HK1150704B - Method and apparatus for initializing, preserving and reconfiguring token buckets - Google Patents

Description

Method and apparatus for initializing, maintaining, and reconfiguring token buckets

Technical Field

The present application relates to wireless communications.

Background

Fig. 1 illustrates a conventional user plane protocol stack 100 for a Long Term Evolution (LTE) architecture. The stack 100 includes a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer in a Wireless Transmit Receive Unit (WTRU) and corresponding layers in an evolved node-B. The eNB is connected to a System Architecture Evolution (SAE) gateway through an S1-U interface.

According to the third generation partnership project (3GPP) standards, the LTE MAC sublayer supports mapping between logical channels and transport channels. The MAC sublayer supports multiplexing MAC Service Data Units (SDUs) from one or more logical channels onto Transport Blocks (TBs) for delivery to the PHY layer via transport channels. The MAC sublayer also supports demultiplexing of MACs from one or more logical channels in TBs passed from the PHY layer via transport channels. In addition, the MAC sublayer supports logical channel prioritization (prioritization) and transport format selection.

One function of the MAC sublayer is to prioritize logical channels. The MAC entity may receive MAC SDUs from different logical channels from the RLC layer. The MAC entity then multiplexes the SDUs onto one transport channel.

Fig. 2 shows a MAC that multiplexes data from multiple logical channels onto one transport channel. The plurality of logical channels may include a Dedicated Traffic Channel (DTCH), a Dedicated Control Channel (DCCH), or a Common Control Channel (CCCH). In the example of fig. 2, the one transport channel is shown as an uplink shared channel (UL-SCH).

Logical channel prioritization is applied when performing new MAC transmissions. The Radio Resource Control (RRC) sublayer in a WTRU controls the scheduling of uplink data by assigning a priority value to each logical channel. An increased priority value indicates a lower priority level for the logical channel. In addition, each logical channel is assigned a Prioritized Bit Rate (PBR) and a Maximum Bit Rate (MBR). The WTRUs provide resources (service) to all logical channels in decreasing priority order until they reach their configured PBR. If there are still any resources, then the resources are provided to all logical channels in decreasing order of priority until the MBR where they are configured is reached. If the MBR is not configured, resources are provided to the logical channel until either of the data or uplink grants for the logical channel are first exhausted. The WTRU provides resources equally to all logical channels configured with the same priority. The MAC controls elements of a padding bit Buffer Status Report (BSR) having a higher priority than a user plane logical channel, except for the BSR.

In the 3GPP standard, a WTRU has an uplink rate control function that manages the sharing of uplink resources between radio bearers. The RRC controls the uplink rate control function by giving priority and PBR to each bearer. The RRC also provides MBR for each Guaranteed Bit Rate (GBR) bearer. The value signaled by the WTRU may not be related to the value signaled to the eNB via S1. If more than one radio bearer has the same priority, the WTRU provides resources for those radio bearers equally.

There are several proposals that discuss the details of logical channel prioritization and MAC multiplexing. The proposal agrees to specify input parameters and constraints for the output of the WTRU.

The proposal assumes a token bucket (bucket) model for the specification of input parameters. The PBR or MBR is obtained from the WTRU using the token rate, is of fixed size, or is signaled from the eNB. PBR or GBR do not limit the reported buffer status. The proposal uses a token bucket model to describe the rate calculations associated with PBR and MBR, whereby each logical channel can have a token bucket. The rate at which tokens are added to the buckets is PBR and MBR. The size of the token bucket does not exceed a predetermined maximum value.

One proposal describes a process for rate calculation or token bucket calculation. For bearer j with PBR, the PBR credit increase value associated with bearer j is TjxPBRj for each time increment Tj. If the bearer also has an MBR, then the MBR credit increase value associated with bearer j is TjxMBRj. If an upper limit is set for the maximum PBR and if the accumulated values exceed the maximum value, they are set equal to the maximum value. If MBR credits are set for bearer j and if the accumulated values exceed the maximum value, they are set equal to the maximum value. At each scheduling occasion Transmission Time Interval (TTI) where the WTRU is allowed to transmit new data, the scheduler selects data from the highest priority bearer having a non-empty buffer status and non-zero PBR credit. The scheduler may add the smaller of the PBR credit size or TB available capacity to TB data equal to the buffer size. The PBR credit and MBR credit are reduced by the amount of data allocated.

If the PBR credits for all bearers are zero and space is available in the TB, the scheduler receives data from the highest priority bearer with buffered data until the lesser of the available space size in the TB or the MBR credit size of the WTRU is reached. MBR credits are reduced by the amount of data received.

Fig. 3 illustrates a conventional MAC Protocol Data Unit (PDU), which includes a MAC header, a MAC control element, a MAC SDU, and padding bits. Both the MAC header and the MAC PDU are of variable size. The MAC PDU header includes at least one MAC PDU subheader, wherein each subheader corresponds to a MAC SDU, a MAC control element, or a padding bit. The MAC layer may generate MAC control elements, such as BSR control elements. The MAC control element may be identified via a specific value for a logical channel id (lcid), as shown in table 1 below.

Indexing	LCID value
		00000-yyyyy	Identification of logical channels
yyyyy-11100	Retention
		11101	Short buffer status reporting
11110	Long buffer status report
		11111	Filling in

TABLE 1

The indexes 00000-yyyyy shown in table 1 above may correspond to actual logical channels having corresponding RLC entities. The remaining index may be used to identify a MAC control element, such as a BSR or padding.

According to the 3GPP standard, some services and functions of the LTE RLC sublayer include the transmission of upper layer PDUs supporting Acknowledged Mode (AM) or Unacknowledged Mode (UM). The RLC sublayer also includes Transparent Mode (TM) data transfer, error correction by automatic repeat request (ARQ), in-order delivery of upper layer PDUs (except for handover in the upper link), flow control between eNB and WTRU, SDU discard, and RLC reset. Thus, the RLC supports three modes of operation: AM, UM, and TM.

To ensure continuity of service and minimize service interruption, it would be beneficial to provide a method and apparatus for initializing a token bucket, maintaining the token bucket after certain events, reconfiguring the token bucket, and communicating the state of the token bucket using an enhanced BSR or a new control element.

Disclosure of Invention

A method and apparatus are provided for initializing a token bucket to a non-zero value, receiving a scheduling grant, and transmitting data in response to the receiving grant.

A method and apparatus are provided for initiating a Medium Access Control (MAC) reset, deciding whether to retain a value of a token bucket or reinitialize a value of the token bucket during the MAC reset, retaining the value of the token bucket in response to the decision to retain the value of the token bucket, and reinitializing the value of the token bucket in response to the decision to reinitialize the value of the token bucket.

A method and apparatus are provided for receiving a request to generate a token status report, the request received as part of a Medium Access Control (MAC) element, generating the token status report in response to the request, and transmitting a total number of tokens as part of a buffer status report.

Drawings

The invention will be understood in more detail from the following description, given by way of example and understood in conjunction with the accompanying drawings, in which:

figure 1 shows a conventional LTE user plane protocol stack;

fig. 2 is a diagram of conventional MAC mapping and multiplexing for uplink communications;

fig. 3 illustrates a conventional structure of a MAC PDU according to the 3GPP standard specification;

figure 4 illustrates an example wireless communication system including an eNB and a plurality of WTRUs;

figure 5 is an example functional block diagram of a WTRU and an eNB of the wireless communication system shown in figure 4; and

FIG. 6 is an example flow diagram of a method of processing a token report.

Detailed Description

The term "wireless transmit/receive unit (WTRU)" as referred to below includes, but is not limited to, a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a Personal Digital Assistant (PDA), a computer, or any other type of user equipment capable of operating in a wireless environment. The term "base station" as referred to below includes, but is not limited to, a node-B, a site controller, an Access Point (AP), or any other type of interfacing device capable of operating in a wireless environment.

Hereinafter, RLC PDU or RLC PDU segment may be considered to be equivalent to MAC SDU. Further, when referring to updating a token/credit bucket, it may be considered as subtracting a certain number of tokens/credits from a bucket having a number corresponding to the size of a MAC SDU, or adding tokens/credits at a bucket update interval. Additionally, token buckets, or credit calculations, may be considered equivalent to data rate calculations or rate control calculations. Furthermore, the token/credit bucket will be referred to as token bucket hereinafter.

Figure 4 illustrates an example wireless communication system 400 including multiple WTRUs 410 and enbs 420. As shown in fig. 4, a WTRU410 communicates with an eNB 420. Although three WTRUs 410 and one eNB420 are shown in figure 1, it should be noted that any combination of wireless and wired devices may be included in the wireless communication system 400.

Figure 5 is a functional block diagram 500 of the WTRU410 and the eNB420 of the wireless communication system 400 in figure 4. As shown in fig. 5, the WTRU410 communicates with the eNB420 and both may be configured to initialize, maintain, and reconfigure token buckets.

In addition to the components that may be found in a typical WTRU, the WTRU410 includes a processor 415, a receiver 416, a transmitter 417, and an antenna 418. Processor 415 is configured to perform methods of initializing, maintaining, and reconfiguring token buckets. The receiver 416 and the transmitter 417 are in communication with the processor 415. The antenna 418 is in communication with both the receiver 416 and the transmitter 417 to facilitate the transmission and reception of wireless data. The WTRU410 also includes a token bucket management entity 450, the token bucket management entity 450 being described in more detail below.

In addition to the components that may be found in a typical eNB, eNB420 includes a processor 425, a receiver 426, a transmitter 427, and an antenna 428. The processor 425 is configured to perform a method of initializing, maintaining, and reconfiguring token buckets. The receiver 426 and the transmitter 427 are in communication with the processor 425. The antenna 428 is in communication with both the receiver 426 and the transmitter 427 to facilitate the transmission and reception of wireless data.

With continued reference to fig. 5, token bucket management entity 450 processes the token bucket. That is, the token bucket management entity 450 determines whether there is an initialization, handover, reconfiguration, or reset event. If there is a reset event, token bucket management entity 450 performs a bucket reset function. If there is a bucket reconfiguration, token bucket management entity 450 performs a bucket reconfiguration function.

The WTRU410 may be configured to initialize the PBR bucket to a number of tokens corresponding to one token update time interval. Additionally, the WTRU410 may be configured to initialize the MBR bucket to a number of tokens corresponding to one token update interval. For example, PBR may be initialized to a value TjxPBRj and MBR may be initialized to a value TjxMBRj.

Initializing token buckets based on non-zero values allows the WTRU410 to minimize fragmentation and begin transmitting information when the WTRU410 receives scheduling grants instead of beginning to incur delays due to the need to accumulate more tokens.

Alternatively, the maximum value of the bucket may be PBR or MBR at the update rate multiplied by the number of updates. The bucket update rate multiplied by the number of updates can be considered the bucket duration. The WTRU410 may be configured to initialize the PBR and MBR buckets to a number of tokens corresponding to the N token update time intervals. For example, PBR may be initialized to a value NxTjxPBRj and MBR may be initialized to nxtjxmmbrj, where Tj is the token update time increment for the jth bearer and N is a configurable integer. The value of N may be configured using RRC. Alternatively, Nj may be used instead of N.

The WTRU410 may also be configured to initialize the PBR and MBR buckets to their maximum values. The bucket may be initialized to the maximum number of tokens that the bucket is allowed to accumulate. Once a bucket reaches this level, it does not increase in size in subsequent bucket update intervals. The bucket update rate multiplied by the maximum number of updates, N, may be considered the maximum bucket duration.

The WTRU410 may be configured to initialize PBR and MBR to zero. Alternatively, the WTRU410 may be configured to initialize the PBR and MBR to predetermined values, which are indicated using an RRC Information Element (IE) carried in the RRC message. These IEs may include initial values or may include PBR and/or MBR token update sizes, update periods, and maximum bucket sizes or bucket durations.

The token bucket may be maintained at handover or at MAC reset, during which the WTRU410 may maintain the token bucket value. The last value of the PBR bucket and/or MBR bucket determined in the previous cell is used as an initial value in the new cell. Thereby a minimization of service continuity and interruption time can be achieved. The WTRU410 may be configured to not reinitialize the token bucket values during handover or during MAC reset, or the WTRU410 may be configured to maintain the token bucket values during all handover events.

The WTRU410 may be configured to use a predetermined RRC indication to indicate whether the WTRU410 may maintain or re-initialize the token bucket values during the MAC reset. The predetermined RRC indication may be an RRC primitive or an RRC IE. In addition, maintenance of the token bucket may be selectively applied to logical channels. For example, the token bucket value for one logical channel may be maintained while the token bucket value for another logical channel is reinitialized.

Alternatively, if the token bucket is reinitialized during handover or MAC reset, the WTRU410 may be reconfigured to reinitialize the token bucket to a non-zero value during handover or MAC reset. For example, the bucket may be initialized to PBR × Tj or N × PBR × Tj.

During intra-LTE handover, the WTRU410 may move from one cell or eNB420 to another. During a handover operation, the MAC entity may be reset or reconfigured. The MAC entity may also be reset or reconfigured when there is a radio link failure, which may occur due to an RLC reset or an upper layer reset. In each of these cases, the token bucket may be reset or held as described above.

The PBR or MBR of the WTRU410 may be reconfigured by the eNB420 at any time or during handover. Additionally, the reconfiguration of the PBR and/or MBR of the WTRU410 may be performed as part of a MAC reconfiguration procedure.

Thus, the WTRU410 may need to re-initialize the token bucket of the WTRU410 according to the newly configured bit rate. The token bucket management entity 450 may be located at the RRC layer or may be located at the MAC layer (not shown). The calculation of the token bucket size may be performed by MAC or RRC. If the token bucket size calculation is performed by RRC, then RRC can reconfigure the MAC. This may require signaling of primitives between MAC and RRC.

For example, the MAC provides the RRC with the current bucket value of the MAC upon reconfiguration. The RRC then uses the signaled information and reconfiguration parameters to calculate a new bucket value. The RRC signals the new bucket value to the MAC.

Upon PBR or MBR reconfiguration, the WTRU410 may be configured to re-initialize the token bucket. The WTRU410 may be configured to compare the size of the token bucket and the WTRU410 may be configured to resize or scale the size of the token bucket.

Upon PBR or MBR reconfiguration, the WTRU410 may reinitialize the token buckets by initializing the PBR and MBR buckets to the maximum values of the PBR and MBR buckets, respectively. The WTRU410 may be configured to initialize the PBR and MBR buckets to a number of tokens corresponding to the N token update time intervals.

For example, PBR may be initialized to a value of NxTjxPBRj and MBR may be initialized to a value of NxTjxMBRj, where Tj is the token update time increment for j bearers and N is a configurable integer. The value of N may be configured using RRC. Alternatively, Nj may be used instead of N.

Alternatively, the WTRU410 may initialize PBR and MBR to their maximum values or to zero. Alternatively, the WTRU410 may initialize the PBR and MBR buckets to predetermined values using the RRC IE indication carried in the RRC message.

The WTRU410 may initialize the PBR and MBR token buckets to a number of tokens corresponding to one token update interval. For example, PBR may be initialized to a value of TjxPBBRj, and MBR may be initialized to a value of TjxMBRj, where Tj is the token update time increment.

Upon PBR or MBR reconfiguration, the RRC entity of the WTRU410 or the MAC entity of the WTRU410 may be configured to compare the current size of the token bucket to the new specific maximum bucket size. The WTRU may be configured to maintain the current token bucket size if the current token bucket size is less than the new maximum bucket size. The WTRU may be configured to set the bucket size equal to the new maximum bucket size if the current token bucket size is greater than the new maximum bucket size. Setting the bucket size to the minimum of the current bucket size and the new maximum bucket size may be referred to as a token bucket clamp (clamp).

Upon PBR or MBR reconfiguration, the RRC entity of the WTRU410 or the MAC entity of the WTRU410 may be configured to readjust or scale the token bucket size in proportion to the ratio of the maximum bucket size. For example, the number of new tokens is a function of the number of old tokens multiplied by the ratio of the new maximum bucket size to the old maximum bucket size. The token bucket is then scaled relative to the ratio of the old maximum bucket size to the new maximum bucket size.

Alternatively, the token bucket size may be scaled in proportion to the ratio of the bit rates. For example, the size of the new token is a function of the number of old tokens multiplied by the ratio of the new bit rate to the old bit rate. The token bucket is then scaled relative to the ratio of the old bit rate to the new bit rate.

Fig. 6 shows a diagram of a token status report. The eNB420 transmits a request to the WTRU410 to request the WTRU410 to generate a signaling status report (step 605). The request from eNB420 is received as a new MAC control element or part of an RRC IE in an RRC message. The event that triggers the eNB420 to transmit the request to the WTRU410 is determined by the eNB implementation. For example, the trigger event may be as defined below.

The WTRU410 may be configured to generate a token status report requested by the eNB420 (step 610). The WTRU410 may be configured to transmit a total number of tokens upon a triggering event. This information may be communicated as part of a Buffer Status Report (BSR) (step 615). The WTRU410 may be configured to transmit a token status report that includes the WTRU 410's current PBR or MBR token bucket value. The token status report may also contain any information related to or obtained from the token bucket.

The token status report may be included as an enhancement to the BSR. For example, the enhanced BSR may include information of the token bucket. The token status report may be included in the new MAC control element. Alternatively, the token status report may be included in an RRC IE, which is included in the RRC. The WTRU410 may generate a token status report based on the internal trigger.

The internal trigger and trigger event may be any one of the following: handover, MAC reset, reset at a specific layer, MAC reconfiguration, reconfiguration at a specific layer, and request from eNB. The trigger event or internal trigger may be periodic, or at any other predefined time or event.

The WTRU410 may be configured to generate a token status report in response to a request from the eNB 420. The eNB420 can use the ability of token status reporting to optimize scheduling operations. The eNB420 may be configured to synchronize the local computation of the eNB420 with the computation of the WTRU410 using token status reporting capabilities. Further, eNB420 may reconfigure the bit rate parameters or token bucket values after receiving the token status reporting capability.

The token status report may include the absolute size of the PBR or MBR buckets, the PBR or MBR bucket size relative to the maximum bucket size of the PBR or MBR buckets, a bit indicating whether the PBR or MBR buckets are full, a bit indicating whether the PBR or MBR buckets are empty, an indication of whether the WTRU410 is a PBR or MBR-limited WTRU, or any other information related to or obtained from the PBR or MBR token. The information may be aggregated over multiple logical channels or buckets, or on a per logical channel basis.

The BSR is enhanced to provide token status reporting information by extending the BSR. For example, the BSR may include an extension flag. Alternatively, the WTRU410 may be configured to transmit the total number of aggregated tokens, PBR or MBR tokens to the eNB420 as part of the BSR to assist the eNB420 in scheduling. Alternatively, the WTRU410 may be configured to compare the aggregated tokens to a predefined threshold, which may be configured by the RRC IE. The WTRU410 may then be configured to report a value of 1 if the number of aggregated tokens reaches a predefined threshold, or a value of 0 if the number of aggregated tokens does not reach a predefined threshold.

Examples

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

a processor configured to initialize a token bucket to a non-zero value.

2. The WTRU of embodiment 1, further comprising:

a receiver configured to receive a scheduling grant; and

a transmitter configured to transmit data in response to receiving the grant.

3. The WTRU as in any of embodiments 1-2 wherein the processor is further configured to initialize the token bucket based on a maximum value of a Prioritized Bit Rate (PBR).

4. The WTRU of embodiment 3 wherein the PBR is initialized based on a number of tokens corresponding to a token update time interval.

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

a processor configured to initiate a Medium Access Control (MAC) reset.

6. The WTRU of embodiment 5, wherein the processor is further configured to maintain a value of a token bucket during the MAC reset.

7. The WTRU as in any of embodiments 5-6, wherein the processor is further configured to initiate the MAC reset in response to a handover command.

8. The WTRU as in any one of embodiments 6-7 wherein values of the token bucket are maintained until a logical channel has been established.

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

a processor configured to trigger a handover.

10. The WTRU of embodiment 9 wherein the processor is further configured to reset a Medium Access Control (MAC) layer during the handover and reset a token bucket to a non-zero value.

11. The WTRU of embodiment 10 wherein the processor is configured to reset the token bucket based on a ratio of a new maximum bucket size to an old maximum bucket size.

12. The WTRU as in any one of embodiments 10-11 wherein the processor is further configured to compare a current size of the token bucket to a new predetermined maximum bucket size in response to a reconfiguration.

13. The WTRU of embodiment 12 wherein the processor maintains the current size of the token bucket if the current size is less than the maximum bucket size.

14. The WTRU as in any one of embodiments 12-13 wherein if the current size is greater than the maximum bucket size, the processor uses the token bucket size as the maximum size.

15. The WTRU as in any one of embodiments 10-14 wherein the processor is further configured to readjust the token bucket based on a ratio between a new maximum size and an old maximum size.

16. The WTRU as in any one of embodiments 10-15 wherein the processor readjusts the token bucket based on a ratio of a new bit rate to an old bit rate.

17. The WTRU as in any one of embodiments 10-16 wherein the processor is further configured to reinitialize the token bucket based on a maximum value of a Prioritized Bit Rate (PBR).

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

a receiver configured to receive a request to generate a token status report, wherein the request is received as part of a Medium Access Control (MAC) element.

19. The WTRU of embodiment 18, comprising:

a processor configured to generate the token status report in response to the request; and

a transmitter configured to transmit the total number of tokens as part of a buffer status report.

20. The WTRU as in any one of embodiments 18-19 wherein the request is received in response to a MAC reset.

21. The WTRU as in any one of embodiments 18-20 wherein the request is received in response to a MAC reconfiguration.

22. The WTRU as in any one of embodiments 18-21 wherein the request is received in response to a layer reset.

23. The WTRU as in any one of embodiments 18-22 wherein the request is received in response to a layer reconfiguration.

24. The WTRU as in embodiment 19 wherein the transmitter is further configured to transmit the token status report including a Prioritized Bit Rate (PBR) token bucket value.

Although the features and elements of the present invention are described in the particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements. The methods or flow charts provided herein may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of the computer-readable storage medium include Read Only Memory (ROM), Random Access Memory (RAM), registers, buffer memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and Digital Versatile Disks (DVDs).

For example, suitable processors include: a general-purpose processor, a special-purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any Integrated Circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a Wireless Transmit Receive Unit (WTRU), User Equipment (UE), terminal, base station, Radio Network Controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a video phone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, and BluetoothA module, a Frequency Modulation (FM) radio unit, a Liquid Crystal Display (LCD) display unit, an Organic Light Emitting Diode (OLED) display unit, a digital music player, a media player, a video game player module, an internet browser, and/or any Wireless Local Area Network (WLAN) or Ultra Wideband (UWB) module.

Claims (14)

1. An apparatus for wireless transmission reception, the apparatus comprising:

means for initializing a token bucket to a non-zero value in response to a reset of a medium access control, MAC, layer initiated by a handover command, the reset of the MAC layer changing a size of the token bucket, and the initialization minimizing data fragmentation transmitted by the WTRU after the reset of the MAC layer; and

means for generating a token status report.

2. The apparatus of claim 1, wherein the non-zero value is based on a ratio of a new maximum bucket size to an old maximum bucket size.

3. The apparatus of claim 1, wherein the apparatus further comprises means for comparing a current size of the token bucket to a newly determined maximum bucket size in response to a reconfiguration.

4. The apparatus of claim 3, wherein a current size of the token bucket is maintained if the current size is less than the maximum bucket size.

5. The apparatus of claim 3, wherein the size of the token bucket is adjusted to the maximum bucket size if the current size is greater than the maximum bucket size.

6. The apparatus of claim 3, wherein the apparatus further comprises means for resizing the token bucket based on a ratio of the newly determined maximum bucket size to a previous maximum bucket size.

7. The apparatus of claim 3, wherein the apparatus further comprises means for resizing the token bucket based on a ratio of a new bit rate to an old bit rate.

8. The apparatus of claim 3, wherein the non-zero value is based on a maximum value of a Prioritized Bit Rate (PBR).

9. The apparatus of claim 8, wherein the PBR is initialized based on a number of tokens corresponding to a token update interval.

10. An apparatus for wireless transmission reception, the apparatus comprising:

means for receiving a request to generate a token status report, wherein the request is received as part of a Medium Access Control (MAC) element, the token status report comprising a Prioritized Bit Rate (PBR) token bucket value and a current PBR token bucket size relative to a maximum PBR token bucket size;

means for generating the token status report in response to the request; and

means for transmitting the total number of tokens as part of a buffer status report.

11. The apparatus of claim 10, wherein the request is received in response to a reset of a MAC.

12. The apparatus of claim 10, wherein the request is received in response to a MAC reconfiguration.

13. The apparatus of claim 10, wherein the request is received in response to a reset of a layer.

14. The apparatus of claim 10, wherein the request is received in response to a reconfiguration of a layer.