HK1189722B - A flexible segmentation scheme for communication systems - Google Patents

Description

Flexible segmentation scheme for communication systems

The application is a divisional application of Chinese invention patent applications with application numbers of 200780005634.4 (international application numbers of PCT/IB2007/000020), international application dates of 2007 of 1, 4 and invented name of 'a flexible segmentation scheme for communication systems'.

Technical Field

The exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems and, more specifically, relate to segmentation schemes.

Background

The following abbreviations are thus defined:

3G third generation mobile network

AR access router

ARQ automatic repeat request

BS base station (also called node B)

E-UTRAN evolved universal terrestrial radio access network

HSDPA high speed downlink packet access

IP internet protocol

L1 layer 1 (physical layer)

L2 layer 2(MAC layer)

LCID logical channel identification

MAC media access control layer (L2)

PHY physical layer (L1)

PDU protocol data unit

QoS quality of service

RNC radio network controller

SDU service data unit

SSN Service Data Unit (SDU) sequence numbers

TB transport block

TCP transmission control protocol

UDP user datagram protocol

UE user equipment

UL uplink

UTRAN Universal terrestrial radio access network

VoIP voice over internet protocol

WCDMA wideband code division multiple access

WLAN wireless local area network

In E-UTRAN, application flows with different QoS requirements are provided over the radio path by different logical channels in the MAC protocol layer. MAC SDUs, which are higher layer packets such as IP packets, are queued in a priority queue, which is arranged for logical channels. The amount of data to be transmitted for each logical channel is determined for each radio frame transmission, which attempts to meet the QoS requirements of each IP traffic flow. Then, for each UE, the MAC multiplexes (concatenates) the scheduled data from the priority queue into one TB. In this procedure, the MAC may need to segment MAC SDUs to make them fit into TBs. After triggering the TBs from the MAC, the PHY multiplexes the TBs from different UEs into radio frames.

In prior art cellular systems (e.g. 3G), SDUs are segmented and concatenated into constant size PDUs, which are defined for each transport channel. This increases the segmentation and multiplexing overhead. The reason is that the transmission capacity of the wireless link changes over time and small payloads are often available. Therefore, PDUs of constant size are usually required to be small. Small PDUs fit well to low rate channels but will cause much overhead when segmenting large SDUs into small PDUs. On the other hand, many small PDUs need to be created for the high rate channel, which will cause multiplexing overhead. Preferably, the PDU size should be modified according to the capability of the transport channel and its temporary condition. However, the modification of the PDU size in 3G requires a large number of point-to-point procedures and re-segmentation. Therefore, it is not generally preferred.

In prior art wireless systems (e.g., WLAN), SDUs are transmitted as full packets. Multiple access is based on random access/collision detection in the uplink and scheduling in the downlink. Thus, once transmission resources are indicated for a given user, it is allowed to use the full bandwidth for a short period as required for the transmission of the entire SDU available. In this way, there is less fragmentation and multiplexing overhead. However, the desired large multi-user multiplexing gain will not be available.

The problems of these prior art segmentation schemes are even more pronounced in newer cellular and wireless systems, where the available bandwidth is large, bandwidth flexibility is large and the symbol rate is high, but varying radio conditions give the transmission of each radio link receiver-dependent and time/frequency-dependent characteristics. On the other hand, for any receiver, the gain obtainable by frequency scheduling, the gain obtainable by exploiting frequency diversity in the channel, and the gain obtainable by adaptive transmission bandwidth selection are significant. Also, the multi-user gain achieved by efficiently allocating independent radio links in time and frequency is significant. Therefore, the segmentation scheme should be flexible and efficient, allowing any of these types of transmission techniques to be used. The mentioned prior art schemes, i.e. fixed PDU sizes and trivial segmentation schemes, do not efficiently comply with these contradictory requirements. In such conditions, full SDU transmission is feasible and generally preferred for low overhead. However, segmentation may still be required for large SDUs to be received over difficult low bit rate wireless links.

In the conventional segmentation methods for WCDMA and HSDPA, segmentation is performed before the TB size is decided. Thus, the system may only deliver fixed size or at least off-the-shelf segments, and therefore the segments must be concatenated to effectively fill the TB. This increases the amount of headers and complicates the process by trying to match the segments to the tail of the TB.

In another prior art segmentation scheme, SDU retransmission using SSN is used. However, full SDU retransmission is generally inefficient and may cause problems under low bit rate radio link conditions. Efficiency also depends on the size distribution and traffic class of the data. If an application generates large TCP/UDP segments in an IP packet and the system bandwidth is narrow, one SDU must be segmented into many small segments. For example, the Maximum Transmission Unit (MTU) or Maximum Segment Size (MSS) of an IP packet over ethernet is typically 1500 bytes, and one subframe over a 1.25MHz system with 1/2 code rate and Quadrature Phase Shift Keying (QPSK) modulation has only about 450 information bits. For this system this means that one SDU will be segmented into 28 segments, which therefore increases the probability of SDU errors. A large SDU in such a system will likely be retransmitted one or more times. Not only will the throughput of the radio link be greatly reduced, but the cell throughput will also be reduced because retransmissions are usually prioritized.

Disclosure of Invention

In an exemplary aspect of the invention, a method is provided. The method comprises the following steps: determining a size of a transport block based on a criterion including a size of at least one data block to be transmitted, wherein the transport block size is determined such that the transport block will include at least one segment of a data block of the at least one data block; segmenting a data block of the at least one data block into a plurality of segments including at least one segment; and filling the transport block with at least the at least one segment.

In another exemplary aspect of the invention, a computer program product is provided. The computer program product includes program instructions embodied on a tangible computer-readable medium. Execution of the program instructions results in operations comprising: determining a size of a transport block based on a criterion including a size of at least one data block to be transmitted, wherein the transport block size is determined such that the transport block will include at least one segment of a data block of the at least one data block; segmenting a data block of the at least one data block into a plurality of segments including the at least one segment; and filling the transport block with at least the at least one segment.

In other exemplary aspects of the invention, another method is provided. The method comprises the following steps: segmenting the data block into a plurality of segments, wherein each segment of the plurality of segments has a data block identifier, a length value, and an offset value, wherein the data block identifier has an identification of the segmented data block, wherein the length value has a length of the segment, wherein the offset value has a boundary of the segment relative to the segmented data block, wherein the segmented data block is to be transmitted by a plurality of transmission blocks; filling a transport block of the plurality of transport blocks with at least one segment of the plurality of segments; and retransmitting the indicated segment in response to receiving a retransmission notification indicating a segment of the plurality of segments, wherein the retransmission notification includes a data block identifier, a length value, and an offset value for the indicated segment.

In another example, a computer program product is provided. The computer program product includes program instructions embodied on a tangible computer-readable medium. Execution of the program instructions results in operations comprising: segmenting a data block into a plurality of segments, wherein each segment of the plurality of segments has a data block identifier, a length value, and an offset value, wherein the data block identifier comprises an identification of a segmented data block, wherein the length value has a length of the segment, wherein the offset value has a boundary relative to the segment of the segmented data block, wherein the segmented data block is transmitted by a plurality of transmission blocks; filling a transport block of a plurality of transport blocks with at least one segment of the plurality of segments; and retransmitting the indicated segment in response to receiving a retransmission notification indicating a segment of the plurality of segments, wherein the retransmission notification includes the data block identifier, the length value, and the offset value for the indicated segment.

In another exemplary aspect of the present invention, an electronic device is provided. The electronic device includes: a memory configured to store at least one data block to be transmitted through a transport block; and a data processor coupled to the memory, wherein the data processor is configured to perform operations comprising: determining a size of a transport block based on a criterion of a size of a data block comprising at least one data block, wherein the transport block size is determined such that the transport block will comprise at least one segment of the data block; segmenting a data block into a plurality of segments including at least one segment; and filling the transport block with at least the at least one segment and at least one full data block.

In another exemplary aspect of the present invention, an information block is provided. The information block is to be transmitted from the first node to the second node and stored on a tangible computer readable medium prior to transmission. The information block includes: a portion of a data block, wherein the portion of the data block does not include a complete data block; the data block identifier has an identification of the data block; the length value has the size of the portion of the data block; and the offset value has a boundary of the portion of the data block relative to the complete data block.

In another exemplary aspect of the present invention, an electronic device is provided. The electronic device includes: a data processor; and a transmitter coupled to the data processor. The transmitter is configured to transmit a retransmission notification indicating a segment of the plurality of segments. The retransmission notification includes a request to retransmit the indicated segment. The plurality of segments includes segmented data blocks. The retransmission informs the data block identifier, the length value, and the offset value of the segment with the indication. The data chunk identifier has an identification of the segmented data chunk. The length value has the length of the indicated segment. The offset value has an indicated boundary of the segment relative to the segmented data block.

Drawings

The foregoing and other aspects of the invention will become more apparent in the following detailed description when read in conjunction with the accompanying drawings, wherein:

FIG. 1A shows a simplified block diagram of various electronic devices when connected to a wireless network suitable for use in implementing exemplary embodiments of the present invention;

FIG. 1B shows a simplified block diagram of various electronic devices suitable for use in implementing exemplary embodiments of the present invention when connected to a base station (which itself is connected to a network with one or more access routers);

FIG. 2 illustrates an exemplary segmentation structure of a segment as used in an exemplary embodiment of the present invention;

FIG. 3 illustrates a data flow for implementing an exemplary embodiment of the present invention;

fig. 4 illustrates a detailed message signaling diagram for a downlink data transmission procedure of an exemplary embodiment of the present invention;

fig. 5 illustrates a detailed message signaling diagram for an uplink data transmission procedure of an exemplary embodiment of the present invention;

fig. 6 shows a detailed message signaling diagram for an uplink data transmission procedure of an exemplary embodiment of the present invention on a longer time scale than fig. 5;

fig. 7 shows a detailed message signaling diagram for an uplink data transmission procedure of another exemplary embodiment of the present invention on a longer time scale than fig. 5;

FIG. 8 illustrates an exemplary embodiment of the present invention with vector passing per logical channel arrangement;

fig. 9 illustrates a message sequence diagram for an exemplary embodiment of the present invention using the LCID and SDU of fig. 8;

fig. 10 illustrates an exemplary embodiment of the present invention in which SDUs are segmented based on a determined TB size;

fig. 11 shows other implementations of the exemplary embodiment of fig. 10 in which the SDU is further segmented based on another determined TB size;

FIG. 12 illustrates a flow chart showing one non-limiting example of a method for implementing exemplary embodiments of the present invention; and

FIG. 13 illustrates a flow chart showing another non-limiting example of a method for implementing an exemplary embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention improve both transmission efficiency and segmentation efficiency by providing an intelligent TB size determination method and a flexible segmentation scheme for retransmission. The description focuses on downlink transmissions and is mainly for the BS, but these are non-limiting exemplary embodiments of the invention. Additional exemplary embodiments of the present invention include various applications of the method for UE and UL transmissions. In the transmission example of the downlink, the receiver function is located in the UE. In the uplink transmission example, the receiver function is located in the BS. Note that the present invention can be applied to any protocol layer having a segmentation and retransmission function. As a non-limiting example, it may be applied to the L1/L2 interface of E-UTRAN.

Reference is first made to FIG. 1A, which illustrates a simplified block diagram of various electronic devices that are suitable for use in implementing the exemplary embodiments of this invention. In fig. 1A, a wireless network 1 is adapted to communicate with a UE10 via a node B (base station) 12. The network 1 may include an RNC14, which may be referred to as a serving RNC (srnc). The UE10 includes a Data Processor (DP)10A, a memory (MEM)10B storing a Program (PROG)10C, and a suitable RF transceiver 10D (with a Transmitter (TX) and a Receiver (RX)) for bidirectional wireless communication with the node B12, the node B12 further includes a DP12A, a MEM12B storing a PROG12C, and a suitable RF transceiver 12D. The node B12 is coupled via data path 13(Iub) to an RNC14 that also includes a DP14A and a MEM14B that stores an associated PROG 14C. The RNC14 may be coupled to another RNC (not shown) by another data path 15 (Iur). At least one of the PROGs 10C, 12C, and 14C is assumed to include program instructions that, when executed by the associated DP, enable the electronic device to operate in accordance with the exemplary embodiments of this invention, as will be discussed in greater detail below.

FIG. 1B illustrates a simplified block diagram of various electronic devices suitable for use in implementing exemplary embodiments of the present invention. As shown in fig. 1A, fig. 1B illustrates a wireless network suitable for communicating with a UE10 via a node B (base station) 12. The UE10 includes a Data Processor (DP)10A, a memory (MEM)10B storing a Program (PROG)10C, and a suitable RF transceiver 10D (with a Transmitter (TX) and a Receiver (RX)) for bidirectional wireless communication with the node B12, the node B12 further includes a DP12A, a MEM12B storing a PROG12C, and a suitable RF transceiver 12D. Node B12 is coupled to network 17 via data path 16. Network 17 includes one or more Access Routers (ARs) 17A, 17B, and 17C to facilitate connectivity with node B12. At least one of the PROGs 10C and 12C is assumed to include program instructions that, when executed by the associated DP, enable the electronic device to operate in accordance with the exemplary embodiments of this invention, as will be discussed in greater detail below.

In general, the various embodiments of the UE10 can include, but are not limited to, cellular telephones, Personal Digital Assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, internet appliances permitting wireless internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.

Embodiments of the present invention may be implemented by computer software executable by the DP10A of the UE10 and other DPs such as the DP12A, or by hardware, or by a combination of software and hardware.

The MEMs 10B, 12B, and 14B may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 10A, 12A, and 14A may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), processors based on a multi-core processor architecture, and Application Specific Integrated Circuits (ASICs), as non-limiting examples.

Exemplary embodiments of the present invention provide a TB size determination method considering an SDU boundary and a flexible segmentation scheme allowing flexible segment retransmission. According to an exemplary embodiment of the present invention, the TB size is determined in consideration of an SDU boundary and segmentation is performed after the TB size has been determined. If the TB size and SDU boundary are given, the MAC segments the MAC SDUs to fit them into the TB by considering the boundary of the MAC SDUs. For example, if a MAC SDU is very small, such as for a VoIP packet, the MAC does not segment the SDU at all. Another non-limiting example of a small MAC SDU is TCP acknowledgement. Further, if the remaining part of the SDU is very small, further segmentation is avoided, if possible. Each TB conveys as many as possible of all, unsegmented SDUs. In the remainder of the TB, i.e. the part that cannot be filled by a complete SDU, a sequence of bytes (variable length segments of SDUs) is inserted to fill the TB. Note that the header, which is the payload overhead, can be subtracted from the variable length SDU size that exactly fills the TB.

With respect to retransmission techniques, exemplary embodiments of the present invention provide a fragmentation structure using offset and length fields. "offset" and "length" refer to the starting position of a segment in the original SDU and the length of the segment (e.g., in bytes), respectively. The receiver is configured to maintain a receiver window for the full SDU by signaling an offset and length for segments of the partially transmitted SDU. The receiver window indicates which SDUs are missing, which SDUs have been received in their entirety, which SDUs have been received partially, and which portion(s) of SDUs are missing. A partially received SDU may have one or more segmentation misses. However, once the later segments are correctly received, the receiver can track between offsets with missing data. In fact, the receiver does not need to know whether the transmitter initially attempted to deliver the missing portion in one or more segments. When generating the ARQ status report, the receiver calculates the missing data between the received offsets for any partially received SDU. Thus, the retransmission request is an indication from (offset (early) + length) to the offset (late) part, which is announced as a retransmission request; offset is offset (early + length) and length is offset (late) - (offset (early) + length). After the transmitter receives an ARQ status report or Negative Acknowledgement (NACK), the transmitter retransmits the missing data for the requested missing full SDU and the requested partially missing SDU. The transmitter may decide to retransmit the entire SDU or only the missing segment. Using the fragmentation scheme of the present invention, the retransmission of the missing fragments is not necessarily the original fragment size compared to the original transmission, and the transmitter can append them to TB transmissions in a larger number of smaller fragments or a smaller number of larger fragments. The selection may also depend on the TB size, which is determined at this time based on frame scheduling (multiuser scheduling) and logical channel priority.

As a non-limiting example, one method used in connection with the exemplary embodiments of this invention may include using a segment sequence number to indicate a renumbering (i.e., offset value) of the segment. In general, using the segment sequence numbers of the retransmission requests independently of aspects of the exemplary embodiments of this invention is not preferred because the segment sizes may change depending on the radio link conditions and their retransmissions in accordance with the segment sequence numbers will require re-segmentation and re-numbering. However, in this case, the segment sequence number (of the re-segmented segments having re-numbered segment sequence numbers) may be used in conjunction with aspects of the exemplary embodiments of this invention, for example, by using the segment sequence number as an offset value for the boundary that includes the indicated segment.

For large SDUs that require retransmission, the transmitter may segment only the missing portions of the large SDU and attempt to deliver them again, potentially as a sequence of smaller segments. (note that re-segmentation is not necessary, since in the prior art, instead, the full SDU, which is not segmented, resides in the priority queue). Such smaller segments will consume the margin (margin) capacity of the subframe and cell throughput will be maintained by other serving radio links even if the throughput of a particular radio link drops significantly. Also, more robust transport formats (low order modulation, low rate channel coding, enhanced diversity mode) may be applied to smaller segments than transport format selection for larger segments or full SDUs. Note that retransmissions that are not suitable for smaller segments or more robust transport formats are also possible and within the scope of the exemplary embodiments of this invention.

When the TB size for each radio link (UE) is determined in a given subframe instance, the SDU boundaries are taken into account, as a non-limiting example, in addition to other factors such as the expected channel conditions for that radio link, each priority queue according to the logical channel, and the amount of data to be transmitted according to the priority of the UE. The amount of data to be transmitted may be any amount from the minimum guaranteed data in the queue to all available data. This becomes possible because the scheduler and allocation function has a large degree of freedom to schedule less UEs per subframe with a larger payload less frequently or more UEs per subframe with a smaller payload more frequently. These choices result in different transmission gain factors and different amounts of fragmentation and multiplexing overhead.

In an exemplary embodiment of the present invention, the two methods identified herein as (a) and (B) may be used when requesting data transmission.

(A) The amount of data to be transmitted for each traffic flow (priority queue) and the mac sdu boundaries closest to these values are provided. Then, the TB size allocated to each UE is determined by using all available information so that the block size contains an SDU with a minimum value or no segmentation.

(B) The amount of data to be transmitted for each traffic flow (priority queue), referred to herein as SDU alignment data amount, is calculated based on the scheduling decision and aligned as much as possible to the SDU boundaries. When data transmission is requested, the SDU alignment data volume is provided.

The block size is determined using one of two methods, given the information, in order to avoid fragmentation as much as possible. However, this is only a guide and if, for example, the difference is large, the block size or requested data size does not have to always align with the SDU boundaries.

For method (a) above, a vector is provided using the interface that includes the minimum amount of data to be transmitted and the MAC SDU boundary closest to the minimum amount (the element corresponding to the traffic flow). Other parameters such as priority may also be provided using the interface.

For method (B) above, a vector of SDU alignment data quantities (the elements correspond to traffic flows) is provided. Other parameters such as priority may also be provided using the interface.

If a TB size is given, segmentation is performed in order to group SDUs into TBs, if necessary. Each segment includes an SDU sequence number, length, and a partial SDU, where the partial SDU additionally includes a segment offset within the full SDU. As described above, the "offset" indicates the start position of the segment in the original SDU and the "length" indicates the length of the segment, which may be in bytes.

Fig. 2 shows an exemplary segmentation structure of the segment 20. The fragment 20 comprises a fragment header 21 and a payload 26. The segment header 21 includes an SDU Sequence Number (SSN)22, a length value OF the segment 23, an offset value 24 (optional), and Other Fields (OF)25 in the segment header, if desired. The payload 26 contains information from the SDU.

When retransmission is required, the receiver can request retransmission of the missing SDU by indicating the SSN. The receiver may request retransmission of the missing portion of the SDU by indicating the SSN, offset, and length of the missing portion. These retransmission requests are signaled in an ARQ status report. When retransmission is requested and the original segment size cannot be accommodated by a given new TB size, the transmitter can perform segmentation for any size by using the length and offset fields.

Fig. 3 shows the data flow. Starting from the logical channel queues 30, 34, the MAC SDUs are segmented 31, 35 if necessary and multiplexed (concatenated) 32, 32 into transport blocks 33, 37 for each UE. The TBs 33, 37 are then multiplexed 38 into a physical radio frame 40 and sent out via L139. As shown, for TB-n37, TB33, 37 includes a header with one or more combinations of SDUs, represented in the figure as SUD1 and SDU2 and/or fragments. The radio frame 40 includes a header with one or more multiplexed TBs, denoted TB-1 and TB-n in the figure.

Fig. 4 and 5 show detailed message signaling diagrams of downlink and uplink data transmission procedures, respectively. The amount of data to be transmitted for each logical channel for each UE is determined according to scheduling (e.g., at the MAC layer). The MAC then provides vector information for the amount of data (which may be option (a) or (B) above), where each element corresponds to each logical channel. In this vector information, SDU boundaries are considered. The allocation unit then determines the TB size (e.g., at the PHY) by using given information including, among other factors, the amount of data and radio link conditions, and returns the TB size information to the MAC layer for each active radio link. If the TB size is given, the MAC starts segmentation by considering the SDU boundaries. The segmented structure may be as shown in fig. 2. Retransmissions (at the MAC layer) may use flexible segment sizes according to the present invention.

For the above signal transmission process, the primitives are defined in table 1.

TABLE 1

Fig. 6 and 7 show two different candidate message signal transmission diagrams for an uplink data transmission procedure on a longer time scale than fig. 5. In order to implement uplink packet scheduling in the BS as described in fig. 5, the UE informs the BS of the amount of uplink data to be scheduled in the next uplink scheduling period. In these candidate examples, the uplink scheduling period is set to a plurality of radio frames. For this uplink data indication from the UE to the BS, an RRC message (e.g., a capacity request message) and a MAC control PDU (e.g., an uplink buffer status report) are used in fig. 6 and 7, respectively. Any of these may be used in exemplary embodiments of the present invention.

Fig. 8 shows an overview of a flexible fragmentation method including retransmission. The figure shows the invention with vector delivery arranged for each logical channel. "KSx, y" and "LSx, y" denote the y-th segment of the K-th logical channel of SDU number x and the y-th segment of the L-th logical channel of SDU number x, respectively. For different logical channels K and L, the SDU boundaries are considered. The use of offsets and lengths for retransmissions enables fully flexible segment sizes. The method used supports the transmission of complete SDUs, but it further allows segmentation of SDUs into any byte aligned size, which is decided at the transmission moment. Therefore, the segment size can be freely changed for any retransmission. Included in addition to the full SDU error bitmap is an ARQ status report, which may inform the offset and length of missing segments of a partially received SDU.

In FIG. 8, five TBs are depicted, numbered 1 through 5 (i.e., TB)₁To TB₅). Among the five TBs, no TB was received₂And TB₃. Thus, according to an exemplary embodiment of the present invention, in TB₅And (3) medium retransmission LS1, 2 and LS1, 3 (also called LS1, 23).

Fig. 9 is a message sequence diagram based on the LCID, SDU and TB of fig. 8. As the transmission progresses, the Transmitter (TX) and Receiver (RX) windows show their respective contents. According to an exemplary embodiment of the present invention, the receiver initially receives partial SDUs LS1, 1 and LS1, 3 which fail later in the TB₅Is retransmitted as LS1, 23. As mentioned above, the retransmission request for SDU LS1, 23 may include an ARQ status report or NACK, as non-limiting examples.

Fig. 10 illustrates an exemplary embodiment of the present invention in which an SDU is segmented based on a determined TB size. In FIG. 10(A), three SDUs are shown, SDU₀62、SDU₁64 and SDU₂66 each having a length L₀、L₁And L₂. As shown, L₀100 bytes, L₁400 bytes and L₂300 bytes. Three SDUs 62, 64, 66 of fig. 10(a) will be transmitted.

In fig. 10(B), based on size L including SDU62₀Size L of SDU64₁And size L of SDU66₂To determine TB₁Length (L) of 68_TB1). As a non-limiting example of this process, consider the following. It is desirable to transmit at least one complete SDU. Therefore, the TB size should preferably not be less than 100 bytes (i.e. the TB should preferably be able to accommodate at least the smallest SDU, SDU₀62). However, due to scheduling and logical channel priority, the communication link and SDU have been allocated 200 bytes (TB) for that particular time and TB formation₁Length L_TB1200 bytes). Although shown in FIG. 10(B) for illustrative purposes, TB is₁68 have not actually been created (e.g., filled).

Since it is desirable to transmit the complete SDU, TB, when possible₁68 would include SDU₀62. Thus, a length equivalent to 100 bytes will be left to be padded, possibly by one or more other SDUs, SDUs₁64 and/or SDU₂66 filling.

In fig. 10(C), based on the above preference for transmission of at least one complete SDU and further based on the determined TB₁Length L_TB1SDU (here, SDU)₁64) Segmenting into a plurality of segments, segment 1-1 (S)_1-1)70 and the segments 1-R (S)_1-R)72, each segment having a corresponding 100 bytes (L)_1-1) And 300 bytes (L)_1-R) Length of (d). Will SDU₁64 are intentionally segmented to produce a segment having a length L of 100 bytes_1-1S of_1-170, so that S_1-170 is a padding TB₁Suitable size of the usable portion of 68, in TB₁68 has passed through SDU₀62 after filling, the usable part becomes TB₁68. In anotherIn TB, SDUs can be transmitted in whole or in part₁The remainder of 64, i.e. S_1-R72. (see FIG. 11 and the following discussion thereof.)

In FIG. 10(D), SDU₀62 and S_1-170 pack TB₁68. The TB₁68 may then be transmitted using the methods and components discussed in fig. 3, as a non-limiting example.

It is obvious that TB₁Size L of 68_TB1By considering the length L of the SDU62₀Length L of SDU64₁And length L of SDU66₂To be determined appropriately. Furthermore, TB₁68 (200 bytes) by supporting SDUs (i.e., SDUs)₁64) Efficient use is made of the segmentation of (a).

Fig. 11 shows a scheme in which an SDU is further segmented based on another determined TB size₁64 of fig. 10. In fig. 11, a second TB (TB) is configured and padded with the remaining SDUs 64, 66 or parts thereof according to fig. 10(a)₂)78。TB₂78 TB discussed in FIG. 10₁68 after transmission.

In fig. 11(a), S is based on including SDUs (or partial SDUs, i.e., segments) that remain to be transmitted_1-RSize L of 72_1-RAnd SDU₂Size L of 66₂To determine TB₂Length (L) of 78_TB2). As other non-limiting examples of this process, consider the following. If there is any remaining, it is desirable to transmit at least one complete SDU. Therefore, the TB size should preferably not be less than 300 bytes (i.e. the TB should preferably be able to accommodate at least the smallest remaining SDU, SDU₂66). Since the scheduling and logical channel priority is already due to the first TB, TB₁68, the communication link and data has been allocated 500 bytes (TB) for that particular time and TB formation₂Length L_TB2500 bytes). Although shown in FIG. 11(A) for illustrative purposes, TB is₂78 are still not actually created (e.g., filled).

TB since it is desirable to transmit a complete SDU when possible₂78 will include SDU₂66. Thus, a length equivalent to 200 bytes will remain to be padded, possibly by one or more segments (e.g., S) in other SDUs_1-R72) padding.

In fig. 11(B), based on the above preference for transmission of at least one complete SDU and further based on the determined TB₂Length L_TB2To put SDU₁Of (2) is_1-R72 re-segmentation into a plurality of segments, segments 1-23 (S)_1-23)80 and segments 1-4 (S)_1-4)82, each segment having a corresponding 200 bytes (L)_1-23) And 100 bytes (L)_1-4) Length of (d). Will SDU₁Remainder S of 64_1-R72 are intentionally segmented to produce a segment having a length L of 200 bytes_1-23S of_1-2380, thus S_1-2380 is filled TB₂78, in TB₂78 have passed through SDU₂66 after filling, the usable portion is taken as TB₂78 to the remainder of the process. SDU not yet assigned to TB₁The remainder of 64, i.e. S_1-482, may be transmitted in whole or in part in another TB.

In FIG. 11(C), SDU₂66 and S_1-2380 pack TB₂78. The TB₂78 may then be transmitted using the methods and components discussed in fig. 3, as a non-limiting example.

It is obvious that TB₂Size L of 78_TB2By taking into account the remaining part (S) of the SDU_1-R72) Length L of_1-RAnd SDU (SDU)₂66) Length L of₂As determined appropriately. Furthermore, TB₂78 (500 bytes) by supporting the remaining portion of the SDU (i.e., SDU)₁The remainder of 64, S_1-R72) Are efficiently used.

Although the exemplary SDUs and TBs in fig. 10 and 11 are described with respect to their respective lengths, any suitable size indication may be used. Moreover, any suitable measurement scale and/or unit may be used. Although the TBs of fig. 10 and 11 are shown as including only SDUs or portions thereof, the TBs typically include additional, non-SDU portions, such as portions used for signaling or identification purposes, as non-limiting examples.

The exemplary embodiments described in fig. 10 and 11 may also be used in conjunction with retransmissions if such are necessary. Each transmitted segment will include an SSN, a length, and an offset. If it is indicated that a segment should be retransmitted, the segment is identifiable by its SSN, length, and offset. In this manner, only certain portions of the SDU (i.e., the portion that includes the identified segment) must be retransmitted. In this way, it is not necessary to retransmit a complete SDU in its entirety, unless the TB is filled with said complete SDU.

Other non-limiting examples of exemplary electronic devices suitable for use in conjunction with aspects of the exemplary embodiments of this invention are provided. The electronic device includes: a data processor; and a transmitter coupled to the data processor. The transmitter is configured to transmit a retransmission notification indicating a segment of the plurality of segments. The retransmission notification includes a retransmission request for the indicated segment. The plurality of segments includes segmented data blocks. The retransmission notification includes a data block identifier, a length value, and an offset value for the indicated segment. The data chunk identifier includes an identification of the segmented data chunk. The length value comprises the length of the indicated segment. The offset value includes a boundary of the indicated segment relative to the segmented data block. In other embodiments, the electronic device further comprises: a receiver coupled to the data processor. In other embodiments, the electronic device comprises a mobile terminal. In other embodiments, the electronic device includes a base station in an evolved universal terrestrial radio access network (E-UTRAN) system. In other embodiments, the electronic device may include any other aspect or component of the exemplary embodiments of the invention as described herein.

FIG. 12 illustrates a flow chart showing one non-limiting example of a method for implementing exemplary embodiments of the present invention. The method comprises the following steps. In block 101, the size of the transport block is determined based on a criterion. The criterion includes the size of at least one data block to be transmitted. The transport block size is determined such that the transport block will include at least one segment of a data block of at least one data block. In block 102, a data block of at least one data block is segmented into a plurality of segments including at least one segment. In block 103, the transport block is filled with at least one segment.

In other embodiments, the method further comprises transmitting the padded transport block. In other embodiments, the criteria further include multi-user scheduling and/or logical channel priority. In other embodiments, the criteria further include at least one of the following criteria: the expected channel conditions for the multiple radio links, the amount of data to be transmitted from each priority queue, and the priority value for each terminal that assigned a logical channel. In other embodiments, each segment of the plurality of segments comprises a data block identifier, a length value, and an offset value, wherein the data block identifier comprises an identification of a segmented data block, wherein the length value comprises a length of the segment, wherein the offset value comprises a boundary of the segment relative to the segmented data block.

In other embodiments, the method further comprises: in response to receiving a retransmission notification indicating a segment of the plurality of segments, retransmitting the segment, wherein the retransmission notification includes a data block identifier, a length value, and an offset value for the indicated segment. In other embodiments, determining the transport block size includes calculating an amount of data to be transmitted for each priority queue based on the scheduling decision, wherein the retransmission notification includes the amount of data to be transmitted for each priority queue.

In other embodiments, determining the transport block size comprises providing an amount of data to be transmitted for each priority queue and a size of at least one close (close) block of data, wherein the at least one close block of data comprises at least one block of data having a size relatively close to the amount of data to be transmitted for each priority queue, wherein the criteria further comprises the amount of data to be transmitted for each priority queue and the size of the at least one close block of data, wherein determining the transport block size such that the transport block comprises one of: an entire data block, a data block with a minimum segmentation, or a combination of an entire data block and a data block with a minimum segmentation. In other embodiments, providing the amount of data to be transmitted for each priority queue includes providing a vector including a minimum amount of data to be transmitted, wherein a size of the proximity data block includes a value relatively close to the minimum amount of data to be transmitted. In other embodiments, providing each priority queue with an amount of data to be transmitted and at least one size of a near data block includes using an interface.

In other embodiments, determining the transport block size includes calculating an amount of data to be transmitted for each priority queue based on the scheduling decision. In other embodiments, the amount of data to be transmitted for each priority queue includes a value that is relatively close to the size of each of the plurality of data blocks. In other embodiments, determining the transport block size further comprises providing a vector of an amount of data to be transmitted for each priority queue, wherein the vector comprises elements corresponding to each priority queue. In other embodiments, the method is used in conjunction with an evolved universal terrestrial radio access network (E-UTRAN) system.

FIG. 13 illustrates a flow chart showing another non-limiting example of a method for implementing an exemplary embodiment of the present invention. The method comprises the following steps. In block 151, a data block is segmented into a plurality of segments. Each of the plurality of segments includes a data block identifier, a length value, and an offset value. The data chunk identifier includes an identification of the segmented data chunk. The length value includes the length of the segment. The offset value includes a boundary of the segment relative to the segmented data block. The segmented data block is transmitted through a plurality of transport blocks. In block 152, a transport block of the plurality of transport blocks is populated with at least one segment of the plurality of segments. In block 153, in response to receiving a retransmission notification indicating a segment of the plurality of segments, the indicated segment is retransmitted. The retransmission notification includes a data block identifier, a length value, and an offset value for the indicated segment.

In other embodiments, the method further comprises transmitting the padded transport block. In other embodiments, the retransmission notification includes an automatic repeat request (ARQ) status report. In other embodiments, the retransmission notification includes a Negative Acknowledgement (NACK). In other embodiments, retransmitting the indicated segment includes re-segmenting the indicated segment into smaller segments and applying at least one of low order modulation, low rate channel coding, and enhanced diversity mode.

The exemplary, non-limiting methods illustrated in and discussed with respect to fig. 12 and 13 may be implemented as a computer program comprising program instructions embodied on a tangible computer-readable medium, the execution of which results in operations comprising the steps of the method.

Embodiments of the present invention are not limited to the protocol layers L1(PHY) and L2(MAC) used in the above examples. Rather, embodiments of the present invention may be implemented for any protocol layer that is only used to efficiently perform segmentation for scheduling and resource allocation. The scheduler and allocation functions as they relate to the segmentation process of the present invention may be included in different protocol layers with defined interfaces or alternatively they may be included in the same protocol layer without such specific interfaces. Further, the scheduler and allocation functions may be included in different physical or logical processing units (or portions thereof), or they may be included in the same processing unit.

In one embodiment of the invention, the described method may be implemented for interfacing the scheduling and allocation functions of the MAC segments and PHY. Thus, all tags of PHY/MAC/RRC, signal transport streams and primitives are used as non-limiting examples. It is obvious to a person skilled in the art that such tags may be replaced by any other description of the relevant function and/or protocol split. As a non-limiting example, segmentation, scheduling, and allocation may occur in the same layer.

Although described above with respect to the boundary of an SDU, the exemplary embodiments of this invention may utilize any suitable size characteristic of an SDU, such as length, as non-limiting examples. Also, although discussed with respect to an offset from the beginning of an SDU, the offset can comprise any suitable value that indicates the location of a segment relative to the entire SDU. As a non-limiting example, the offset value may indicate the renumbering of the segment as described above. As another non-limiting example, the offset value may indicate a boundary of a segment closest to the tail end of the SDU (i.e., the end). Further, although the example embodiments have been discussed with respect to SDUs, the example embodiments may be used in connection with the transmission of any suitable set of data (e.g., a block of data).

Based on the foregoing, it should be appreciated that the exemplary embodiments of this invention provide a method, apparatus and computer program product for improving segmentation efficiency by providing an intelligent TB size determination method and a flexible segmentation scheme for transmission.

Although the exemplary embodiments are described in the context of an E-UTRAN system, it should be appreciated that the exemplary embodiments of this invention are not limited for use with only one particular type of wireless communication system, and that they may be advantageously employed in other wireless communication systems such as 3G High Speed Packet Access (HSPA) evolution, wireless ad hoc networks, cognitive radios, beyond third generation (B3G) systems, and fourth generation (4G) systems, as non-limiting examples. It is desirable for such systems to include techniques that allow various methods for wireless adaptation, such as bandwidth adaptation, spectral condition adaptation, radio capacity adaptation, radio link adaptation, and transport format adaptation, as non-limiting examples.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. Embodiments of the invention may be implemented in various components, such as integrated circuit modules. In general, the design of integrated circuits is a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

Various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. For some examples, however, one skilled in the art may attempt to use other similar or equivalent data flows and transmission procedures. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

Moreover, some of the features of the examples of this invention could be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings, examples and exemplary embodiments of this invention, and not in limitation thereof.

Claims (21)

1. A method of communication, comprising:

transmitting an uplink buffer status report to a base station;

determining a size of a transport block, wherein the transport block size is such that the transport block will comprise at least one segment of a data block of at least one data block to be transmitted;

segmenting the data block of the at least one data block into a plurality of segments including the at least one segment, wherein each segment of the plurality of segments includes a data block identifier, a length value field, and an offset value field, wherein the data block identifier includes an identification of the segmented data block, wherein a length value of the length value field indicates a length of the segment, wherein an offset value of the offset value field indicates a starting position of the segment relative to the segmented data block; and

filling the transport block with at least the at least one segment,

in response to receiving a retransmission notification indicating one of the plurality of segments, retransmitting the indicated segment, wherein the retransmission notification includes a data block identifier and an offset value for the indicated segment.

2. The method of claim 1, further comprising:

transmitting the transport block that is padded.

3. The method of claim 1, wherein determining the size of the transport block comprises providing an amount of data to be transmitted for each priority queue and a size of at least one near data block, wherein the at least one near data block comprises at least one data block having a size near the amount of data to be transmitted for each priority queue, wherein the size of the transport block is based on criteria including the size of the at least one data block to be transmitted, the amount of data to be transmitted for each priority queue, and the size of the at least one near data block, wherein the size of the transport block is determined such that the transport block comprises one of: an entire data block, a data block with a minimum segmentation, or a combination of an entire data block and a data block with a minimum segmentation.

4. The method of claim 1 or 2, wherein determining the size of the transport block comprises calculating an amount of data to be transmitted for each priority queue.

5. The method according to claim 1 or 2, wherein the retransmission notification further comprises a length value of the indicated segment.

6. The method of claim 5, further comprising:

transmitting the transport block that is padded.

7. The method of claim 5, wherein the retransmission notification comprises one of an automatic repeat request (ARQ) status report or a Negative Acknowledgement (NACK).

8. A communication device, comprising:

means for transmitting an uplink buffer status report to a base station;

means for determining a size of a transport block, wherein the transport block is of a size such that the transport block will include at least one segment of a data block of at least one data block to be transmitted;

means for segmenting the data block of the at least one data block into a plurality of segments including the at least one segment, wherein each segment of the plurality of segments includes a data block identifier, a length value field, and an offset value field, wherein the data block identifier includes an identification of the segmented data block, wherein a length value of the length value field indicates a length of the segment, wherein an offset value of the offset value field indicates a starting position of the segment relative to the segmented data block; and

means for filling the transport block with at least the at least one segment,

means for retransmitting the indicated segment in response to receiving a retransmission notification indicating one of the plurality of segments, wherein the retransmission notification includes a data block identifier and an offset value for the indicated segment.

9. The apparatus of claim 8, further comprising:

means for transmitting the padded transport blocks.

10. The apparatus of claim 8, wherein means for determining a size of the transport block comprises means for providing an amount of data to be transmitted for each priority queue and at least one near data block size, wherein the at least one near data block comprises at least one data block having a size near the amount of data to be transmitted for each priority queue, wherein the transport block size is based on criteria including the at least one data block size to be transmitted, the amount of data to be transmitted for each priority queue, and the at least one near data block size, wherein the transport block size is determined such that the transport block comprises one of: an entire data block, a data block with a minimum segmentation, or a combination of an entire data block and a data block with a minimum segmentation.

11. The apparatus according to claim 8 or 9, wherein the means for determining the size of the transport block comprises means for calculating an amount of data to be transmitted for each priority queue.

12. The apparatus according to claim 8 or 9, wherein the retransmission notification further comprises a length value of the indicated segment.

13. The apparatus of claim 12, further comprising:

means for transmitting the padded transport blocks.

14. The apparatus of claim 12, wherein the retransmission notification comprises one of an automatic repeat request (ARQ) status report or a Negative Acknowledgement (NACK).

15. A communication device, comprising:

a processor; and

a memory storing a computer program, the memory and the computer program configured to, with the processor, cause the apparatus to perform at least:

transmitting an uplink buffer status report to a base station;

determining a size of a transport block, wherein the transport block size is such that the transport block will comprise at least one segment of at least one data block to be transmitted;

segmenting the data block into a plurality of segments including the at least one segment, wherein each segment of the plurality of segments includes a data block identifier, a length value field, and an offset value field, wherein the data block identifier includes an identification of the segmented data block, wherein a length value of the length value field indicates a length of the segment, wherein an offset value of the offset value field indicates a starting position of the segment relative to the segmented data block; and

filling the transport block with at least the at least one segment,

in response to receiving a retransmission notification indicating one of the plurality of segments, retransmitting the indicated segment, wherein the retransmission notification includes a data block identifier and an offset value for the indicated segment.

16. The apparatus of claim 15, further comprising:

a transmitter configured to transmit the transport block.

17. The apparatus of claim 15, wherein determining the size of the transport block comprises providing an amount of data to be transmitted for each priority queue and a size of at least one near data block, wherein the at least one near data block comprises at least one data block having a size near the amount of data to be transmitted for each priority queue, wherein the size of the transport block is based on criteria including the size of the at least one data block to be transmitted, the amount of data to be transmitted for each priority queue, and the size of the at least one near data block, wherein the size of the transport block is determined such that the transport block comprises one of: an entire data block, a data block with a minimum segmentation, or a combination of an entire data block and a data block with a minimum segmentation.

18. The apparatus of claim 15 or 16, wherein determining the size of the transport block comprises calculating an amount of data to be transmitted for each priority queue.

19. The apparatus according to claim 15 or 16, wherein the retransmission notification further comprises a length value of the indicated segment.

20. The apparatus of claim 19, further comprising:

a transmitter configured to transmit the transport block.

21. The apparatus of claim 19, wherein the retransmission notification comprises one of an automatic repeat request (ARQ) status report or a Negative Acknowledgement (NACK).