The MAC-ehs (enhanced MAC-hs) payload unit is a segment of the MAC-ehs SDU (service data unit) or MAC-ehs SDU contained within the MAC-ehs PDU. A MAC-ehs sorted PDU is a set of MAC-ehs payload units in a MAC-ehs PDU that belongs to the same priority queue. The enhanced cell is a cell that supports L2-enhanced, i.e., a flexible size RLC PDU. Unenhanced cells are L2-enhanced cells that do not support fixed size RLC PDUs.

As referred to below, R6 includes cells, nodes B, or RNCs (wireless network controllers) that do not support flexible sized RLC PDUs (ie, fixed sized RLC PDUs are supported). It is not limited to that. As referred to below, R7 includes, but is not limited to, cells, nodes B, or RNCs that support flexible sized RLC PDUs.

As referred to below, UTRAN includes, but is not limited to, cell, node B, RNC, or network nodes.

FIG. 1 moves between unenhanced and enhanced cells and operates with the new RLC and MAC-ehs sublayers when a handover message is received during the serving cell change procedure. It is an exemplary block diagram of WTRU100 configured as above. As shown in FIG. 1, the WTRU 100 includes an RRC unit 105, an RLC unit 110, a MAC unit 115, and a PHY (physical) L1 (layer 1) unit 120. The initiation of the serving cell change can be made in response to the receipt of the RRC reconfiguration message 125, such as an RB RRC reconfiguration message, a transport channel RRC reconfiguration message, or a physical channel RRC reconfiguration message. The RLC unit 110 includes a transmitting subassembly 130 and a receiving subassembly 135. The transmitting subassembly 130 includes a transmitting buffer 140.

The RRC reconstruction message 125 can be generated by UTRAN. FIG. 2 is a block diagram showing an example of a protocol stack configuration in UTRAN200. The UTRAN 200 can include an RRC unit 205, an RLC unit 210, a MAC unit 115, and a PHY L1 unit 220. The RLC unit 210 includes a transmitting subassembly 230 and a receiving subassembly 235. The transmitting subassembly 230 includes a transmitting buffer 240. The RRC unit 205 generates an RRC reconstruction message 125 that initiates a serving cell change.

The UTRAN 200 can also include a target node B, a source node B, a CRNC (control RNC), and an SRNC (serving RNC) (not shown). The RNC can include an RLC unit and an RRC unit (not shown). Alternatively, the RNC function is included within node B, so that neither the control RNC nor the serving RNC exists.

The RLC instance is not required to have the same RLC configuration for all RBs mapped to HS-DSCH. For example, a WTRU connected to a reinforced cell can simultaneously support one or more RLC instances configured to have a fixed size RLC PDU and / or a flexible size RLC PDU. Enhanced MAC-ehs can support reception of both fixed size RLC PDUs and flexible size RLC PDUs.

However, WTRUs operating in unenhanced cells cannot support RLC instances with flexible sized RLC PDUs. All RLC entities mapped to normal HS-DSCH (ie, MAC-hs) must be configured to have a fixed size RLC PDU operation. This is due to the fact that normal MAC-hs configurations do not support the reception and signaling of flexible sized RLC PDUs. Therefore, an RLC that supports a fixed size RLC PDU can refer to an AM RLC instance or a UM (Unconfirmed Mode) RLC instance.

To avoid reestablishment, the logical channels corresponding to the RLC instance do not have to change the configuration of those channels when moving from the unenhanced cell to the enhanced cell. For example, when a WTRU moves from a cell with a normal MAC-hs configuration to a cell with an enhanced MAC-ehs configuration, the RLC instance configured to support a fixed size RLC PDU is flexible in size. It does not have to be reconfigured to support the RLC PDU.

RBs that support fixed-size RLC PDUs in enhanced cells can maintain a fixed-size RLC PDU configuration, or have flexible-sized RLC PDUs at the time of handover or at a later time. It can be reconfigured to support, and if reconfigured, the RB reconfiguration procedure is triggered and the RRC performs the required steps. This allows the signaling RB to maintain the existing RLC configuration and avoid reestablishment of the RLC entity. If the handover between the unenhanced cell and the enhanced cell is often done in the network, this method is enhanced if the WTRU moves frequently between the unenhanced cell and the enhanced cell. Avoid reestablishing an unestablished RLC AM instance. This method also allows optimization for UM RLC instances. If the UM RLC instance is not extended to support flexible sized RLC PDUs in R7, then UM The RLC instance does not have to be reestablished or reconfigured when moving from an unenhanced cell to an enhanced cell, or from an enhanced cell to a non-enhanced cell. When flexible sized PDUs are introduced for UM RLC instances, the same methods described for AM RLC apply.

Reestablish RLC behavior per RB when moving between enhanced and unenhanced cells

If the WTRU modifies the serving cell during a handover that supports different releases (ie, R6 and R7), the WTRU maintains the existing RLC instance without changing the configuration of that instance (ie, enhanced). It has the option of (supporting fixed size RLC PDUs) on the MAC configuration, or it is possible to reconfigure an existing RLC instance. However, when an RLC instance that supports a fixed size RLC PDU within an enhanced L2 cell moves to an unenhanced L2 cell, the normal MAC-hs should support the reception of a fixed size RLC PDU. Cannot maintain the configuration of that instance. Therefore, to minimize data loss, RLC re-establishment is required or new procedures are required to handle changes in the RLC configuration. Changes in the reconfiguration of the RLC unit can also be made for SRNS relocation, where SRNS relocation is from SRNC, which supports flexible sized RLC PDUs, to flexible sized RLC. Includes moving to an SRNC that does not support PDUs.

A method of performing RLC re-establishment and assessing the need for RLC re-establishment is required for each RB. If the WTRU moves between the enhanced L2 cell and the non-enhanced L2 cell, or if the RLC changes configuration, no RLC reconstruction will occur, so no RLC re-establishment will be performed and no RLC re-establishment will be performed. In addition / or a change in RLC configuration from fixed size RLC PDUs to flexible size RLC PDUs is made. In this case, the RLC reconstruction procedure can be triggered. In this case, reestablishment of the RLC entity is not always required, but can optionally be performed.

The reconfiguration procedure configures the RLC entity only to begin supporting flexible sized RLC PDUs. No data loss occurs. This is because fixed size RLC PDUs can be transmitted and transparent to WTRU and MAC-ehs. The reconfiguration procedure configures the RLC entity only to begin supporting flexible sized RLC PDUs. Fixed size RLC PDUs can be transmitted to WTRU and MAC-ehs, so there is no data loss. RLC configuration changes from flexible sized RLC PDUs to fixed sized RLC PDUs require RLC re-establishment or, optionally, address the change and attempt to minimize data loss. It is possible to carry out new procedures. WTRU always stays in R7 RLC, flexible size RLC It is configured to support PDUs. UTRAN can change the RLC configuration without notifying WTRU that the change from R6 to R7 or the change from R7 to R6 has been made.

Evaluation Criteria for Performing RLC Reconstruction or RLC Reestablishment

When the RLC changes the configuration of the RLC, the RB reconstruction procedure is triggered. The need for RLC re-establishment is assessed and demonstrated using the RRC RB reconstruction procedure and the RRC RB information element.

The need for RLC re-establishment for signaled RBs is due to RRC explicit signaling that adds new fields within the existing RB or within the SRB (Signaling RB) IE (Information Element) indicating RLC re-establishment. It is possible to decide. RRC explicit signaling can indicate unilateral or complete reestablishment. The RRC procedure corresponding to the RB reconfiguration procedure includes the new configuration parameters supplied (ie, the flexible or fixed size of the RLC PDU) and the old configuration parameters of the reconstructed RLC entity (ie, the RLC PDU). It is possible to perform a conditional test on the flexible or fixed size) and modify it to assess the need for RLC re-establishment.

The evaluation of the reestablishment criteria is further / in the description of the general action when the RB mapping information IE is received, in the description of the general action when the "RLC information" IE is received. Alternatively, it can be done by adding a new section that describes the general actions when a DL (downlink) RLC configuration IE or UL (uplink) RLC configuration IE is received.

The following sections describe the various possibilities of evaluating and implementing RLC reestablishment criteria and are applicable to both RLC DL entities, both RLC UL entities, and optionally UM entities.

Option 1 For this option, the RLC re-establishment evaluation is performed within the actions of the "RB Mapping Information" IE, or within a new section dealing with the actions when the "RLC Configuration" IE is received. Note that the RLC configuration (ie, whether the RLC choice is fixed or flexible) is given in the "RB Mapping Information" IE for this option. However, the "RLC configuration" IE can also be given among other information elements. The "RLC Configuration" IE may provide WTRU with information on whether an RLC instance is configured to support fixed size RLC PDUs or flexible size RLC PDUs. It is possible.

If the "RLC Configuration" IE is set to the value "Enhanced" and the previously stored value is set to "Normal" (or if that value is different from the currently set value) , RLC entity (or layer) is reconfigured according to DL RLC configuration IE. Optionally, the RLC entity is reestablished if reestablishment is required. Instead, if the "RLC Configuration" IE is set to a value of "normal" and the previously stored value is set to "enhanced" (or that value is currently set). If different). The RLC entity is reestablished by performing a one-sided reestablishment or a full reestablishment.

Upon receiving the RRC message that results in the reconstruction of the RB, the WTRU performs a set of actions associated with the RB mapping. For UL RLC operations, the conditions for re-establishment can be carried out as an option in this case. More specifically, the RB uses AM, and the RLC PDU configuration applicable to UL logical channels (ie, RLC PDU size selection) is fixed from the configuration that supports flexible sized RLC PDUs. If the size is changed to an RLC PDU, and if an IE "one-sided RLC reestablishment" is included in the RRC message and this IE is set to TRUE, the WTRU will send the corresponding RLC entity. Reestablish. Otherwise, WTRU reestablishes the corresponding RLC entity.

If the configuration that supports fixed size RLC PDUs is changed to a configuration that supports flexible size RLC PDUs, RLC reconstruction is optional and the length indicated in the length indicator field of the RLC PDU. It can be executed when the indicator changes between 7 and 15 bits. As mentioned above, only the sender subassemblies 130 and 230 (if the IE "one-sided RLC reestablishment" is included), or the entire RLC units 110 and 210 (ie, the sender subassemblies 130 and 230 and the receiver subassembly). Both 135 and 235) can be reestablished.

Option 2 The RLC re-establishment criteria are evaluated in the action when the "RLC Information" IE is received. When the action corresponding to the "RLC Information" IE is performed, the procedure needs to be aware of the configuration of the RLC entity (ie, a flexible size RLC PDU, or a fixed size RLC PDU). This can be done by adding a new IE within the "RLC Information" IE that indicates the RLC configuration. The new IE indicates whether flexible RLC PDU size can be used or fixed RLC PDU size can be used. The new IE also indicates whether enhanced RLC will be used or regular RLC will be used.

The DL RLC PDU size IE value set can be extended to include reserved values that implicitly indicate that RLC supports flexible size RLC PDUs. For example, a value of 0 or 8 can be used, or "all 1s" in the binary can be used. The "RB Mapping Information" IE and the "DL RLC Configuration" IE that specifies the version of the RLC configuration used are examined. Information on the RLC configuration is obtained from any other IE that contains this information. If this new IE is not included in the "RLC Information" IE, the re-establishment procedure will be based on information from other factors, or the re-establishment procedure will be done in the RB Mapping Information IE.

The new RB is configured to support fixed size RLC PDUs (ie, start working with fixed size RLC PDUs) and older RBs support (ie, flexible size). If it was configured to work with RLC PDUs), the RLC entity is reestablished. The re-establishment can be a one-sided re-establishment. For example, for DL RLC, only the receiving side can be reestablished, and for UL RLC, only the transmitting side can be reestablished. It is possible to use the existing IE called "One-sided Re-establishment" in the "RLC Information" IE to perform one-sided re-establishment. Optionally, the RRC procedure specifically demonstrates reestablishing a receiving entity or a transmitting entity without using the IE "one-sided reestablishment".

Reestablishment can be optional if the new RB supports flexible sized RLC PDUs, the old RB supports fixed sized RLC PDUs, and the RLC units 110 and 210 are reconfigured. ..

A description of the RRC procedure is given below. The RRC procedure has been modified in response to the "RLC Information" IE. For this explanation, a new information element called "DLRLC size indicator" is added to the "RLC information" IE, or UL with fixed RLC or normal RLC values, "UL RLC size indicator". An example of a new IE is shown in Table 1.

The RRC procedure corresponding to the action taken when the "RLC Information" IE is present is modified to take into account changes in the RLC instance configuration. The "RLC size label" IE is used as an example in the procedure described below. However, in general, the "RLC size label" IE represents an indication of the RLC configuration and can be referred to differently and can have different enumerations such as enhanced / normal or values. ..

The modified RRC procedure can be carried out as follows. That is, When the IE "RLC information" is received, the WTRU will 1&gt; When there is an IE called "Downlink RLC mode" and it is set to "AM RLC": 2&gt; When there is an IE called "DL RLC size indicator" and it is set to a value of "fixed"; 3&gt; If the value is different from the value currently set in the RLC entity: 4&gt; When the IE "One-sided RLC reestablishment" is set to TRUE: 5&gt; Reestablish the receiver of the corresponding RLC entity. 4&gt; else: 5&gt; Reestablish the corresponding RLC entity. 3&gt; Configure the corresponding RLC entity according to the new RLC PDU size indicator; 2&gt; else, when "DL RLC size indicator" is present and set to "flexible"; 3&gt; When the value is different from the value currently set in RLC; 4&gt; Reconfigure the RLC entity (optionally reestablish the RLC if the RRC is configured to reestablish when moving from the unenhanced cell to the enhanced cell). 2&gt; else; (following the else statement is a procedure that deals with fixed RLC PDU size instances or cases where there is no DL RLC size indicator. The steps that follow this else statement correspond to the steps in R6. ); 3&gt; When there is no IE called "DL RLC PDU size"; 4&gt; Determining the downlink RLC PDU size is handled at the RLC level, without configuration from the RRC. Note: Cases where the required IE does not exist are intended to handle interaction with the network using earlier releases of the specification. 3&gt; else, if there is an IE called "DL RLC PDU" size and the downlink RLC PDU size is not currently set in the RLC entity: 4&gt; Link the corresponding RLC entity to its downlink RLC It is configured to have a PDU size. 3&gt; else, if there is an IE called "DL RLC PDU size" and the value of this IE is different from the value currently set in the RLC entity: Note: The downlink RLC PDU size set within the RLC entity can be explicitly configured or, if no explicit configuration is given, by the first received RLC PDU. It can be derived. 4&gt; When "One-sided RLC reestablishment" IE is set to TRUE: 5&gt; Reestablish the receiver of the corresponding RLC entity. 4&gt; else: 5&gt; Reestablish the corresponding RLC entity. 4&gt; Configure the corresponding RLC entity to have a new downlink RLC PDU size.

The conditional inspection for RLC re-establishment is not limited to the order specified in the two options described above, and thus can be performed in any order. In addition, the names of new IEs such as DL RLC Configuration IE and DL RLC Size Label IE are subject to change. The procedure corresponding to this IE remains the same regardless of the IE name.

For option 2, examples of "RLC information" IE function definitions are provided in Table 1 below.

<tables num="1-1"></tables>

<tables num="1-2"></tables>

If the RLC re-establishment for a different RLC configuration is not evaluated in the "RLC Information" IE, the conditional check for DL RLC PDU size in the "RLC Information" IE is when the AM RLC instance supports a fixed RLC PDU size. It should be done only. Otherwise, a conditional check is performed and unnecessary re-establishment can result if the DL RLC PDU size is present for the flexible RLC configuration.

With reference to FIGS. 1 and 2, an alternative method for adjusting the new RLC configuration in WTRU100 and UTRAN200 is then disclosed. This alternative method is applicable when the receiving subassemblies 135 and 235 are configured to explicitly signal the RLC configuration via RB RRC reconfiguration messages to support flexible sized RLC PDUs. Is. If the receiving subassemblies 135 and 235 are configured to support flexible sized RLC PDUs, the receiving subassemblies 135 and 235 are used by the transmitting subassemblies 130 and 230 (fixed size). It is possible to receive RLC PDU size instructions from higher layers (if configured to support RLC PDUs). This method is also applicable to cases where the RLC units 110 and 220 resize the length indicator field of the RLC PDU between 7 and 15.

When changing from an RLC configuration that supports flexible size RLC PDUs to an RLC configuration that supports fixed size RLC PDUs, the sender subassemblies 130 and 230, and the receiver subassemblies 135 and 235 are flexible sized. The RLC PDU must be destroyed. More specifically, at a given activation, the sender subassemblies 130 and 230 have been transmitted once and have not yet been identified with a flexible size RLC PDU (or fixed AMD (confirmation mode data) PDU). Discard the RLC PDU) having a size other than. An exemplary activation time can be the time when node B begins to use normal MAC-hs in the case of DL or MAC-i / is in the case of UL. is there. Transmitter subassemblies 130 and 230 may discard the RLC PDU according to any one or combination of the following rules: 1) Any RLC PDU with a size different from the length of the fixed RLC PDU (a flexible size RLC that has been created but not necessarily transmitted yet) Applies to PDU), 2) Applies only to any RLC PDU (transmitted or submitted to a lower layer) having a size different from the length of the fixed RLC PDU already transmitted at least once, and the result. , RLC PDUs that have been created but not yet sent will not be destroyed), 3) All RLC PDUs with SN (sequence number), including up to the last RLC PDU with flexible RLC PDU size (or size different from the fixed PDU length), 4) All RLC PDUs with SN, including up to the last RLC PDU with flexible RLC PDU size (or size different from the fixed PDU length) being transmitted at least once, 5) All RLC SDUs up to the last SDU contained within the last RLC PDU with flexible PDU size (or a size different from the configured fixed PDU length), 6) Last RLC with flexible PDU size (or different size than the configured fixed PDU length) All RLC SDUs up to the last SDU contained in the PDU, 7) All RLC SDUs and / or which contained at least one segment in a PDU of a size different from the configured fixed PDU size transmitted at least once. 8) All RLC PDUs in the retransmission buffer that have been sent to the lower layers and have SN assigned.

If the last RLC PDU discarded contains a segment of RLC SDU, the RLC SDU can optionally be reconfigured using a new configuration (ie, a new fixed RLC PDU size). ..

The sending subassemblies 130 and 230 do not reinitialize the state parameters and sequence numbers. The transmitting subassemblies 130 and 240 then begin to indicate the discarded RLC PDU or RLC SDU to the receiving subassemblies 135 and 235.

The MRW (Mobile Receive Window) control SUFI (Superfield) can be used to indicate a discarded RLC PDU or a discarded RLC SDU. If the "transmitting MRW" is not configured, the MRW SUFI is assembled using the discard information. More specifically, the MRW SUFI must indicate the abandoned RLC PDU or the last SN of the abandoned RLC SDU (SN_MRW = last abandoned RLC PDU SN + 1). The receiving subassemblies 135 and 235 then discard all RLC PDUs with SN &lt;SN_MRW and move the receiving window accordingly.

If the "transmit MRW" is not configured, it is possible to show only 15 discarded SDU information. This may not be sufficient to indicate all RLC SDUs to be destroyed, especially if a large number of SDUs are destroyed. Therefore, multiple MRW SUFIs may have to be transmitted.

The N-length field can always be set to 0, or optionally set to indicate the length of the last SDU associated with that PDU.

Next, a new MRW SUFI used only for handover purposes will be outlined. This new MRW SUFI can include an SN_MRW field indicating the sequence number of the last PDU or SDU to be discarded. The receive window is updated accordingly and all RLC PDUs with SN including up to the SN_MRW field are discarded. Optionally, prior to discarding all RLC PDUs, the receiving subassemblies 135 and 235 can assemble all RLC PDUs into RLC SDUs and deliver these RLC SDUs to higher layers. The receiving subassemblies 135 and 235 can then discard all RLC PDUs, including up to SN_MRW, which cannot be reassembled into the RLC SDU.

RLC reestablishment provides a flexible size RLC PDU when the serving cell is changed to legacy node B or added to the E-DCH (enhanced dedicated channel) activity set for the case where legacy node B is UL. It can be avoided by using the SDU discard function that discards the SDU that has been created. The RLC then uses the MRW SUFI to move the receive window and indicate to the WTRU to discard the same RLC PDU.

This method results in the same amount of data loss as RLC reestablishment if the reconstruction is done at activation time. However, if the transmitting subassemblies 130 and 230 initiate to generate a fixed RLC PDU when a handover decision is made or when the transmitting subassemblies 130 and 230 are made aware of the handover. Data loss can be minimized. At the time of the handover (ie, at a given activation), the discard function is initiated. This allows the RLC unit 110 to attempt to erase some RLC PDUs with flexible size until the activation time expires. At the time the data was transmitted over the target cell radio link (ie, the handover was performed), all unidentified flexible sized RLC PDUs in the retransmission buffers 140 and 240 were included in those RLC PDUs. Is not supported by target node B and must be destroyed using the PDU discard feature.

This means that sender subassemblies 130 and 230 can update transmit parameters and state variables only after receiving MRW_ACK from WTRU, which can cause the transmit window to temporarily stall. Therefore, it may be disadvantageous. However, the advantage of this method is that data loss can be minimized.

The initiation of this procedure can be indicated by one or a combination of the following options: That is, 1) This procedure can be demonstrated via explicit signaling from higher layers (ie, initiate SDU discard for handover purposes). 2) This procedure is performed when a change from a flexible RLC PDU size to a fixed RLC PDU size is detected (ie, when a flexible to fixed reconstruction is indicated in the RRC message). Can be triggered internally by. 3) A procedure initiated at a given activation for handover purposes if synchronized changes are required.

SDU discard function for confirmed mode, unconfirmed mode, and transparent mode

Discard for RLC reconstruction purposes This alternative form is only applicable for RLC confirmation mode entities. This alternative form is triggered when the RLC configuration is changed from a flexible RLC PDU size to a fixed RLC PDU size. Optionally, this procedure can also be triggered when the RLC configuration is changed from a fixed size RLC PDU configuration to a flexible size RLC PDU configuration and / or the length indicator size is changed.

When the RLC configuration is changed from a flexible size RLC PDU configuration to a fixed size RLC PDU configuration, all AMD PDUs transmitted to lower layers that have a segment or "length indicator" indicating the end of the SDU. SDU is discarded (optionally including up to the last AMD PDU), has a size different from the newly configured AMD PDU size, and also utilizes explicit signaling to take advantage of the receiving subassembly 135 and 235 will be notified.

Transmitter RLC behavior to minimize data loss Optionally, the behavior of the transmit subassemblies 130 and 230 can be modified to minimize data loss when switching from flexible PDU size to fixed PDU size. Once the sender subassemblies 130 and 230 are made aware of the switch to a fixed PDU size, the sender subassemblies 130 and 230 will be at the time of activation (ie, at the time the switch is made) specified by the higher layers. Prior to this, the generation of fixed size RLC PDUs must be started. All PDUs that have not yet been sent, have already been created (ie, these PDUs must be regenerated according to the fixed size), and newly received or buffered to these fixed size RLC PDUs. It is possible to include all new PDUs created from the ringed SDUs. Alternatively, transmit subassemblies 130 and 230 continue to generate RLC PDUs with flexible size, but with a fixed RLC configured when the handover is made. The maximum RLC PDU size configured can be changed to fit the PDU size.

At activation, if all PDUs in sender subassemblies 130 and 230, including PDUs in retransmission buffers 140 and 240, are equal in size to the configured fixed-size RLC PDUs, then sender sub-associations Assemblies 130 and 230 must continue normal operation using fixed size RLC PDUs without discarding any PDUs. If they are not of equal size, the transmitting subassemblies 130 and 230 must discard only RLC PDUs that are not the same size as the configured fixed length, including RLC PDUs that have already been transmitted.

When the RLC reestablishment procedure is performed, it must be modified to take into account that not all PDUs are destroyed upon activation. If the sender subassemblies 130 and 230 instruct the receiver subassemblies 135 and 235 to move the receive window (MRW instruction), which PDU has been destroyed using the PDU discard procedure described above. Can be shown.

Optionally, this procedure can be modified so that MRW instructions are sent earlier and the receiving subassemblies 135 and 235 only adjust the receiving window upon activation. It is also possible to explicitly indicate in the MRW instructions when the receiving subassemblies 135 and 235 must adjust the receiving window, or the receiving subassemblies 135 and 235 may re-channel the transport channel. The receive window may be adjusted at activation when the configuration should be done.

The sender subassemblies 130 and 230 must be notified of the switch from flexible PDU size to fixed PDU size as soon as a decision is made at a higher layer, rather than waiting until activation. This allows more time to successfully transmit the remaining flexible sized PDUs prior to activation, limiting the number of flexible sized PDUs discarded during activation.

How to avoid RLC re-establishment and minimize data loss This method may be used alone or in combination with any of the methods described above.

At the time of the change from the flexible sized RLC PDU to the fixed size RLC PDU to minimize data loss, the transmitting subassemblies 130 and 230 are either of the flexible sized RLC PDUs created and transmitted. Do not discard. However, normal MAC-hs or MAC-e / es correspond to either the SID (size index identifier) for the DL configured for each priority queue or each logical channel, or the DDI (data descriptor identifier) for the UL. Retransmitted RLC PDUs via regular MAC-hs or MAC-e / es must correspond to any of these predefined sizes, as they only support the reception of RLC PDUs with a fixed size. It doesn't become.

Padding can be used to ensure that the RLC PDU is a valid size. At the time of the RLC configuration change, at the time of the handover decision, or at a given activation, the transmitting subassemblies 130 and 230 use padding to all the flexible RLC PDUs that should be retransmitted. That is, they can be resized (having a size different from fixed) so that their RLC PDUs match one or a combination of the following sizes: That is, 1) If the flexible RLC PDU size is smaller than the fixed RLC PDU size, then the configured fixed RLC PDU size. 2) Flexible maximum RLC PDU size configured prior to reconstruction. The RNC must ensure that MAC-hs or MAC-e / es are also configured to the maximum RLC PDU size. 3) Maximum RLC PDU size present in the retransmission buffer. The RNC must ensure that MAC-hs or MAC-e / es are also configured to support reception of this size (ie, one of the SIDs is this maximum RLC. Must support PDU size). 4) For each flexible RLC PDU, the logical channel (MAC-d flow) is also sized to the second largest SID size or DDI size configured for the corresponding MAC-hs queue.

If the RLC PDU size is larger than any of the sizes listed in the previous section to be matched, padding cannot be used. However, WTRU can destroy those RLC PDUs using the SDU destruction procedure described above.

Alternatively, the RLC PDU can be resegmented to fit the new fixed RLC PDU size, and the last remaining segment is less than the fixed RLC PDU size (or configured to fit). If it is less than the size), it is possible to use padding.

The flexible size to fixed size change can be signaled to the receiving subassemblies 135 and 235, or optionally transparent to the receiving subassemblies 135 and 235 (). That is, the receiving subassemblies 135 and 235 always operate in a flexible RLC).

When adding padding, the length indicator fields in the RLC PDU may have to be updated to reflect those changes and indicate where the padding begins.

Embodiment 1. 1. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). That the RLC unit should be reconfigured to receive a fixed size RLC PDU over the downlink channel from receiving a flexible size RLC PDU (protocol data unit) over the downlink channel. Upon receiving the indicated RRC (Radio Resource Control) reconfiguration message, the RLC unit contains a sender subassembly and a receiver subassembly, and A method that involves at least reestablishing the receiving subassembly. 2. If an IE (information element) called "one-sided RLC reestablishment" is present in the RRC reconstruct message, reestablish only the receiving subassembly, and The method of embodiment 1, further comprising reestablishing both the receiving and transmitting subassemblies if the IE "one-sided RLC reestablishment" is not present in the RRC reconstructing message. 3. 3. The receiving subassembly is flexible in size as the WTRU moves from a first cell that supports MAC-ehs (enhanced high-speed medium access control) to a second cell that does not support enhanced MAC-ehs. The method according to any one of embodiments 1 and 2, which is reconstructed from receiving the RLC PDU of the above to receiving a fixed size RLC PDU. 4. The receiving subassembly receives the flexible sized RLC PDU when the WTRU moves from the first cell that supports the flexible sized RLC PDU to the second cell that does not support the flexible sized RLC PDU. Therefore, the method according to any one of the first to third embodiments, which is reconfigured to receive a fixed size RLC PDU. 5. The receiving subassembly is a flexible sized RLC PDU when the RRC connection is transferred from an SRNC (serving wireless network controller) that supports a flexible sized RLC PDU to an SRNC that does not support a flexible sized RLC PDU. From receiving a fixed size RLC The method according to any one of embodiments 1 to 4, which is reconfigured to receive PDUs. 6. The method in any one of embodiments 1-5 where the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 7. The RLC re-establishment criterion is the method of Embodiment 6 which is evaluated for each RB (radio bearer). 8. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, That the RLC unit should be reconfigured to receive a fixed size RLC PDU over the downlink channel from receiving a flexible size RLC PDU (protocol data unit) over the downlink channel. A WTRU (Wireless Transmitting / Receiving Unit) in which at least the receiving subassembly is reestablished, including an RRC unit configured to receive the indicated RRC (Radio Resource Control) reconfiguration message. 9. If the IE (information element) "one-sided RLC reestablishment" is present in the RRC reconfiguration message, only the receiving subassembly is reestablished and the IE "one side RLC reestablishment" is the RRC reconfiguration message. WTRU of Embodiment 8, where both the receiving and transmitting subassemblies are reestablished if they are not present in. 10. The receiving subassembly is flexible in size as the WTRU moves from a first cell that supports MAC-ehs (enhanced high-speed medium access control) to a second cell that does not support enhanced MAC-ehs. WTRU in any one of embodiments 8 and 9, which is reconfigured to receive a fixed size RLC PDU from receiving the RLC PDU. 11. The receiving subassembly receives the flexible sized RLC PDU when the WTRU moves from the first cell that supports the flexible sized RLC PDU to the second cell that does not support the flexible sized RLC PDU. Therefore, the WTRU in any one embodiment of embodiments 8-10 reconfigured to receive a fixed size RLC PDU. 12. The receiving subassembly is a flexible sized RLC PDU when the RRC connection is transferred from an SRNC (serving wireless network controller) that supports a flexible sized RLC PDU to an SRNC that does not support a flexible sized RLC PDU. WTRU in any one of embodiments 8-11, which is reconfigured to receive a fixed size RLC PDU from receiving. 13. WTRU in any one of embodiments 8-12 where the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 14. The RLC reestablishment criterion is the WTRU of Embodiment 13, which is evaluated for each RB (radio bearer). 15. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). Since the RLC unit receives a fixed size RLC PDU (protocol data unit) via the downlink channel, a flexible size RLC via the downlink channel. Upon receiving an RRC (Radio Resource Control) reconfiguration message indicating that it should be reconfigured to receive the PDU, the RLC unit includes a sender subassembly and a receiver subassembly, and A method that includes at least determining if a reestablishment of the receiving subassembly is required. 16. If it is determined that reestablishment is required If an IE (information element) called "one-sided RLC reestablishment" is present in the RRC reconstruct message, reestablish only the receiving subassembly, and The method of embodiment 15, further comprising reestablishing both the receiving and transmitting subassemblies if the IE "one-sided RLC reestablishment" is not present in the RRC reconstructing message. 17. The receiving subassembly is of fixed size when the WTRU moves from a first cell that does not support MAC-ehs (enhanced high-speed medium access control) to a second cell that supports enhanced MAC-ehs. The method according to any one of embodiments 15 and 16, which is reconfigured from receiving an RLC PDU to receiving a flexible size RLC PDU. 18. The receiving subassembly receives a fixed size RLC PDU when the WTRU moves from the first cell, which does not support the flexible size RLC PDU, to the second cell, which supports the flexible size RLC PDU. Thus, the method according to any one of embodiments 15-17, which is reconfigured to receive a flexible size RLC PDU. 19. The receiving subassembly will transfer the fixed size RLC PDU when the RRC connection is transferred from an SRNC (serving wireless network controller) that does not support flexible sized RLC PDUs to an SRNC that supports flexible sized RLC PDUs. The method according to any one of embodiments 15-18, which is reconfigured from receiving to receiving a flexible size RLC PDU. 20. The method in any one of embodiments 15-19, wherein the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 21. The RLC re-establishment criterion is the method of embodiment 20 which is evaluated for each RB (radio bearer). 22. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, That the RLC unit should be reconfigured to receive a flexible size RLC PDU over the downlink channel from receiving a fixed size RLC PDU (protocol data unit) over the downlink channel. A WTRU (Wireless Transmission /) that includes an RRC unit configured to receive the indicated RRC (Radio Resource Control) reconfiguration message and at least determines whether a reestablishment of the receiving subassembly is required. Receiving unit). 23. If it is determined that re-establishment is required and an IE (information element) of "one-sided RLC re-establishment" is present in the RRC reconstruct message, only the receiving subassembly is re-established and "one-sided RLC reestablished". WTRU of Embodiment 22, where both the receiving and sending subassemblies are reestablished if the IE "reestablishment" is not present in the RRC reconfiguration message. 24. The receiving subassembly is of fixed size when the WTRU moves from a first cell that does not support MAC-ehs (enhanced high-speed medium access control) to a second cell that supports enhanced MAC-ehs. WTRU in any one of embodiments 22 and 23 reconfigured from receiving RLC PDUs to receiving flexible sized RLC PDUs. 25. The receiving subassembly receives a fixed size RLC PDU when the WTRU moves from a first cell that does not support a flexible size RLC PDU to a second cell that supports a flexible size RLC PDU. WTRU in any one of embodiments 22-24 reconfigured to receive a flexible sized RLC PDU. 26. The receiving subassembly will transfer the fixed size RLC PDU when the RRC connection is transferred from an SRNC (Serving Wireless Network Controller) that does not support flexible size RLC PDUs to an SRNC that supports flexible size RLC PDUs. Flexible size RLC from receiving WTRU in any one of embodiments 22-25 reconfigured to receive PDUs. 27. WTRU in any one of embodiments 22-26 where the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 28. The RLC re-establishment criterion is the WTRU of Embodiment 27, which is evaluated for each RB (radio bearer). 29. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). It should be reconfigured that the RLC unit sends a flexible size RLC PDU (protocol data unit) over the uplink channel to a fixed size RLC PDU over the uplink channel. Upon receiving the indicated RRC (Radio Resource Control) reconfiguration message, the RLC unit contains a sender subassembly and a receiver subassembly, and A method that involves at least reestablishing the sender subassembly. 30. If an IE (information element) called "one-sided RLC reestablishment" is present in the RRC reconstruct message, reestablish only the sender subassembly, and The method of embodiment 29, further comprising reestablishing both the receiving and transmitting subassemblies if the IE "one-sided RLC reestablishment" is not present in the RRC reconstructing message. 31. The sender subassembly transmits a flexible sized RLC PDU when the WTRU moves from a first cell that supports a flexible sized RLC PDU to a second cell that does not support a flexible sized RLC PDU. Thus, the method in any one of embodiments 29 and 30, which is reconfigured to transmit a fixed size RLC PDU. 32. The sender subassembly sends a flexible sized RLC PDU when adding a new cell that does not support the flexible sized RLC PDU to a set of activities that contains only cells that support the flexible sized RLC PDU. Therefore, fixed size RLC The method according to any one of embodiments 29-31 reconfigured to transmit PDUs. 33. The sender subassembly is a flexible sized RLC PDU when the RRC connection is transferred from an SRNC (serving wireless network controller) that supports a flexible sized RLC PDU to an SRNC that does not support a flexible sized RLC PDU. The method according to any one of embodiments 29-32, which is reconfigured to transmit a fixed size RLC PDU. 34. The method according to any one of embodiments 29-33, wherein the RLC reestablishment criteria are evaluated when an action related to RB (radio bearer) mapping is performed. 35. The RLC reestablishment criterion is the method of embodiment 34, which is evaluated for each RB (radio bearer). 36. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, Since the RLC unit transmits a flexible size RLC PDU (protocol data unit) via the uplink channel, a fixed size RLC via the uplink channel. A WTRU (at least the transmitting subassembly is reestablished, including an RRC unit configured to receive an RRC (Radio Resource Control) reconfiguration message indicating that it should be reconfigured to send a PDU. Wireless transmission / reception unit). 37. If the IE (information element) "one-sided RLC re-establishment" is present in the RRC reconfiguration message, only the sending subassembly is re-established and the IE "one-sided RLC re-establishment" is the RRC reconfiguration message. WTRU of embodiment 36, where both the receiving and transmitting subassemblies are reestablished if they are not present in. 38. The sender subassembly transmits a flexible sized RLC PDU when the WTRU moves from a first cell that supports a flexible sized RLC PDU to a second cell that does not support a flexible sized RLC PDU. Therefore, the WTRU in any one embodiment of embodiments 36-37 reconfigured to transmit a fixed size RLC PDU. 39. The sender subassembly is a flexible sized RLC into a set of activities containing only cells that support a flexible sized RLC PDU. In any one of the embodiments 36 to 38, the flexible size RLC PDU is transmitted when a new cell that does not support the PDU is added, and the RLC PDU is reconfigured to transmit a fixed size RLC PDU. WTRU. 40. The sender subassembly is a flexible sized RLC PDU when the RRC connection is transferred from an SRNC (serving wireless network controller) that supports a flexible sized RLC PDU to an SRNC that does not support a flexible sized RLC PDU. WTRU in any one of embodiments 36-39, which is reconfigured to transmit a fixed size RLC PDU. 41. WTRU in any one embodiment of embodiments 36-40 where the RLC reestablishment criteria are evaluated when an action related to RB (radio bearer) mapping is performed. 42. The RLC re-establishment criterion is WTRU of Embodiment 41, which is evaluated for each RB (radio bearer). 43. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). That the RLC unit should be reconfigured to send a flexible size RLC PDU over the uplink channel from sending a fixed size RLC PDU (protocol data unit) over the uplink channel. Upon receiving the indicated RRC (Radio Resource Control) reconfiguration message, the RLC unit contains a sender subassembly and a receiver subassembly, and A method that includes at least determining if a reestablishment of the sending subassembly is required. 44. Reestablishment is the method of embodiment 43 required when the RLC protocol header format of the header in the RLC PDU has changed. 45. Changing the RLC protocol header format is the method of embodiment 44 that corresponds to changing the size of the length indicator field in the header. 46. If it is determined that reestablishment is required If an IE (information element) called "one-sided RLC reestablishment" is present in the RRC reconstruct message, reestablish only the sender subassembly, and Any one of embodiments 43-45, further comprising reestablishing both the receiving and transmitting subassemblies if the IE "one-sided RLC reestablishment" is not present in the RRC reconfiguring message. Method in form. 47. The sender subassembly adds new cells to the active set that support flexible sized RLC PDUs, and also removes cells that do not support flexible RLC PDUs from the active set, fixed sized RLC PDUs. Reconstructed from transmitting to transmitting a flexible sized RLC PDU, the final set of activities is any one of embodiments 43-46 comprising only cells supporting the flexible sized RLC PDU. The method in the embodiment. 48. The transmitting subassembly will transfer the fixed size RLC PDU when the RRC connection is transferred from an SRNC (Serving Wireless Network Controller) that does not support flexible size RLC PDUs to an SRNC that supports flexible size RLC PDUs. Flexible size RLC from transmitting The method according to any one of embodiments 43-47, which is reconfigured to transmit PDUs. 49. The sender subassembly decides to include a second cell that supports a flexible sized RLC PDU because the path through which the RLC PDU is transmitted contains a first cell that does not support a flexible sized RLC PDU. The method according to any one of embodiments 43-48, which, when changed, reconfigures the transmission of a fixed size RLC PDU to the transmission of a flexible size RLC PDU. 50. The method in any one of embodiments 43-49, wherein the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 51. The RLC reestablishment criterion is the method of embodiment 50, which is evaluated for each RB (radio bearer). 52. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, RLC unit is fixed size RLC via uplink channel To receive an RRC (Radio Resource Control) reconfiguration message indicating that it should be reconfigured to send a flexible size RLC PDU over the uplink channel from sending a PDU (Protocol Data Unit). A WTRU (Wireless Transmitting / Receiving Unit) in which at least a determination is made as to whether a reestablishment of a transmitting subassembly is required, including an RRC unit configured in. 53. Reestablishment is the WTRU of embodiment 52, which is required when the RLC protocol header format of the header in the RLC PDU has been changed. 54. The change in the RLC protocol header format corresponds to the change in the size of the length indicator field in the header in WTRU of embodiment 53. 55. If it is determined that re-establishment is required and an IE (information element) of "one-sided RLC re-establishment" is present in the RRC reconstruct message, then only the sending subassembly is re-established and "one-sided RLC reestablished". WTRU in any one of embodiments 52-54 in which both the receiving and transmitting subassemblies are reestablished if the IE "reestablishment" is not present in the RRC reconfiguration message. 56. The sender subassembly adds new cells to the active set that support flexible sized RLC PDUs, and also removes cells that do not support flexible RLC PDUs from the active set, fixed sized RLC PDUs. Reconstructed from transmitting to transmitting a flexible sized RLC PDU, the final set of activities is any one of embodiments 52-55 comprising only cells supporting the flexible sized RLC PDU. WTRU in the embodiment. 57. The transmitting subassembly is from SRNC (Serving Wireless Network Controller), where the RRC connection does not support flexible sized RLC PDUs, to flexible sized RLC. WTRU in any one of embodiments 52-56 reconfigured to transmit a flexible size RLC PDU from transmitting a fixed size RLC PDU when transferred to an SRNC that supports PDUs. .. 58. The sender subassembly decides to include a second cell that supports a flexible sized RLC PDU because the path through which the RLC PDU is transmitted contains a first cell that does not support a flexible sized RLC PDU. The WTRU in any one of embodiments 52-57, which, when changed, reconfigures to transmit a flexible size RLC PDU from transmitting a fixed size RLC PDU. 59. WTRU in any one of embodiments 52-58 where the RLC reestablishment criteria are evaluated when an IE (information element) called "RLC information" is present in the RRC reconstruction message. 60. The RLC re-establishment criterion is the WTRU of embodiment 59, which is evaluated for each RB (radio bearer). 61. UTRAN (Universal Terrestrial Radio Access) A wireless communication method that reconfigures an RLC (Wireless Link Control) unit in Network). Determining that reconfiguration of the RLC unit is required, Reconfiguring the RLC unit from a fixed RLC PDU (protocol data unit) size to a flexible RLC PDU size, the RLC unit includes a transmitting subassembly and a receiving subassembly, and A method that involves reestablishing at least one of the sending and receiving subassemblies. 62. The transmitting subassembly supports a second enhanced MAC-ehs because the path through which the RLC PDU is transmitted contains a first cell that does not support MAC-ehs (enhanced high speed medium access control). The method of embodiment 61, which is reconfigured to transmit a flexible size RLC PDU from transmitting a fixed size RLC PDU when it changes to include cells of. 63. The receiving subassembly is a flexible RLC because the path on which the RLC PDU is received contains a first cell that does not support the flexible RLC PDU. Any one of embodiments 61 and 62 reconfigured to receive a flexible size RLC PDU from receiving a fixed size RLC PDU when changed to include a second cell supporting the PDU. The method in the embodiment. 64. An RRC (Radio Resource Control) reconfiguration message indicating that the WTRU (Wireless Transmit / Receive Unit) should be reconfigured to receive a flexible size RLC PDU from receiving a fixed size RLC PDU. The method according to any one of embodiments 61-63, further comprising transmitting to WTRU. 65. The method of embodiment 64, wherein the RRC reconfiguration message comprises an IE (information element) of "one-sided RLC reestablishment" if the WTRU determines that the RLC reestablishment of the receiving subassembly is required. 66. Since the WTRU (wireless transmission / reception unit) transmits a fixed size RLC PDU, a flexible size RLC The method according to any one of embodiments 61-63, further comprising transmitting an RRC (Radio Resource Control) reconfiguration message to the WTRU indicating that it should be reconfigured to transmit a PDU. 67. The method of embodiment 66, wherein the RRC reconfiguration message comprises an IE (information element) of "one-sided RLC reestablishment" if the WTRU determines that the RLC reestablishment of the transmitting subassembly is required. 68. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, Determined that reconfiguration of the RLC unit is required, reconfigure the RLC unit from a fixed RLC PDU (protocol data unit) size to a flexible RLC PDU size, and at least one of the transmitting and receiving subassemblies. UTRAN (Universal Terrestrial Radio Access Protocol), which includes an RRC (Radio Resource Control) unit configured to reestablish one. 69. The sender subassembly is RLC The path through which the PDU is transmitted changes from containing a first cell that does not support MAC-ehs (enhanced high-speed medium access control) to including a second cell that supports enhanced MAC-ehs. Then, the UTRAN of the 68th embodiment is reconfigured to transmit a flexible size RLC PDU from transmitting a fixed size RLC PDU. 70. The receiving subassembly is fixed when the path on which the RLC PDU is received changes from containing a first cell that does not support the flexible RLC PDU to containing a second cell that supports the flexible RLC PDU. UTRAN in any one of embodiments 68 and 69 reconfigured from receiving a size RLC PDU to receiving a flexible size RLC PDU. 71. Since the WTRU (wireless transmission / reception unit) receives the fixed size RLC PDU, the flexible size RLC In any one embodiment of embodiments 68-70, further comprising a transmitter configured to transmit an RRC (Radio Resource Control) reconfiguration message to the WTRU indicating that it should be reconfigured to receive the PDU. UTRAN. 72. The RRC reconfiguration message is UTRAN of embodiment 71, which includes an IE (information element) of "one-sided RLC reestablishment" if the WTRU determines that the RLC reestablishment of the receiving subassembly is required. 73. An RRC (Radio Resource Control) reconfiguration message indicating that the WTRU (Wireless Transmit / Receive Unit) should be reconfigured to transmit a flexible size RLC PDU from transmitting a fixed size RLC PDU. UTRAN in any one of embodiments 68-70, further comprising a transmitter configured to transmit to WTRU. 74. The UTRAN of embodiment 73 includes an IE (information element) of "one-sided RLC reestablishment" if the RRC reconfiguration message is determined by WTRU to require RLC reestablishment of the transmitting subassembly. 75. UTRAN (Universal Terrestrial Radio) It is a wireless communication method that executes the reconstruction of the RLC (Wireless Link Control) unit in Access Network). Determining that reconfiguration of the RLC unit is required, Reconfiguring the RLC unit from a flexible RLC PDU (protocol data unit) size to a fixed RLC PDU size, the RLC unit includes a transmitting subassembly and a receiving subassembly, and A method that involves reestablishing at least one of the sending and receiving subassemblies. 76. The RLC unit does not support enhanced MAC-ehs because the path through which the RLC PDU is transmitted contains a first cell that supports MAC-ehs (enhanced high-speed medium access control). The method of embodiment 75, which is reconfigured to transmit a fixed size RLC PDU from transmitting a flexible size RLC PDU when changed to include. 77. The RLC unit is a flexible size RLC from the first cell where the WTRU supports a flexible size RLC PDU. The method in any one of embodiments 75 and 76, where moving to a second cell that does not support PDUs reconfigures the flexible sized RLC PDU into a fixed sized RLC PDU. 78. The RLC unit is fixed from the flexible sized RLC PDU when the RRC connection is transferred from the SRNC (Serving Wireless Network Controller) that supports the flexible sized RLC PDU to the SRNC that does not support the flexible sized RLC PDU. The method in any one embodiment of embodiments 75-77 reconstructed into RLC PDUs of size. 79. An RRC (Radio Resource Control) reconfiguration message indicating that the WTRU (Wireless Transmit / Receive Unit) should be reconfigured to receive a fixed size RLC PDU from receiving a flexible size RLC PDU. The method according to any one of embodiments 75-78, further comprising transmitting to WTRU. 80. The RRC reconstruction message is the method of embodiment 79 comprising an IE (information element) of "one-sided RLC reestablishment". 81. WTRU (wireless transmission / reception unit) is a flexible size RLC Any of embodiments 75-78, further comprising transmitting an RRC (Radio Resource Control) reconfiguration message to the WTRU indicating that it should be reconfigured to transmit a fixed size RLC PDU from transmitting the PDU. The method in one embodiment. 82. The RRC reconstruction message is the method of embodiment 81 that includes an IE (information element) called "one-sided RLC reestablishment". 83. An RLC (Wireless Link Control) unit containing a transmitting subassembly and a receiving subassembly, Determining that the RLC unit needs to be reconfigured, it reconfigures the RLC unit from a flexible RLC PDU (protocol data unit) size to a fixed RLC PDU size, and at least one of the sender and receiver subassemblies. UTRAN (Universal Terrestrial Radio Access Protocol), which includes an RRC (Radio Resource Control) unit configured to reestablish one. 84. RLC unit is RLC The path through which the PDU is transmitted changes from containing a first cell that supports MAC-ehs (enhanced high-speed medium access control) to including a second cell that does not support enhanced MAC-ehs. Then, the UTRAN of the embodiment 83 is reconfigured to transmit a fixed size RLC PDU from transmitting a flexible size RLC PDU. 85. The RLC unit moves from the flexible size RLC PDU to the fixed size RLC when the WTRU moves from the first cell that supports the flexible size RLC PDU to the second cell that does not support the flexible size RLC PDU. UTRAN in any one of embodiments 83 and 84 reconstructed into PDUs. 86. The RLC unit is fixed from the flexible size RLC PDU when the RRC connection is transferred from the SRNC (Serving Wireless Network Controller) that supports the flexible size RLC PDU to the SRNC that does not support the flexible size RLC PDU. UTRAN in any one embodiment of embodiments 83-85 reconstructed into RLC PDUs of size. 87. An RRC (Radio Resource Control) reconfiguration message indicating that the WTRU (Wireless Transmit / Receive Unit) should be reconfigured to receive a fixed size RLC PDU from receiving a flexible size RLC PDU. UTRAN in any one of embodiments 83-86, further comprising a transmitter configured to transmit to WTRU. 88. The RRC reconstruction message is UTRAN of Embodiment 87, which includes an IE (information element) of "one-sided RLC reestablishment". 89. An RRC (Radio Resource Control) reconfiguration message indicating that the WTRU (Wireless Transmit / Receive Unit) should be reconfigured to transmit a fixed size RLC PDU from transmitting a flexible size RLC PDU. UTRAN in any one of embodiments 83-86, further comprising a transmitter configured to transmit to WTRU. 90. The RRC reconstruction message is UTRAN of Embodiment 89, which includes an IE (information element) of "one-sided RLC reestablishment". 91. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). Reconfiguring the RLC unit from a flexible RLC PDU (protocol data unit) size to a fixed RLC PDU size, the RLC unit includes a transmitting subassembly and a receiving subassembly, and The transmitting subassembly comprises discarding a flexible sized RLC PDU. 92. The method of embodiment 91 further comprising sending a message indicating a discarded flexible sized RLC PDU. 93. The method of embodiment 92, wherein the message further indicates an RLC SDU (service data unit) corresponding to the discarded flexible sized RLC PDU. 94. The method in any one of embodiments 92 and 93, wherein the message comprises an MRW (Mobile Receive Window) Control SUFI (Superfield) indicating the discarded RLC PDU. 95. MRW SUFI is the method of embodiment 94 that indicates the SN (sequence number) of the last RLC PDU or last RLC SDU that was discarded. 96. RLC with a size different from the length of the fixed size RLC PDU The PDU is the method according to any one of embodiments 91-95 that is discarded. 97. The method according to any one of embodiments 91-95, wherein the RLC PDU has a size different from the length of the fixed size RLC PDU that has already been transmitted at least once. 98. All RLC PDUs having an SN (sequence number) including up to the last RLC PDU with a flexible RLC PDU size or an RLC PDU size different from the fixed RLC PDU length are discarded. The method in any one embodiment. 99. All RLC PDUs with SN (sequence number) including up to the last RLC PDU with flexible RLC PDU size or RLC PDU size different from the length of the fixed RLC PDU being transmitted at least once are discarded. The method according to any one of the embodiments 91 to 95. 100. The last RLC with a flexible RLC PDU size or an RLC PDU size different from the fixed RLC PDU length The method in any one of embodiments 91-95, wherein all RLC SDUs up to the last SDU (Service Data Unit) contained within the PDU are discarded. 101. Any of embodiments 91-95 in which at least one segment is contained in an RLC PDU of a size different from the fixed size RLC PDU that has been transmitted at least once is discarded. The method in one embodiment. 102. The method in any one of embodiments 91-95, wherein all RLC PDUs in the retransmission buffer that are transmitted to the lower layer and are assigned the assigned SN (sequence number) are discarded. .. 103. The method according to any one of embodiments 91-102, wherein data loss is minimized by creating and transmitting a fixed size RLC PDU when the handover decision is made. 104. The method of any one of embodiments 91-103, wherein the transmitting subassembly discards the flexible sized RLC PDU in response to explicit signaling from a higher layer. 105. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). Receiving a message indicating when activated from a higher layer, and A method comprising reconfiguring an RLC unit to generate a fixed size RLC PDU from generating a flexible sized RLC PDU (protocol data unit) prior to activation. 106. The method of embodiment 105, further comprising regenerating all PDUs that have been created, but have not yet been transmitted, depending on the fixed size. 107. The method of embodiment 105 further comprising regenerating all new PDUs created from newly received or newly buffered SDUs (Service Data Units), depending on the fixed size. 108. The handover is a method according to any one of embodiments 105 to 107, which is performed at the time of activation. 109. The remaining flexible sized RLC PDU is discarded according to the method of embodiment 106. 110. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). The RLC unit produces a flexible size RLC PDU (protocol data unit), Receiving a message indicating the time of activation from a higher layer, Prior to activation, changing the configured maximum RLC PDU size associated with the flexible RLC PDU to fit the fixed RLC PDU size, and A method comprising reconfiguring an RLC unit to generate a fixed size RLC PDU from generating a flexible sized RLC PDU (protocol data unit) upon activation. 111. The method of embodiment 110, wherein the handover is performed at the time of activation. 112. A wireless communication method for reconfiguring an RLC (wireless link control) unit in a WTRU (wireless transmission / reception unit). RLC with a size selected from a predefined RLC PDU size set from transmitting flexible size RLC PDUs Reconfiguring the RLC unit to send PDUs, and A method comprising resizing a flexible size RLC PDU to be resent to fit a particular size in a predefined RLC PDU size set. 113. Flexible size RLC PDU padding is performed according to the method of embodiment 112, which is performed to fit that particular size. 114. The method of embodiment 113, in which the flexible RLC PDU is padded to the next highest available size in the predefined set. 115. The flexible size RLC PDU with a size higher than the maximum size of the RLC PDU size in the predefined set is discarded according to the method of embodiment 114. 116. The method of embodiment 112, wherein all flexible size RLC PDUs that are not transmitted or submitted to the lower layers are regenerated to fit into a fixed size RLC PDU. 117. UTRAN (Universal Terrestrial Radio Access) A wireless communication method that reconfigures an RLC (Wireless Link Control) unit in Network). Reconfiguring the RLC unit from transmitting flexible sized RLC PDUs to transmitting RLC PDUs with a size selected from a predefined RLC PDU size set, and A method comprising resizing a flexible size RLC PDU to be resent to fit a particular size in a predefined RLC PDU size set. 118. Flexible size RLC PDU padding is performed according to the method of embodiment 117, which is performed to fit that particular size. 119. The flexible RLC PDU is the method of embodiment 118, which is padded to the next highest available size in the predefined set. 120. The flexible size RLC PDU having a size higher than the maximum size of the RLC PDU size in the predefined set is discarded according to the method of embodiment 119. 121. All flexible size RLCs that are not transmitted or submitted to the lower layers The method of embodiment 117, wherein the PDU is regenerated to fit into a fixed size RLC PDU.

Although features and elements are described in a particular combination, each feature, or each element, can also be used alone without other features, and other features, or other features, and others. It can also be used in various combinations with or without other features, and other elements. The provided method or flowchart can be implemented in a computer program, software, or firmware materialized as a computer-readable storage medium for execution by a general purpose computer or processor. Examples of computer-readable storage media include ROM (read-only memory), RAM (random access memory), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, optomagnetic media, and CD-ROMs. Optical media such as discs and DVDs (digital versatile discs) are included.

Suitable processors include, for example, general purpose processors, dedicated processors, conventional processors, DSPs (digital signal processors), multiple microprocessors, one or more microprocessors associated with DSP cores, controllers, microcontrollers, ASICs. Includes application specific integrated circuits, FPGA (field programmable gate array) circuits, any other type of IC (integrated circuits), and / or state machines.

Software-related processors implement radio frequency transceivers for use in WTRUs (wireless transmit / receive units), UEs (user equipment), terminals, base stations, RNCs (wireless network controllers), or any host computer. Can be used to. WTRU is a camera, video camera module, video phone, speakerphone, vibration device, speaker, microphone, TV transmitter / receiver, hands-free handset, keyboard, Bluetooth® module, FM (frequency modulation) wireless unit, LCD (liquid crystal display). In hardware and / or software such as display) display units, OLED (organic light emitting diode) display units, digital music players, media players, video game player modules, internet browsers, and / or WLAN (wireless local area network) modules. It can be used in conjunction with the implemented module.