CN201345665Y - Wireless transmitting/receiving unit - Google Patents

Abstract

A wireless transmit/receive unit comprising a receiver configured to receive wireless data, a transmitter configured to transmit wireless data, and connected to and in communication with the receiver and the transmitter processor. The processor is configured to flush the Hybrid Automatic Repeat Request (HARQ) procedure, set the state variable CURRENT_TSN to zero for all logical channels mapped to the Enhanced Dedicated Channel (E-DCH), and discards are kept in the Segmentation Entity segment.

Description

Wireless Transmitter/Receiver Unit

technical field

This application relates to a wireless transmitting/receiving unit in wireless communication.

Background technique

In 3rd Generation Partnership Project (3GPP) Release 6 (R6) systems, the Radio Link Control (RLC) layer in Answered Mode (AM) operates with a fixed Protocol Data Unit (PDU) size. Additionally, the medium access control high-speed (MAC-hs) layer in the base station and the medium access control (MAC) in the wireless transmit/receive unit (WTRU) do not support segmentation of service data units (SDUs) from higher layers. These limitations can lead to performance limitations, especially as High Speed Packet Access (HSPA) moves towards higher data rates.

In order to achieve higher data rates and reduce protocol overhead and padding, many new features for Layer 2 (L2) protocols were introduced in Release 7 of the 3GPP specifications. Variable RLC PDU size and MAC segmentation in the downlink are among the concepts introduced. It is also proposed to enhance L2 operation in the uplink system. Some of the enhancements that have been proposed point to, for example: introducing support for variable RLC PDU size, introducing support for MAC segmentation, allowing smooth transition between old and new protocol formats, and supporting CELL_DCH, CELL_FACH, CELL_PCH and URA_PCH Seamless state transitions between (e.g., depending on potential enhancements to CELL_FACH UL transmissions).

Figure 1 shows a legacy protocol architecture 100 (eg with a MAC layer and below) and the use of an Enhanced Dedicated Channel (EDCH) eg as described in Release 7 of the 3GPP specification. The MAC sublayers specific to the use of E-DCH are the MAC-es and MAC-e sublayers. Potentially, improvements to the L2 protocol can be achieved by enhancing the RLC sublayer (not shown in FIG. 1 ), MAC-es and MAC-e sublayers. Note that only the MAC-e sublayer is terminated in the base station.

The improved L2 enhanced MAC-e/es entity may be called a MAC-i-is entity. The improved L2 feature can be used as E-DCH transmission in CELL_DCH or as E-DCH transmission in CELL_FACH. The latter is also referred to as E-RACH transmission.

Due to the use of new features, such as the use of improved uplink (UL) layer 2 protocols in the system usually cannot be carried out in the whole system at the same time, for a period of time, there will be areas covered by base stations that do not support the new features. This is the case even if these base stations are part of a radio network subsystem controlled by a radio network controller (RNC) supporting the new features. As these legacy base stations will be adjacent to base stations implementing the new features ("enhanced base stations"), there will be WTRUs that start their communication within the area covered by the enhanced base station and move within the area covered by the legacy base station.

Accordingly, it would be advantageous to provide a method and apparatus for supporting uplink protocols in an area covered by an enhanced base station while providing a smooth transition when a WTRU moves into an area covered by a legacy base station.

Utility model content

To support uplink protocols in areas covered by enhanced base stations while providing a smooth transition when the WTRU moves into areas covered by legacy base stations, the present invention provides a wireless transmit/receive unit (WTRU). The WTRU includes a receiver configured to receive wireless data, a transmitter configured to transmit wireless data, and a processor coupled to and in communication with the receiver and the transmitter. The processor is configured to flush Hybrid Automatic Repeat Request (HARQ) procedures, set the state variable CURRENT_TSN of all logical channels mapped to Enhanced Dedicated Channel (E-DCH) to zero and discard the Segmentation.

The present invention provides a WTRU capable of supporting uplink protocols in an area covered by an enhanced base station while providing a smooth transition when moving into an area covered by a legacy base station.

Description of drawings

A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which:

Figure 1 shows a traditional protocol architecture;

Figure 2 shows an example of a wireless communication system including a WTRU and multiple Node-Bs;

FIG. 3 is an exemplary functional block diagram of the WTRU and Node-B of FIG. 2;

4 is a flowchart of a method for performing a MAC reset;

Figure 5 shows the E-DCH protocol architecture;

Figure 6 shows an example diagram of MAC PDU creation;

Figure 7 shows an example diagram of replacement MAC PDU creation; and

Figure 8 shows an example diagram of another alternative MAC PDU creation.

Detailed ways

References below to "Wireless Transmit/Receive Unit (WTRU)" include, but are not limited to, User Equipment (UE), Mobile Station, Fixed or Mobile Subscriber Unit, Pager, Cellular Phone, Personal Digital Assistant (PDA), Computer or Capable Any other type of user equipment operating in a wireless environment. A "base station" referred to below includes, but is not limited to, a Node-B, a site controller, an access point (AP), or any other type of interface device capable of operating in a wireless environment.

Figure 2 shows a wireless communication system 200 comprising a WTRU 210 and a plurality of Node-Bs 220 (referred to as ₂₂₀₁ and ₂₂₀₂ ). As shown in Figure 2, the WTRU 210 communicates with a Node-B ₂₂₀₁ . In the example of FIG. 2, WTRU 210 may transition from communicating with Node-B ₂₂₀₁ to communicating with Node-B ₂₂₀₂ , where Node-B ₂₂₀₁ is an enhanced Node-B (e.g., Node-B in Release 8 of the 3GPP specification -B), while Node-B ₂₂₀₂ is a non-enhanced Node-B (eg, version 6 or 7) that has been added to the active set. It is noted that although an example configuration of WTRU 210 and Node-B 220 is depicted in FIG. 2 , any combination of wireless and wired devices may be included in wireless communication system 200 . For example, a Radio Network Controller (RNC—not shown) may be included in the wireless communication system 200 and communicate with one or more Node-Bs 220 .

3 is an exemplary functional block diagram 300 of the WTRU 210 and the Node-B 220 of the wireless communication system 200 of FIG. 2 . As shown in FIG. 3, WTRU 210 communicates with Node-B 220.

WTRU 210 includes processor 215, receiver 216, transmitter 117, and antenna 218, in addition to elements that may be found in a typical WTRU. Receiver 216 and transmitter 117 are in communication with processor 215 . Antenna 218 communicates with both receiver 216 and transmitter 117 to facilitate wireless data transmission and reception. The processor 215 of the WTRU 210 is configured to support the UL protocol.

Node-B 220 includes processor 225, receiver 226, transmitter 227 and antenna 228, in addition to elements found in a typical Node-B. Receiver 226 and transmitter 227 are in communication with processor 225 . An antenna 228 communicates with both receiver 226 and transmitter 227 to facilitate wireless data transmission and reception. The processor 225 of the Node-B 220 is configured to support the UL protocol.

A number of methods are described below to allow the WTRU 210 to operate as a legacy Node-B 220 when connected to an Enhanced UL L2 Serving Radio Network Controller (SRNC). Thus, if the SRNC is an R8 SRNC, the WTRU 210 is able to implement the enhanced L2 protocol when connected to a legacy (eg, R6, R7) Node-B 220. Additionally, the methods described below may provide a smooth transition when the WTRU 210 transitions to or from a region that supports or does not support the Enhanced L2 protocol, as well as provide a method for restoring data.

Additionally, although some of the methods described below refer to the UL context, they are also applicable to the downlink (DL) with a collapsed architecture, e.g., in which Node-B and RNC functionality are in one node . The term "MAC-i/is" entity refers to an enhanced MAC-e/es entity with UL L2 improvements. Therefore, MAC-i/is and MAC-e/es may be used interchangeably in the following description.

A WTRU 210 operating in the enhanced L2 protocol may also fall back to operating in the legacy L2 protocol if a non-enhanced Node-B 220 is added to the active set. Conversely, if all Node-Bs 220 in the Active Set are Enhanced Node-Bs, then a WTRU 210 operating in the legacy L2 protocol may need to perform some reconfiguration functions if it wants to operate using the Enhanced L2 protocol.

In one example, when the MAC protocol transitions from an enhanced protocol to a non-enhanced protocol, or from a non-enhanced protocol to an enhanced protocol, any hybrid automatic repeat request (HARQ) procedures are flushed. Additionally, a full MAC-e/es reset can be performed. A MAC-e/es reset may be signaled via a radio resource control (RRC) message, such as an RRC reconfiguration message (ie, radio bearer reconfiguration, transport channel reconfiguration, etc.), or via an active set update message.

FIG. 4 is a flowchart of a method 400 of performing a MAC reset. In step 410, the MAC protocol may be changed to or from an enhanced protocol. For example, when all Node-Bs in the active set are enhanced Node-Bs, the MAC protocol can be changed from a non-enhanced protocol to an enhanced protocol, and when a non-enhanced Node-B is added to the active set, the MAC protocol Can be changed from enhanced protocol to non-enhanced protocol.

When the MAC protocol changes (step 410), a MAC-e/es reset may be triggered (step 420). Once this happens, the HARQ process is flushed (step 430), the state variable CURRENT_TSN is set to zero for all logical channels mapped to E-DCH (step 440), and any reserved segment (step 450).

As described above, RRC signaling may be utilized to identify the WTRU 210 of the L2 protocol change. To accomplish this, one or more of the following messages may be used to signal the reconfiguration:

- Active Set Update: One or more of the following Configuration Information Elements (IEs) or information may be added to the Active Set Update message:

o "RLC Info" alerts the WTRU 210 to change between fixed and variable RLC PDUs when needed.

o Changes between Enhanced MAC-e/es and Normal MAC-e/es. This should be signaled within this message, as part of the E-DCH message or reconfigured linkage.

○MAC-e/es reset indicator.

o Radio bearer (RB) mapping information.

o "RB Information for Reconfiguration" IE - List of all radio bearers reconfigured with new protocol. The IE "RB Information for Reconfiguration" may contain some of the other information elements listed above, eg, RLC information, RB mapping information, and so on.

- Reconfiguration message (radio bearer/transport channel reconfiguration): Active Set Update can be used to update layer 2 protocol parameters after the RRC reconfiguration message. Alternatively, the layer 2 reconfiguration can be signaled directly with an RRC reconfiguration message without requiring an active set update. The change of UL RLC protocol from fixed to variable may be signaled in this message. Furthermore, the IE "RLC Info" can be changed so that it indicates which RLC protocol version is used for the uplink (eg, fixed or variable). The RRC message should also signal whether enhanced MAC-e/es or old MAC-e/es is used.

One way to employ reconfiguration from or to an enhanced L2 protocol is to utilize the operations and interfaces of sub-layers of devices in a wireless communication system, such as the wireless communication system 200 of FIG. 2 . Thus, FIG. 5 shows an E-DCH protocol architecture 500 . Protocol architecture 500 includes WTRU 210, Node-B 220, DRNC 230 and SRNC 240.

As shown in Figure 1, the MAC-e sublayer in the protocol architecture 500 from the legacy architecture is unchanged. Enhanced MAC functionality, such as segmentation and/or logical channel multiplexing, is fully supported by the enhanced MAC-es sublayer, referred to as "MAC-ees" in FIG. 5 . This allows WTRU 210 and SRNC 240 to use enhanced functionality for legacy Node-B 230.

The adaptation sublayer (ie, the MAC-e adaptation sublayer in Figure 5) is inserted between the MAC-ees and the MAC-e, and in the WTRU 210 and SRNC 240. The adaptation sublayer at the WTRU 210 side constructs a MAC-e PDU that can be fully processed by a legacy Node-B. This structure will be described in more detail below with reference to the layers or sublayers described in Figure 5 and the MAC PDU creation diagrams of Figures 6, 7 and 8. Legacy Node-B 220 receives data generated by MAC-ees within a MAC-e PDU and recognizes the data as a legacy MAC-es PDU. Thus, the Node-B 220 handles it as a legacy MAC-es PDU. The MAC-es PDUs are then forwarded to the SRNC 240 where they are again initially treated as legacy MAC-es PDUs. However, these MAC-es PDUs transmitted using the E-DCH frame protocol are then processed in the SRNC 240 by the adaptation sublayer, which converts them into MAC-es PDUs.

Therefore, when the non-enhanced Node-B 220 is added to the active set, the WTRU 210 does not have to transition to the legacy L2 protocol, (ie old MAC-e/es and fixed RLC PDU size). As long as the SRNC 240 is an R8 SRNC 240, (ie, contains the MAC-ees and MAC-e adaptation sublayers), the WTRU 210 may operate with the enhanced L2 protocol. Logical channel identification and MAC-ees functionality can be handled in many ways.

For example, in one embodiment, the meaning of the logical channel index (index) is maintained at the MAC-e sublayer in terms of quality of service (QoS) characteristics. This means the meaning of logical channel #n at the MAC-e sublayer and logical channel #n at the upper layer. In this way, the Node-B 220 can properly schedule the WTRU 210 according to the QoS of its different logical channels. Also, the Node-B 220 performs demultiplexing of MAC-ePDUs to MAC-es PDUs and forwards them to the SRNC via the Iub interface.

FIG. 6 shows an example diagram 600 of MAC PDU creation. The different functionalities, adaptation functions and MAC-e layers of each MAC-ees are fully illustrated in FIG. 6 . The functionality of the MAC-ees sublayer includes the following. On the WTRU 210 side, MAC-ees SDUs (or MAC-d PDUs) from a given logical channel or possibly from a given MAC-d flow are concatenated and/or segmented to fit the logical channel ( or MAC-d stream) valid bits. The resulting data except the MAC-ees header forms a MAC-ees PDU. For each record PDU, the MAC-ees header includes the following information:

- A Transmission Sequence Number (TSN) field used to facilitate logging at the SRNC.

- Segment description (SD) field to indicate whether the first and last part of the MAC-ees PDU is a segment or a complete PDU (in the same way as MAC-ehs).

- A field indicating the length of each MAC-ees SDU or its segments (eg, a Length Indicator (LI) indicating the number of bytes per segment).

As in Release 6/7 of the 3GPP specification, the logical channel identity may be omitted from the MAC-ees header and indicated through the Data Description Indicator (DDI) field of the MAC-e header. However, a logical channel identity may also be provided per MAC-ees SDU (or a segment thereof) or per MAC-ees.

The functionality of the adaptation function includes the following. On the WTRU 210 side, for each recorded PDU, the sublayer determines a combination of the DDI and N fields representing the actual MAC-es PDU size that is greater than or equal to the size of the MAC-es PDU including header. The adaptation sublayer selects a combination representing a size (minus the size of the TSN field) as close as possible to the actual size of the MAC-ees PDU.

For example, if a MAC-ees PDU has a size of 3100 bits and there is a DDI value mapped to a corresponding logical channel with a MAC-d PDU size of 320 bits, the adaptation function may select this DDI value with N=10. Once a suitable combination of DDI and N is established, an adaptation sublayer is appended to each MAC-ees PDU with the required number of padding bits to make the size of the extension match the size of the actual MAC-es PDU corresponding to the combination of DDI and N . In the described example, the adaptation sublayer requires an additional 106 bits, (i.e. 320×10-3100+6), so in addition to the 6-bit TSN, the size of the extended MAC-ees PDU is 320 bits The size of the MAC-es PDU composed of 10 MAC-es SDUs matches the size of the MAC-es PDU.

Likewise, the adaptation layer may choose to avoid adding any padding to the MAC-ees PDU. This addition can be avoided by defining the MAC-ee sublayer to produce a MAC-ees PDU with the same size as one of the predetermined combinations of bit groups. However, in case there is not enough data, the adaptation function adds padding to the MAC-ees PDU. The selected MAC-ees PDU size is chosen to be as close as possible to the maximum allowed number of bits or effective number of bits for a logical channel. Segmentation or the ability to request RLC to send variable RLC PDU sizes makes this possible.

The MAC-e sublayer of the WTRU 210 then constructs a MAC-e PDU consisting of the selected DDI and N value of each MAC-es PDU, the MAC-ees PDU extended with the required number of padding bits, and Optionally consists of DDI and/or Scheduling Information fields. It should be noted that the multiplexing of different logical channels into a MAC-e PDU (i.e. MAC-es PDU) is kept at the MAC-e layer.

Therefore, as shown in Figure 6, the MAC-e header part of the MAC-e PDU includes the DDI and N fields appended to the MAC-e payload. The MAC-e payload is then formed from the appropriate MAC-es PDU, which includes the MAC-ees PDU header and payload.

On the Node-B 220 side, the MAC-e sublayer processes MAC-e PDUs in a similar manner as in conventional wireless communication systems. That is, each MAC-e PDU is demultiplexed into MAC-es PDUs delivered using the E-DCH frame protocol, and the DDI and N fields of each MAC-es PDU are delivered over Iub. Since the MAC-e sublayer in legacy Node-B 220 is not aware of padding bits, the MAC-e sublayer handles each extended MAC-ees PDU as an R6/R7 MAC-es PDU.

On the network side, the operations described above are generally reversed. For example, different MAC-ees PDUs are demultiplexed and data are routed to reordering, disassembly and reassembly entities corresponding to respective logical channels (or MAC-d flows). Then at the output of the disassembly and reassembly entity, MAC-ees SDUs are sent to upper layers.

For example, SRNC 240 receives MAC-es PDUs on their respective MAC-d flows and the reassignment function layer in SRNC 240 sends them to the correct logical channel flow based on the DDI field. Alternatively, if the DDI field is not utilized and the MAC-ees header contains a logical identification (LCH-ID), the column allocation function may route PDUs based on the LCH-ID field.

Then, the adaptation sublayer at the SRNC 240 side extracts the MAC-ees PDU from the MAC-es PDU. This is done by removing any padding bits that were added to fit the MAC-ees PDU into one of the predetermined sizes. Removal of padding bits can be achieved by reading the MAC-ees header field (eg in the LI field) indicating the length of the individual MAC-ees SDU or segment. Alternatively, removal of a suitable number of padding bits is performed in the MAC-ees sublayer. Thus, MAC-ees PDUs can be routed to the MAC-ees sublayer. Once the MAC-ees PDU reaches the MAC-ees sublayer in the SRNC 240, the header of the MAC-ees PDU can be used to reorder and disassemble the MAC-ees PDU into MAC-ees SDUs and their segments.

It should be noted that the removal of stuffing bits can be done before or after reordering as part of the disassembly/combination process. It should also be noted that in order to facilitate efficient operation with the adaptation sublayer, the DDI values for each logical channel may be designed in such a way as to minimize the number of padding bits.

As an alternative to Figure 6, the logical channel index does not have to be identifiable between MAC-e and other sublayers. To facilitate the mapping of different DDI values to different payload sizes, different logical channels at the MAC-e sublayer may be defined. From the WTRU 210 side, the DDI mapped value and N are used to increase the set of possible sizes that the WTRU 210 can indicate to the Node-B 220. More specifically, DDI*N will give the total size of the MAC-es PDU or alternatively give the total size of the MAC-ees PDU (i.e. the size of all reordered PDUs multiplexed together).

Thus, 6 bits of the DDI field are used by the WTRU 210 to give a larger set of possible sizes. The R8 Node-B 220 perceives that the DDI field corresponds to a set of MAC-ees PDU sizes and is sure not to associate the DDI with logical channels, MAC-d flows and MAC-d PDU sizes. However, the R7 Node-B 220 interprets the DDI field differently, and the R7 Node-B 220 can be configured to also consider the logical channel and the MAC-d flow of the DDI field. However, even though MAC-es PDUs are forwarded with DDI and N fields over the Iub frame, SRNC 240 ignores the provided DDI and N fields and thus processes the received PDUs.

FIG. 7 shows an example diagram 700 of replacement MAC PDU creation. In FIG. 7, the functionality of the MAC-ees sublayer includes the following items. On the WTRU 210 side, MAC-ees SDUs (or MAC-d PDUs) from a given logical channel (or possibly from a given MAC-d flow) are concatenated and/or segmented to fit the logical channel ( or MAC-d stream) effective number of bits. The result of this operation is called a "Record PDU". Furthermore, the MAC-ees sublayer multiplexes together record PDUs from different logical channels (or MAC-d flows) and appends the result using a MAC-ees header to form a MAC-ees PDU. For each record PDU, the MAC-ees header includes the following information:

- A Transmission Sequence Number (TSN) field used to facilitate logging at the SRNC.

- Segment description (SD) field to indicate whether the first and last part of the recorded PDU is a segment or a complete PDU (in the same way as MAC-ehs).

- A field indicating the length of each MAC-ees SDU or its segments (eg, a Length Indicator (LI) indicating the number of bytes per segment).

- Logical channel identification for each MAC-ees SDU (or fragment thereof), or possibly just for each record PDU.

On the WTRU 210 side, for a generated MAC-es PDU, the adaptation sublayer determines the combination of the DDI and N fields representing the actual MAC-es PDU size greater than or Equal to the size of MAC-ees PDU. One difference is only that one MAC-ees PDU is provided in the MAC-e PDU, and thus only one DDI and N field will be incorporated in the MAC-e PDU. This adaptation function also ensures that the number of stuffing bits is minimized.

The MAC-e sublayer of the WTRU 210 then constructs a MAC-e PDU consisting of the selected DDI and N value of the MAC-ees PDU, the MAC-ees PDU extended with the required number of padding bits, and Optionally consists of DDI (DDI 2), Scheduling Information (SI) field, and/or padding bits. In this operation, the MAC-e header shall include the DDI and N fields, and optionally any additional DDI fields (eg DDI 2). The MAC-e payload part will then include the MAC-es PDU (which includes the MAC-ees PDU and any padding bits) and optionally any SI fields.

Furthermore, at the Node-B 220 side, the MAC-e sublayer can process MAC-ePDUs in a conventional manner. That is, since only one DDI and N fields are provided, the MAC-esPDU is extracted from the MAC-e PDU, and then the MAC-es PDU is transmitted by the Iub framework protocol. Furthermore, since the MAC-e does not see the padding bits in the MAC-es PDU, it does not see that the MAC-es PDU contains data from more than one logical channel.

On the SRNC 240 side, generally, the reverse operation is performed. For example, different reordering PDUs are demultiplexed and data is routed to reordering, disassembly and reassembly entities corresponding to respective logical channels (or MAC-d flows). The MAC-ees SDUs at the output of the disassembly and reassembly entities are then sent to upper layers.

The adaptation sublayer at the SRNC 240 side extracts the MAC-ees PDU from the MAC-es PDU. This is achieved by removing padding bits that are added to fit the MAC-ees PDU to one of the predetermined sizes. Removal of padding bits can be achieved by reading the MAC-ees header field indicating the length of the individual reordering PDUs, MAC-ees SDUs or segments within each reordering PDU. The MAC-ees PDU can then be routed to the MAC-ees sublayer, where the header of the MAC-ees PDU is used to demultiplex the MAC-ees PDU into the original reordered PDU. The reordered PDUs can then be routed to the correct reordering flow where reordering, disassembly and reassembly are performed.

Alternatively, removal of a suitable number of padding bits may be performed in the MAC-ees sublayer, which may be done when performing demultiplexing of MAC-es PDUs into reordered PDUs. Furthermore, it should be noted that in order to facilitate efficient operation of the adaptation sublayer, the DDI values for each logical channel can be designed in such a way as to minimize the number of padding bits.

FIG. 8 shows an example diagram 800 of another alternative MAC PDU creation. In this way, several DDI and N fields (such as DDI 1...DDI K and N1...NK) are used to describe the length of the MAC-ees PDU, whether it is the MAC-ees PDU described in Figure 6 above or in Figure 7 Described MAC-ees PDU. The DDI value consists of multiple base values (eg, 1, 10, 1000, 10000, etc.), and a combination of different base values and the N field may indicate the total length of the MAC-ees PDU or transmitted data. The sum of the DDI*N fields gives the total size of the MAC-ees PDU. For example, if the size of the PDU is 23040 bits, then the corresponding DDI and N fields will be the following: (DDI ₁ Index = 10000, N ₁ = 2), (DDI ₂ Index = 1000, N ₂ = 3) and ( DDI ₃ index 10, N ₃ =4). In this example, the MAC-e header includes the DDI1/N1...DDIK/NK fields and any additional DDI (eg DDI 2) fields, while the MACe-payload part in turn includes the MAC-ees PDU and any padding or SI fields.

On the network side, legacy Node-B 220 should in this case be configured with the same base as used above. To ensure backward compatibility and to avoid the situation where Node-B 220 receives DDI fields belonging to the same logical channel, the network can configure all DDI bases to belong to different logical channels (i.e. base DDI=10 for logical channel 1, And for logical channel 2, DDI = 1000, and so on). This can be done through Node-B Application Part (NBAP) signaling. Alternatively, the DDI bases may be part of the same logical channel and MAC-d flow.

When Node-B 220 receives a MAC-e PDU, it may assume that each DDI and N field belongs to a MAC-es PDU and therefore demultiplex or segment the MAC-e PDU into many segments. The segments are sent to SRNC 240, and the adaptation layer in SRNC 240 reassembles all segmented data into MAC-ees PDUs. The MAC-ees PDU is then sent to the MAC-ees sublayer and processed.

When the legacy Node-B 220 is added to the R8 active set, so that all Node-B R8 Node-B 220, WTRU 210 and R8 Node-B 220 change the MAC-e header format, start the adaptation sublayer function and start to apply MAC- The e header format is interpreted as the legacy MAC-e protocol.

The R8 MAC-e format can be static and is the same as the legacy MAC-e format. This can be achieved by using one of the options described in Figures 5, 6, 7 and 8 above, where the adaptation layer becomes an entity that is always present when the WTRU 210 is connected to the R8 SRNC 240.

However, when the R8MAC-e format differs from the format used when a legacy Node-B 220 is added to the active set or vice versa, some method may be needed to handle changes in the MAC-e protocol behavior. For example, when an Active Set update occurs and a Legacy Node-B 220 is added to the Active Set with only R8 Node-B 220 or vice versa, the WTRU 210 and Node-B should be aware of the change. In particular, all R8 Node-B 220 will need to be aware of the change.

The WTRU 210 may be informed of the change of the MAC-e header through an RRC Active Set Update message or the WTRU 210 may implicitly detect that an R7/R6 Node-B 220 is added. When the WTRU 210 receives this indication or detects a change, at a given activation moment or handover moment, the WTRU 210 may perform one or a combination of the following steps as part of the Active Set Update procedure:

● Refresh the HARQ process containing MAC-e PDU in R8MAC-e format.

• Perform a MAC-e/es reset (ie reset TSN, flush HARQ process and discard any reserved segments in the segment entity or buffer).

● Extract old MAC-e PDUs already in the HARQ process and recreate these old MAC-e PDUs using the new MAC-e format.

• Activate/deactivate the MAC-e adaptation layer and start using the new MAC-e format.

Additionally, the Node-B 220 already in the active set starts interpreting the new MAC-e header format when the WTRU 210 starts using the same format. A change in format may be signaled through the NBAP signaling process, and a change in protocol may occur at a given activation moment in the WTRU 210 and Node-B 220.

In another embodiment, the WTRU 210 may start operating continuously or in semi-variable RLC PDU mode when a non-enhanced cell is added to the enhanced active set. The semi-variable AMRLC format is a mode that allows the WTRU 210 to create RLC PDUs of different sizes but within a fixed set of sizes.

When a non-enhanced cell is added to the active set and while the WTRU 210 remains connected to the enhanced SRNC 240, the network configures the logical channel entity to start operating using the semi-variable RLCPDU mode. The network signals a set of RLC PDU sizes that can be used in Acknowledged Mode (AM) and its corresponding DDI field. RLC is allowed to create RLC PDUs with a set size selected from the configured set, which may be created just before the transmission moment or earlier.

The size selected by the RLC may be based on one or a combination of the following criteria:

- Enhanced Uplink Transport Format Combination (E-TFC) selection: MAC requests RLC to transmit N PDU with a size selected from the configured set. The RLC creates a PDU of the requested size if the PDU matches one of the configured sizes.

● Configure RLC with a maximum PLC PDU size. If enough data is available, set the RLC PDU to the maximum size. If not enough data is available to satisfy the maximum RLC PDU size, the next smallest RLC PDU size is selected from the configured set whereby the available data is transmitted with the smallest padding added.

The MAC informs the RLC of the size of the RLC PDU every TTI.

● The MAC first requests the RLC PDU size. RLC PDUs keep creating RLC PDUs with the requested size until a MAC change is requested.

●Configurable absolute maximum RLC PDU size and minimum RLC PDU size.

The semi-variable RLC PDU may allow the WTRU 210 to tune to the selected E-TFC while still being able to use the same non-enhanced MAC header, i.e. being able to indicate the size of the RLC PDU from the configured set and having the same size The number of RLC PDUs (ie DDI and N fields).

However, current non-enhanced MACs have the limitation of only including MAC SDUs of the same size from one logical channel in a MAC-es PDU. Thus, a MAC may execute one or more processes.

For example, the MAC may only allow RLC PDUs of the same size in one MAC-es PDU. This will restrict RLC from establishing or sending MAC RLC PDUs with different sizes. This can lead to a situation where the retransmitted RLC PDU has a different size than the first transmitted RLC PDU. The transmitter may then only transmit the retransmitted RLC PDU in a TTI and wait for the next TTI to transmit the next RLC PDU. Alternatively, if a retransmission situation occurs and there is still space available in the TB, the RLC PDU can wait and at a given TTI, the RLC PDU can create one or more RLC PDUs with the same A new RLC PDU of the size. Alternatively, a restriction may be applied to this rule whereby the RLC is not allowed to create an RLC PDU with a size larger than that requested by the MAC, even if the retransmitted RLC PDU is larger.

Likewise, the MAC can support RLC PDUs of different sizes within one TTI. This can be achieved by creating several MAC-es PDUs corresponding to the same logical channel but with different DDI fields.

When a non-enhanced Node-B 220 is added to the active set and the transmitter is configured with a semi-variable RLC PDU mode, the MAC protocol should be changed to enable the non-enhanced Node-B 220 to decode MAC-e PDUs. Therefore, MAC configuration can be performed.

In one embodiment, the MAC is configured to operate as a non-enhanced MAC. Thus, current Release 6 MAC-es and MAC-e header formats may be used, and the MAC may not have fragmentation capability.

Alternatively, the MAC can be configured to use the current non-enhanced MAC-e header format, however with the ability to perform fragmentation. This will allow the MAC to handle RLC retransmissions with a larger size than the selected transport block size. In order to support segmentation along with the old MAC-e header format, the WTRU 210 may only create segments of a size equal to one of the configured set of RLC PDU sizes. The MAC-es header signals TSN and SI values, whereas MAC-e will signal DDI and N values.

If the reserved segment is smaller than or does not fit exactly in one of the DDI sizes, padding may be used to make the PDU have the next smallest DDI value. Alternatively, the MAC may not be able to fragment the RLC PDU if there is no possible combination of fragments, which would result in all fragments having a size matching one of the DDI values.

If padding in the MAC is allowed in case segmentation is performed, the MAC-es header shall signal to the network that padding bits have been added. This can be achieved by adding an additional bit to the MAC-es header format, and if that bit is set, another field indicating where the segment ends and padding bits are added. Optionally, the receiver side (i.e. Node-B 220 and RNC) only checks if the padding bit indicator is present if it knows that the MAC-es contains a segment. The functionality to remove added bits and reassemble segments is introduced to the receiving MAC-es side.

A change in configuration from variable to semi-variable or vice versa, or from fixed to semi-variable or vice versa, and a change in MAC can be signaled using one of the previously described methods inform.

Also, some of the above methods may result in data loss. Therefore, data recovery may be useful when an event occurs that may result in data loss. For example, any of the following procedures may create the need for data recovery operations:

The WTRU 210 moves from enhanced to non-enhanced L2 protocol.

Change SRNS.

Execute the command MAC_i/is to reset or reconfigure the switch.

Perform a MAC_i/is reset on CELL_DCH or CELL_FACH.

Perform a MAC_i/is reset.

Release of E-DCH resources under CELL_FACH is indicated by explicit indication from Node_B 220, and WTRU 210 shall discard segments from MAC_i/is segmentation entity and shall not perform MAC_i/is reset.

Immediately after transitioning from CELL_FACH to CELL_DCH, a MAC_i/is reset is performed, or the WTRU 210 is required to refresh the HARQ process.

The WTRU 210 is required to discard segments in the Segmentation entity in the MAC_i/is entity.

When one of the above-mentioned situations occurs, the MAC communicates with the RLC, whereby the RLC can recover data that was not successfully or completely transmitted by the MAC. The MAC can notify the RLC of failed RLC PDUs.

For example, segments are stored in one of the MAC's segment buffers/entities. In the case described above, the segment in the segment entity will be discarded, so it is not possible for the RLC PDU to be successfully delivered/reassembled without this segment. Therefore, the MAC informs the corresponding RLC entity that, if the RLC entity corresponds to the AM RLC entity, the segments belonging to the RLC PDU are never transmitted. The RLC can trigger a retransmission as soon as it receives an indication to allow faster recovery of the data. Likewise, if the segment corresponds to a UM RLC entity, the MAC may inform the RLC of the failed PDU, and the UM RLC entity may discard the RLC SDU and any other PDUs associated with the corresponding SDU.

Additionally, the MAC may inform the RRC layer of the discarded segment if the segment corresponds to an SRB or if the segment belongs to a CCCH message. This allows the RRC to recover the message and retransmit the message without waiting for the RRC progress timer to expire.

Another method of recovering data involves HARQ processes involving transmitted but unacknowledged data. In this case, the MAC informs the RLC of all PDUs in its HARQ buffer.

To support the data recovery method described above, the MAC-i/is reset procedure can be modified whereby the MAC-i/is entity notifies the segment stored in its buffer and the RLC PDU it belongs to before discarding the stored segment The corresponding RLC. It should also be noted that the described data recovery methods are also applicable to MAC-e/es entities.

Although features and elements of the present invention have been described in particular combinations, each feature or element can be used alone without other features and elements, or in various combinations with or without other features and elements. use below. The methods or flowcharts provided herein can be implemented in a computer program, software or firmware executed by a general purpose computer or processor. Examples of computer-readable storage media include read-only memory (ROM), random-access memory (RAM), registers, buffer memory, semiconductor storage devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and CDs - Optical media such as ROM discs and Digital Versatile Discs (DVD).

Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, Controller, microcontroller, application specific integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any kind of integrated circuit (IC) and/or state machine.

模块、调频(FM)无线单元、液晶显示器(LCD)显示单元、有机发光二极管(OLED)显示单元、数字音乐播放器、媒体播放器、视频游戏机模块、因特网浏览器和/或任何无线局域网(WLAN)或超宽带(UWB)模块。A processor associated with 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 any host computer . A WTRU may be used in conjunction with modules implemented in hardware and/or software, such as cameras, camera modules, video phones, speaker phones, vibrating devices, speakers, microphones, television transceivers, hands-free headsets, keypads, Bluetooth

modules, frequency modulation (FM) wireless units, liquid crystal display (LCD) display units, organic light emitting diode (OLED) display units, digital music players, media players, video game console modules, Internet browsers, and/or any wireless local area network ( WLAN) or ultra-wideband (UWB) modules.

Claims (5)

1, a kind of wireless transmitter/receiver unit is characterized in that, this wireless transmitter/receiver unit comprises:

Receiver is configured to receiving radio data;

Transmitter is configured to transmit wireless data; And

With the coupling of described receiver and described transmitter and with the processor of described receiver and described transmitter communications, this processor is configured to refresh mixed automatic repeat request process, state variable CURRENT_TSN that all are mapped to the logic channel of enhancement type special channel and is set to zero and abandon the segmentation that is retained in the segmentation entity.

2, wireless transmitter/receiver unit according to claim 1 is characterized in that, described processor is the processor that is configured to the radio link controller Packet Data Unit of failure is informed radio link controller.

3, wireless transmitter/receiver unit according to claim 2 is characterized in that, described processor is to be configured to retransfer the processor of radio link controller Packet Data Unit of described failure.

4, wireless transmitter/receiver unit according to claim 3 is characterized in that, described processor is the processor that is configured to abandon described radio link controller Packet Data Unit after transmitting.

5, wireless transmitter/receiver unit according to claim 2 is characterized in that, described processor is to be configured to inform the processor of described radio link controller with being present in Packet Data Unit in the mixed automatic repeat request buffer.

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