RU2447595C2 - Method and wireless communication device to support radio line control parameters reconfiguration - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: disclosure of various methods and wireless communication devices to support Radio Line Control (RLC) parameters reconfiguration. Radio Resources Control (RRC) configuration message is generated, which indicates that RLC unit in Wireless Transmission/Receive Unit (WTRU) or Universal Terrestrial Radio Access Network (UTRAN) must be reconfigured from support of RLC Protocol Data Units (PDU) of flexible size to support of RLC PDUs of fixed size. If in RRC reconfiguration message there is data entry "Unidirectional repeated RLC establishment", then in RLC unit, subunit of receiving side only is reestablished. Otherwise, both subunit of receiving side and subunit of transmitting side is reestablished. RLC PDUs of flexible size may be discarded, and the message indicating discarded RLC PDUs of flexible size may be transmitted. PDUs of flexible size can be modified to correspond set of predefined sizes.

EFFECT: lower transmission quality losses.

14 cl, 2 dwg, 1 tbl

Description

FIELD OF THE INVENTION

The present invention relates to wireless communications.

State of the art

The main objectives of the High Speed Packet Access (HSPA) enhancement are higher data rates, higher system throughput and wider coverage, improved packet service support, reduced latency, reduced operator overhead, and backward compatibility. To achieve these goals, improvements to the radio interface protocol and network architecture are required. More specifically, in order to achieve the above objectives, a number of enhancements and architectural changes are required to the second level functions (Layer 2, L2) (i.e., Radio Link Control (RLC) and Media Access Control (MAC)).

Some L2 enhancements include flexible size RLC Protocol Data Unit (PDUs) (i.e., flexible size RLC PDUs), high-speed MAC (MAC-hs) segmentation / combining, and multiplexing. According to Option 6 (R6) of the Universal Terrestrial Radio Access (UTRA), RLC Receive Acknowledgment (AM) entities may use only fixed-size RLC PDUs (i.e., fixed-size RLC PDUs). In addition, the MAC-hs sublayer in Node B (Node-B) can only support combining dedicated MAC blocks (MAC-d) PDUs. The L2 enhancements in UTRA Option 7 (R7) lead to significant RLC / MAC changes for R6 features.

Currently, when Radio Carriers (RBs) are installed or reconfigured via Radio Resource Control (RRC) signaling, the information element RB Display Information is present. "RB mapping information" contains information about an RLC instance and transport channels corresponding to a given radio carrier.

The MAC-hs configuration must be the same for all radio carriers mapped to the High Speed Downlink Shared Channel (HS-DSCH), otherwise an invalid configuration occurs.

In the HSPA, the Wireless Transmission / Reception Unit (WTRU) monitors high-speed shared channels in a single cell (i.e., a serving HS-DSCH cell). Due to mobility, when the WTRU moves from one cell to another, the WTRU needs to change the serving cell by switching to the new HS-DSCH serving cell and disconnecting from the old HS-DSCH serving cell. In the Node-B move procedure, a relay transition occurs between the Node-B from the old Node-B (i.e., the original Node-B) to the new Node-B (i.e., the target Node-B).

At the time of changing the serving Node-B, the target Node-B should begin transmitting data in the new configuration. Handoff may occur between HSPA Node-B nodes that support L2 enhancements, and / or from / to cells with or without L2 enhancements. In both cases, the WTRU should be able to perform handoff, make adjustments to new configurations, and minimize data loss.

With the introduction of new L2 enhancements, new procedures must be defined to optimize and minimize data loss during the relay switch between cells R7 or between cell R7 and cell R6. In particular, the procedures that deal with the reinstallation of the MAC-hs object must be modified to take into account new enhancements to L2.

In addition, you cannot rely on all Node-B R6 nodes to be updated on R7 at the same time. Therefore, handoffs between cells R6 and R7 can often occur. Due to functional changes in the RLC and MAC, methods must be defined to perform handoffs with minimal loss of quality and data between these cells. In particular, on the WTRU side, MAC-hs and RLCs must perform functional changes during handoffs.

SUMMARY OF THE INVENTION

Various wireless communication methods and devices are disclosed to support reconfiguration of RLC parameters. An RRC reconfiguration message is generated that indicates that the RLC in the WTRU or UTRAN should be reconfigured from supporting flexible size RLC PDUs to supporting fixed size RLC PDUs or vice versa. If the RRC re-establishment information element is present in the RRC reconfiguration message, then only the receiving side or the transmitting side subassembly is reinstalled in the RLC unit. Otherwise, both the sub-assembly of the receiving side and the sub-assembly of the transmitting side are reinstalled. Flexible size RLC PDUs may be dropped, and a message indicating the dropped flexible size RLC PDUs may be transmitted. Flexible RLC PDUs can be modified to fit a set of predefined sizes.

Brief Description of the Drawings

A deeper understanding of the present invention can be obtained by studying the following description and the accompanying drawings, in which:

FIG. 1 is an illustrative block diagram of a WTRU that moves between cells R6 and R7 and that is configured to operate with new RLC and MAC-hs when a handoff message is received during a serving cell change procedure; and

FIG. 2 is an illustrative block diagram of a UTRAN that transmits an RRC reconfiguration message to a WTRU of FIG. 1.

Detailed description

As used herein, the term “Wireless Transmit / Receive Unit” (WTRU) includes, but is not limited to, a User Equipment (UE), a mobile station, a fixed or mobile subscriber station, a pager, a cell phone, a Personal Digital Assistant (PDA) , a computer, or any other type of user device capable of operating in a wireless environment. As used herein, the term “base station” includes, but is not limited to, Node-B, Site Controller, Access Point (AP), or any other type of interface device capable of operating in a wireless environment.

Various wireless communication methods are disclosed herein that optimize handover scenarios, reinstall procedures, reconfiguration procedures for an RLC entity. Furthermore, various wireless communication methods for handoffs between cells are disclosed, one or both of which support L2 enhancements. These wireless communication methods are applicable to both the uplink (UL) and the downlink (DL).

The following is a brief description of the terms that are used in this description. The Enhanced MAC-hs Payload Block (MAC-ehs) is a MAC-ehs Service Data Unit (SDU) or a MAC-ehs SDU segment of a MAC-ehs PDU. A reordering MAC-ehs PDU is a set of MAC-ehs payload blocks in a MAC-ehs PDU that is in the same priority order. An advanced cell is a cell that supports L2 enhancements, that is, flexible-sized RLC PDUs. An unimproved cell is a cell that does not support L2 enhancements, that is, supports fixed-size RLC PDUs.

For further reference, the term “R6” includes, but is not limited to, a cell, Node-B, Radio Network Controller (RNC), which do not support flexible size RLC PDUs (that is, fixed size RLC PDUs are supported). The term “R7” includes, but is not limited to, a cell, Node-B, or RNC that support fixed size RLC PDUs.

The term "UTRAN" includes, but is not limited to, a cell, Node-B, RNC, or network node.

FIG. 1 is an illustrative flowchart of a WTRU 100 that moves between non-enhanced cells and advanced cells and that is configured to function with new RLC and MAC-hs when a handoff message is received during a serving cell change procedure. As shown in FIG. 1, the WTRU 100 includes an RRC unit 105, an RLC unit 110, a MAC unit 115, and a Physical (PHY) Layer 1 (L1) unit 120. Initiation of a serving cell change may occur in response to receiving an RRC reconfiguration message 125, such as a radio carrier RRC reconfiguration message, a transport channel RRC reconfiguration message, or a physical channel RRC reconfiguration message. RLC unit 110 includes a transmitter side subassembly 130 and a receiver side subassembly 135. The transmitter-side subassembly 130 includes a transmission buffer 140.

An RRC reconfiguration message 125 may be generated by the UTRAN. 2 is a block diagram that illustrates an example protocol stack configuration in the UTRAN 200. The UTRAN 200 may include an RRC unit 205, an RLC unit 210, a MAC unit 215, and a PHY unit L1 220. RLC unit 210 includes a transmitter side subassembly 230 and a receiver side subassembly 235. Transmission side subassembly 230 includes a transmission buffer 240. RRC unit 205 generates a reconfiguration message 125 to initiate a serving cell change.

The UTRAN 200 may include a target Node-B, a source Node-B, a Managing RNC (CRNC), and a Serving RNC (SRNC) (not shown). An RNC may include an RLC block and an RRC block (not shown). Alternatively, RNC functions are part of Node-B, and accordingly, there is no RNC manager or serving RNC.

To obtain the same RLC configuration for all radio carriers mapped to the HS-DSCH, RLC instances are not required. For example, a WTRU connected to an enhanced cell may simultaneously support one or more RLC instances configured by fixed size RLC PDUs and / or flexible size RLC PDUs. Enhanced MAC-ehs is capable of supporting both fixed-size RLC PDUs and flexible-sized RLC PDUs.

However, a WTRU operating in an unimproved cell cannot support RLC instances with flexible size RLC PDUs. All RLC objects mapped to normal HS-DSCH (i.e. MAC-hs) must be configured to work with fixed-size RLC PDUs. The reason for this is the fact that the normal MAC-hs configuration does not support the reception and signaling of flexible size RLC PDUs. Accordingly, an RLC supporting fixed-size RLC PDUs may refer to an RLC AM instance or an Unacknowledged Acceptance Mode (UM) RLC instance.

To avoid re-setting, the logical channels corresponding to the RLC instance should not change their configuration when moving from an unimproved cell to an advanced cell. For example, when a WTRU moves from a normal MAC-hs configuration cell to a MAC-ehs advanced configuration cell, RLC instances configured to support fixed size RLC PDUs do not need to be reconfigured to support flexible size RLC PDUs.

A radio carrier supporting fixed size RLC PDUs in an advanced cell can save a fixed size RLC PDU or can be reconfigured to support flexible RLC PDUs during a handoff or later, in which case a radio carrier reconfiguration procedure will be initiated and the RRC will perform the necessary stages. This allows signaling radios to maintain their existing RLC configuration and to avoid re-setting the RLC entity. If handoffs between unimproved and advanced cells often occur within the network, this method avoids the re-installation of unimproved RLC AM instances if the WTRU often moves between unimproved and advanced cells. This method also allows for optimizations for UM RLC instances. If UM RLC instances are not expandable to support flexible size RLC PDUs in R7, then UM RLC instances do not need to be re-installed or reconfigured when moving from an unperformed cell to an advanced cell and vice versa. If flexible size PDUs are introduced for UM RLC instances, then the same methods apply as for AM RLCs.

Resetting the RLC behavior for each radio carrier when moving between advanced cells and unimproved cells

When a WTRU changes service cells during a handoff that supports various options (i.e., R6 and R7), the WTRU is able to save an existing RLC instance without changing its configuration (i.e. with support for fixed size RLC PDUs according to an advanced MAC configuration), or an existing RLC instance can be reconfigured. However, an RLC instance that supports flexible size RLC PDUs in an advanced L2 cell cannot save its configuration when moving to an unimproved L2 cell because normal MAC-hs cannot support receiving flexible size RLC PDUs. Therefore, to minimize data loss, you must reinstall the RLC or a new procedure for processing RLC configuration changes. A change in the configuration of the RLC unit may also occur due to an SRNC move that moves from an SRNC that supports flexible RLC PDU sizes to an SRNC that does not support flexible RLC PDUs.

Methods for performing and evaluating the need to reinstall the RLC are necessary for each radio carrier base. When the WTRU moves between advanced and unimproved L2 cells or when the RLC changes configuration, the RLC does not reconfigure and, accordingly, the RLC does not reinstall and / or the RLC configuration changes from fixed size RLC PDUs to flexible RLC PDUs. In this case, the RLC reconfiguration procedure may be started. Reinstalling the RLC object is optional, but optionally can be performed.

The reconfiguration procedure mentioned only configures the RLC entity to start supporting flexible size RLC PDUs. No data loss occurs since fixed size RLC PDUs can be transmitted and they will be transparent to WTRUs and MAC-ehs. The reconfiguration procedure mentioned only configures the RLC entity to start supporting flexible size RLC PDUs. No data loss occurs because fixed-size RLC PDUs can be transmitted to WTRUs and MAC-ehs. When a RLC configuration is changed from flexible-sized RLC PDUs to fixed-sized RLC PDUs, RLC reinstallation is required, or, optionally, a new procedure can be performed that processes the change and can attempt to minimize data loss. The WTRU is configured to always remain in the R7 RLC and support flexible size RLC PDUs. A UTRAN can change RLC configurations without an explicit indication in the WTRU of a change from R6 to R7 or vice versa.

Evaluation Criteria for Performing RLC Reconfiguration or Reinstallation

When the RLC changes its configuration, the radio carrier reconfiguration procedure is started. RRC radio carrier reconfiguration procedures and information elements are used to evaluate and indicate the need to reinstall the RLC.

The need to reinstall the RLC for the signaling radio carrier can be determined by explicit RRC signaling, which adds a new field to the existing radio carrier or radio carrier signaling information element that indicates the reinstallation of the RLC. Explicit RRC signaling may indicate one-way or full re-installation. The RRC procedures corresponding to the RB reconfiguration procedure can be modified to verify the conditions of the provided new configuration parameters (i.e., the size of the RLC PDU - flexible or fixed) and the old configuration parameters of the reconfigured RLC object (i.e. the size of the RLC PDU - flexible or fixed ) and evaluate the need to reinstall the RLC.

Evaluation of the reset criteria can be performed in the description of the general actions when receiving the information element of the information display of the radio carrier, in the description of the general actions when receiving the information element "RLC Information", and / or by adding a new section that describes the general actions when receiving the information element of the RLC configuration downlink (DL) link or uplink (UL).

The following sections describe the various options for evaluating and fulfilling reset criteria that are applicable to downlink RLC entities, uplink RLCs, and optionally, UM entities.

Option 1

For this option, the RLC reinstallation is evaluated as part of the actions of the Radio Carrier Mapping Information element or in a new section that deals with the actions when receiving the RLC Configuration information element. It should be noted that for this option, the RLC configuration (that is, whether the RLC selection is fixed or flexible) is provided in the information element "Radio display information". However, the RLC Configuration information element may be provided in other information elements. The RLC Configuration information element may provide information to the WTRU as to whether a given RLC instance is configured to support fixed size or flexible size RLC PDUs.

If the RLC Configuration information element is set to advanced and the previously saved value is set to normal (or if this value is different from the current one), then the RLC object (or level) is reconfigured according to the downlink RLC information element. Optionally, if reinstallation is required, the RLC object is reinstalled. Otherwise, if the RLC Configuration information element is set to normal and the previously saved value has been set to advanced (or if this value is different from the current one). The RLC object is reinstalled by performing a one-way or full re-installation.

Upon receipt of the RRC message, this leads to reconfiguration of the radio carrier, and the WTRU performs a series of actions related to the display of the radio carrier. For the uplink RLC function, optionally, a condition for re-establishment may be fulfilled. In particular, if the radio carrier uses AM, and the RLC PDU (i.e. RLC PDU size selection) configuration applicable to the uplink logical channel moves from a configuration that supports flexible size RLC PDUs to fixed size RLC PDUs, and if the one-way RLC re-establishment information element is included in the RRC message and set to TRUE, then the WTRU re-sets the transmitting side of the corresponding RLC entity. Otherwise, the WTRU re-installs the corresponding RLC entity.

When a configuration that supports fixed size RLC PDUs is changed to a configuration that supports flexible RLC PDUs, re-setting the RLC is optional and can be done when the length indicator specified in the RLC PDU length indicator field changes between 7 and 15 bits. As described above, either the transmission-side subassembly 130 and 230 (if the “one-way RLC re-establishment” information element is present) or the entire RLC unit 110 and 210 (i.e., both the transmission-side sub-assembly 130 and 230 and the receiving-sub-assembly can be reinstalled). sides 135 and 235).

Option 2

RLC re-establishment criteria are evaluated in actions upon receipt of the RLC Information information element. When the actions corresponding to the RLC Information information element are performed, the procedure requires configuration information for the RLC object (that is, a flexible RLC PDU size or a fixed RLC PDU size). This can be accomplished by adding a new information element indicating the RLC configuration to the RLC Information information element. The new information element indicates whether flexible or fixed size RLC PDUs can be used. The new information element also indicates whether advanced or normal RLC is being used.

The set of downlink RLC PDU size information element values may be expanded to include a redundant value that explicitly indicates that the RLC supports flexible size RLC PDUs. For example, a value of 0 or 8, or “all units” in binary form, etc. can be used. The information element "Radio Carrier Display Information" and the information element "Downlink RLC Configuration", which specifies the version of the RLC configuration used, are examined. RLC configuration information is obtained from any other information element that contains this information. If the new information element is not included in the information element "RLC Information", then the re-establishment procedure is based on information from other elements, or the re-establishment procedure occurs in the information element "Radio display information".

If the new radio carrier supports (that is, configured to start working with) fixed-size RLC PDUs and the old radio carrier supports (that is, configured to work with flexible-size RLC PDUs), then the RLC object is reinstalled. Said re-establishment may be a one-way re-establishment. For example, for the downlink RLC, only the receiving side can be re-established, and for the uplink RLC, only the transmitting side can be re-established. To perform a one-way re-establishment, the existing “one-way re-establishment” information element in the “RLC Information” information element can be used. Optionally, the RRC procedure specifically indicates to re-establish the receiving entity or the transmitting entity without using the one-way re-establishment information element.

If the new radio carrier supports flexible size RLC PDUs and the old radio carrier supports fixed size RLC PDUs, and the RLC units 110 and 210 are reconfigured, then re-establishment may not be necessary.

The RRC procedure is described below. The RRC procedure has been modified according to the RLC Information information element. For the purposes of the present description, a new information element, “Downlink RLC Size Indicator” or “Uplink RLC Size Indicator”, which has a fixed or normal RLC value, is added to the “RLC Information” information element. An example of this new information item is given in table 1.

The RRC procedure corresponding to actions in the presence of the information element "RLC Information" is modified in such a way as to take into account changes in the configuration of this RLC instance. In the procedure described below, the RLC Size Indicator information element is used as an example. However, in general, the “RLC Size Indicator” information element represents an indication of the RLC configuration and may be referred to differently or may have a different designation, such as advanced / normal, and / or other values.

The modified RRC procedure can be performed as follows:

Upon receipt of the RLC Information Information Element, the WTRU shall:

1> if the information element "Downlink RLC mode" is present and it is set to "AM RLC":

2> If there is an information element "Downlink RLC size indicator" and it is set to "fixed";

3> if this value differs from the value currently set in the RLC object:

4> if the "one-way RLC re-establishment" information element is set to TRUE:

5> Re-establish the receiving side of the corresponding RLC entity.

4> Otherwise:

5> Reinstall the appropriate RLC object.

3> configure the corresponding RLC object according to the new RLC PDU size indicator;

2> otherwise, if the “Downlink RLC Size Indicator” is present and it is set to “flexible”;

3> if this value differs from the value currently set in the RLC object:

4> reconfigure the RLC object (optional, reinstall the RLC if the RRC is configured to re-establish when moving from an unimproved cell to an advanced cell).

2> Otherwise (the statement “otherwise” is followed by procedures that process instances of fixed RLC PDU sizes, or the case where there is no DL RLC size indicator. The steps following this statement “otherwise” correspond to the steps in R6 );

3> if the "Downlink RLC PDU Size" information element is missing;

4> RLC PDU sizing will be processed at the RLC level, without any configuration from the RRC.

Note: The case when this required information element is missing involves processing interaction with the network through an older version of the specification.

3> otherwise, if the "Downlink RLC PDU Size" information element is present, and no downlink RLC PDU size is currently set in the RLC entity:

4> configure the corresponding RLC entity by the size of the RLC downlink PDU.

3> Otherwise, if the "Downlink RLC PDU Size" information element is present and its value differs from the value currently set in the RLC object:

Note: The downlink RLC PDU size set in the RLC entity may be explicitly configured, or if no explicit configuration is provided, it may be output using the first received RLC PDU.

4> If the "one-way RLC re-establishment" information element is set to TRUE:

5> Re-establish the receiving side of the corresponding RLC entity.

4> Otherwise:

5> Reinstall the appropriate RLC object.

4> configure the corresponding RLC entity with the new downlink RLC PDU size.

The status check for re-establishing the RLC is not limited to the order indicated by the above two options, and thus can be performed in any order. In addition, the names of new information elements, such as the "Downlink RLC Configuration" information element and the "Downlink RLC Size Indicator" information element, may be changed. The procedure corresponding to this information element remains unchanged, regardless of the change in the names of information elements.

For Option 2, an example of a functional description of the "RLC Information" information element is given in Table 1.

Table 1
Modified RLC Information Information Element Information item name / group Necessity A bunch of Type and reference Semantics description Version SELECTION
uplink RLC mode OP Indicates which mode should be used - acknowledgment mode, non-acknowledgment mode, or transparent mode. > AM RLC >> Drop RLC Transmission MP Drop RLC Transmission 10.3.4.25

>> Transmission window size MP Integer (1, 8, 16, 32, 64, 128, 256, 512, 768, 1024, 1536, 2047, 2560, 3072, 3584, 4095) The maximum number of RLC PDUs transmitted without receiving acknowledgment. This parameter is necessary if the acknowledgment mode is used. The WTRU may assume that the UTRAN receiver window is equal to this value. >> Timer_RST MP Integer (50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 700, 800, 900, 1000) Elapsed time in milliseconds. Used to initiate a retransmission of a RESET PDU. >> Max_RST MP Whole (1, 4, 6, 8, 12, 16, 24, 32) >> Poll information OP Poll information 10.3.4.4 > UM RLC >> Drop RLC Transmission OP Drop RLC Transmission
10.3.4.25 > TM RLC >> Drop RLC Transmission OP Drop RLC Transmission
10.3.4.25 >> segmentation indication MP Boolean variable A value of TRUE indicates that segmentation is in progress.

SELECTION
Downlink RLC mode OP Indicates which mode should be used - acknowledgment mode, non-acknowledgment mode, or transparent mode. > AM RLC >> Downlink RLC PDU Size Indicator MP Numbered Variable
(fixed, flexible) Indicates whether fixed RLC PDU sizes should be used. REL-7 >> Downlink RLC PDU Size MP Integer (16..500 in increments of 8) Unit in bits REL-5 >> Delivery in order MP Boolean variable A value of TRUE indicates that the RLC should preserve the order of the highest level PDUs upon delivery.
A value of FALSE indicates that the receiving RLC may allow delivery of SDUs to a higher layer in a different order than that proposed by the RLC sublayer on the transmitting side.

>> Receive window size MP Integer (1, 8, 16, 32, 64, 128, 256, 512, 768, 1024, 1536, 2047, 2560, 3072, 3584, 4095) The maximum number of RLC PDUs that can be accepted. This parameter is necessary if the acknowledgment mode is used. The WTRU may also assume that the UTRAN transmitter window is equal to this value. >> Downlink RLC Status Information MP Downlink RLC Status Information
10.3.4.1 > UM RLC >> UM RLC LI downlink size MP Whole (7, 15) The bit size to be used for the UM LI downlink RLC. REL-5 >> Downlink Receive Window Size CV-Not- SIB16o Whole (32, 48, 64, 80, 96, 112) REL-6 > TM RLC >> segmentation indication MP Boolean variable A value of TRUE indicates that segmentation is in progress. One-way RLC re-establishment MP Boolean variable A value of TRUE indicates that only one side of the AM RLC object is reinstalled. REL-5 Alternative interpretation on E bits CV-Not-SIB16o Numbered Variable (TRUE) The absence of this information element means that a normal interpretation of the E bits should be applied. REL-6

If the RLC re-establishment for different RLC configurations is not evaluated in the RLC Information information element, then state checks for the downlink RLC PDU size in the RLC Information information element should only be performed if the AM RLC instance supports fixed sizes RLC PDU Otherwise, if a status check is performed and the downlink RLC PDU size is present for flexible RLC configurations, unnecessary re-establishment may occur.

Referring to FIGS. 1 and 2, an alternative method for setting up a new RLC configuration in the WTRU 100 and UTRAN 200 is disclosed. This alternative method is applicable when the host subassembly 135 and 235 explicitly signals the RLC configuration via the RRC radio carrier reconfiguration messages and is configured so as to support flexible size RLC PDUs. When the receiving side sub-assembly 135 and 235 is configured to support flexible size RLC PDUs, the receiving side sub-assembly 135 and 235 may receive upper-level indication of the RLC PDU size used by the transmit-side sub-assembly 130 and 230 (when configured to support fixed-size RLC PDUs ) This method also applies to the case when the RLC unit 110 and 220 changes the size of the field length indicator of the RLC PDUs between the values 7 and 15.

When moving from an RLC configuration that supports flexible size RLC PDUs to an RLC configuration that supports fixed sizes of RLC PDUs, the transmitter side subassembly 130 and 230 and the receiver side subassembly 135 and 235 must discard the flexible size RLC PDUs. In particular, at a predetermined activation time, the transmitter-side subassembly 130 and 230 discards flexible RLC PDUs (or RLC PDUs with a size that differs from the fixed size of the Received Acknowledgment Mode (AMD) PDU that were transmitted once and acknowledged admission which has not yet been received. An example of an activation time would be the time when Node-B starts using normal MAC-hs in the case of a downlink and / or MAC-i / is in the case of an uplink. The transmitter-side subassembly 130 and 230 may discard RLC PDUs according to one or a combination of the following rules.

1) Any RLC PDU whose size is different from the length of a fixed RLC PDU (applicable to flexible size RLC PDUs that have been created but which may not yet be transmitted);

2) Any RLC PDU whose size differs from the length of fixed RLC PDUs that have already been transmitted at least once (applies only to RLC PDUs that have been transmitted or routed to lower layers, and thus the blocks RLC PDUs that have been created but not yet transmitted are not discarded);

3) All RLC PDUs with a Sequence Number (SN) up to the last RLC PDUs with a flexible size inclusive (or with a size that differs from the length of a fixed PDU);

4) All RLC PDUs with SN up to and including the last RLC PDU with a flexible size (or with a size that differs from the length of the fixed PDU) that has been transmitted at least once;

5) All RLC SDUs up to and including the last SDU, which is part of the last RLC PDU with a flexible PDU size (or with a size that differs from the configured fixed PDU length);

6) All RLC SDUs up to and including the last SDU, which is part of the last RLC PDU with a flexible PDU size (or with a size that differs from the configured fixed PDU length);

7) All RLC SDUs for which at least one segment is part of a PDU with a size that is different from the configured fixed size PDU that has been transmitted at least once; and / or

8) All RLC PDUs in the retransmission buffer that have been transmitted to the lower layers and which have an assigned SN number.

If the last discarded RLC PDU contains an RLC SDU segment, then this RLC SDU may optionally be reconstructed using a new configuration (i.e., a new fixed size RLC PDU).

The transmitter-side subassembly 130 and 230 does not re-initialize the status parameters and sequence numbers. Then, the transmitter side subassembly 130 and 230 indicates the receiver side subassembly 135 and 235 of the RLC PDUs or RLC SDUs that have been dropped.

The Supervisory Control Field (SUFI) Reception Window Movement (MRW) can be used to indicate dropped RLC PDUs and RLC SDUs. If the "Send MRW" parameter is not configured, then MRW SUFI is collected using the exception information. In particular, the last SN of the discarded RLC PDU or RLC SDU (SN_MRW = SN of the last discarded RLC PDU + 1) should be indicated. Then, the receiving side sub-assembly 135 and 235 discards all RLC PDUs for which SN <SN_MRW, and accordingly moves the receive window.

If the "Send MRW" parameter is not configured, only 15 discarded SDUs can be indicated. This may not be sufficient to indicate all RLC SDUs that should be discarded, especially if a large number of SDUs are discarded. Therefore, it may be necessary to transfer more than one MRW SUFI.

A field of length N can always be set to zero, or it can optionally be set to indicate the length of the last SDU related to a given PDU.

A new MRW SUFI is being introduced, which is used only for relay switching purposes. The new MRFI SUFI may include an SN_MRW field to indicate the sequence number of the last PDU or SDU to be discarded. The receive window is updated accordingly, and all RLC PDUs with SN number up to and including SN_MRW are discarded. Optionally, prior to discarding all RLC PDUs, the receiving side sub-assembly 135 and 235 may assemble all RLC PDUs into RLC SDUs and deliver them to higher layers. The host side assembly 135 and 235 may then discard all RLC PDUs up to and including SN_MRW, which cannot be reassembled into RLC SDUs.

RLC re-establishment can be avoided by using the SDU discard function to discard SDUs that were created using flexible-sized RLC PDUs when the serving cell changes to a legacy Node-B node, or when a legacy Node-B node is added to the Active Enhanced Dedicated Set. Channel (E-DCH) for the uplink case. Then the RLC uses MRW SUFI to tell the WTRU to shift the receive window and discard the same RLC PDUs.

As a result of applying this method, the amount of data loss is the same when re-establishing the RLC, if reconfiguration takes place during activation. However, data loss can be minimized if the transmitter-side subassembly 130 and 230 starts generating fixed-length RLC PDUs when a handoff decision is made or when the transmitter-side subassembly 130 and 230 is notified of a handoff. During a handoff (that is, at a given activation moment), a drop function is initiated. This allows the RLC unit 110 to attempt to exclude some flexible size RLC PDUs before the activation time has elapsed. When data is transmitted through the radio link of the target cell (that is, after a handoff has been completed), all RLC PDUs in the retransmission buffer 140 and 240 that have not been acknowledged must be discarded by the SDU discard function, since they are not supported by the Node target -B.

This can lead to a problem since the transmitter-side subassembly 130 and 230 can only update their transmission parameters and state variables after receiving the MRW_ACK from the WTRU, which may temporarily stop the transmission window. However, the advantage of this method is that data loss can be minimized.

The initiation of this procedure may be indicated by one or a combination of the following options:

1) The procedure can be indicated through explicit signaling from the upper levels (i.e. by initiating the discarding of the SDU for relay switching purposes).

2) The procedure can be started internally by the RLC when a change from flexible to fixed size RLC PDU is detected (that is, when reconfiguration from flexible to fixed size is indicated in RRC messages).

3) The procedure can be initiated at a given activation time for relay switching purposes if a synchronized shift is requested.

SDU discard function for acknowledgment mode, acknowledgment mode and transparent mode

Drop for RLC reconfiguration

This alternative is applicable only to acknowledgment mode RLC entities. It starts when the RLC configuration changes from a flexible to a fixed size RLC PDU. Optionally, this procedure can also be started if the RLC configuration changes from a fixed size RLC PDU configuration to a flexible RLC PDU size configuration and / or the size of the length indicator changes.

If the RLC configuration changes from a flexible RLC PDU configuration to a fixed RLC PDU configuration, all SDUs that have segments or “length indicators” indicating the end of the SDUs in the AMD PDUs that were transferred to the lower layers are discarded (optional, up to the last AMD PDU inclusive) with a size that is different from the size of the newly configured AMD PDU, and explicit signaling is used to notify the host sub-assembly 135 and 235.

RLC transmitter behavior to minimize data loss

Optionally, the behavior of the transmitter-side subassemblies 130 and 230 can be modified to minimize data loss when switching from flexible PDU sizes to fixed PDU sizes. When the transmitter-side subassembly 130 and 230 are notified of switching to fixed PDU sizes, the transmitter-side subassembly 130 and 230 should start generating fixed-size RLC PDUs until the activation specified by higher levels (that is, when the switchover occurs). These fixed-size RLC PDUs can include all previously created PDUs that have not yet been transmitted (that is, they must be regenerated according to the fixed size), and all new PDUs that were created from new or buffered SDUs. Alternatively, the transmitter-side subassembly 130 and 230 may continue to generate flexible size RLC PDUs, but change the configured maximum size of the RLC PDUs so that it matches the fixed size of the RLC PDUs that must be configured during handoff.

During activation, if all the PDUs in the sub-assembly 130 and 230 of the transmitting side (including the PDUs in the retransmission buffer 140 and 240) have a size equal to the configured fixed size of the RLC PDUs, the sub-assembly 130 and 230 of the transmitting side should continue to function normally with the blocks Fixed-size RLC PDUs without dropping any PDUs. Otherwise, the transmitter-side subassembly 130 and 230 should discard RLC PDUs that do not have the same size equal to the configured fixed length, including RLC PDUs that have already been transmitted.

When the RLC re-establishment procedure is performed, this procedure must be modified to take into account that not all PDUs are discarded at the time of activation. When the transmitter-side subassembly 130 and 230 instructs the receiver-side subassembly 135 and 235 to move the receive window (MRW indication), the above PDU drop procedure may be used to indicate PDUs that have been dropped.

Optionally, the procedure may be modified so that the MRW indication is transmitted earlier, and the receiving side sub-assembly 135 and 235 adjusts its receive window only at the time of activation. The time when the receiving side sub-assembly 135 and 235 should adjust its receive window may be explicitly indicated in the MRW indication, or the receiving side sub-assembly 135 and 235 may adjust its receive window during activation when a transport channel reconfiguration is to be performed.

The sub-assembly 130 and 230 of the transmitting side should be notified of the switch from a flexible to a fixed size PDU as soon as the appropriate decision is made at the highest levels, and not after waiting until the activation time. This enables the remaining flexible size PDUs to be transmitted for a longer period prior to activation time and allows you to limit the number of flexible size PDUs that will be discarded during activation.

Method of eliminating RLC re-establishment and minimizing data loss

This method may be used alone or in combination with any other methods described herein.

To minimize data loss, during a change from a flexible size RLC PDU to a fixed size RLC PDU, the transmitter side subassembly 130 and 230 does not discard any flexible size created and transmitted RLC PDUs. However, since normal MAC-hs or MAC-e / es will only support receiving fixed-size RLC PDUs corresponding to one of the Downlink Size Index Identifiers (SIDs) or Uplink Data Descriptor Identifiers (DDIs) The retransmitted RLC PDUs through normal MAC-hs or MAC-e / es must match one of these predefined sizes.

To ensure the correct RLC PDU block size, padding can be used. During an RLC configuration change, at the time of making a decision about handoff or at a given moment of activation, the transmitter-side subassembly 130 and 230 can use padding to resize all flexible RLC PDUs (i.e. change to a size other than fixed), which must be retransmitted so that they match one or a combination of the following sizes:

1) A configured fixed RLC PDU size if the flexible RLC PDU size is less than the fixed RLC PDU size.

2) Configured flexible maximum RLC PDU size before reconfiguration. The RNC must ensure that MAC-hs or MAC-e / es is also configured for the maximum size of the RLC PDU.

3) The maximum size of the RLC PDU present in the retransmission buffer. The RNC must ensure that MAC-hs or MAC-e / es is also configured to support receptions of this size (i.e., one of the SIDs must match this maximum RLC PDU size).

4) For each flexible RLC PDU, adjust the size to the size of the next largest SID or DDI configured for the MAC-hs queue to which the logical channel corresponds (MAC-d flow).

If the size of the RLC PDU is larger than any size that must be matched as described above, then padding cannot be used. However, the WTRUs can drop them using the SDU drop procedure as described above.

Alternatively, the RLC PDUs may be re-segmented to match the new fixed size of the RLC PDUs, and if the last remaining segment is smaller than the fixed size of the RLC PDUs (or less than the configured size that must be matched), then filling with insignificant elements may be used.

A change from a flexible size to a fixed size may be signaled by the host side assembly 135 and 235, or, optionally, it may be transparent to the host side assembly 135 and 235 (i.e., the host side assembly 135 and 235 always operates in a flexible RLC).

When adding padding with insignificant elements, it may be necessary to update the fields of the RLC PDU length indicator to reflect the changes and indicate where the filling started with insignificant elements.

Options for implementation

1. A wireless communication method for performing a reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

receive a Radio Resource Control (RRC) reconfiguration message indicating that the RLC should be reconfigured from receiving flexible size RLC Protocol Data Blocks (PDUs) through a downlink channel to receive fixed size RLC PDUs through a downlink channel, wherein the RLC contains subassembly of the transmitting side and subassembly of the receiving side; and

re-install at least the subassembly of the receiving side.

2. The method according to claim 1, additionally containing stages in which:

if the RRC re-establishment information element is present in the RRC reconfiguration message, then only the receiving side sub-assembly is re-established; and

if the RRC re-establishment information element is missing from the RRC reconfiguration message, then both the receiving side sub-assembly and the transmit-side sub-assembly are reinstalled.

3. The method according to any one of claims 1 and 2, wherein the receiving side sub-assembly is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the WTRU moves from a first cell that supports Advanced High Speed Media Access Control (MAC) -ehs), into a second cell that does not support MAC-ehs.

4. The method according to any one of claims 1 to 3, in which the receiving side subassembly is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second A cell that does not support flexible RLC PDUs.

5. The method according to any one of claims 1 to 4, wherein the receiving side sub-assembly is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports RLC PDUs flexible size, in an SRNC that does not support flexible size RLC PDUs.

6. The method according to any one of claims 1 to 5, in which the criteria for re-establishing the RLC are evaluated when the information element "RLC Information" is present in the RRC reconfiguration message.

7. The method of claim 6, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

8. A wireless Transmit / Receive Unit (WTRU), comprising:

an RLC unit including a transmitting side subassembly and a receiving side subassembly; and

a radio resource control unit (RRC) configured to receive an RRC reconfiguration message indicating that the RLC should be reconfigured from receiving flexible size RLC PDUs through a downlink channel to receiving a fixed size RLC PDUs through a downlink channel, wherein re-installed at least the subassembly of the receiving side.

9. The WTRU of claim 8, wherein if the "one-way RLC re-establishment" information element is present in the RRC reconfiguration message, then only the receiving side reassembly is set, and if the "one-way RLC re-establishment" information element is not present in the RRC reconfiguration message, both the sub-assembly of the receiving side and the sub-assembly of the transmitting side are set.

10. The WTRU according to any one of claims 8 and 9, wherein the receiving side assembly is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the WTRU moves from a first cell that supports Advanced High Speed Media Access Control (MAC) -ehs), into a second cell that does not support MAC-ehs.

11. The WTRU according to any one of claims 8 to 10, wherein the receiving side sub-assembly is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second A cell that does not support flexible RLC PDUs.

12. The WTRU according to any one of claims 8 to 11, wherein the receiving side subconfiguration is reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports RLC PDUs flexible size, in an SRNC that does not support flexible size RLC PDUs.

13. The WTRU according to any one of claims 8-12, wherein the RLC re-establishment criteria are evaluated when the RLC Information information element is present in the RRC reconfiguration message.

14. The WTRU of claim 13, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

15. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

receive a Radio Resource Control (RRC) reconfiguration message indicating that the RLC should be reconfigured from receiving fixed-size Protocol RLC Data Units (PDUs) through a downlink channel to receive flexible size RLC PDUs through a downlink channel, wherein the RLC contains subassembly of the transmitting side and subassembly of the receiving side; and

determine whether re-establishment of at least the sub-assembly of the receiving side is required.

16. The method according to clause 15, which, if it is determined that a re-installation is required, contains the following additional steps:

if the RRC re-establishment information element is present in the RRC reconfiguration message, then only the receiving side sub-assembly is re-established; and

if the RRC re-establishment information element is missing from the RRC reconfiguration message, then both the receiving side sub-assembly and the transmit-side sub-assembly are reinstalled.

17. The method according to any one of claims 15 and 16, wherein the receiving side subassembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the WTRU moves from a first cell that does not support Advanced High Speed Media Access Control ( MAC-ehs), into a second cell that supports MAC-ehs.

18. The method according to any one of claims 15-17, wherein the receiving side sub-assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the WTRU moves from a first cell that does not support flexible size RLC PDUs to a second cell that supports flexible RLC PDUs.

19. The method according to any one of claims 15-18, wherein the receiving side assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that does not support RLC blocks Flexible size PDUs, in an SRNC that supports flexible size RLC PDUs.

20. The method according to any one of claims 15-19, wherein the RLC re-establishment criteria are evaluated when the RLC Information information element is present in the RRC reconfiguration message.

21. The method of claim 20, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

22. A wireless Transmit / Receive Unit (WTRU), comprising:

an RLC unit including a transmitting side subassembly and a receiving side subassembly; and

an RRC unit configured to receive an RRC reconfiguration message indicating that the RLC unit should be reconfigured from receiving fixed size RLC PDUs through a downlink channel to receiving flexible size RLC PDUs through a downlink channel, and determination is made whether re-establishment of at least the sub-assembly of the receiving side is required.

23. The WTRU of claim 22, wherein if it is determined that a re-establishment is required, and if the “one-way RLC re-establishment” information element is present in the RRC reconfiguration message, then only the receiving side sub-assembly is reinstalled, and if the “one-way re-establishment” information element RLC "is missing from the RRC reconfiguration message, both the receiving side subassembly and the transmitting side subassembly are reinstalled.

24. The WTRU according to any one of claims 22 and 23, wherein the receiving side sub-assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the WTRU moves from a first cell that does not support Advanced High Speed Media Access Control ( MAC-ehs), into a second cell that supports MAC-ehs.

25. The WTRU according to any one of claims 22-24, wherein the receiving side sub-assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the WTRU moves from a first cell that does not support flexible size RLC PDUs in a second cell that supports flexible RLC PDUs.

26. The WTRU as claimed in any one of claims 22 to 25, wherein the receiving side sub-assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that does not support RLC blocks Flexible size PDUs, in an SRNC that supports flexible size RLC PDUs.

27. The WTRU according to any one of claims 22 to 26, wherein the RLC re-establishment criteria are evaluated when the RLC Information information element is present in the RRC reconfiguration message.

28. The WTRU of claim 27, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

29. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

receive a Radio Resource Control (RRC) reconfiguration message indicating that the RLC should be reconfigured from transmitting flexible size RLC Protocol Data Blocks (PDUs) through the uplink channel to transmit fixed size RLC blocks through the uplink channel, wherein the RLC contains subassembly of the transmitting side and subassembly of the receiving side; and

re-install at least the sub-assembly of the transmitting side.

30. The method according to clause 29, further comprising stages in which:

if the RRC re-establishment information element is present in the RRC reconfiguration message, then only the transmitter-side subassembly is re-established; and

if the RRC re-establishment information element is missing from the RRC reconfiguration message, then both the receiving side sub-assembly and the transmit-side sub-assembly are reinstalled.

31. The method according to any one of claims 29 and 30, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second A cell that does not support flexible RLC PDUs.

32. The method according to any one of claims 29-31, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when a new cell that does not support flexible size RLC PDUs is added to the active set which contains only cells supporting flexible size RLC PDUs.

33. The method according to any one of claims 29-32, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports RLC PDUs flexible size, in an SRNC that does not support flexible size RLC PDUs.

34. The method according to any of paragraphs.29-33, in which the criteria for re-establishing the RLC are evaluated based on the actions associated with the comparison of the radio carrier.

35. The method of claim 34, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

36. A wireless Transmit / Receive Unit (WTRU), comprising:

an RLC unit including a transmitting side subassembly and a receiving side subassembly; and

an RRC unit configured to receive an RRC reconfiguration message indicating that the RLC unit should be reconfigured from transmitting flexible size RLC PDUs via an uplink channel to transmitting a fixed size RLC PDUs through an uplink channel, and is re-established, by at least a sub-assembly of the transmitting side.

37. The WTRU according to clause 36, wherein if the "one-way RLC re-establishment" information element is present in the RRC reconfiguration message, then only the transmitter-side sub-assembly is re-established, and if the "one-way RLC re-establishment" information element is not present in the RRC reconfiguration message, then both the sub-assembly of the receiving side and the sub-assembly of the transmitting side are re-installed.

38. The WTRU according to any one of claims 36-37, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second A cell that does not support flexible RLC PDUs.

39. The WTRU according to any one of claims 36-38, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when a new cell that does not support flexible size RLC PDUs is added to the active set which contains only cells supporting flexible size RLC PDUs.

40. The WTRU according to any one of claims 36-39, wherein the transmitter-side subassembly is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports RLC PDUs flexible size, in an SRNC that does not support flexible size RLC PDUs.

41. The WTRU according to any one of claims 36-40, wherein the criteria for re-establishing the RLC are evaluated based on actions related to the radio carrier mapping.

42. The WTRU of claim 41, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

43. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

receive a Radio Resource Control (RRC) reconfiguration message indicating that the RLC should be reconfigured from transmitting RLC Protocol Data Blocks (PDUs) through an uplink channel to transmit flexible size RLC blocks through an uplink channel, wherein the RLC contains subassembly of the transmitting side and subassembly of the receiving side; and

determine whether re-establishment of at least the sub-assembly of the transmitting side is required.

44. The method of claim 43, wherein re-establishment is required if the RLC protocol header format is changed in RLC PDUs.

45. The method according to item 44, in which changing the format of the RLC protocol header corresponds to changing the size of the length indicator field in the headers.

46. The method according to any one of paragraphs 43-45, which, if it is determined that a re-installation is required, comprises the following additional steps:

if the RRC re-establishment information element is present in the RRC reconfiguration message, then only the transmitter-side subassembly is re-established; and

if the RRC re-establishment information element is missing from the RRC reconfiguration message, then both the receiving side sub-assembly and the transmit-side sub-assembly are reinstalled.

47. The method according to any one of claims 43-46, wherein the transmitter-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when a new cell that supports flexible size RLC PDUs is added to the active set, and a cell that does not support flexible size RLC PDUs is removed from the active set, and the resulting active set contains only cells that support flexible size RLC PDUs.

48. The method according to any one of claims 43-47, wherein the transmitter-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when an RRC connection is moved from a Serving Radio Network Controller (SRNC) that does not support RLC blocks Flexible size PDUs, in an SRNC that supports flexible size RLC PDUs.

49. The method according to any one of claims 43-48, wherein the transmitter-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when the path through which the RLC PDUs are transmitted changes from the state in which it includes a first cell that does not support flexible size RLC PDUs, in a state in which it includes a second cell that supports flexible size RLC PDUs.

50. The method according to any of paragraphs 43-49, in which the criteria for re-establishing the RLC are evaluated when the information element "RLC information" is present in the RRC reconfiguration message.

51. The method of claim 50, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

52. A Wireless Transmit / Receive Unit (WTRU), comprising:

an RLC unit including a transmitting side subassembly and a receiving side subassembly; and

an RRC unit configured to receive an RRC reconfiguration message indicating that the RLC unit should be reconfigured from transmitting fixed size RLC PDUs via an uplink channel to transmitting flexible size RLC PDUs through an uplink channel, and determining whether re-establishment of at least the sub-assembly of the transmitting side is required.

53. The WTRU of claim 52, wherein re-establishment is required if the RLC protocol header format is changed in RLC PDUs.

54. The WTRU of claim 53, wherein changing the RLC protocol header format corresponds to changing the size of the length indicator field in the headers.

55. The WTRU according to any one of claims 52-54, wherein if it is determined that a re-establishment is required, and if the “one-way RLC re-establishment” information element is present in the RRC reconfiguration message, then only the transmitter-side sub-assembly is re-established, and if the information element "one-way RLC re-establishment" is missing from the RRC reconfiguration message, both the receiving side sub-assembly and the transmit-side sub-assembly are re-established.

56. The WTRU according to any one of paragraphs 52-55, wherein the transmitter-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when a new cell that supports flexible size RLC PDUs is added to the active set, and a cell that does not support flexible size RLC PDUs is removed from the active set, and the resulting active set contains only cells that support flexible size RLC PDUs.

57. The WTRU according to any one of claims 52-56, wherein the transmit-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when an RRC connection is moved from a Serving Radio Network Controller (SRNC) that does not support RLC blocks Flexible size PDUs, in an SRNC that supports flexible size RLC PDUs.

58. The WTRU according to any one of claims 52-57, wherein the transmit-side sub-assembly is reconfigured from transmitting fixed-size RLC PDUs to transmitting flexible-sized RLC PDUs when the path through which the RLC PDUs are transmitted changes from the state in which it includes a first cell that does not support flexible size RLC PDUs, in a state in which it includes a second cell that supports flexible size RLC PDUs.

59. The WTRU according to any one of claims 52 to 58, wherein the RLC re-establishment criteria are evaluated when the RLC Information information element is present in the RRC reconfiguration message.

60. The WTRU of claim 59, wherein the RLC re-establishment criteria are evaluated based on each radio carrier.

61. A wireless communication method for performing a reconfiguration of a Radio Link Control (RLC) unit in a Universal Terrestrial Radio Access Network (UTRAN), comprising the steps of:

determine that reconfiguration of the RLC block is necessary;

reconfiguring the RLC unit from the fixed sizes of the RLC PDUs to the flexible sizes of the RLC PDUs, the RLC unit comprising a transmitting side subassembly and a receiving side subassembly; and

re-install at least one of the subassembly of the transmitting side and the subassembly of the receiving side.

62. The method of claim 61, wherein the transmit-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when the path through which the RLC PDUs are transmitted changes from the state in which it includes the first a cell that does not support MAC-ehs, in a state in which it includes a second cell that supports MAC-ehs.

63. The method according to any one of claims 61 and 62, wherein the receiving side subassembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the path through which RLC PDUs are received changes from the state in which it includes a first cell that does not support flexible size RLC PDUs, in a state in which it includes a second cell that supports flexible size RLC PDUs.

64. The method according to any one of claims 61-63, further comprising the step of:

transmitting an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs.

65. The method of claim 64, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element if it is determined that the WTRU requires re-establishing the RLC sub-assembly of the receiving side.

66. The method according to any one of claims 61-63, further comprising the step of:

transmitting an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs.

67. The method of claim 66, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element, if it is determined that the WTRU requires re-establishing the RLC sub-assembly of the transmitting side.

68. Universal Terrestrial Radio Access Network (UTRAN), comprising:

an RLC unit including a transmitting side subassembly and a receiving side subassembly; and

an RRC unit configured to determine whether or not to reconfigure the RLC unit, reconfigure the RLC unit from fixed RLC PDU sizes to flexible RLC PDU sizes, and reinstall at least one of the transmitter-side sub-assembly and the receive-side sub-assembly.

69. The UTRAN of claim 68, wherein the transmit-side subassembly is reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs when the path through which the RLC PDUs are transmitted changes from the state in which it includes the first a cell that does not support MAC-ehs, in a state in which it includes a second cell that supports advanced MAC-ehs.

70. UTRAN according to any one of claims 68 and 69, wherein the receiving side assembly is reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs when the path through which the RLC PDUs are received changes from the state in which it includes a first cell that does not support flexible size RLC PDUs, in a state in which it includes a second cell that supports flexible size RLC PDUs.

71. UTRAN according to any one of claims 68-70, further comprising:

a transmitter configured to send an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from receiving fixed size RLC PDUs to receiving flexible size RLC PDUs.

72. The UTRAN of claim 71, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element if it is determined that the WTRU requires re-establishing the RLC sub-assembly of the receiving side.

73. UTRAN according to any one of claims 68-70, further comprising:

a transmitter configured to send an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from transmitting fixed size RLC PDUs to transmitting flexible size RLC PDUs.

74. The UTRAN of claim 73, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element if it is determined that the WTRU requires re-establishing the RLC sub-assembly of the transmitting side.

75. A wireless communication method for performing a reconfiguration of a Radio Link Control (RLC) unit in a Universal Terrestrial Radio Access Network (UTRAN), comprising the steps of:

determine that reconfiguration of the RLC block is necessary;

reconfiguring the RLC unit from the flexible sizes of the RLC PDUs to the fixed sizes of the RLC PDUs, the RLC unit comprising a transmitting side subassembly and a receiving side subassembly; and

re-install at least one of the subassembly of the transmitting side and the subassembly of the receiving side.

76. The method of claim 75, wherein the RLC unit is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the path through which RLC PDUs are transmitted changes from a state in which it includes a first cell that supports MAC-ehs, in a state in which it includes a second cell that does not support MAC-ehs.

77. The method according to any of claims 75 and 76, wherein the RLC unit is reconfigured from flexible size RLC PDUs to fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second cell that Does not support flexible RLC PDUs.

78. The method according to any one of claims 75-77, wherein the RLC unit is reconfigured from flexible size RLC PDUs to fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports flexible size RLC PDUs, in an SRNC that does not support flexible size RLC PDUs.

79. The method according to any one of claims 75-78, further comprising the step of:

transmitting an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs.

80. The method of claim 79, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element.

81. The method according to any one of paragraphs.75-78, further comprising the step of:

transmitting an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs.

82. The method of claim 81, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element.

83. Universal Terrestrial Radio Access Network (UTRAN), comprising:

a radio link control unit (RLC) including a transmitting side subassembly and a receiving side subassembly; and

a radio resource control unit (RRC) configured to determine whether or not to reconfigure the RLC unit, reconfigure the RLC unit from flexible RLC PDU sizes to fixed RLC PDU sizes, and reinstall at least one of the transmitter side and the receiver side sub-assemblies.

84. The UTRAN of claim 83, wherein the RLC is reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs when the path through which RLC PDUs are transmitted changes from the state in which it includes the first cell , which supports improved high-speed access control of the MAC-ehs environment, in a state in which it includes a second cell that does not support MAC-ehs.

85. The UTRAN according to any one of claims 83 and 84, wherein the RLC unit is reconfigured from flexible size RLC PDUs to fixed size RLC PDUs when the WTRU moves from a first cell that supports flexible size RLC PDUs to a second cell that Does not support flexible RLC PDUs.

86. UTRAN according to any one of claims 83-85, wherein the RLC unit is reconfigured from flexible size RLC PDUs to fixed size RLC PDUs when the RRC connection is moved from a Serving Radio Network Controller (SRNC) that supports flexible size RLC PDUs, in an SRNC that does not support flexible size RLC PDUs.

87. UTRAN according to any one of paragraphs 83-86, further comprising:

a transmitter configured to send an RRC reconfiguration message to the Wireless Transmit / Receive Unit (WTRU) indicating that the WTRU should be reconfigured from receiving flexible size RLC PDUs to receiving fixed size RLC PDUs.

88. The UTRAN of claim 87, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element.

89. UTRAN according to any one of paragraphs 83-86, further comprising:

a transmitter configured to send an RRC reconfiguration message to the WTRU indicating that the WTRU should be reconfigured from transmitting flexible size RLC PDUs to transmitting fixed size RLC PDUs.

90. The UTRAN of claim 89, wherein the RRC reconfiguration message includes a one-way RLC re-establishment information element.

91. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

reconfiguring the RLC unit from the flexible sizes of the RLC PDUs to the fixed sizes of the RLC PDUs, the RLC unit comprising a transmitting side subassembly and a receiving side subassembly; and

Flexible-side RLC PDUs are discarded by transmitting side subassemblies.

92. The method of claim 91, further comprising transmitting a message indicating discarded flexible size RLC PDUs.

93. The method of claim 92, wherein the message further indicates RLC SDUs corresponding to discarded flexible size RLC PDUs.

94. The method according to any of paragraphs 92 and 93, in which the message includes a Reception Window Relocation Control (SUW) Superfield (MRW) to indicate discarded RLC PDUs.

95. The method of claim 94, wherein the MRW SUFI indicates a Sequence Number (SN) of the last RLC PDU or RLC SDU that has been dropped.

96. The method according to any one of claims 91-95, wherein any RLC PDU whose size is different from the length of the fixed size RLC PDUs is discarded.

97. The method according to any one of claims 91-95, wherein any RLC PDU that is different from the length of the fixed size RLC PDUs that have already been transmitted at least once is discarded.

98. The method according to any one of claims 91-95, wherein all RLC PDUs with a Sequence Number (SN) are dropped to the last RLC PDUs of a flexible size inclusively or with a size that differs from the length of a fixed RLC PDU.

99. The method according to any one of claims 91-95, wherein all RLC PDUs with a Sequence Number (SN) are discarded to the last flexible RLC PDU, inclusive or with an RLC PDU size that is different from the length of the fixed RLC PDU that was transmitted at least once.

100. The method according to any one of claims 91-95, wherein all RLC SDUs are discarded to the last SDU included in the last RLC PDU with a flexible size or RLC PDU size that is different from the length of a fixed RLC PDU.

101. The method according to any one of claims 91-95, wherein all RLC SDUs are discarded for which at least one segment is part of an RLC whose size is different from the fixed size of the RLC PDU that was transmitted at least , once.

102. The method according to any one of claims 91-95, wherein all RLC PDUs in the retransmission buffer that have been transmitted to the lower layers and to which the SN sequence number has been assigned are discarded.

103. The method according to any one of claims 91-102, wherein data loss is minimized by creating and transmitting fixed size RLC PDUs when a handoff decision is made.

104. The method according to any one of claims 91-103, wherein the transmitter-side subassembly discards flexible size RLC PDUs in response to explicit signaling from higher layers.

105. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

receive a message from the upper levels indicating the moment of activation; and

prior to activation, reconfigure the RLC from generating flexible size RLC PDUs to generating fixed size RLC PDUs.

106. The method of claim 105, further comprising the step of:

regenerate according to a fixed size all PDUs that have been created but not yet transferred.

107. The method of claim 105, further comprising the step of:

regenerate according to a fixed size all new PDUs that were created from new or buffered SDUs.

108. The method according to any of paragraphs.105-107, in which the relay switching occurs at the time of activation.

109. The method of claim 106, wherein the remaining flexible size RLC PDUs are discarded.

110. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

flexible RLC PDUs are generated by the RLC;

receive a message from the upper levels indicating the moment of activation;

prior to activation, the configured maximum RLC PDU size associated with the flexible RLC PDUs is changed so as to bring it into line with the fixed RLC PDU size; and

at the time of activation, the RLC unit is reconfigured from the generation of flexible size RLC PDUs to the generation of fixed size RLC PDUs.

111. The method according to p, in which the relay switching occurs at the time of activation.

112. A wireless communication method for performing reconfiguration of a Radio Link Control (RLC) unit in a Wireless Transmit / Receive Unit (WTRU), comprising the steps of:

reconfiguring the RLC unit from transmitting flexible size RLC PDUs to transmitting RLC PDUs with a size selected from a group of predefined RLC PDU sizes; and

resize flexible size RLC PDUs that need to be retransmitted so as to fit a specific size in a predefined size set of RLC PDUs.

113. The method according to p. 112, in which filling in the insignificant elements of the blocks of RLC PDUs of a flexible size to bring them into line with a specific size.

114. The method according to p, in which the flexible RLC PDUs are filled with insignificant elements to the next highest available size in a predefined set.

115. The method of claim 114, wherein the flexible RLC PDUs that are larger than the maximum size of the RLC PDUs in the predefined set are discarded.

116. The method of Claim 112, wherein all flexible size RLC PDUs that have not been transmitted or routed to lower layers are regenerated so as to correspond to fixed size RLC PDUs.

117. A wireless communication method for reconfiguring a Radio Link Control (RLC) unit in a Universal Terrestrial Radio Access Network (UTRAN), comprising the steps of:

reconfiguring the RLC unit from transmitting flexible size RLC PDUs to transmitting RLC PDUs with a size selected from a group of predefined RLC PDU sizes; and

resize flexible size RLC PDUs that need to be retransmitted so as to fit a specific size in a predefined size set of RLC PDUs.

118. The method according to p. 117, in which filling in the insignificant elements of blocks of RLC PDUs of a flexible size, to bring them into line with a specific size.

119. The method according to p, in which the flexible RLC PDUs are filled with insignificant elements to the next highest available size in a predefined set.

120. The method of claim 111, wherein the flexible size RLC PDUs that are larger than the maximum size of the RLC PDU in the predefined set are discarded.

121. The method of claim 117, wherein all flexible size RLC PDUs that have not been transmitted or routed to lower layers are regenerated so as to correspond to fixed size RLC PDUs.

Despite the fact that the signs and elements have been described above in specific combinations, each sign or element can be used individually, without other signs and elements, or in various combinations with other signs and elements or without them. The methods or flowcharts of the present invention may be implemented in a computer program, software, or firmware implemented in a computer-readable medium for execution by a general purpose computer or processor. Examples of computer-readable media include ROM, RAM, register, cache, semiconductor storage devices, magnetic media such as internal hard drives and removable drives, magneto-optical drives, and optical media such as CD-ROMs and DVDs.

Suitable processors include, for example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, a controller, a microcontroller, specialized programmable integrated circuits gate arrays, other types of integrated circuits and / or state machine.

The processor, together with the software, can be used to implement a radio frequency transceiver for use in a wireless transmit / receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or in any host computer. The WTRU can be used in conjunction with modules implemented in hardware and / or software, such as a camera, camcorder, video phone, hands-free phone, vibrating device, speaker, microphone, television transceiver, hands free headset, keyboard, Bluetooth module ®, frequency-modulated radio block (FM), liquid crystal display (LCD), organic light-emitting diode (OLED) display, digital music player, media player, video game module, Internet browser and / or any module wirelessly bottom of the local area network (WLAN).

Claims (14)

1. A method for configuring a Radio Link Control (RLC) object in a Wireless Transmit / Receive Unit (WTRD), comprising the steps of:
receive a Radio Resource Management (RRC) reconfiguration message including
a size indicator information element indicating whether the RLC object will be reconfigured between reception of fixed size Protocol Data Unit (RLC) blocks and flexible size RLC PDUs, and a length indicator information element indicating the length of the Protocol Data Unit (PDU), the RLC object comprising a transmit side and receiving side;
if the size indicator information element indicates that the RLC object will be reconfigured from receiving a fixed size PDU to receiving a flexible size PDU, compare the length in the RRC reconfiguration message length indicator information element with the length of the currently set length indicator, and if the length changes, reinstall, at least the receiving side of the RLC object in accordance with the length in the information element of the RRC reconfiguration message length indicator, also continue to work with the current configuration an association; and
if the size indicator information element indicates that the RLC object should be reconfigured from receiving a fixed size PDU to receiving a flexible size PDU, at least the receiving side of the RLC object is re-set in accordance with the length in the RRC reconfiguration message length indicator information element. 2. The method of claim 1, further comprising configuring the RLC entity to receive fixed size RLC PDUs if the size indicator information element indicates a fixed size reconfiguration, wherein the length of the RLC PDUs is indicated by an RRC reconfiguration message length indicator information element . 3. The method of claim 1, further comprising configuring the RLC entity to receive flexible size RLC PDUs if the size indicator information element indicates reconfiguration to a flexible size, wherein the length of the RLC PDUs is indicated by the RRC reconfiguration message length indicator information element . 4. The method of claim 1, wherein the RLC re-establishment criteria is evaluated when the RLC Information information element is present in the RRC reconfiguration message. 5. The method of claim 1, wherein the RRC reconfiguration message includes an “Downlink RLC Mode” information element that is set to “AM RLC.” 6. The method according to claim 1 further comprising stages in which:
determining whether a one-way RLC re-establishment information element is present in the RRC reconfiguration message;
re-establish only the receiving side if the determination is positive; and
reinstall both the transmitting side and the receiving side if the determination is negative. 7. The method of claim 1, wherein the length indicator information message indicates that the length of the RLC PDUs is between 7-15 bits. 8. A wireless Transmit / Receive Unit (WTRU), comprising:
A Radio Link Control (RLC) entity including a transmitting side and a receiving side;
wherein the RLC entity is configured to receive a Radio Resource Management (RRC) reconfiguration message that includes a size indicator information element indicating whether the RLC entity will be reconfigured between receiving fixed-size Protocol Data Unit Blocks (PDUs) and flexible-sized RLC PDUs, and a length indicator information element indicating the length of the Protocol Data Unit (PDU);
the RLC object is additionally configured to compare the length in the RRC reconfiguration message length indicator information element with the length of the currently set length indicator if the size indicator information element indicates that the RLC object will be reconfigured from receiving a fixed size PDU to receiving a flexible size PDU, if the length is changed, at least the receiving side of the RLC object is re-set in accordance with the length in the reconfiguration message length indicator information element and RRC, also continue to work with the current configuration; and
the RLC object is further configured to re-establish at least the receiving side according to the length in the RRC reconfiguration message length indicator information element if the size indicator information element indicates that the RLC object should be reconfigured from receiving a fixed size PDU to receiving a flexible size PDU. 9. The WTRU of claim 8, wherein the RLC entity is further configured to receive fixed size RLC PDUs if the size indicator information element indicates a fixed size reconfiguration, wherein the length of the RLC PDUs is indicated by an RRC reconfiguration message length indicator information element. 10. The WTRU of claim 8, wherein the RLC entity is further configured to receive flexible size RLC PDUs if the size indicator information element indicates flexible size reconfiguration, wherein the length of the RLC PDUs is indicated by the RRC reconfiguration message length indicator information element. 11. The WTRU of claim 8, further configured to evaluate RLC re-establishment criteria when the RLC Information information element is present in the RRC reconfiguration message. 12. The WTRU of claim 8, wherein the RRC reconfiguration message includes a downlink RLC mode information element that is set to AM RLC. 13. The WTRU of claim 8, wherein the RLC entity is further configured to:
re-install only the receiving side if the RLC one-way re-establishment information element is present in the RRC reconfiguration message and is set to TRUE; and
reinstall both the transmitting side and the receiving side if the RLC one-way re-establishment information element is present in the RRC reconfiguration message but is not set to TRUE. 14. The WTRU of claim 8, wherein the length indicator information element indicates that the length of the RLC PDUs varies between 7-15 bits.

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