WO2009055971A1

WO2009055971A1 - Data processing method and device

Info

Publication number: WO2009055971A1
Application number: PCT/CN2007/003109
Authority: WO
Inventors: Pingping Wen; Yan Zhao
Original assignee: Alcatel Shanghai Bell Co., Ltd.; Alcatel Lucent
Priority date: 2007-11-01
Filing date: 2007-11-01
Publication date: 2009-05-07
Also published as: CN101836418A; CN101836418B

Abstract

A data processing method for communication systems comprises the following steps: arranging in descending order according to length RLC PDUs (301) (radio link control - protocol data units) which aim at one or more radio bearers; determining the length of the LF field for every RLC PDU according to the size of MAC PDU (media access control - protocol data unit) and the data amount of the previous RLC PDU (303); and, according to the lengths of said LF fields, multiplexing/de-multiplexing to/from the MAC PDU (305) the RLC PDUs which aim at the one or more radio bearers.

Description

Data processing method and device

Technical field

The present invention relates to a data processing method and apparatus in a communication system, and more particularly to an LTE (Long Term Evolution) communication system, the data processing method and apparatus capable of reducing an RLC PDU (Radio Link Control-Protocol Data Unit) for indicating The overhead of the length of the LF field. Background technique

In the LTE uplink, the MAC layer supports multiplexing/demultiplexing of RLC PDUs for one or more radio bearers (logical channels) to/from MAC PDUs (Medium Access Control-Protocol Data Units). A MAC PDU consists of one or more RLC PDUs for one or more radio bearers. The amount of data included in each of the radio bearers in the MAC PDU varies depending on the decision of the scheduler. Although many schemes have been proposed to design the MAC PDU format, one thing in common is that the basic MAC PDU consists of a header and a payload, and a field, that is, a length field LF, is required to indicate each RLC PDU included in the MAC PDU header. length. Since the size of the MAC PDU is flexible (supporting flexible RLC PDUs), it is important to optimize the length of the LF to reduce the unnecessary overhead caused by the LF.

In most prior art solutions, the length of the LF is fixed regardless of the actual amount of data to be actually indicated. The length of the LF is determined by the size of the largest supported MAC PDU. In order to support 200 Mbps, each TTI (transmission time interval, eg 1 ms) needs to transmit 200 kilobits = 25 kilobytes of data. At least a 15-bit length field is required to support the MAC PDU of this length. However, in the case where the amount of data actually represented is smaller than the maximum supported length of the MAC PDU, unnecessary bits will be generated and resources will be wasted. For example, a streaming service consisting of small-sized packets may require a small number of bits for the length field of the MAC PDU header, while an FTP service consisting of large-sized packets may require a large number of bits for the length field of the MAC PDU header.

There is also a second conventional method in which the length of the LF is variable, which is determined by the transmitted MAC PDU. The LFs for all RLC PDUs have the same length. Compared to the previous method of fixed length, the improvement is to reduce the credit. However, when the MAC PDU consists of multiple parts that require LF to be indicated separately, the method will generate unnecessary bits, and is not a good enough choice. Summary of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to propose an indication that can be degraded for indication

RLC PPU is a data processing method and device in a communication system with an overhead of LF.

In order to achieve the above object, the present invention provides a data processing method in a communication system, comprising the steps of: RLC PDUs for one or more radio bearers according to the length of RLC PDUs (Radio Link Control - Protocol Data Units) Performing a descending order; determining a length of an LF field for each RLC PDU according to a size of a MAC PDU (Medium Access Control - Protocol Data Unit) and a data amount of a previous RLC PDU; and according to the determined length of the LF field /Reuse/demultiplex RLC PDUs for one or more radio bearers from the MAC PDU o

Preferably, the determining step comprises: determining a length of the first LF field for the first RLC PDU according to the size of the MAC PDU; determining, according to the size of the MAC PDU and the data amount of the first RLC PDU, for the second RLC

The length of the second LF field of the PDU; determining the length of the third LF field for the third RLC PDU based on the size of the MAC PDU and the amount of data of the first and second RLC PDUs; and so on.

Preferably, the data volume of the current RLC PDU is less than or equal to the difference between the size of the MAC PDU and the data amount of the previous RLC PDU, and the length of the current LF field for the current RLC PDU is less than or equal to the previous RLC.

The length of the LF field of the PDU.

Preferably, the data volume of the current R1X PDU is less than or equal to the difference between the size of the MAC PDU and the data amount of the previous RLC PDU, and for the same radio bearer, the length of the current LF field for the current RLC PDU is less than or equal to the length of the previous RLC PDU. The length of the LF field.

Preferably, the sorting step comprises: performing a descending ordering of RLC PDUs for different radio bearers according to the length of the RLC PDU;

Preferably, the sorting step comprises: performing a descending order of RLC PDUs for the same radio bearer according to the length of the RLC PDU; and Descending the RLC PDUs for different radio bearers according to the length of the RLC PDU for each radio bearer .

Preferably, the sorting step comprises: performing a descending order of RLC PDUs for the same radio bearer according to the length of the RLC PDU; and differentiating the length and minimum of the RLC PDUs for each radio bearer by searching for all possible combinations The carried RLC PDUs are arranged in descending order.

Preferably, the communication system is an LTE (Long Term Evolution) communication system.

According to the present invention, there is also provided a data processing apparatus in a communication system, comprising: means for targeting one or more radio bearers according to a length of an RLC PDU (Radio Link Control - Protocol Data Unit) The RLC PDUs are arranged in descending order; the apparatus determines the length of the LF field for each RLC PDU according to the size of the MAC PDU (Medium Access Control - Protocol Data Unit) and the data amount of the previous RLC PDU; and the device, according to the determined Length of LF field to multiplex/demultiplex RLC PDUs for one or more radio bearers to/from MAC PDUs c

1 is a diagram showing an example of determining the length of an LF in the case of a first MAC PDU format;

2 is a diagram showing another example for determining the length of an LF in the case of the second MAC PDU format;

3 is a flow chart showing a data processing method according to the present invention;

4 is a block diagram showing the configuration of a data processing device according to the present invention. detailed description

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

First, the order of the RLC PDUs in the MAC PDU should be designed. Currently, there are two types of MAC PDU formats. The first type of MAC PDU is that for each RLC PDU, there is an LCID (logical channel identifier that identifies the logical channel that will forward the included RLC PDU). The second MAC PDU format LCID is combined with the extended bit E to indicate RLC PDUs from the same radio bearer. The method proposed for both cases will be explained below.

For the first MAC PDU format, each RLC PDU is accompanied by an LCID, and the RLC PDUs can be sorted in descending order according to the length of the RLC PDU.

For the second MAC PDU format, RLC PDUs from the same radio bearer must be contiguous in the MAC PDU. There are two optimization methods for the second MAC PDU format.

- The first optimization method is a partial optimization method. The RLC PDUs from the same wireless bearer are sorted in descending order according to the length of the RLC PDU. The RLC PDUs from different radio bearers are arranged in descending order according to the length and length of the RLC PDUs from each radio bearer. This method is relatively simple.

A second optimization method is a full optimization method. The RLC PDUs from the same radio bearer are arranged in descending order according to the length of the RLC PDU. The RLC PDUs from different radio bearers are arranged by searching all possible combinations to minimize and minimize the length of all LFs. This method is relatively complicated, but it is a bit more Optimized method. The complexity (calculation) of the method depends on the number of radio bearers included in the MAC PDU, which is generally acceptable. For example, if the MAC PDU includes RLC PDUs from four radio bearers, then only the best results need to be found in the 24 sets of combinations. According to the invention, the length of the LF is variable. For example, the length of the LF of each RLC PDU can be determined as follows.

For the first MAC PDU format,

The length of the first LF in the MAC PDU is:

LF_Size_Opt(l) = ROUNDUP (Log2 (MAC_PDU_Size _byte ) )

The length of the second LF in the MAC PDU is:

LF—Size— Opt (2) = Min ( ROUNDUP (Log2 (MAC— PDU—Si ze _byte − (the amount of data indicated by the first LF + the header length of the first RLC PDU) _byt e)), ROUNDUP (Log2( The amount of data indicated by the first LF) hyte) )

The length of the iLF in the MAC PDU is:

LF—Size— Opt (i) = Mi n (ROUNDUP (Log2(MAC— PDU—Si ze _byte − (the amount of data indicated by ra LF + header length of the mth RLC PDU) _byte )), ROUNDUP (Log2 ( Instructed by (i-1) LF

For the second MAC PDU format

In the partial optimization method,

The length of the first LF in the MAC PDU for the RLC PDU from the first logical channel:

A LF Size- Opt (l) = ROUNDUP ( Log2 (MAC_PDU_Size hne))

If the second RLC PDU is from the same logical channel as the previous RLC PDU, the length of the second LF: LF - Size - Opt (2): Min ( ROUNDUP (Log2 (MAC_PDU_Size _byte - (the amount of data indicated by the first LF) + header length of the first RLC PDU) _byt .)), ROUNDUP (Log2 (the amount of data indicated by the first LF) byte)

If the second RLC PDU and the previous RLC PDU are from different logical channels, the length of the second LF: LF - Size - Opt (2) = Min ( ROUNDUP (Log2 (MAC_PDU_Size _be - (indicated by the first LF) Data amount + header length of the first RLC PDU) _bm )), ROUNDUP (Log2) The amount of the i-th LF if the RLC PDU is from the same logical channel as the previous RLC PDU: LF—Size— Opt(i) = Min (ROUNDUP (Log2 (MAC— PDU— Size _byte - ^ (M LF refers to

m=l The amount of data shown + the header length of the mth RLC PDU) _byte )), ROUNDUP (Log2 (the amount of data indicated by the (i-1) LF)))

If the RLC PDU and the previous RLC PDU are from different logical channels, the length of the ith LF: LF_Size - Opt (i) = Min ( ROUNDUP (Log2 ( MAC - PDU - Size _byte - (indicated by m LF) Data amount + header length of the mth RLC PDU) _byte )), ROUNDUP (Log2 ( j amount of data indicated by jLF)

Where N is the number of RLC PDUs from the previous logical channel. In the full optimization method,

LF—Size— Opt (1) = ROUNDUP (Log2 (MAC_PDU_Size _byte ) )

If the second RLC PDU is from the same logical channel as the previous RLC PDU, the length of the second LF: LF_Size - Opt (2) = Min ( ROUNDUP (Log2 (MAC_PDU_Size _byle - (the amount of data indicated by the first LF) + header length of the first RLC PDU) _hyt J), ROUNDUP (Log2) The amount of data of the second LF if the second RLC PDU and the previous RLC PDU are from different logical channels:

LF—Size— Opt (2) = ROUNDUP (Log2 (MAC—PDU—Si ze _byte − (the amount of data indicated by the first LF + the header length of the first RLC PDU)

If the RLC PDU is from the same logical channel as the previous RLC PDU, the length of the i LF:

LF—Size— Opt (i) = Mi n (ROUNDUP (Log2 ( AC_PDU_Size _byte - (M LF refers to

m=l The amount of data shown + the header length of the mth RLC PDU) _by " )), ROUNDUP (Log2 (the amount of data indicated by the (i-1) LF) J) If the RLC PDU and the previous RLC PDU are from different logical channels, the length of the ith LF: LF_Size_0pt(i) = ROUNDUP (Log2(MAC_PDU_ Size _byte - (the amount of data indicated by the m LF + the mth RLC) The header length of the PDU) _byte )). The invention can be applied to any MAC PDU format including the amount of data used to indicate the unit (PDU or SDU) included. To explain the present invention, the MAC PDU format in the following two examples lists only the fields of interest. A first example of the invention is shown in FIG. Assume that the MAC PDU is 12.1 kilobytes, the header is 0.1 kilobytes, and the payload is 12 kilobytes. The lengths of the three ?01] are 8.5 kilobytes, 3.4 kilobytes, and 0.1 kilobytes, respectively.

Then the length of the first LF: LF_Size - 0pt (l) = bit;

Length of the second LF: LF_Size_0pt (2) = Min (Roundup (log2 (12. IK- 0. IK- 8.5K)), Roundup (log2(8.5K))) = 12 bits;

The length of the last LF: LF—Size— Opt (3) =

Min (Roundup (log2 (12. IK- 0. IK- 8.5K- 3.4 )), Roundup (log2 (3.4K))) = 7 bits;

The total length of LF is 33 (14 + 1 + 7) bits. A second example of the invention is shown in Figure 2. Assume that the MAC PDU is 12.1 kilobytes, the header is 0.1 kilobytes, and the payload is 12 kilobytes. The lengths of the five !^11: ?01] are 7.5 kilobytes, 1.5 kilobytes, 0.1 kilobytes, 2.9 kilobytes, and 0.1 kilobytes, respectively.

If you use a partial optimization method, then:

Length of the first LF: LF - Size_0pt (l) = 14 bits;

Length of the second LF: LF_Size_0pt (2) = Min (Roundup (log2 (12. IK- 0· 1K-7.5K)), Roundup (log2 (7.5K))) = 12 bits;

Length of the third LF: LF—Size— Opt (3) =

Min(Roundup(log2(12. IK - 0. IK- 7.5K-1.5K)), Roundup (log2(l.5K)))=11 bits; length of the fourth LF:

LF_Size_0pt(4)=Min( Roundup (log2 (12.1K-0. IK- 7.5K-1.5K-0. IK)), Roundup (log2 (7.5K+1.5K+0. IK) ) ) = 12 bits;

The length of the last LF: LF_Size_0pt(5)- Min (Roundup (log2 (12.1K-0.1 - 7.5 K -1.5 K -0.1 K - 2.9 K)), Roundup(log2(2.9K)))=7 bits;

The length of LF is 57 (14+12+11+12+7) bits. If you use the full optimization method, then

Length of the first LF: LF - Size - Opt (1) = 14 bits;

Length of the second LF: LF_Size_0pt (2) =Min (Roundup (log2 (12. IK- 0. IK- 7.5K)), Roundup (log2 (7.5K))) = 12 bits;

Length of the third LF: LF—Size— Opt (3) =

Min (Roundup (log2 (12. IK- 0. IK- 7.5K- 1.5K)), Roundup (log2 (1.5K))) = 11 bits; length of the fourth LF:

LF—Size— Opt (4) ^Roundup (log2 (12.1K-0.1K-7.5K- 1.5K- 0. IK))=12 bits;

The length of the last LF: LF-Size- Opt (5) = Min (Roundup (log2 (12. IK- 0.1 K - 7.5 K -1.5 K -0.1 K -2.9 K)), Roundup (log2 (2.9K) ) ) = 7 bits;

The length of LF is 57 (14+12+11 + 12+7) bits. 3 is a flow chart showing a data processing method in accordance with the present invention.

As shown in FIG. 3, in accordance with the method of the present invention, in step 301, RLC PDUs for one or more radio bearers are arranged in descending order according to the length of the RLC PDU (Radio Link Control - Protocol Data Unit). At step 303, the length of the LF field for each RLC PDU is determined based on the size of the MAC PDU (Medium Access Control - Protocol Data Unit) and the amount of data of the previous RLC PDU. At step 305, RLC PDUs for one or more radio bearers are multiplexed/demultiplexed to/from the MAC PDU according to the determined length of the LF field. 4 is a block diagram showing the configuration of a data processing device according to the present invention.

As shown in FIG. 4, the apparatus according to the present invention includes means 401 for performing a descending order of RLC PDUs for one or more radio bearers according to the length of the RLC PDU (Radio Link Control - Protocol Data Unit); The size of the MAC PDU (Medium Access Control - Protocol Data Unit) and the amount of data of the previous RLC PDU to determine the length of the LF field for each RLC PDU; and means 405, to/from the length of the determined LF field The MAC PDU multiplexes/demultiplexes RLC PDUs for one or more radio bearers. According to the present invention, unnecessary bits of the LF for the MAC PDU header can be removed, and transmission efficiency can be improved. The optimization method can be applied to any MAC PDU format including the length used to indicate the unit (PDU or SDU) included. The present invention, which optimizes the length of the LF of the MAC PDU header, can reduce the overhead of the LF while clearly identifying the length of the RLC PDU. Compared to the first example of the present invention as shown above, if a fixed LF method is used and 15 bits are used for LF, the three LFs will require a total of 45 (15*3) bits. If the second conventional method is used, 14 bits will be used and the three LFs will require 42 (14*3) bits. However, according to the first example of the invention, it only requires 33 bits. Compared to the second example of the present invention as shown above, if the fixed LF method is used and 15 bits are used for the LF, the five LFs will require 75 (14*5) bits. However, according to the second example of the present invention, it requires only 57 bits.

It should be noted that the above examples are merely illustrative of the invention. When multiple RLC PDUs are multiplexed into one MAC PDU, the gain is more pronounced. This situation will occur frequently in the LTE uplink because the rate control function of the UE (mobile station) and the AMBR (collectively large bit rate) are defined so that resources can be shared among many no.: line bearers. In addition, due to the byte alignment requirement for the MAC header, a one-bit reduction in the MAC header will result in more gain.

While the invention has been described in connection with the preferred embodiments of the embodiments of the present invention, it will be understood . Therefore, the present invention should not be limited by the foregoing embodiments, but by the appended claims and their equivalents.

Claims

Rights request

1. A data processing method in a communication system, comprising the steps of:

RLC PDUs for one or more radio bearers are arranged in descending order according to the length of the RLC PDU (Radio Link Control - Protocol Data Unit);

Determining the length of the LF field for each RLC PDU based on the size of the MAC PDU (Medium Access Control - Protocol Data Unit) and the amount of data of the previous RLC PDU;

Reusing/demultiplexing RLC PDUs for one or more radio bearers according to the determined length of the LF field to/from the MAC PDU o

2. The method of claim 1 wherein the determining step comprises:

Determining a length of a first LF field for the first RLC PDU according to a size of the MAC PDU; determining a length of the second LF field for the second RLC PDU according to a size of the MAC PDU and a data amount of the first RLC PDU; The size of the PDU and the amount of data of the first and second RLC PDUs determine the length of the third LF field for the third RLC PDU; and so on.

3. Method according to claim 1 or 2, characterized in that the data amount of the current RLC PDU is less than or equal to the difference between the size of the MAC PDU and the data amount of the previous RLC PDU, and the length of the current LF field for the current RLC PDU. Less than or equal to the length of the LF field for the previous RLC PDU.

The method according to claim 1 or 2, wherein the data amount of the current RLC PDU is less than or equal to the difference between the size of the MAC PDU and the data amount of the previous RLC PDU, and for the same radio bearer, for the current RLC PDU. The length of the current LF field is less than or equal to the length of the LF field for the previous RLC PDU.

5. The method of claim 1 wherein the ordering step comprises:

RLC PDUs for different radio bearers are arranged in descending order according to the length of the RLC PDU;

6. The method of claim 1 wherein the ordering step comprises:

The RLC PDUs for the same radio bearer are arranged in descending order according to the length of the RLC PDU; and the RLC PDUs for different radio bearers are arranged in descending order according to the length of the RLC PDUs for each radio bearer.

7. The method of claim 1 wherein the ordering step comprises:

Descending the RLC PDUs for the same radio bearer according to the length of the RLC PDU; The RLC PDUs for different radio bearers are arranged in descending order by searching all possible combinations to make the length and minimum of the RLC PDUs for each radio bearer.

8. Method according to claim 1, characterized in that the communication system is an LTE (Long Term Evolution) communication system.

9. A data processing device in a communication system, comprising:

The device, in descending order of RLC PDUs for one or more radio bearers according to the length of the RLC PDU (Radio Link Control-Protocol Data Unit);

The device determines the length of the LF field for each RLC PDU according to the size of the MAC PDU (Medium Access Control - Protocol Data Unit) and the data amount of the previous RLC PDU;

And means, according to the determined length of the LF field, multiplexing/demultiplexing RLC PDUs for one or more radio bearers to/from the MAC PDU.