RU2447591C2 - Method and device for data rearrangement in advanced system of high-speed packet access - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: invention discloses method and device to receive transmissions of High Speed Downlink Shared Channel (HS-DSCH). HS-DSCH Medium Access Control (MAC-ehs) entity receives MAC-ehs Protocol Data Units (PDUs) via HS-DSCH in one of statuses Cell_FACH, Cell_PCH or URAPCH. Rearranged PDUs comprising PDU MAC-ehs can be transferred to the next processing entity without rearrangement of these PDUs. Certain rearrangement queue may enter standby mode when triggering event occurs, and PDU MAC-ehs distributed in arrangement queue in wait status may be redirected to the next processing entity without being rearranged. MAC-ehs reset procedure can be extended for certain transmission so that MAC-ehs reset could be executed after MAC-ehs PDU receive in destination cell.

EFFECT: lower delay in cell updating procedure.

22 cl, 4 dwg

Description

Technical field

The present invention relates to wireless communications.

State of the art

Evolved High Speed Packet Access (HSPA) systems are currently being developed as part of Release 7 of the Third Generation Partnership Project (3GPP). One of the innovations of 3GPP Release 7 is the ability for User Equipment (UE) to receive user data and / or control data through the High-Speed Downlink Shared Channel (HS-DSCH), not only in the Cell_DCH state, but also in the states of Cell_FACH, URA_PCH, Cell_PCH.

With High Speed Downlink Packet Access (HSDPA), the UE receives a packet (i.e., Protocol Data Unit (PDU) MAC-hs or MAC-ehs PDU) from Node-B (Node-B ), which implements the Hybrid Automatic Repeat Request (HARQ) method. In the Cell_DCH state, the UE transmits an Acknowledgment (ACK) or Acknowledgment (NACK) to the Node-B after each HARQ transmission to indicate whether the UE has been successfully received.

Due to the delay required by the UE to decode and transmit this feedback, Node-B transmits (or retransmits) different packets after the transmission of a given packet, but before receiving the appropriate feedback for continuous transmission of packets. Since the number of transmissions necessary for successful decoding in the UE differs from packet to packet, there is a possibility that the HARQ object in the UE will not deliver the packets in the same order in which their respective original transmissions from Node-B were performed. To mitigate this problem, the Medium Access Control (MAC) layer in the UE reorders before the received packets are delivered to higher layers. The reordering is based on the Transmission Sequence Number (TSN) in the MAC-hs header.

In the Cell_DCH state, the UE determines whether the HS-DSCH transmission from Node-B is intended to a specific UE by marking the Cyclic Redundancy Check (CRC) of the High-Speed Shared Control Channel (HS-SCCH) through a unique ( specific to a specific UE) of the HS-DSCH Radio Network Temporary Identifier (H-RNTI). However, in the Cell_PCH, URA_PCH, or Cell_FACH state, the UE may not have an H-RNTI. For example, when a cell is re-selected, the UE may not know its H-RNTI, which should be applied to the target cell when the UE receives a cell update confirmation message. To solve this problem, the network can use a common H-RNTI, which all WTRUs can decode and use in-band signaling to identify a given UE. In addition, a common H-RNTI may be required to enable the broadcasting of messages (for example, Broadcast Control Channel (BCCH) messages to all WTRUs located in a given cell.

A number of problems arise when trying to implement a reordering function with UEs that receive data through the HS-DSCH using a common H-RNTI. The first problem is that the UE potentially delays data delivery to higher levels because the reordering function expects packets that are not even intended for this UE to arrive.

Another problem occurs when the UE performs a MAC-hs or MAC-ehs reset (for example, when reselecting a cell). After performing cell reselection, the UE initializes some reordering related variables (for example, next_expected_TSN and RcvWindow_UpperEdge) during MAC-ehs reset. However, when using a common H-RNTI, the target cell cannot reinitialize the TSN value without affecting all other WTRUs that already use this common H-RNTI in the target cell. Therefore, the UE that joins the target cell cannot rely on reinitializing the TSN to reorder the sequence. As a result, a number of undesirable effects may occur. For example, if the Sequence Number (SN) of the first received packet after resetting the MAC-ehs is in the original receive window and lower than the initial next_expected_TSN value, then this packet will be excluded.

In the prior art, because of this, excessive delays could occur during the cell update procedure using HS-DSCH in the Cell_FACH state. High-speed Node-B transmissions that run without UE identity information (i.e., using a common H-RNTI) create difficulties to support reordering. Node-B cannot use TSNs that are specific to a specific UE, since the identity of the target receiver is unknown in the MAC-ehs of the given UE. Thus, a UE that begins to listen to such transmissions will not have information about the next TSN to be expected for delivery in sequence.

SUMMARY OF THE INVENTION

A method and apparatus for receiving HS-DSCH transmissions is disclosed. The MAC-ehs object in the Wireless Transmit / Receive Unit (WTRU) receives MAC-ehs PDUs via the HS-DSCH, operating in one of the Cell_FACH, Cell_PCH, and URA_PCH states. The reordering PDUs included in the MAC-ehs PDUs can be transmitted to the next processing entity without reordering these PDUs.

One HARQ process can be used to receive MAC-ehs PDUs, and all retransmissions of MAC-ehs PDUs can be completed before the start of transmission of the next MAC-ehs PDU. Alternatively, no HARQ retransmissions may be performed for MAC-ehs PDUs, and all MAC-ehs PDUs may be transmitted only once. Alternatively, the HARQ entity may hold the received MAC-ehs PDU and deliver the received MAC-ehs PDUs only after the final HARQ transmissions of the received MAC-ehs PDUs. Alternatively, the HARQ entity may immediately deliver the successfully decoded MAC-ehs PDUs to the next processing entity and transmit an indication of when the last HARQ transmission for the successfully decoded MAC-ehs PDUs occurs. The Duplicate Avoidance and Reordering (DAR) function can be applied at the Radio Link Control (RLC) level to all logical channels and the data of the Acknowledged Mode (AM).

A specific reordering queue can enter standby mode when a triggering event occurs, and MAC-ehs PDUs distributed in the standby ordering queue can be redirected to the next processing object without performing reordering of the PDUs. The MAC-ehs reset procedure can be extended for a specific transmission so that the MAC-ehs reset is performed after receiving the MAC-ehs PDUs in the target cell. When performing a MAC-ehs reset, the variables next_expected_TSN and RcvWindow_UpperEdge are set to "Wait".

A TSN that should be used in some cell to transmit MAC-ehs PDUs using a common HS-DSCH H-RNTI can be provided in the WTRU, and a MAC-ehs can be configured by this TSN. The Radio Resource Control (RRC) message transmitted via the HS-DSCH using the H-RNTI of the HS-DSCH can be small enough to fit in one MAC-ehs PDU.

In the reordering pending state, reordering variables can be transmitted based on the TSN of the first MAC-ehs PDU. Received MAC-ehs PDUs may be stored in a reordering buffer and delivered to a higher-level entity based on HARQ information. When the TSNs are bounded, the module x can be used for all arithmetic operations of the reordering entity, where x is the smallest bounded TSN. The TSN can be assigned to each WTRU independently.

Brief List of Drawings

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

Figure 1 is a block diagram of an example WTRU;

Figure 2 is a structural diagram of a MAC-ehs object;

Figure 3 is a block diagram of a MAC-ehs WTRU without reordering for data received from certain prioritized queues; and

4 is a block diagram of a MAC-ehs WTRU without reordering and without reassembly for data received from certain prioritized queues.

Detailed description

As used herein, the term "Wireless Transmit / Receive Unit (WTRU) includes, but is not limited to, User Equipment (UE), a mobile station, a fixed or mobile subscriber station, a pager, a cell phone, 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 “Node-B” includes, but is not limited to, a base station, a local controller, an Access Point (AP), or any other type of interface device capable of operating in a wireless environment. The following is a description of embodiments where the Cell_FACH state is considered as an example. It should be noted that the embodiments are also applicable to the Cell_PCH and URA_PCH states.

1 is a block diagram of an example WTRU 100. The WTRU 100 includes a physical layer 110, a Medium Access Control (MAC) layer 120, a Radio Link Control (RLC) layer 130, a Radio Resource Control layer 140 (Radio Resource Control, RRC), highest (s) level (s) 150, etc. MAC layer 120 includes a MAC-ehs entity. It should be noted that the MAC-ehs object may also be referred to by the term "MAC-hs object" or another name. Only the term "MAC-ehs" is used in this document.

2 is a block diagram of a MAC-ehs object 200. The MAC-ehs object 200 includes a HARQ object 202, a disassembly object 204, a reordering queue distribution object 206, a plurality of ordering queues 208, demultiplexing objects 210, and reassembly objects 212. The MAC-ehs PDU received through the HARQ entity 202 is parsed into reordering PDUs by the disassembly entity 204. The reordering PDUs are allocated to the reordering queue 208 by the distribution object 206 to the reordering queue based on the received logical channel identifier. Reordering PDUs are reorganized according to the TSN. Upon receipt, reordering PDUs with sequential TSNs are delivered to the higher layer. The timer mechanism determines the delivery of inconsistent data blocks to higher levels. For each prioritized queue, there is one reordering entity 208. The demultiplexing entity 200 directs the reordered PDUs to the reassembly entity 212 based on the logical channel identifier. The reassembly unit 202 reassembles the segmented MAC-ehs Service Data Unit (SDUs) into the source MAC-ehs SDUs and routes these MAC-ehs SDUs to higher layers.

According to a first embodiment, the MAC-ehs PDUs are delivered one after another from the HARQ entity, and the MAC-ehs layer can be relieved of its reordering obligation by confirming that packets are always received in the correct order in the WTRU. If the MAC-ehs layer does not need to perform reordering, then the MAC-ehs reset function can be simplified when the WTRU is not assigned to an H-RNTI that is specific to a particular WTRU. Four options are described below for implementing the first embodiment. According to a first option, a single HARQ process is used for certain transmissions for the first embodiment. These transmissions may be from a specific prioritized queue, a specific logical channel, or for them, the identity of the target WTRU may not be known in the MAC-ehs object (that is, when the MAC-ehs PDUs are transmitted using a common H-RNTI). In the Cell_FACH state, the MAC-ehs in the Node-B repeatedly transmits the MAC-ehs PDUs a predetermined number of times without receiving feedback from the WTRU. This is called a HARQ repeating scheme. Node-B completes all retransmissions of MAC-ehs PDUs before starting the next MAC-ehs PDU transmission for certain transmissions for which delivery in a given order is important.

According to the first option, the large delay caused by the minimum interval between successive HARQ transmissions within the same HARQ process according to the current 3GPP specifications can create a problem. According to current 3GPP specifications, the WTRU can exclude any MAC-ehs PDUs destined for the HARQ process if it is received in a period of five (5) subframes from the last data received destined for the same HARQ process. This restriction is justified when HS-DSCH is used in the Cell_DCH state, since the HARQ feedback from the WTRU sets a certain minimum round-trip time. However, when an HS-DSCH in the Cell_FACH state is used, the WTRU does not transmit ACK / NACK feedback to the Node-B and, accordingly, a shorter interval is possible.

The delay problem can be solved by configuring the MAC-ehs object otherwise when the WTRU is in the Cell_FACH state. For example, in the Cell_FACH state, the MAC-ehs object can be configured to exclude packets received in a period of five subframes from the last packet received for the same HARQ process, and it can implement this scheme only in the Cell-DCH state.

Alternatively, in the Cell_FACH state, the MAC-ehs may be configured to exclude a packet destined for the HARQ process if it is received in a period n of subframes since the last packet received for the same HARQ process. The number n can be fixed, and it can be predefined in the specifications. Obviously, if n = 0, then the minimum is not specified for the case when the WTRU is in the Cell_FACH state. The number n may depend on the specific WTRU. The minimum number of n subframes may be signaled by higher layers as the ability of a particular WTRU. For example, the WTRU may pre-signal its capabilities to the Radio Network Controller (RNC) (as part of a higher level protocol information element). The RNC may signal a minimum number of subframes n applicable to certain data. Alternatively, the RNC may signal in Node-B the minimum number n that should be used for each logical channel, for each prioritized queue, or for each H-RNTI.

The above two alternatives can be combined in such a way that a fixed and predefined minimum number of subframes m , which is applicable to any WTRU using HS_DSCH in the Cell_FACH state, can be provided by higher levels as the capabilities of a given WTRU along with the smallest value n (< m) depending on the specific WTRU. This is usually for transmission over certain logical channels that are not allocated to a specific WTRU, such as a Common Control Channel (CCCH) or BCCH. In this case, Node-B can use the minimum value m for logical channels that are not allocated to a specific WTRU, and use a lower minimum value depending on a given WTRU for data destined for a specific WTRU.

When one HARQ process is used only with a common H-RNTI, the HS-SCCH format can be changed so that the usual 3-bit HARQ Process Information field can be deleted. As a result, fewer information bits will need to be encoded in the HS-SCCH, and there will be lower transmission power requirements. The WTRUs may determine which circuit has been applied based on whether this transmission has been labeled by a common H-RNTI.

Node-B can be explicitly notified of the need to use one HARQ process using one of the usual Node-B Application Part (NBAP) messages used to configure and reconfigure HS-DSCH resources. A new Information Element (IE) may be added, indicating the number of HARQ processes to be used by the MAC-ehs.

Alternatively, the conventional information element in NBAP messages used to configure HS-DSCH resources may be extended for this purpose. For example, the HARQ memory allocation for an information item may be expanded to include a new field indicating the number of HARQ processes to be used, or a bit string can be set for all HARQ processes to indicate which HARQ process can be used. for a specific logical channel or a specific common H-RNTI.

Alternatively, Node-B may be notified explicitly by another information element. For example, when timer T1 is set to zero (0), this may explicitly mean that only one HARQ process is used. Alternatively, a new information element that indicates a prohibition on the use of reorganization or segmentation may explicitly signal the use of a single HARQ process.

Alternatively, the MAC-ehs object in Node-B may be instructed not to include in the TSN or to include in the TSN, but not to increment the TSN, and this may explicitly indicate the use of a single HARQ process and vice versa.

Alternatively, Node-B may be notified via the Iub frame protocol. A new field may be added to the Iub frame protocol that indicates whether a particular message should be transmitted using one HARQ process or multiple HARQ processes.

Any combination of the above alternatives may be used. According to a second option, for the first embodiment, for certain transmissions, HARQ retransmissions are not performed. Node-B does not transmit any HARQ retransmissions for PDUs from a specific prioritized queue, from a specific logical channel, or for which the identity of the target WTRU is unknown in the MAC-ehs (that is, when a common H-RNTI is used), and MAC- ehs for this data is transmitted through the air channel only once. MAC-ehs PDUs will be received in the original order, and the WTRU will not need to perform any reordering for a particular transmission. The MAC-ehs object in the WTRU redirects successfully decoded PDUs directly to the higher-level object, bypassing the reordering function.

Through L3 configuration information (e.g., BCCH / BCH), the WTRU can be explicitly notified that one HARQ transmission is performed for each PDU, for a particular prioritized queue or logical channel, or for specific transmissions. Alternatively, a new L1 signaling (e.g., a new field in the HS-SCCH) may be used to indicate no HARQ retransmissions. Alternatively, the fields in the HS-SCCH may be modified to indicate that there will be no HARQ retransmissions for a particular packet. Alternatively, a new field may be added to the MAC-ehs header to indicate a single HARQ transmission of a given packet.

According to a third option for the first embodiment, a repeated HARQ transmission scheme is used and the delivery of the decoded packet is delayed in the HARQ entity of the WTRU. With this option, Node-B can use more than one HARQ process (for example, to provide better temporal diversity). However, there is a certain limitation that the latest HARQ transmissions of consecutive MAC-ehs PDUs are transmitted in order in Node-B. In other words, the last HARQ transmission for MAC-ehs No. n-1 PDUs is always transmitted until the last transmission for MAC-ehs No. n PDUs. A similar limitation can be satisfied, for example (but not limited to) when HARQ retransmissions occur at a fixed interval (synchronous HARQ).

The HARQ object in the WTRU does not deliver a successfully decoded packet until all transmissions (i.e., a predetermined number of repetitions) for that packet have been completed. In order to determine whether all transmissions for a packet have been completed, the HARQ entity in the WTRU may wait until the HS-SCCH transmission is received with the New Data Indicator (NDI) flag indicating the new PDU. Alternatively, the WTRU may calculate the number of transmissions (for example, based on HS-SCCH transmissions) for MAC-ehs PDUs and deliver a successfully decoded MAC-ehs PDU only after a predetermined maximum number of transmissions with respect to that MAC-ehs PDU has been reached. This maximum number is signaled in the WTRU through higher layers.

According to a fourth option for the first embodiment, the HARQ object in the WTRU immediately delivers the successfully decoded packets to the upstream objects (i.e., the reordering object), to the MAC-ehs object, and the reordering object stores the delivered MAC-ehs PDU until it receives from The HARQ object indicates that the last HARQ transmission has been completed. After receiving the indication, the reordering entity transmits the MAC-ehs PDUs to the upstream entities / sublevels. The HARQ entity can make this determination based on one of the methods described above for the third option.

According to this option, the reordering entity does not need to use the MAC-ehs PDU TSN field (if present) to determine the time when it is necessary to transfer the PDUs to higher objects, but it can still use a shutter timer (such as T1) to deliver MAC-ehs PDU for which no indication was received from the HARQ object. Certain reordering queues can rely on the indication provided by the HARQ to determine when the PDU should be delivered to the parent objects, while other reordering queues can use the usual reordering mechanism.

According to a second embodiment, the MAC functions (i.e., the MAC-ehs functions) can be simplified for certain prioritized queues to avoid problems associated with reordering in the Cell_FACH state. Simplification of MAC functions can be implemented in connection with the first embodiment, and this minimizes (or eliminates) the delivery of MAC-ehs PDUs to higher-order objects out of order.

According to a second option for the second embodiment, reordering is excluded for data transmitted from certain prioritized queues. The MAC-ehs functions in the WTRU are modified so that data received from certain prioritized queues is directly transferred to the reassembly object without reordering. The reassembly entity reassembles the MAC-ehs SDUs from the MAC-ehs SDU segments.

FIG. 3 is an illustration of a MAC-ehs entity 300 according to this option. It should be noted that the exact order of the demultiplexing and reassembling functions may differ from that shown in FIG. 3. MAC-ehs PDUs received through the HARQ entity 302 are redirected to the disassemble entity 304. The disassembly entity 304 parses the MAC-ehs PDUs into reordering PDUs. Reordering PDUs can be placed in reordering queue 308 by means of distribution object 306 in reordering queue. According to this option, for certain prioritized queues, reordering is eliminated and reordering PDUs are directly routed to demultiplexing entity 310a. The demultiplexing entity 310a directs the reordering PDUs to the corresponding reassembly entity 312a based on the logical channel identifier. The reassembly unit 312a reassembles the segmented MAC-ehs SDUs to obtain integer MAC-ehs SDUs.

Various criteria can be used to determine whether to distribute data to a reordering object for reordering or to a reassembly object without reordering. If the identity of the WTRU to which the data from the MAC-ehs PDUs are destined is unknown to the MAC-ehs entity (that is, when the MAC-ehs PDUs are transmitted using a common H-RNTI), the MAC-ehs PDUs can be transmitted to the reassembly entity without reordering. The MAC-ehs will know the WTRU identity if the MAC-ehs PDU was received using a dedicated H-RNTI or if the WTRU identity is contained in the MAC-ehs PDU itself. Node-B can always use a common H-RNTI for any data from a prioritized queue that does not support reordering.

Whether data should be distributed to the reordering object for reordering or to the reassembly object without reordering may depend on the identity of the logical channel of the received data, regardless of whether the data was received using a common H-RNTI or dedicated H-RNTI. This allows you to multiplex data from prioritized queues that support reordering, with data from prioritized queues that do not support reordering. It also eliminates the need for reordering, even when dedicated H-RNTI is applied.

Logical channels that support reordering can be predefined based on the type of channel (e.g. CCCH, BCCH, Paging Control Channel (PCCH), DCCH, etc.) and / or logical channel identity.

Alternatively, the WTRU may be notified by higher layers (eg, Radio Resource Control (RRC) signaling of logical channels that support reordering. For example, the Radio Carrier Mapping Information information element contains information on the downlink RLC logical channels. An information element may be added to indicate whether reordering is performed in MAC-ehs for each logical channel. Alternatively, in the radio carrier mapping information information element, th, the reordering queue ID information element, which can be added to support L2 enhancements, can take on a special value indicating a queue that does not support ordering. Alternatively, an information element indicating the queue parameters (for example, Added or reconfigured MAC stream -d ", the common MAC stream sent to the information system, etc.) can be modified or expanded to indicate whether the queue supports reordering. A similar indication can be given by adding a new information element indicating whether reordering is supported, or, alternatively, some ordinary information elements can take on a new possible value that will indicate that reordering is not supported. For example, the information element "T1" can take one of the possible values (for example, "0"), indicating that reordering is not supported in this queue. The MAC-hs window size information element can also take one of the possible values (for example, "0"), indicating that reordering in this queue is not supported.

Alternatively, another indication may be used in the MAC-ehs PDU header indicating which logical channels support reordering and which logical channels do not support reordering. For example, a special field may be added indicating whether ordering should be applied or not. Another example is the use of a special value for the TSN field (for example, "111111").

Any combination of the above alternatives can be used to indicate which logical channels support reordering and which logical channels do not support reordering. For example, logical channel identity in combination with a WTRU ID can be used to indicate whether to send MAC-ehs PDUs to the reordering queue for reordering or to the reassembly entity without performing reordering. Signaling Radio Bearer (SRB) # 1 messages will be transmitted over DCCH using a common H-RNTI, but other messages can be transmitted over DCCH using dedicated H-RNTI. DCCH messages with a common H-RNTI can be transmitted to the reassembly entity without performing reordering, while DCCH messages with a dedicated H-RNTI can be transmitted in reordering queues to perform reordering.

Although reordering is not performed, the TSN field can still be used by the MAC-ehs object in Node-B when the MAC-ehs PDU is generated, and the TSN field can be used to facilitate the reassembly operation performed in the WTRU. For example, a reassembly entity may delete any segment present in the reassembly buffer if inconsistent TSNs are received.

Alternatively, the TSN may be removed from the MAC-ehs header. In this case, the WTRU can still use the segmentation indication to reassemble the packets, even though there is a possibility of unsuccessful assembly due to the lack of PDUs. If the TSN field is not used, the WTRU will know whether to expect the TSN field in the MAC-ehs header for the logical channel based on the mapping information between this logical channel and the queue that does not support reordering.

The following describes the reassembly process of segmented MAC-ehs SDUs when the TSN field is stored in the MAC-ehs header but reordering is not performed. After receiving the MAC-ehs PDU, the WTRU determines whether the MAC-ehs PDU payload is an integer MAC-hs SDU or segment, and if it is a segment, then the WTRU determines whether this segment is the first segment, intermediate segment, or last segment. If the payload is an entire MAC-ehs SDU, then this MAC-ehs SDU is redirected to the highest level or to the object following the reassembly object.

If the payload is the first segment of the MAC-ehs SDU and if the WTRU has retained intermediate segments with sequential sequence numbers that are larger than the received PDU, then the first segment is combined with subsequent segments. If the WTRU has saved the last segment, followed by a sequence number that is higher than the received PDU, then they are combined and the full MAC-ehs SDU is delivered to the highest level. Otherwise, the payload is stored in the reassembly object.

If the payload is the last segment of the MAC-ehs SDU, and if the reassembly object has retained a sequential segment with a TSN that is lower than the received packet, then they are combined. If an entire MAC-ehs SDU is formed, then it is delivered to the highest level. Otherwise, the payload is stored in the reassembly buffer.

If the payload is an intermediate segment of the MAC-ehs SDU, and if the reassembly object has retained sequential segments with TSNs that are higher or lower than the received packet, then they are combined. If an entire SDU is created, then it is redirected to the highest level. Otherwise, it is stored in the reassembly buffer.

A timer-based exclusion mechanism can be used to exclude segments from the reassembly object. Optionally, a packet can be excluded if the buffer is full or if the maximum number of segments that can be stored is reached. Segments with the oldest TSNs may be excluded. In addition, the usual reordering options — RcvWindow_UpperEdge, next_expected_TSN, T1_TSN, and TSN_Flush — do not need to be stored and processed.

A timer-based exclusion mechanism may be implemented according to one of the following options, or according to a combination of the following options. Each segment is stored in the reassembly buffer for a predetermined period of time (that is, each time a segment corresponding to the MAC-ehs SDU is received, a timer for that segment starts). When the timer expires, all segments corresponding to this MAC-ehs SDU are excluded. The timer only starts when a segment corresponding to a reordering PDU with a TSN number that is greater than the next expected TSN is received. The variable Tseg_TSN is set equal to the value of this TSN. When the timer expires, the following actions can be performed.

a. If the Segment Indicator (SI) Tseg_TSN is "01",

i. Exclude all payload blocks with TSN ≤ Tseg_TSN; and

ii. Set next_expected_TSN to TSN of the next unaccepted segment.

b. If the SI of the segment T1_TSN is "10",

i. Exclude all payload blocks with TSN <Tseg_TSN; and

ii. Set next_expected_TSN to TSN of the next unaccepted segment.

c. If the segment SI Tseg_TSN is "11",

i. Exclude the first payload block corresponding to this TSN and all payload blocks with TSN <T1_TSN. This step ensures that the last payload block corresponding to this TSN is not excluded since this payload block corresponds to the first payload block.

According to a second option for the second embodiment, segmentation, reordering, and reassembly are excluded for data transmitted from certain prioritized queues. Any data transferred from certain prioritized queues is not segmented, reassembled or reordered. 4 is an illustration of a MAC-ehs entity in a WTRU according to this option. As in the first option for the second embodiment, various criteria can be used to determine whether data should be allocated to the reordering queue or not.

According to this option, it is not necessary to add TSN and SI fields to MAC-ehs PDUs for the respective queues. Alternatively, the TSN and SI fields can be added, but the SI field can always be set to a specific value (for example, “00”), and the TSN can be set to a constant value, or optionally can be incremented, but it will not be used for reordering or reassembly purposes. Moreover, when queues are set up in the WTRU, there is no need to maintain and process the following variables: TSN_number, RcvWindow_UpperEdge, next_expected_TSN, T1_TSN and TSN_Flush.

When a MAC-ehs PDU is received, the WTRU determines that TSN and SI fields are not available for a particular logical channel based on mapping this logical channel to a given queue that does not support reordering and segmentation / reassembly, or based on the use of a common H- RNTI when transmitting on this channel. In this case, the MAC-ehs SDUs are immediately disassembled and demultiplexed according to the logical channel and transferred to the higher level.

In a second embodiment, the MAC-ehs reset procedure may be modified. According to the usual MAC-ehs reset procedure, if a MAC-ehs reset is requested by a higher level, then at the time of activation indicated by the higher levels, the WTRU should:

a) clear the program buffer for all configured HARQ processes;

b) stop all active reordering delay timers (T1) and set all timers T1 to their original value;

c) start with a TSN with a value of "0" for the next transmission for each configured HARQ process;

d) initialize the variables RcvWindow_UpperEdge and next_expected_TSN to their original values;

e) parse all the MAC-ehs PDUs in the reordering buffer and deliver all the MAC-d PDUs to the MAC-d object;

f) clear reordering buffer; and

g) if the reset of the MAC-ehs was initiated due to the reception of the MAC-hs Reset Indicator information element from higher levels, instruct all RLC AM objects associated with the HS-DSCH to generate a status report.

If the first option of the second embodiment is implemented, then this procedure is modified so that step (d) is performed only for queues that support reordering. If the first option is implemented with a reassembly function, then the reset procedure can ensure that the reassembly buffer is cleared after processing the last MAC-ehs PDU.

If the second option of the second embodiment is implemented, then this procedure needs to be modified so that steps (b) - (f) are performed only for queues that support reordering. In addition, segments in the reassembly buffer that cannot be reassembled should be excluded.

It should be noted that some of these steps need to be modified to support other future features of the Enhanced HSPA, such as L2 enhancements.

The simplifications described above for the functions of the MAC-ehs object can lead to the delivery of MAC SDUs to the RLC object out of order. This can be difficult, especially when the MAC-ehs SDUs carry RRC signaling. These difficulties can be avoided if the RLC object performs reordering. Typically, the DAR function is defined for the Unacknowledged Mode (UM) RLC. However, the DAR function is currently only available on the Multimedia Broadcast / Multicast Service (MBMS) Traffic Channel (MTCH).

According to a third embodiment, the DAR function is applied to other logical channels other than the MTCH, such as DCCH or DTCH. Such an extension of the RLC UM DAR function will be especially useful for the case of Signaling Radio Bearer (SRB) No. 1, which is defined in the RLC UM.

There are several possible ways to enable the use of the DAR function in other logical channels. The WTRU may be notified by higher layers of the parameters to be used for the DAR function, or these parameters may be predefined. For example, the RRC signaling may be modified so that the "Duplication and Reordering Exclusion Information" may optionally be present not only in the "RLC Mode MBMS Information" information element, but also in the "RLC Information" information element if the UM RLC mode is selected. The default parameter values for the radio configurations can also be updated with a new parameter for SRB1 and other RBs.

Similarly, a DAK or similar function can be implemented in the AM RLC, where it can be configured so that the AM RLC in order delivers the SDU to higher layers. Normal AM RLC does not perform any reordering on the receiving side.

The reordering function can be modified to prevent excessive delays during the cell update procedure when the HS-DSCH is used in the Cell_FACH state. This scheme can be used if it is desired to preserve the reordering function for a particular prioritized queue. This scheme does not imply any modification to the behavior of the HARQ object, but it will be effective regardless of the presence or absence of such modifications.

It should be noted that the embodiments described below are applicable not only to the cell update procedure (cell reselection), but also to the initial configuration and configuration of the MAC-ehs object upon entering the CELL_FACH state or initializing HS-DSCH reception in the CELL_FACH, CELL_PCH or URA_PCH state .

According to a fourth embodiment, the reordering queue may enter the reordering stop state when a specific triggering event occurs. In the normal state, normal reordering procedures are performed. When the reordering queue is in the reordering stop state, the received data included in the reordering queue in the stop state is directly transferred to the next processing object (for example, a reassembly object, a disassembly object, a demultiplexing object - depending on the MAC-ehs architecture, or a layer above the MAC-ehs object) without considering the TSN associated with this data.

Triggering events for entering the reordering stop state can be, for example, executing the MAC-ehs reset procedure (possibly after a command from the RRC object) or an explicit command from the RRC object indicating entering the reordering stop state. An RRC entity may issue this command, for example, when initializing a cell update procedure due to cell reselection. If an explicit command is issued, then the RRC entity may optionally clear the reordering buffer.

The reordering queue (s) that undergoes reordering stops can be signaled by higher layers along with the RRC command (or as part of it), if applicable. Higher level alarms can be performed using one of the above options. Alternatively, pre-signaling can be performed when setting a logical channel mapped to a queue, or the signaling can be pre-set depending on the type of logical channel mapped to this queue (for example, it can be predefined so that any queue mapped to a CCCH logical channel , was stopped when resetting MAC-ehs).

The reordering queue returns to normal when a specific transition event occurs. Transition events can be, for example, packet reception for a logical channel mapped to a given queue after entering a stop state. After receiving the packet, the WTRU performs the following actions:

(a) Set next_expected_TSN = TSN - x, where, for example, -1 ≤x <6 (value x> 0 to ensure that if the first packet is received out of order, the next packets with lower TSNs will not be excluded), and The TSN is the transmission sequence number of the received packet, wherein the value x can be predefined or pre-signaled by higher layers;

(b) If x is not zero or -1, then set T1_TSN = TSN of this packet and start timer T1;

(c) Set RcvWindow_UpperEdge = TSN + y, where y can be predefined or pre-signaled by higher levels; and

(d) Return to normal reordering state.

It should be noted that for the above event, the definition of a new state is not formally required, since the WTRU does not receive any data for a given sequence while in the stopped reordering state. That is, the MAC-ehs reset procedure for the queues in question is completed only after receiving data for these queues.

The transition event may constitute an explicit command from the RRC entity to return to the normal reordering state. In this case, the RRC entity notifies the MAC-ehs entity of the time when the MAC-ehs entity should return to the normal reordering state. Such a command may be triggered by an RRC entity that receives a cell update confirmation message from its peer entity, or any other event related to RRC procedures. Before receiving the command to return to the normal reordering state (that is, in the reordering stop state), the WTRU must support the next_expected_TSN and RcvWindow_UpperEdge variables for each queue in question as follows:

(a) When a packet is first received for a queue after a MAC-ehs reset:

(i) Set next_expected_TSN to TSN + 1 of this packet.

(ii) Set RcvWindow_UpperEdge to TSN + y, where y can be predefined or pre-signaled by higher layers.

(iii) Optionally, the variable "TSN_init" may be set equal to the TSN of the received packet.

(b) For subsequent packets for the same queue with transmission sequence number = TSN:

(i) Set next_expected_TSN to TSN + 1 if TSN≥next_expected_TSN.

(ii) Set RcvWindow_UpperEdge to TSN + y if TSN + y> RcvWindow_UpperEdge, where y can be predefined or pre-signaled by higher levels.

The transition event for returning to the normal state may be the expiration of the timer (T_init), which was started upon transition to the standby state. This timer can be the same as a regular T1 timer. If it is not the same, then the T_init timer value can either be specified by higher levels (for example, using the same RRC signaling messages that contain the T1 timer value, without adding an information element for the value of this new T_init timer), or predefined. This value may be less than or equal to timer T1 to avoid excessive delays.

When a triggering event occurs to enter the reordering stop state (for example, when MAC-ehs is reset), the reordering queue enters and remains in the reordering stop state for the duration of the T_init timer (plus, possibly, the period between the reset of MAC-ehs and the reception of the first valid MAC-ehs PDU, if selected to start the T_init timer when receiving this PDU). Optionally, the values "next_expected_TSN" and "RcvWindow_UpperEdge" can be set to a special value ("wait") when resetting MAC_ehs instead of setting them to the initial values, as in the usual procedure, which is described in more detail below.

Alternatively, the transition event may be the successful reception of N PDUs with sequential TSNs or N of M successful PDUs with M sequential TSNs.

It should be noted that if a MAC-ehs reset is performed after the higher layers receive cell update confirmation, the variables and contents of these queues should not be reset when the MAC-ehs reset is indicated. In this case, if the queue is in the reordering stop state, the MAC-ehs reset will indicate that the confirmation of the cell update has been accepted by higher levels, and this queue may return to normal.

According to a fifth embodiment, the MAC-ehs reset procedure is modified so that for certain reordering queues, the reset procedure is extended to receive data in the target cell. The variables next_expected_TSN and RcvWindow_UpperEdge are not reset to the initial values for the considered reordering queues immediately, but only after receiving data for these queues in the target cell.

If the higher layers request a reset of the MAC-ehs object, then at the time of activation indicated by the higher layers, the WTRU should:

(1) clear the program buffer for all configured HARQ processes;

(2) stop all active reordering delay timers (T1) and set all timers T1 to their original value;

(3) parse all MAC-ehs PDUs in the reordering buffer and deliver all MAC-d PDUs to the MAC-d object (this step may be modified according to changes in the MAC-ehs procedure in future Releases);

(4) clear reordering buffer; and

(5) if the MAC-hs reset was initialized due to the reception of the MAC-hs Reset Indicator information element from higher levels, instruct all RLC AM objects associated with the HS-DSCH to generate a status report.

For reordering queues for which the extended MAC-ehs procedure applies:

(1) When data (reordering PDU) is received for this reordering queue, set next_expected_TSN = TSN-x, where, for example, 0≤x <6, and TSN is the transmission sequence number of the received reordering PDU, and the value x can be predefined or pre-signaled by higher levels;

(2) Optionally, if x is not equal to zero, then set T1_TSN = TSN of this packet and start the timer T1;

(3) Set RcvWindow_UpperEdge = TSN + y, where y can be predefined or pre-signaled by higher levels; and

(4) Complete the MAC-ehs reset procedure for this reordering queue.

For all other sequencing queues:

(1) start with a TSN with a value of "0" for the next transmission for each configured HARQ process; and

(2) initialize the variables RcvWindow_UpperEdge and next_expected_TSN to their original values.

Queues that use the extended MAC-ehs procedure can be signaled by higher layers along with the RRC command (or as part of it), which triggers a MAC-ehs reset, if applicable. Alternatively, pre-signaling can be performed when setting a logical channel mapped to a queue, or the alarm can be pre-set depending on the type of logical channel mapped to this queue (for example, a queue can be predefined so that any queue mapped to a CCCH logical channel was subjected to an extended MAC-ehs reset procedure). This alarm can be performed using one of the above options.

According to a sixth embodiment, additional special values are set for the variables next_expected_TSN and RcvWindow_UpperEdge. This special meaning can be indicated, for example, by one of the following types: Waiting, Uncertain, or Waiting (hereinafter, the designation “Waiting” is used).

For certain reordering queues, the procedure for resetting MAC-ehs or configuring a new MAC-ehs is modified so that the variables "next_expected_TSN" and "RcvWindow_UpperEdge" are set to "Wait" instead of their original values specified in the normal procedure. Moreover, the reordering function is also modified so that when MAC-ehs PDUs with TSN = SN are received, if the value of "next_expected_TSN" is set to "Wait", then the following actions are performed:

(1) Timer T1 does not start;

(2) Next_expected_TSN is set to TSN + 1 (or alternatively, to TSN + x, where x is predefined or set by higher levels); and

(3) RcvWindow_UpperEdge is set to TSN + y, where y can be predefined or pre-signaled by higher layers.

Reordering queues for which the aforementioned modified MAC-ehs procedure is applied can be signaled by higher layers together with the RRC command (or as part of it) that triggers a MAC-ehs reset, if applicable.

Alternatively, pre-signaling can be performed when setting a logical channel mapped to a queue, or the alarm can be pre-set depending on the type of logical channel mapped to this queue (for example, a queue can be predefined so that any queue mapped to a CCCH logical channel was subjected to an extended MAC-ehs reset procedure). This alarm can be performed using one of the above options.

The modified reordering function for the receiver operation is as follows:

When a MAC-hs PDU with TSN = SN is received:

If next_expected_TSN is NOT set to Pending

- if SN is in the receiver window:

- if SN <next_expected_TSN or if this MAC-hs PDU has been previously received:

- This MAC-hs PDU should be excluded;

- otherwise:

- This MAC-hs PDU must be placed in the reordering buffer, at the location indicated by the TSN;

- if SN is outside the receiver window:

- this received MAC-hs PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any MAC-hs PDUs with TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the disassembly object;

- if next_expected_TSN is below the updated receiver window:

- the variable next_expected_TSN should be set equal to:

RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- if the MAC-hs PDU with TSN = next_expected_TSN is stored in the reordering buffer:

- all received MAC-hs PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unaccepted MAC-hs PDU must be delivered to the disassemble object;

- the variable next_expected_TSN should be increased to the TSN of this first unaccepted MAC-hs PDU.

If the WTRU does not have enough memory to process the received MAC-ehs PDU, then the WTRU performs the following operations:

- select TSN_flush so that:

next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1;

- deliver all correctly received MAC-hs PDUs with TSN <TSN_flush to the disassembly object;

- if the MAC-hs PDU with TSN = TSN_flush was previously received:

- Deliver all received MAC-hs PDUs with sequential TSNs with TSN_flush (inclusive) to the first unaccepted MAC-hs PDU to the disassemble object;

- increment the next_expected_TSN variable to the TSN of this first unaccepted MAC-hs PDU.

- otherwise:

- set next_expected_TSN to TSN_flush.

Finish if next_expected_TSN is NOT set to Pending

Otherwise (for example, if next_expected_TSN is set to "wait")

- The timer T1 does not start;

- Next_expected_TSN is set to SN + 1 (or alternatively, to SN + x, where x is predefined or set by higher levels);

- RcvWindow_UpperEdge is set to TSN + y, where y can be predefined or pre-signaled by higher layers.

END

The reordering function can be modified so that two different timers (T_init and T1) can be used. When the reordering queue is in the idle state, the timer T1 used in the normal procedure cannot be started. Accordingly, the usual procedure should be modified as follows.

If there is no T1 active timer:

- timer T1 should be started when the reordered PDU with TSN> next_expected_TSN is correctly received, provided that next_expected_TSN is not set to "wait" (or if "reordering_state" is not set to "wait");

- T1_TSN must be set equal to the TSN of this MAC-hs PDU.

The second modification is that when the reordering queue is in the “wait” state, the variable “next_expected_TSN” is not updated and remains in the “wait” value. In addition, any comparison between the variable "next_expected_TSN" in the normal procedure should give a negative result when the reordering queue is in the "waiting" state. If the MAC-ehs reset procedure sets the RcvWindow_UpperEdge variable to "wait", this variable must be initialized when the first reordered PDU is received. These modifications may be implemented, for example, by modifying a conventional procedure. It should be understood that other options for this procedure are also possible.

Receiver Operations:

When a MAC-hs PDU with TSN = SN is received:

- (Optional, if RcvWindow_UpperEdge is set to "wait" during MAC-ehs reset) if the receiver window is in the "wait" state (RcvWindow_UpperEdge is set to "wait");

- RcvWindow_UpperEdge should be set equal to SN;

- if SN is in the receiver window:

- if next_expected_TSN is not set to "wait" and SN <next_expected_TSN or this MAC-hs PDU has been previously received:

- This MAC-hs PDU should be excluded;

- otherwise:

- This MAC-hs PDU must be placed in the reordering buffer, at the location indicated by the TSN;

- if SN is outside the receiver window:

- this received MAC-hs PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any MAC-hs PDUs with:

TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, those located outside the receiver window after updating its position should be removed from the reordering buffer and delivered to the disassembly object;

- if next_expected_TSN is not set to "wait" and next_expected_TSN is below the updated receiver window:

- next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- if next_expected_TSN is not set to "wait" and the MAC-hs PDU with TSN = next_expected_TSN is stored in the reordering buffer:

- all received MAC-hs PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unaccepted MAC-hs PDU must be delivered to the disassemble object;

- the variable next_expected_TSN should be increased to the TSN of this first unaccepted MAC-hs PDU.

If the WTRU does not have enough memory to process the received reordered PDU, then the WTRU performs the following operations:

- select TSN_flush so that next_expected_TSN <TSN_flush ≤ RcvWindow_UpperEdge + 1 (or any other value if next_expected_TSN is set to "wait");

- deliver all correctly received MAC-hs PDUs with TSN <TSN_flush to the disassembly object;

- if the MAC-hs PDU with TSN = TSN_flush was previously received:

- Deliver all received MAC-hs PDUs with sequential TSNs with TSN_flush (inclusive) to the first unaccepted MAC-hs PDU to the disassemble object;

- if next_expected_TSN is not set to "wait", increase next_expected_TSN to the TSN of this first unaccepted MAC-hs PDU;

- if next_expected_TSN is not set to "wait":

- set next_expected_TSN to TSN_flush.

The third modification simplifies the procedure when the reordering queue is in the waiting state (for example, when the T_init timer is active, if this trigger was selected). The following must be added to the normal reordering procedure (it should be understood that the Tinit_TSN variable can be replaced with T1_TSN without changing the value).

If next_expected_TSN is set to “wait” (or reordering_state is set to “wait”) and a reordering PDU for a given queue with TSN = SN is received:

(1) (Optional, applicable to the case when T_init does not start immediately after the MAC-ehs reset procedure.) If there is no T_init active timer:

(a) T_init timer starts,

(b) Tinit_TSN is set equal to SN.

(2) (Optional, applicable to the case when T_init starts immediately after the MAC-ehs reset procedure.) If Tinit_TSN is set to "wait":

(a) Tinit_TSN is set to SN.

When the T_init timer expires (or when the reordering_state is reset to a "normal" value for some reason):

(1) Optionally, applicable to the case when T_init starts immediately after the MAC-ehs reset procedure. If Tinit_TSN is set to pending:

(a) Restart the T_init timer.

(2) If Tinit_TSN is not set to "wait":

(a) All correctly received reordered PDUs up to Tinit_TSN-1 (or optionally Tinit_TSN) are delivered inclusively to the object located above the reordering object (i.e., to the LCH-ID demultiplexer object, disassembly object, or reassembly object).

(b) All correctly received reordering PDUs until the next unacceptable reordering PDU with a TSN that is greater than Tinit_TSN must be delivered to the object located above the reordering object.

(c) next_expected_TSN is set equal to the TSN of the next unaccepted reordering PDU, optionally with a TSN that is greater than T1_TSN; and (if applicable) the reordering_state variable is set to normal. Alternatively, next_expected_TSN can always be set to the next unaccepted MAC-ehs PDU with a TSN that is greater than T1_TSN when the timer expires.

(d) Optionally, if there are still accepted reordering PDUs that cannot be delivered to the higher layer:

(i) timer T1 starts;

(ii) T1_TSN is set equal to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Alternatively, if the reordering_state variable is used in the reordering procedure (optional), the next_expected_TSN variable can be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1 when a reordering PDU with TSN = SN is received.

Alternatively, a single timer (T1) may be used. If one timer is used (i.e., timer T1), the reordering function takes the following form.

If there is no active timer T1 and next_expected_TSN is not set to "wait":

(a) timer T1 must be started when a reordering PDU with TSN> next_expected_TSN is received correctly.

(b) T1_TSN shall be set equal to the TSN of this reordering PDU.

If there is no active timer T1 and next_expected_TSN is set to "wait":

(c) timer T1 must be started when the reordering PDU is received correctly;

(d) T1_TSN is set equal to the TSN of this reordering PDU.

If timer T1 is already activated:

(e) the additional timer should not be started, that is, at a given point in time, only one timer T1 can be active.

Timer T1 must be stopped if:

(f) a reordering PDU with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires and next_expected_TSN is not set to “wait”.

When timer T1 expires, next_expected_TSN is not set to wait and T1_TSN> next_expected_TSN:

(g) all correctly received PDUs with TSN> next_expected_TSN through T1_TSN-1 inclusive must be delivered to the reassembly entity;

(h) all correctly received reordering PDUs before the next unacceptable reordering PDU must be delivered to the reassembly entity;

(i) next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

When timer T1 expires and next_expected_TSN is set to "wait":

(j) all correctly received reordering PDUs up to and including T1_TSN-1 are delivered to the reassembly entity;

(k) all correctly received reordering PDUs until the next unaccepted reordering PDU with a TSN that is greater than T1_TSN must be delivered to the reassembly entity;

(l) next_expected_TSN is set equal to the TSN number of the next unaccepted reordering PDU, optionally with a TSN number that is greater than T1_TSN.

When timer T1 stops or expires and there are still some received reordering PDUs that cannot be delivered to the highest level:

(m) timer T1 starts;

(n) T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Alternatively, the following procedure may be performed.

When timer T1 expires and T1_TSN> next_expected_TSN or next_expected_TSN is set to "wait":

(a) all correctly received PDUs with TSN> next_expected_TSN through T1_TSN-1 inclusive must be delivered to the reassembly entity;

(b) all correctly received reordering PDUs before the next unacceptable reordering PDU must be delivered to the reassembly entity;

(c) next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

The receiver operations for reordering are as follows.

When a reordering PDU with TSN = SN is received:

(a) if RcvWindow_UpperEdge is set to "wait",

(i) RcvWindow_UpperEdge must be set to SN;

(b) if the SN is in the receiver window:

(i) if next_expected_TSN is not set to "wait" and if SN <next_expected_TSN or this reordering PDU has been previously received:

(ii) this reordering PDU should be excluded;

(c) otherwise:

(i) this reordering PDU should be placed in the reordering buffer at the location indicated by the TSN;

(d) if the SN is outside the receiver window:

(i) this received reordering PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

(ii) RcvWindow_UpperEdge must be set to SN, thereby advancing the receiver window;

(iii) any reordering PDUs with TSN ≤ RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the reassembly object;

(iv) if next_expected_TSN is not set to "wait" and if next_expected_TSN is below the updated receiver window:

a. next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

(e) if next_expected_TSN is not set to “wait” and if the reordering PDU with TSN = next_expected_TSN is stored in the reordering buffer:

(i) all received reordering PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unreceived reordering PDU must be delivered to the reassembly entity;

(ii) the next_expected_TSN variable should be incremented to the TSN of this first unaccepted reordering PDU.

If the WTRU does not have enough memory to process the received reordered PDU, then the WTRU performs the following operations:

(a) select TSN_flush so that: next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1 (or any other value if next_expected_TSN is set to "wait");

(b) deliver all correctly received reordering PDUs with TSN <TSN_flush to the reassembly entity;

(c) if a reordering PDU with TSN = TSN_flush was previously received:

(i) deliver to the reassembly entity all received reordering PDUs with sequential TSNs from TSN_flush (inclusive) to the first unreceived reordering PDU;

(ii) increment the variable next_expected_TSN to the TSN of this first unacceptable reordering PDU;

(d) otherwise:

(i) set next_expected_TSN to TSN_flush.

According to a seventh embodiment, Node-Bs can send TSNs for the next MAC-ehs SDU to be transmitted for WTRUs using a common H-RNTI. This information can be sent in one System Information Block (SIB), which is formed in Node-B. When the WTRU performs a MAC-ehs reset and selects a new cell, the WTRU reads the SIB containing the TSN. Upon receipt of this TSN, the WTRU may perform the following actions:

(1) set next_expected_TSN = TSN + 1 obtained from the SIB; and

(2) set Rcv_Window_UpperEdge = TSN. This allows the WTRU to properly process the next received MAC-ehs PDU using a common H-RNTI and perform reordering.

Alternatively, Node-B may provide a TSN on the HS-SCCH. A TSN may be provided according to one or a combination of the following options:

(1) for each transmission on a common H-RNTI; and

(2) only for the first x (configurable number) transmissions after adding the WTRU to a new cell.

Alternatively, Node B and WTRUs may reset the TSN of a particular queue to the default value. This can be done when a packet is transmitted to a new WTRU in a cell. The default value can be signaled through higher levels, or it can be predefined. Node B can signal a TSN reset to all other WTRUs that perform H-RNTI monitoring. Node B can signal a TSN reset using any of the following methods:

(1) using a new or regular Layer 3 signaling (e.g., a BCCH message or another RRC message);

(2) using a new or conventional Layer 3 signaling (for example, the MAC-ehs header may be modified to include TSN reset information); and

(3) using new or conventional physical layer signaling (for example, a modified HS-SCCH format can be used to indicate a TSN reset).

According to an eighth embodiment, the network always ensures that the RRC messages transmitted through the common H-RNTI are small enough to fit in one MAC-ehs PDU by minimizing the contents of the message. An RRC message may be “segmented” into smaller RRC messages. For example, the initial message may contain RNTI Cells (Cell RNTI, C-RNTI) and / or H-RNTI, and the rest of the configuration may be signaled via separate RRC messages. After the WTRU receives the dedicated H-RNTI, subsequent RRC messages can be of any size because the reordering function in MAC-ehs works properly with the dedicated H-RNTI.

However, the network must guarantee the successful reception of the initial RCC message (for example, containing only C-RNTI and / or H-RNTI) by the WTRU before transmitting the subsequent message (configuration) via the dedicated H-RNTI. This can be achieved if the RRC entity waits long enough given the number of HARQ retransmissions and the RRC delay requirements in the WTRU. Depending on the particular implementation, the RRC entity may not “notice” the delay required by the lower layers to transmit the message. In this case, the RRC entity must wait long enough to verify that the transmission is complete.

In addition, when segmenting an RRC message, the RNC must ensure that the size of the generated MAC-ehs SDUs is within a range that does not require segmentation in the MAC-ehs object. The MAC-ehs PDU size reference may use the smallest available transport block size. Alternatively or in combination, the size of the transport block that will be used by the Node B can be derived from the received measurement results from the Random Access Channel (RACH), which are included in the "Transmission Power Level" field.

If segmentation of the RRC message occurs, then the receiver side needs to be modified to act on the information elements of the received message as in the case of transmitting one RRC message (i.e., not expecting another part or segment of the RRC message).

According to a ninth embodiment, the first received packets are not delivered immediately. The first received MAC_ehs PDU is always placed in the reordering buffer and its SN is used to determine the values of some or all reordering variables (next_expected_TSN, RcvWindow_UpperEdge, T1_TSN). For example, the top edge of the receive window (RcvWindow_UpperEdge) and / or T1_TSN can be set to the SN value of the received MAC-ehs PDU, and next_expected_TSN can be set to SN-RECEIVE_WINDOW_SIZE + 1. This ensures that any subsequent received PDU with a lower TSN is not excluded, but is properly stored in the reordering buffer. Alternatively, next_expected_TSN may be set to another value, such as RcvWindow_UpperEdge - x, where x is some predefined constant. A timer (either timer T1 or timer T1_init) starts when this first MAC-ehs PDU is received. Before the timer expires, all subsequent MAC-ehs received PDUs are allocated to the reordering buffer according to their TSN. These PDUs do not deliver to the reassembly if they should not be removed from the reordering buffer according to the usual procedure.

When the timer expires, some or all of the PDUs present in the reordering buffer may be delivered to the reassembly entity. For example, all PDUs from TSN to T1_TSN-1, including the last, can be delivered, and then all PDUs can be delivered until the next unaccepted PDU. The next_expected_TSN variable can be set (or re-set) to the TSN value of this next unaccepted PDU. In addition, the T1 timer can be restarted at this point if other PDUs that cannot be delivered are present. In this case, the variable T1_TSN can be set to the highest TSN from the MAC-ehs PDUs that cannot be delivered. From this point, the normal reordering operation continues.

The initial value of at least one of the variables next_expected_TSN and RcvWindow_UpperEdge is set to a special value ("Wait"), so that the WTRU performs the corresponding operations from the beginning of the procedure. Alternatively, a new Boolean variable can be defined (for example, "Reordering_InitialState") to indicate whether the procedure is in the initial state or not. When the value of this variable is True, the WTRU executes the procedure as described above, and this variable takes the value False when the original timer expires.

According to one option for the ninth embodiment, the initial value of the variable RcvWindow_UpperEdge is set to "Pending" for certain reordering queues to be processed according to a modified procedure. Timer T1 starts when the first PDU is received, when RcvWindow_UpperEdge has a value of "Wait", indicating that it is in its original state. Details of this procedure are outlined below.

If there is no T1 active timer:

- timer T1 must be started when a reordered PDU with TSN> next_expected_TSN is correctly received , or when a reordered PDU is correctly received and RcvWindow UpperEdge is set to "Wait".

- T1_TSN must be set equal to the TSN of this reordering PDU.

If timer T1 is already activated:

- the additional timer should not be started, that is, at a given point in time only one timer T1 can be active.

Timer T1 must be stopped if:

- reordering PDUs with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires.

When timer T1 expires and T1_TSN> next_expected_TSN:

- all correctly received reordering PDUs with TSN> next_expected_TSN to T1_TSN-1 inclusive must be delivered to the reassembly object;

- all correctly received reordered PDUs before the next unaccepted reordered PDU must be delivered to the reassembly object;

- next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

When timer T1 stops or expires and there are still some received reordering PDUs that cannot be delivered to the highest level:

- timer T1 starts

- T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Transmitter Operations:

After the transmitter has transmitted a reordering PDU with TSN = SN, no reordering PDUs with TSN≤SN - TRANSMIT_WINDOW_SIZE should be retransmitted to avoid ambiguity of the sequence number in the receiver.

Receiver Operations:

When a reordering PDU with TSN = SN is received:

- if RcvWindow UpperEdge is set to "Wait":

- RcvWindow UpperEdge must be set to SN:

- next expected TSN should be set to RcvWindow UpperEdge - WINDOW SIZE + 1.

- if SN is in the receiver window:

- if SN <next_expected_TSN or if this reordering PDU has been previously received:

- This reordering PDU should be excluded;

- otherwise:

- This reordering PDU must be placed in the reordering buffer at the location indicated by the TSN.

- if SN is outside the receiver window:

- this received reordering PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any reordering PDUs with TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the reassembly object;

- if next_expected_TSN is below the updated receiver window:

- next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- if the reordering PDU with TSN = next_expected_TSN is stored in the reordering buffer:

- all received reordered PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unreceived reordered PDU must be delivered to the reassembly entity;

- the variable next_expected_TSN should be increased to the TSN of this first unaccepted reordered PDU.

If the WTRU does not have enough memory to process the received reordered PDU, then the WTRU must perform the following set of operations:

- select TSN_flush so that next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1;

- deliver all correctly received reordering PDUs with TSN <TSN_flush to the reassembly object;

- if a reordering PDU with TSN = TSN_flush was previously received:

- deliver to the reassembly entity all received reordering PDUs with sequential TSNs with TSN_flush (inclusive) to the first unreceived reordering PDU;

- increment the next_expected_TSN variable to the TSN of this first unaccepted reordering PDU.

- otherwise:

- set next_expected_TSN to TSN_flush.

According to a second option, for the ninth embodiment, the initial value of both the variables RcvWindow_UpperEdge and RcvWindow_UpperEdge is set to “Pending” for certain reordering queues to be processed according to the modified procedure. Upon receipt of the first PDU, the variables RcvWindow_UpperEdge and T1_TSN are set equal to the SN of this PDU, while next_expected_TSN remains in the value "Waiting". In addition, the timer T1 starts. The comparison between the SNs of the received PDUs and next_expected_TSN is omitted when next_expected_TSN is set to “Pending”. After the timer T1 expires or stops (stopping may occur if PDUs with SN equal to T1_TSN can be delivered by advancing the receiver window), all PDUs from SN to T1_TSN - 1 and from SN to the next unaccepted PDU are delivered to the reassembly object. The next_expected_TSN variable is set to the SN of the next unaccepted PDU, and the normal sequencing procedure can continue from this point. Details of this procedure are outlined below.

If there is no active timer T1 and next_expected TSN is not set to "Wait" :

- timer T1 must be started when the reordering PDU with TSN> next_expected_TSN is received correctly;

- T1_TSN must be set equal to the TSN of this reordering PDU.

If there is no active timer T1 and next_expected TSN is set to "Wait":

- timer T1 must be started when the reordering PDU is received correctly;

- T1_TSN is set equal to the TSN of this reordering PDU.

If timer T1 is already activated:

- the additional timer should not be started, that is, at a given point in time only one timer T1 can be active.

Timer T1 must be stopped if:

- reordering PDUs with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires.

When timer T1 expires, next_expected_TSN is not set to wait and T1_TSN> next_expected_TSN:

- all correctly received reordering PDUs with TSN> next_expected_TSN to T1_TSN-1 inclusive must be delivered to the reassembly object;

- all correctly received reordered PDUs before the next unaccepted reordered PDU must be delivered to the reassembly object;

- next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

When timer T1 stops or expires and next_expected TSN is set to Pending:

- all correctly received reordering PDUs up to and including T1_TSN-1 are delivered to the reassembly object;

- all correctly received reordering PDUs until the next unacceptable reordering PDU with a TSN that is greater than T1_TSN must be delivered to the reassembly object;

- next_expected_TSN is set equal to the TSN number of the next unacceptable reordering PDU with a TSN number that is greater than T1_TSN.

When timer T1 stops or expires and there are still some received reordering PDUs that cannot be delivered to the highest level:

- timer T1 starts;

- T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Transmitter Operations:

After the transmitter has transmitted a reordering PDU with TSN = SN, no reordering PDUs with TSN≤SN - TRANSMIT_WINDOW_SIZE should be retransmitted to avoid ambiguity in the sequence number in the receiver.

Receiver Operations:

When a reordering PDU with TSN = SN is received:

- if RcvWindow UpperEdge is set to "Wait":

- RcvWindow UpperEdge must be set to SN:

- if SN is in the receiver window:

- if next_expected_TSN is not set to "Wait" and SN <next_expected_TSN or this reordering PDU has been previously received:

- This reordering PDU should be excluded;

- otherwise:

- This reordering PDU must be placed in the reordering buffer, at the location indicated by the TSN;

- if SN is outside the receiver window:

- this received reordering PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any reordering PDUs with TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, those located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the reassembly object;

- if next_expected_TSN is not set to "wait" and next_expected_TSN is below the updated receiver window:

- next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- if next_expected_TSN is not set to "wait" and the reordering PDU with TSN = next_expected_TSN is stored in the reordering buffer:

- all received reordered PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unreceived reordered PDU must be delivered to the reassembly entity;

- the variable next_expected_TSN should be increased to the TSN of this first unaccepted reordered PDU.

If the WTRU does not have enough memory to process the received reordered PDU, then the WTRU must perform the following set of operations:

- select TSN_flush so that: next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1, or (if next expected TSN is set to "Wait") RcvWindow UpperEdge - RECEIVE WINDOW SIZE <TSN flush≤RcvWindow UpperEdge + :

- deliver all correctly received reordering PDUs with TSN <TSN_flush to the reassembly object;

- if a reordering PDU with TSN = TSN_flush was previously received:

- deliver to the reassembly entity all received reordering PDUs with sequential TSNs with TSN_flush (inclusive) to the first unreceived reordering PDU;

- increment the variable next_expected_TSN to the TSN of this first unacceptable reordering PDU;

- otherwise:

- set next_expected_TSN to TSN_flush.

According to the third option, for the ninth embodiment, RcvWindow_UpperEdge and next_expected_TSN retain their original values, as in the prior art, and a new variable "Reordering_InitialState" is defined that takes the initial value "True" for reordering queues that are to be processed according to the modified procedure. The condition for starting the timer T1 is modified in such a way as to ensure that the timer starts when the first PDU is received, when the Reordering_InitialState is set to True, indicating that this is its initial state. Before processing the received PDU, the MAC-ehs WTRU first checks to see if the Reordering_InitialState variable is set to True. If so, then the RcvWindow_UpperEdge variable is set to the SN of this PDU, the next_expected_TSN variable is set to the bottom edge of the receiver window, and the Reordering_InitialState variable is set to False to return to normal. Details of this procedure are outlined below.

If there is no T1 active timer:

- timer T1 should be started when the reordering PDU with TSN> next_expected_TSN is correctly received or when the reordering PDU is correctly received and the Reordering InitialState is set to True.

- T1_TSN must be set equal to the TSN of this reordering PDU.

If timer T1 is already activated:

- the additional timer should not be started, that is, at a given point in time only one timer T1 can be active.

Timer T1 must be stopped if:

- reordering PDUs with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires.

When timer T1 expires and T1_TSN> next_expected_TSN:

- all correctly received reordering PDUs with TSN> next_expected_TSN to T1_TSN-1 inclusive must be delivered to the reassembly object;

- all correctly received reordered PDUs before the next unaccepted reordered PDU must be delivered to the reassembly object;

- next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

When timer T1 stops or expires and there are still some received reordered PDUs that cannot be delivered to the higher layer;

- timer T1 starts

- T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Transmitter Operations:

After the transmitter has transmitted a reordering PDU with TSN = SN, no reordering PDUs with TSN ≤ SN - TRANSMIT_WINDOW_SIZE should be retransmitted to avoid ambiguity in the sequence number in the receiver.

Receiver Operations:

When a reordering PDU with TSN = SN is received:

- if the Reordering InitialState is set to True,

- RcvWindow UpperEdge should be set equal to SN;

- Reordering InitialState should be set to "False";

- next expected TSN should be set to RcvWindow UpperEdge - WINDOW SIZE + 1;

- if SN is in the receiver window,

- if SN <next_expected_TSN or if this reordering PDU has been previously received:

- This reordering PDU should be excluded;

- otherwise:

- This reordering PDU must be placed in the reordering buffer, at the location indicated by the TSN;

- if SN is outside the receiver window,

- this received reordering PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any reordering PDUs with TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, those located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the reassembly object;

- if next_expected_TSN is lower than the updated receiver window,

- next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- if the reordering PDU with TSN = next_expected_TSN is stored in the reordering buffer,

- all received reordered PDUs with sequential TSNs from next_expected_TSN (inclusive) to the first unreceived reordered PDU must be delivered to the reassembly entity;

- the variable next_expected_TSN should be increased to the TSN of this first unaccepted reordered PDU.

If the WTRU does not have enough memory to process the received reordered PDU, then the WTRU must perform the following set of operations:

- select TSN_flush so that next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1;

- deliver all correctly received reordering PDUs with TSN <TSN_flush to the reassembly object;

- if a reordering PDU with TSN = TSN_flush has been previously received,

- deliver to the reassembly entity all received reordering PDUs with sequential TSNs with TSN_flush (inclusive) to the first unreceived reordering PDU;

- increment the next_expected_TSN variable to the TSN of this first unaccepted reordering PDU.

- otherwise:

- set next_expected_TSN to TSN_flush.

According to a fourth option for the ninth embodiment, the reordering function may begin with the original window size (i.e., RECEIVE_WINDOW_SIZE) of 64, which covers all possible sequence numbers for a given queue. This ensures that no reordering PDUs are discarded during the initial phase. Upon receipt of the first reordering PDU, the timer T1 is started with the value T1_TSN set to SN of the first received MAC-ehs PDU if the reordering PDU with the SN set to 0 is not received.

When the timer expires, some or all of the PDUs present in the reordering buffer are delivered to the reassembly object according to the following rules:

(1) all PDUs from TSN to T1_TSN-1 inclusive must be delivered to higher layers;

(2) all PDUs until the next unaccepted PDU must be delivered to higher layers;

(3) next_expected_TSN can be set to the TSN of the next unaccepted PDU (alternatively, it is set to the TSN of the next unaccepted PDU with a TSN that is greater than T1_TSN);

(4) RcvWindow_UpperEdge is set equal to the highest sequence number of the received reordered PDU; and

(5) The variable RECEIVE_WINDOW_SIZE is restored and set to a certain value of normal operation.

In addition, the T1 timer can be restarted at this point if other PDUs that cannot be delivered are present. In this case, the variable T1_TSN is set to the highest TSN from the MAC-ehs PDUs that cannot be delivered. From this point, the normal reordering operation continues.

It should also be noted that for all the above four options, a new timer (for example, T1_init) for the initial phase can optionally be introduced. To use a separate timer, the points in the procedure where "If there is no active timer T1:" is checked are modified as follows.

If there is no active T1 or T1 init timer:

- if RcvWindow UpperEdge (or next expected TSN) is not set to "Wait" (or, optionally, Reordering InitialState is set to "False"), timer T1 should be started when a reordered PDU with TSN> next_expected_TSN is correctly received;

- if the RcvWindow UpperEdge (or next expected TSN) is set to "Wait" (or, optionally, the Reordering InitialState is set to "True"), the T1 init timer should be started when the reordered PDU is correctly received.

All other actions associated with stopping and expiring the timer remain in the same form as for actions associated with timer T1. When the T1_init timer expires, the reordering entity must ensure that the T1 timer is restarted if there are still PDUs that cannot be delivered. These changes are highlighted in the following snippet.

If timer T1 or T1 init is already activated:

- the additional timer should not be started, that is, at a given point in time only one timer T1 (or T1 init) can be active.

Timer T1 or T1 init should be stopped if

- reordering PDUs with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires.

When the timer T1 or T1_init expires and T1_TSN> next_expected_TSN:

- all correctly received reordering PDUs with TSN> next_expected_TSN to T1_TSN-1 inclusive must be delivered to the reassembly object;

- all correctly received reordered PDUs before the next unaccepted reordered PDU must be delivered to the reassembly object;

- next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU.

When the T1 or T1 init timer stops or expires and there are still some received reordered PDUs that cannot be delivered to the highest level:

- timer T1 starts;

- T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

According to the tenth embodiment, it is possible to eliminate the explicit systematic setting of the initial timer T1 upon receipt of the first reordering PDU. For example, the first reordering PDU can be immediately delivered to higher levels and its SN value is used to determine the values of some reordering variables. For this, one or a combination of the following options can be used.

According to the first option, the procedure is started in the "initial" state using one of the methods described above (for example, next_expected_TSN and / or RcvWindow_UpperEdge is initialized to "Wait" or a new variable is defined for the initial state). When the first reordering PDU is received, next_expected_TSN is set to SN + 1, and RcvWindow_UpperEdge is set to SN. The reordering queue continues to operate normally for all subsequent received reordering PDUs.

The first option may cause subsequent received PDUs with SN <next_expected_TSN to be excluded. In order to avoid the exception of PDUs, according to the second option, a new variable initial_TSN is introduced, which contains the TSN number of the first received PDU. The first received PDU is delivered to higher layers and Initial_TSN is set to SN, next_expected_TSN is set to SN + 1, and RcvWindow_UpperEdge is set to SN.

Reordering PDUs with SN <initial_TSN cannot be excluded until the bottom edge of the window (that is, RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE) is moved further than the initial_TSN value. All reordering PDUs with SN <initial_TSN can be immediately delivered to the reassembly object or directly to the LCH-ID demultiplexing object (without reordering). Reordering PDUs with SN> initial_TSN can be normally processed through a reordering procedure. Optionally, in order to avoid data duplication, the list of received PDUs can be maintained until the bottom edge of the window moves beyond the original TSN value. Alternatively, reordering PDUs with SN <initial_TSN cannot be excluded (or delivered to higher levels) until the timer expires (T1 or a new timer).

An example procedure is given below.

If there is no T1 active timer:

- timer T1 must be started when the reordering PDU with TSN> next_expected_TSN is received correctly;

- T1_TSN must be set equal to the TSN of this reordering PDU. If timer T1 is already activated:

- the additional timer should not be started (that is, at a given point in time only one timer T1 can be active).

Timer T1 must be stopped if:

- reordering PDUs with TSN = T1_TSN can be delivered to the reassembly entity before the timer expires.

When timer T1 expires and T1_TSN> next_expected_TSN:

- all correctly received reordering PDUs with TSN> next_expected_TSN to T1_TSN-1 inclusive must be delivered to the reassembly object;

- all correctly received reordered PDUs before the next unaccepted reordered PDU must be delivered to the reassembly object;

- next_expected_TSN should be set equal to the TSN number of the next unaccepted reordering PDU;

- if the reordering InitState is set to True, then the reordering InitState must be set to False.

When timer T1 stops or expires and there are still some received reordering PDUs that cannot be delivered to the higher level:

- timer T1 starts;

- T1_TSN is set to the highest TSN among the set of MAC-ehs SDUs that cannot be delivered.

Transmitter Operations:

After the transmitter has transmitted a reordering PDU with TSN = SN, no reordering PDUs with TSN≤SN - TRANSMIT_WINDOW_SIZE should be retransmitted to avoid ambiguity in the sequence number in the receiver.

Receiver Operations:

When a reordering PDU with TSN = SN is received:

- if initial TSN is set to "Wait":

- RcvWindow UpperEdge should be set equal to SN;

- next expected TSN should be set to SN + 1;

- initial TSN must be set equal to SN;

- Deliver reordering PDUs to the reassembly object;

- if SN is in the receiver window:

- if reordering State is set to True and if SN <initial TSN:

- the reordering PDU must be passed to the reassembly object (or, optionally, it can be passed bypassing the reassembly object - directly to the LCH-ID demultiplexing object);

- otherwise, if the reordering InitState is set to False and if SN <next_expected_TSN or this reordering PDU has been previously received:

- This reordering PDU should be excluded;

- otherwise:

- This reordering PDU must be placed in the reordering buffer, at the location indicated by the TSN;

- if SN is outside the receiver window:

- this received reordering PDU should be placed in the reordering buffer on top of the largest received TSN, at the location indicated by the SN;

- the variable RcvWindow_UpperEdge should be set equal to SN, thereby promoting the receiver window;

- any reordering PDUs with TSN≤RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE, that is, those located outside the receiver window after updating its position, must be removed from the reordering buffer and delivered to the reassembly object;

- if the initial TSN is lower than the updated receiver window:

- reordering InitState is set to "False";

- if next_expected_TSN is below the updated receiver window:

- next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

Alternatively, upon receiving the first received reordering PDU, next_expected_TSN may be set to SN - x, where x may be a statistical value, a number configured by higher layers, or a predetermined value based on the number of HARQ processes (for example, if only 4 processes are used HARQ, then x may be equal to 4 or may be equal to the number of HARQ processes - 1). RcvWindow_UpperEdge is set to SN. This ensures that some PDUs with SN <SN - x will not be excluded for the initial procedure.

Alternatively, the initial value next_expected_TSN may be set equal to the lower edge of the initial window, RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1, instead of being set to 0, as in the prior art. The initial value of RcvWindow_UpperEdge can be set to 63.

In addition, the reordering procedure can be modified by changing the original window size. For example, two receiver window sizes can be configured — the small initial window size and the normal window size can be configured at higher levels. The original window size can be set to a smaller value to speed up the initial process and avoid waiting for the timer T1 to expire. To return to the normal state of the reordering operation, the WTRU can wait until n (where n corresponds to the small initial window size) successive reordering PDUs are received, or until the lower edge of the window is moved further than the SN of the first received PDU, or until the timer expires. Upon entering normal operation, WINDOW_SIZE can be configured and restored to normal.

The window size can also be set to zero or one. With a value of one, the probability of receiving the first PDU inside the window and, accordingly, its exclusion is significantly reduced. The WTRU can be configured so that the receive window is first set to this small value, and when the first PDU is received, the window size is set back to the configured value RECEIVE_WINDOW_SIZE.

According to an eleventh embodiment, the reordering entity may use the HARQ process information as an indication to start a normal reordering operation. This method may be used alone or in combination with any other embodiments described herein. During the initial operation, the WTRU can ensure that the reordering PDU with the smallest possible sequence is received from the cell when the HARQ processes have a new purpose. All received reordering PDUs are stored in the reordering buffer until all new HARQ processes receive a new assignment or until timer T1 expires.

The NDI bit of each HARQ process can be monitored. When the NDI bit for all active processes goes from the value “0” to the value “1” (which indicates a new transfer by the HARQ process), the reordering entity can deliver all stored PDUs to the first received reordering PDU inclusively in the reassembly object. All other PDUs before the first unaccepted PDU, above the first received PDU, can also be delivered to the higher layer. Next_expected_TSN can be set to the SN of the first unaccepted PDU, and RcvWindow_UpperEdge is set to the SN of the highest received TSN. Timer T1 must be stopped if it is running.

Alternatively, a mapping between the HARQ process and possible TSN values may be supported. When at least one reordering PDU from each HARQ process is successfully received or cannot be successfully received, then the WTRU ensures that no other reordering PDUs with sequence numbers lower than any of the received PDUs are transmitted. The WTRU may set RcvWindow_UpperEdge to the SN value of the highest received TSN, and next_expected_TSN to the value of the first unaccepted PDU with the SN number that is higher than the smallest received reordered PDU.

In another option, when the WTRU receives the first reordering PDU, it can check the TSN of all PDUs in all active HARQ processes. If the sequence numbers of the PDUs processed in the HARQ process are higher than the first received PDU, then the WTRU may resume normal operation. Otherwise, the WTRU may wait until the reordering PDU with the lowest number in the HARQ processes is received.

The network can also determine the relationship between the HARQ process ID and the set of possible TSNs for each HARQ process. For example, it can be configured so that the HARQ process #m will only process PDUs with a TSN number that satisfies the condition TSN = 4n + m, where n is an integer. This ratio may be pre-signaled at higher levels by the WTRU. Then the WTRU can use this ratio to determine when the smallest SN PDU is received and, accordingly, resume normal operation.

You can imagine a network-based solution that limits the use of the entire TSN space (that is, the network does not use TSNs 55 to 63). If the receive window size is equal to or less than the number of TSNs that are not used by the network, this eliminates the chance of discarding the first received PDUs. However, this decision can lead to additional delays and the likelihood of PDU delivery out of order. To solve this problem, the following options can be implemented.

According to the first option, the WTRU can use the module x, where x is the smallest restricted TSN (that is, if the numbers 55 to 63 are limited, then x will be 55), for all arithmetic operations of the reordering object. For example, all arithmetic operations performed in the reordering procedure with respect to next_expected_TSN, RcvWindow_UpperEdge, T1_TSN and TSN_flush will be performed modulo x.

Module x can be the basis of operations at any time for reordering CCCH or DCCH (SRB No. 1). For the initial operation, RcvWindow_UpperEdge may be 63 or any other value that is greater than x. The module x should not be applied to this initial value RcvWindow_UpperEdge, or the original value may be considered as an undefined initial value. Using this value can be considered equivalent to setting the RcvWindow_UpperEdge variable to "Pending." When RcvWindow_UpperEdge is set to 63, one or a combination of the following operations may be performed upon receiving the first PDU with TSN = SN:

(1) start the process using module x for all arithmetic operations;

(2) RcvWindow_UpperEdge must be set to SN;

(3) next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1 and

(4) start timer T1 or timer T1_init.

Alternatively, two different module operations can be used for the initial and normal states. For example, the normal module 64 can be used for the initial state. The initial value RcvWindow_UpperEdge is set to 63, the lower edge of the window is within the limited TSN numbers, and accordingly, no data will be excluded. However, upon entering the normal state (that is, upon receiving the first PDU or upon the expiration of timer T1), the reordering procedure may update the arithmetic procedures based on the operation of the module x. This eliminates duplication of T1 delays. Optionally, the four steps described above can be performed to set RcvWindow_UpperEdge, next_expected_TSN, T1, and start using the x module.

According to the second option, module 64 is used all the time, but the procedure is modified so that it takes into account the omitted TSN space. One of the above methods can be used to indicate the state of the reordering operation (i.e., the initial state or normal reordering state):

- next_expected_TSN or RcvWindow_UpperEdge is set to the special value "Waiting"; and

- a new state variable is introduced.

The WTRU enters the normal state of the reordering operation, either when the first PDU is received, or when timer T1 expires. For the initial state of work, arithmetic procedures remain unchanged. Since the TSN space is limited, the first received PDU will never be inside the receive window and therefore will not be excluded. However, upon entering the normal state, the reordering procedure must be updated so as to avoid out-of-order delivery and duplication of T1 timers. For the purpose of describing this procedure, the following variables will be used:

- TSN space will be limited from x to y, where x is the lower value of the limited space, and y is the upper value of the limited space (i.e. 63);

- RcvWindow_lowerEdge is equivalent to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1;

- Nr_restrictedTSNs is equivalent to the number of TSNs whose use is limited, i.e. y-x.

When operating in the normal state, the reordering procedure is modified as follows:

- when x <= RcvWindow_lowerEdge <= y, then a certain receive window is equivalent to RcvWindow_lowerEdge - Nr_restrictedTSNs;

- otherwise, the receive window is calculated as (RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1);

- next_expected_TSN should not be set to a value between x and y;

- if next_expected_TSN is equal to x-1, then the next expected in order PDU MAC-ehs will be y + 1;

- the reordering procedure can consider all TSNs x through y as successfully received PDUs when reordering is performed and when these TSNs are expected to be received.

Optionally, when receiving the first PDU, these variables can be set as follows:

(1) RcvWindow_UpperEdge must be set to SN;

(2) next_expected_TSN should be set to RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE + 1 and

(3) start timer T1 or timer T1_init.

According to a twelfth embodiment, the reordering problem can be solved on the network side instead of the receiver side. Node B can support different TSNs for each WTRU independently in each common H-RNTI. If a new WTRU is added to the cell, then Node B can start numbering the reordering PDUs for this WTRU, starting from zero. TSNs are incremented for each WTRU independently. This solution requires the Node B to be aware of the unique WTRU block ID to which it transmits, in addition to the common H-RNTI. The Iub frame protocol may provide a common H-RNTI. In this embodiment, a dedicated H-RNTI, which was provided by the network for this WTRU, should also be provided.

Alternatively, the RNC may provide an indication that the transmitted message is for the new WTRU. When Node B accepts this indication, Node B can perform one or a combination of the following operations:

- immediately reset the TSNs associated with the shared H-RNTI group; or

- make sure that any previously buffered MAC-ehs PDUs with the same common H-RNTI have been transmitted, and then reset the TSNs so that the message for the new WTRU is transmitted with an initial TSN of zero.

Since other WTRUs associated with this cell with the same common H-RNTI will receive data for the new cell, it may be advisable to indicate to the WTRU that the TSN has been reset. This may be indicated by a single bit in the HS-SCCH.

Options for implementation

1. A method for receiving HS-DSCH transmissions.

2. The method of embodiment 1, comprising the steps of receiving MAC-ehss PDUs via HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states.

3. The method of embodiment 2 comprising the steps of transmitting reordering PDUs included in MAC-ehs PDUs to the next processing entity without performing reordering of the reordering PDUs.

4. The method according to any one of embodiments 2-3, wherein one HARQ process is used to receive MAC-ehs PDUs.

5. The method of embodiment 4, wherein all MAC-ehs PDUs are transmitted several times and all retransmissions of MAC-ehs PDUs are performed before transmission of a subsequent MAC-ehs PDU begins.

6. The method according to any one of embodiments 4-5, wherein one HARQ process is used for at least one of the transmissions from a particular prioritized queue, transmissions from a specific logical channel, and transmissions using a common H-RNTI.

7. The method according to any one of embodiments 4-6, wherein the MAC-ehs PDUs for the HARQ process are not excluded, even if this MAC-ehs PDUs are received within five subframes from the last received MAC-ehs PDUs for that the same HARQ process.

8. The method according to any one of embodiments 4-6, wherein the MAC-ehs PDUs for the HARQ process are excluded even if the MAC-ehs PDUs have been received for n subframes since the last received MAC-ehs PDUs for the same process HARQ, where n is an integer.

9. The method according to any one of embodiments 2-8, wherein the reordering PDUs are passed to the next processing entity without performing reordering of the reordering PDUs if the data carried in the reordering PDUs comes from a specific prioritized queue.

10. The method according to any one of embodiments 2-9, wherein the reordering PDUs are redirected to the next processing entity without reordering the reordering PDUs if the MAC-ehs PDUs are received using a common H-RNTI.

11. The method according to any one of embodiments 2-10, wherein the reordering PDUs are transmitted to the next processing entity without performing reordering of the reordering PDUs if the data carried in the reordering PDUs comes from a specific logical channel.

12. The method of embodiment 11, wherein the logical channel is one of the BCCH and PCCH.

13. The method of embodiment 1, comprising the step of configuring a MAC-ehs entity to receive data through the HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states.

14. The method of embodiment 13 comprising the step of obtaining a TSN to be used in a cell for transmitting MAC-ehs PDUs using a common H-RNTI.

15. The method of embodiment 14, comprising the step of configuring a MAC-ehs entity using said TSN.

16. The method according to any one of embodiments 14-15, wherein said TSN is reset to a default value for a particular queue when the MAC-ehs PDUs are transmitted to the new WTRU.

17. The method according to embodiment 1, comprising the step of configuring a MAC-ehs object to receive data through the HS-DSCH in one of the states Cell_FACH, Cell_PCH and URA_PCH.

18. The method of embodiment 17 comprising the step of receiving a reordering PDU with TSN = SN.

19. The method of embodiment 18, comprising the step of: if RcvWindow_UpperEdge is set to "Wait", set RcvWindow_UpperEdge to SN and set next_expected_TSN to RcvWindow_UpperEdge - WINDOW_SIZE + 1.

20. The method according to any one of embodiments 18-19, further comprising the step of: if the SN is within the receive window and if SN <next_expected_TSN or if this reordering PDU has been previously received, this reordering PDU is deleted; otherwise, this reordering PDU is placed in the reordering buffer at the location indicated by said TSN.

21. The method according to any one of embodiments 18-20, further comprising the step of: if the SN is outside the reception window, the reordering PDU is placed on top of the highest received TSN in the reordering buffer at the position indicated by said SN.

22. The method of embodiment 12, comprising the step of setting RcvWindow_UpperEdge to SN to update the receive window.

23. The method of embodiment 22 comprising the step of delivering any reordering PDUs with TSN ≤ RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE to the reassembly entity.

24. The method according to any one of embodiments 19-23, further comprising the step of: if next_expected_TSN is lower than the updated receive window, set next_expected_TSN to RcvWindow_UpperEdge to RECEIVE_WINDOW_SIZE + 1.

25. The method of embodiment 24, comprising the step of: if a reordering PDU with TSN = next_expected_TSN is stored in the reordering buffer, all received reordering PDUs with consecutive TSNs from next_expected_TSN are delivered to the first unreceived reordering PDU in the reassembly entity and incrementing next_expected_TSN to TSN first unacceptable reordering PDU.

26. The method according to any one of embodiments 18-25, further comprising the step of: if there is not enough memory to process the received reordering PDU, select TSN_flush so that next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1.

27. The method of embodiment 26, comprising the step of delivering all correctly received reordering PDUs with TSN <TSN_flush to the reassembly entity.

28. The method of embodiment 27, comprising the step of: if a reordering PDU with TSN = TSN_flush has been previously received, all received reordering PDUs with consecutive TSNs from TSN_flush are delivered to the first unreceived reordering PDU in the reassembly entity and increment next_expected_TSN to TSN first unacceptable reordering PDU; otherwise set next_expected_TSN to TSN_flush.

29. A method for performing HS-DSCH transmissions.

30. The method of embodiment 29, comprising the step of configuring a MAC-ehs entity to transmit data via the HS-DSCH when the WTRU is in one of the Cell_FACH, Cell_PCH, and URA_PCH states.

31. The method of embodiment 30 comprising transmitting MAC-ehs PDUs, where each MAC-ehs PDU includes a TSN, wherein a TSN is assigned to each WTRU independently.

32. The method of embodiment 31, wherein the TSNs are reset to zero for the new WTRU that has been added to the cell.

33. The method according to any one of embodiments 30-32, further comprising the step of receiving an indication that the message to be transmitted is for the new WTRU.

34. The method of embodiment 33 comprising reinstalling the TSN associated with the common H-RNTI group.

35. The method of embodiment 34, wherein the TSNs are reset after transmitting any previously buffered MAC-ehs PDUs with the same common H-RNTI.

36. WTRU for receiving HS-DSCH transmissions.

37. The WTRU of embodiment 36, which comprises a transceiver.

38. The WTRU of embodiment 37, which comprises a MAC-ehs object for receiving MAC-ehs PDUs via HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states, the reordering PDUs included in the MAC-ehs PDUs being transmitted to the next processing object without performing reordering of reordering PDUs.

39. The WTRU of embodiment 38, wherein the MAC-ehs entity includes a HARQ process for receiving MAC-ehs PDUs.

40. The WTRU of embodiment 39, wherein all MAC-ehs PDUs are transmitted several times and all retransmissions of MAC-ehs PDUs are performed before transmission of a subsequent MAC-ehs PDU begins.

41. The WTRU as in any one of embodiments 39-40, wherein a single HARQ process is used when data comes from a specific prioritized queue, from a specific logical channel, or when data is transmitted using a common H-RNTI.

42. The WTRU as in any one of embodiments 39-41, wherein the MAC-ehs object is configured to not exclude MAC-ehs PDUs for the HARQ process, even if this MAC-ehs PDU is received within five subframes from the last PDU reception MAC ehs destined for the same HARQ process.

43. The WTRU as in any one of embodiments 39-41, wherein the MAC-ehs object is configured to not exclude MAC-ehs PDUs for the HARQ process, even if this MAC-ehs PDU is received within n subframes from the last PDU reception MAC-ehs destined for the same HARQ process, where n is an integer.

44. The WTRU of embodiment 43, wherein the number n depends on the WTRU.

45. The WTRU as in any one of embodiments 43-44, wherein the number n is signaled by a higher level as the ability of the WTRU.

46. The WTRU as in any one of embodiments 39-45, wherein HARQ retransmissions are not performed for MAC-ehs PDUs and all MAC-ehs PDUs are transmitted only once.

47. The WTRU as in any one of embodiments 38-46, wherein the reordering PDUs are transmitted to the next processing entity without performing reordering of the reordering PDUs if the data carried in the reordering PDUs comes from a particular prioritized queue.

48. The WTRU as in any one of embodiments 38-47, wherein the reordering PDUs are redirected to the next processing entity without reordering the reordering PDUs if the MAC-ehs PDUs are received using a common H-RNTI.

49. The WTRU as in any one of embodiments 38-48, wherein the reordering PDUs are transmitted to the next processing entity without reordering the reordering PDUs if the data carried in the reordering PDUs comes from a specific logical channel.

50. The WTRU of embodiment 49, wherein the logical channel is one of the BCCH and PCCH.

51. The WTRU of embodiment 36, which comprises a transceiver.

52. The WTRU of embodiment 51, which contains a MAC-ehs object configured to receive data through the HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states, and if RcvWindow_UpperEdge is set to “Wait” to set RcvWindow_UpperEdge to SN, where SN is the TSN of the received reordered PDU, and to set next_expected_TSN to RcvWindow_UpperEdge is WINDOW_SIZE + 1.

53. The WTRU of embodiment 52, wherein the MAC-ehs is further configured to discard the reordering PDUs if the SN is inside the receive window and if SN <next_expected_TSN or this reordering PDU has been previously received; and - otherwise, to place this reordering PDU in the reordering buffer at the location indicated by said TSN.

54. The WTRU as in any one of embodiments 52-53, wherein the MAC-ehs is further configured to — if the SN is outside the receive window — place the reordering PDU on top of the highest received TSN in the reordering buffer at the location indicated by the SN, set RcvWindow_UpperEdge to SN to update the receive window, and deliver any reordered PDUs with TSN ≤ RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE to the reassembly object.

55. The WTRU as in any one of embodiments 52-54, wherein the MAC-ehs object is configured to — if next_expected_TSN is lower than the updated receive window — set next_expected_TSN to RcvWindow_UpperEdge — RECEIVE_WINDOW_SIZE + 1, and — if the reordered PDU with TSN = next_expected_ in the reordering buffer, to deliver all received reordering PDUs with consecutive TSNs from next_expected_TSN to the first unreceived PDU to the reassembly entity and to increment next_expected_TSN to the TSN of the first unreceived reordering PDU.

56. The WTRU as in any one of embodiments 52-55, wherein the MAC-ehs is configured to — if there is not enough memory to process the received reordered PDU — select TSN_flush so that the next_expected_TSN <TSN_flush≤RcvWindow_UpperEdge + 1 delivers all correctly received reordered PDUs with TSN <TSN_flush to the reassembly entity, and - if the reordered PDU with TSN = TSN_flush was previously received - to deliver all received reordered PDUs with consecutive TSNs with TSN_flush to the first unreceived reordered PDU to the reordered object orc and to increase the next_expected_TSN to TSN of the first not received reordered PDU; otherwise, to set next_expected_TSN to TSN_flush.

57. The WTRU of embodiment 37, which comprises a MAC-ehs object configured to receive data through the HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states, to obtain a TSN to be used in the cell for transmitting MAC-ehs PDUs using a common H-RNTI, and to use said TSN for configuration.

58. The WTRU of embodiment 57, wherein said TSN is reset to a default value for a particular queue when MAC-ehs PDUs are transmitted to a new WTRU.

59. The WTRU of embodiment 37, which comprises a MAC-ehs object configured to receive data through the HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states to place the first MAC-ehs PDU in the reordering buffer if the ordering state matches a wait state, and to set reordering variables based on the TSN of said first MAC-ehs PDU.

60. The WTRU of embodiment 59, wherein RcvWindow_UpperEdge is set to TSN of said first MAC-ehs PDU and next_expected_TSN is set to RcvWindow_UpperEdge to WINDOW_SIZE + 1.

61. The WTRU of embodiment 37, which contains a MAC-ehs object configured to receive data via HS-DSCH in one of the Cell_FACH, Cell_PCH, and URA_PCH states, with the initial value next_expected_TSN being set to the lower edge of the receive window (RcvWindow_UpperEdge - RECEIVE_WINDOW_SIZE_SIZE_SIZE_SIZE_SIZE one).

62. Node-B for HS-DSCH transmissions.

63. The Node-B of embodiment 62, which comprises a transceiver.

64. The Node-B of embodiment 63, which comprises a MAC-ehs configured to transmit data through the HS-DSCH when the WTRU is in one of the Cell_FACH, Cell_PCH, and URA_PCH states, and to transmit MAC-ehs PDUs, each of which includes a TSN, with a TSN being assigned to each WTRU independently.

65. The Node-B of embodiment 64, wherein the TSNs are reset to zero for the new WTRU that has been added to the cell.

66. Node-B according to any one of embodiments 64-65, wherein the MAC-ehs is configured to receive an indication that the message to be transmitted is for a new WTRU and to reset the TSN associated with the common H-RNTI group.

67. The Node-B of embodiment 66, wherein the TSNs are reset after transmitting any previously buffered MAC-ehs PDUs with the same common H-RNTI.

Despite the fact that the functions and elements were described above in specific combinations, each function or element can be used individually, without other functions and elements, or in various combinations with other functions 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, a plurality of microprocessors, one or more microprocessors in connection with a digital signal processor core, a controller, a microcontroller, specialized integrated circuits, programmable 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, terminal, base station, radio network controller, or any host computer. The WTRU can be used in connection with modules implemented in hardware and / or software, such as a camera, camcorder, video phone, speakerphone, vibrating device, speaker, microphone, television transceiver, handsfree headset, keyboard, Bluetooth® module , a frequency-modulated radio (FM) unit, an LCD, an OLED display, a digital music player, a media player, a video game module, an Internet browser and / or any wireless LAN module or an Ultra broadband (Ultra Wide Band, UWB) communications.

Claims (22)

1. A method for receiving transmissions of a High Speed Downlink Common Channel (HS-DSCH), comprising the steps of:
receive HS-DSCH Media Access Control Protocol (MAC-ehs) Protocol Data Units (PDUs) through the HS-DSCH in one of the states of the cell’s direct access channel (Cell_FACH), cell search channel (Cell_PCN) and UTRAN paging channel ( URA_PCH); and
transmit the received PDUs included in the MAC-ehs PDUs to the next processing entity without reordering these received PDUs. 2. The method according to claim 1, in which to receive PDUs MAC-ehs use one process of Hybrid Automatic Repeat Request (HARQ). 3. The method according to claim 2, in which all MAC-ehs PDUs are received several times and all retransmissions of MAC-ehs PDUs are performed before receiving a subsequent MAC-ehs PDU. 4. The method according to claim 2, in which one HARQ process is used for at least one of the receptions from a particular prioritized queue, receptions from a specific logical channel, and receptions using a common HS-DSCH Radio Network Temporary Identifier (H-RNTI). 5. The method according to claim 2, in which the MAC-ehs PDUs for the HARQ process are not excluded, even if this MAC-ehs PDUs are received within five subframes from the last MAC-ehs PDUs destined for the same HARQ process. 6. The method according to claim 2, in which the MAC-ehs PDUs for the HARQ process are excluded even if the MAC-ehs PDUs have been received for n subframes since the last MAC-ehs PDUs destined for the same HARQ process, where n is an integer. 7. The method according to claim 1, in which the received PDUs are transmitted to the next processing entity without performing reordering of the received PDUs if the data carried in the received PDUs comes from a specific prioritized queue. 8. The method of claim 1, wherein the received PDUs are redirected to the next processing entity without reordering the received PDUs if the MAC-ehs PDUs are received using a common HS-DSCH Radio Network Temporary Identifier (H-RNTI). 9. The method of claim 1, wherein the received PDUs are transmitted to the next processing entity without performing reordering of the received PDUs if the data carried in the received PDUs comes from a specific logical channel. 10. The method of claim 9, wherein said logical channel is one of a Broadcast Control Channel (BCCH) or a Search Call Control Channel (RCCH). 11. A wireless transmit / receive unit (WTRU) for receiving transmissions of a High Speed Downlink Common Channel (HS-DSCH), comprising:
transceiver; and
HS-DSCH Media Access Control object (MAC-ehs) for receiving Protocol Data Units (PDUs) of MAC-ehs via HS-DSCH in one of the states of the cell’s direct access channel (Cell_FACH), the cell’s paging channel (Cell_RCН) and the paging channel calling the UTRAN registration area (URA_PCH), the received PDUs included in the MAC-ehs PDUs being transmitted to the next processing entity without reordering the received PDUs. 12. The unit of claim 11, wherein the MAC-ehs entity includes a Hybrid Automatic Repeat Request (HARQ) process for receiving MAC-ehs PDUs. 13. The unit according to item 12, in which all MAC-ehs PDUs are transmitted several times, and all retransmissions of MAC-ehs PDUs are performed before transmission of the subsequent MAC-ehs PDUs begins. 14. The block of claim 12, wherein one HARQ process is used when data originates from a specific prioritized queue, from a specific logical channel, or when this data is transmitted using a common HS-DSCH Radio Network Temporary Identifier (H-RNTI). 15. The block according to item 12, in which the MAC-ehs object is configured so as not to exclude MAC-ehs PDUs intended for the HARQ process, even if this MAC-ehs PDU is received within five subframes from the last MAC-ehs PDU reception, intended for the same HARQ process. 16. The unit according to item 12, in which the MAC-ehs object is configured to exclude MAC-ehs PDUs intended for the HARQ process if this MAC-ehs PDU is received within n subframes from the last MAC-ehs PDUs intended for of the same HARQ process, where n is an integer. 17. The unit according to claim 11, in which retransmissions of the Hybrid Automatic Repeat Request (HARQ) are not performed for MAC-ehs PDUs, and all MAC-ehs PDUs are transmitted only once. 18. The block according to claim 11, in which the received PDUs are transmitted to the next processing object without performing reordering of the received PDUs if the data carried in the received PDUs comes from a certain prioritized queue. 19. The block according to claim 11, in which the received PDUs are redirected to the next processing entity without reordering the received PDUs if the MAC-ehs PDUs are received using a common HS-DSCH Radio Network Temporary Identifier (H-RNTI). 20. The block according to claim 11, in which the received PDUs are transmitted to the next processing entity without reordering the received PDUs if the data carried in the received PDUs comes from a specific logical channel. 21. The block of claim 20, wherein said logical channel is one of a Broadcast Control Channel (BCCH) or a Search Call Control Channel (RCCH). 22. A wireless transmit / receive unit (WTRU) for receiving transmissions of a High Speed Downlink Common Channel (HS-DSCH), comprising:
transceiver; and
The HS-DSCH Media Access Control object (MAC-ehs) configured to receive data via the HS-DSCH in one of the states of the direct access channel of the cell (Cell_FACH), the paging channel of the cell (Cell_PCH) and the UTRAN paging channel (UPJ \ _PCH), and the initial value of the next expected Transmission Sequence Number (next_expected_TSN) is set to the lower edge of the receive window (upper edge of the receive window (RcvWindow_UpperEdge) the size of the receive window (RECEIVE_WINDOW_SIZE) +1).

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