WO2006053490A1

WO2006053490A1 - Data sectional concatenation and reassembly method

Info

Publication number: WO2006053490A1
Application number: PCT/CN2005/001928
Authority: WO
Inventors: Yingzhe Ding; Yanhong Wang; Hao Hu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2004-11-19
Filing date: 2005-11-16
Publication date: 2006-05-26
Also published as: CN1780291B; CN1780291A

Abstract

A data sectional concatenation method can allow specific identification to be encapsulated in PDU and transmitted by transmission side when the procedure in which current service data unit (SDU) is sectionally concatenated and assembled to packet data unit (PDU) needs to be interrupted, said specific identification indicates that current SDU is interrupted. Said method includes sectional concatenation for current SDU is interrupted, SDU to be inserted is sectionally concatenated and assembled to PDU to output, and then remaining data in current interrupted SDU is sectionally concatenated and assembled to PDU to output. A data reassembly method adopts the data sectional concatenation and reassembly method of present invention to allow reception side to correctly reassemble data thereby enhances information transmission reliability.

Description

Method for data segmentation cascading and recombination

The invention relates to information transmission technology, in particular to a method for data segmentation cascading and recombination. Background of the invention

5 With the development of third-generation mobile communication technology, the demand for mobile communication is no longer satisfied with the voice industry. Since third-generation mobile communication can provide higher data rate services than second-generation mobile communication, A large number of multimedia services have emerged, such as: video phones, picture downloads, high-speed browsing Internet services and other services. Among them, some application services require multiple users to receive the same data at the same time, such as: video on demand, TV broadcast, video conferencing, online education, interactive games, and so on.

0 In order to effectively utilize mobile communication network resources, the third generation mobile communication introduces the concept of multicast and broadcast, which is a technology for transmitting data from one data source to multiple targets. Specifically, WCDMA/GSM Global Standards Organization 3GPP proposes Multimedia Broadcast/Multicast Service (MBMS), which is a point in which a data source is provided in a mobile 'communication network to send data to multiple users. To multi-point services, realize network 5 resource sharing, and improve the utilization of network resources, especially air interface resources. MBMS defined by 3GPP can not only realize plain text low-rate message class multicast and broadcast, but also realize multicast and broadcast of high-speed multimedia services.

Figure 1 is a schematic diagram of a wireless network structure supporting broadcast/multicast services. As shown in Figure 1, in the existing 3GPP, the wireless network entity supporting the broadcast/multicast service is a broadcast/multicast service server! 0 (BM-SC) 101. The BM-SC 101 is connected to a TPF Gateway GPRS Support Node (GGSN) 102 through a Gmb interface or a Gi interface. One BM-SC 101 can be connected to multiple TPF GGSNs 102. The TPF GGSN 102 is Gn/Gp. The interface is connected to a Serving GPRS Support Node (SGSN) 103, a GGSN 102. The SGSN 103 can be connected to a Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) 104 via an Iu interface, and then the UTRAN 104 is coupled to a User Equipment (UE) 106 via a Uu interface, SGSN 103 It can also be connected to the Global System for Mobile Communications (GSM) Enhanced Radio Access Network (GERAN) 105 via the Iu/Gb interface, and then the GERAN 105 is connected to the UE 107 via the Um interface. Among them, the GGSN and the SGSN belong to nodes in the core network (CN) in the wireless network.

It can be seen from the network structure shown in FIG. 1 that in order to support the MBMS service, a mobile network functional entity-broadcast/multicast service center, ie, a BM-SC, is added to the third generation mobile communication system, and the BM-SC is The content provider's portal is used to authorize and initiate MBMS bearer services in the mobile network, and to deliver MBMS content according to a predetermined time schedule. In addition, MBMS-related functions are added to functional entities such as UE, UTRAN, GERAN > SGSN, and GGSN.

The MBMS includes a multicast mode and a broadcast mode. The multicast mode requires the user to subscribe to the corresponding multicast group, perform service activation, and generate corresponding charging information. As the multicast mode and the broadcast mode are different in service requirements, the respective service processes are different. As shown in Figure 2 and Figure 3, Figure 2 is a schematic diagram of the service flow of the MBMS multicast mode, and Figure 3 is the MBMS broadcast mode. Schematic diagram of business process.

As shown in FIG. 2, the processing involved in the MBMS multicast service includes: subscription, service announcement, user join, session start, and MBMS notification. , Data transfer, Session Stop, and Leaving. The sign-off process is used to allow the user to subscribe to the required MBMS service in advance; the service announcement process is used to announce the currently available service by the BM-SC; the user join process is the MBMS multicast service activation process, and the UE is notified during the joining process. The network itself is willing to become a member of the current multicast group and receive multicast data of the corresponding service. The joining process creates an MBMS UE context for recording UE information in the network and the UE joining the multicast group. During the session start, the BM-SC Prepare data transmission, notify the network to establish bearer resources of the corresponding core network and access network; MBMS notification process is used to notify the UE that the MBMS multicast session is about to start; According to the transmission process, the BM-SC transmits data to the UE through the bearer resources established during the start of the session. The MBMS service has two modes when transmitting between the UTRAN and the UE: point-to-multipoint (PTM) mode and point-to-point (PTP) Mode, PTM mode sends the same data through the MTCH logical channel, all UEs that join the multicast service or are interested in the broadcast service can receive, and the PTP mode sends data through the DTCH logical channel, only the corresponding one UE can receive; The process is used to release the bearer resources established by the session start process; the user exit process causes the subscribers in the group to leave the multicast group, that is, the user no longer receives the multicast data, and the process deletes the corresponding MBMS UE context.

As shown in FIG. 3, the MBMS broadcast service involves a process similar to the MBMS multicast service, except that the subscription process and the user join process need not be performed before the session starts, and after the session ends, the user exit process does not need to be performed.

In the data transmission phase of multicast and broadcast services, MBMS services can transmit information between UTRAN and UE in two modes: point-to-multipoint (PTM) mode and point-to-point (PTP) mode. The PTM mode sends the same data through the MBMS point-to-multipoint traffic channel (MTCH), and all UEs that join the multicast service or are interested in the broadcast service can receive; the PTP mode sends data through the dedicated traffic channel (DTCH), only A corresponding UE can receive it.

In the MBMS PTM transmission mode, related radio control information includes service information, access information, radio bearer information, frequency layer convergence (FLC) information, etc., all of which are determined by a radio resource control (RRC) layer through a logical channel such as an MBMS point. Point Control Channel (MCCH) transmission. The MCCH information is transmitted based on a fixed scheduling method, and in order to improve reliability, the UTRAN repeats the MCCH information. 4 is a schematic diagram of transmission scheduling of MCCH information. As shown in FIG. 4, all blocks in the figure are MCCH information, and the period of repeatedly transmitting MCCH information is a repetition period, and the complete MCCH information is periodically transmitted in a repetition period; The modification period is defined as an integer multiple of the repetition period, and the MCCH information is modified in each modification period; the MBMS access information may be periodically transmitted in the access information period, and the access information period is repeated. The integer division of the period.

The MCCH information is further divided into a core information (Critical Info) and non-criteria information, where the criterion information is composed of MBMS neighbor cell information, MBMS service information, and MBMS radio bearer information. And the information that needs to be periodically and repeatedly sent, the content sent in each repetition period does not change, and can only be modified when the MCCH information is sent for the first time in the modification period; the non-criteria information refers to the access information. , is information that does not need to be sent periodically, and can be modified at any time. The black-filled squares in FIG. 4 are non-criteria information, the unfilled squares are criterion information, and the squares filled with positive and negative back-slashes respectively are non-criteria information and criterion information whose contents change.

The protocol stack structure of MCCH is shown in Figure 5. The protocol units of MCCH are: RRC layer, Radio Link Control Layer (RLC), Medium Access Control Layer (MAC), Physical Layer (PHY) from top to bottom. The mapping relationship between the MAC layer logical channel and the physical layer FACH channel is shown in FIG. 6. In the existing system, the MCCH information, that is, the MBMS control information is mapped to the forward access channel (FACH) for transmission. The RLC layer uses the unacknowledged mode (UM) to transmit the MCCH information. In the prior art, the data transmission process of the UM mode is as shown in FIG. 7. The transmission method of the MBMS control information mainly includes the sending process of the sender (Sender) RLC UM entity. And the receiving process of the Receiver RLC UM entity. One or several PDUs may be transmitted during each transmission time interval, and the MAC determines the size and number of PDUs in each transmission time interval.

The transmission process of the existing non-acknowledged mode data protocol data unit (UMD PDU) is: after the sender RLC UM entity receives the high-level unacknowledged mode data transmission request, the sender schedules the RLC service data unit (SDU) received from the upper layer. To send; if one or more RLC SDUs have been scheduled to transmit, the RLC UM entity first informs the lower layer to receive data including the number and size of SDUs from the upper layer; then the RLC UM entity segments the SDU according to the PDU size indicated by the lower layer, If possible, cascade; after that, set the sequence number field to VT (US), and set the length indication field for each SDU that ends in the UMD PDU; finally, submit the requested number of UMD PDUs to the lower layer, the MAC layer, and The VT (US) is updated for each UMD PDU submitted to the lower layer, and at the same time, the cache is not submitted to the lower layer SDU.

The receiving process of the UMD PDU is: After the receiving RLC UM entity receives a set of UMD PDUs from the lower layer, the RLC UM entity updates the VR (US) according to the received UMD PDU; if the update step of the VR (US) is not equal to 1 , then discard the SDU with segmentation in the lost UMD PDU, otherwise The received UMD PDU is reassembled into an RLC SDU, and the reassembled RLC SDU is submitted to the upper layer, that is, the RRC layer.

The format of the UMD PDU is shown in Table 1:

Octl

( Optional )

Last Ocetet

Table I

In the format of the RLC protocol UMD PDU, a length indication (LI, Length Indicator) is used to mark the end of the RLC SDU in the PDU. In addition to some predefined special values, the LI indicates the end position of the RLC header in the UMD PDU to the RLC. The number of bytes of the SDU in the last byte of this PDU, LI is 7 or 15 bits. For UM mode, if the largest UMD PDU size is <= 125 bytes, 7 bits of LI are used, and in other cases 15 bits of LI are used. The meanings of each special value of 7-bit LI and 15-bit LI are shown in Table 2 and Table 3, respectively. Table 2 describes the meaning of each special value of 7-bit LI, and Table 3 shows the meaning of each special value of 15-bit LI. .

Bit description

0000000 The previous RLC PDU is exactly filled by one RLC SDU, in the previous RLC

There is no length indicator in the PDU to end the SDU

1111100 UMD PDU: The first byte of this RLC PDU is the first byte of an RLC SDU; AMD PDU: Reserved (current version has this Value PDU is discarded)

1111101 Reserved (In the current version, PDUs with this value are discarded)

1111110 AMD PDU: The remainder of the PDU contains a piggybacked STATUS PDU; UMD PDU: Reserved (in the current version, PDUs with this value are discarded)

The remaining part of the 1111111 RLC PDU is padding bits, and the padding bit length can be zero.

At present, according to the scheduling mode of the MCCH information, in order to ensure the periodic transmission of the access information, and when the criterion information and the non-criteria information need to be processed by the RLC UM at the same time, the non-criteria information may interrupt the transmission of the criterion information, as shown in the figure. 8 is shown. In Figure 8, each square represents a PDU. The blocks of sequence number 0 and sequence number 8 are PDUs containing non-criteria information SDUs, and the blocks of sequence numbers 1 to 6 are the PDUs containing the criterion information SDU, and the blocks of sequence number 7, sequence number 9 to sequence number 14 are included. PDU of the same criteria information SDU. To ensure that the non-criteria information in the second access information period is sent in time, when the RLC UM receives the SDU containing the non-criteria information, the SDU is segmented and encapsulated into the RLC PDU with sequence number 8 and sent. The criteria information that has not been transmitted continues to be transmitted in subsequent PDUs, that is, encapsulated in RLC PDUs of sequence numbers 9, 10, 11, 12, 13, and 14, respectively.

However, for the process of transmitting the non-criteria information transmission of the interruption criterion information, there are some problems on the receiving side: if the PDU with the serial number of 8 is not correctly received by the receiver because of the transmission error, even if the serial number is The PDUs of 7, 9, 10, 11, 12, 13, and 14 are all correctly received. The criterion information SDU contained in these PDUs cannot be reassembled because the receiver does not know whether the lost PDU No. 8 is another SDU or the criterion. A segment of the information SDU. In this way, the receiver cannot be correctly identified and reorganized, thereby reducing the reliability of information transmission. Summary of the invention

In view of this, the main object of the present invention is to provide a data segmentation cascading method, which is convenient for the receiver to determine whether reorganization can be performed, thereby improving the reliability of information transmission.

Another object of the present invention is to provide a data recombination method that enables a receiver to correctly reassemble data, thereby improving the reliability of information transmission.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a method for data segmentation cascading. When the process of segmentally cascading and assembling a packet data unit PDU of a current service data unit SDU needs to be interrupted, the sender will indicate a special identifier that the current SDU is interrupted. The encapsulation is sent in the PDU. The method includes: breaking the segmentation cascading of the current SDU, performing segmentation concatenation assembly into the PDU transmission, and then dividing the remaining data of the interrupted current SDU. Segment cascading, assembled into PDUs for transmission.

The special identifier is a length indication field in which a value in the PDU is a reserved special value, and Different reserved special values indicate different number of inserted PDUs; or a length indication field that takes one or more of the same reserved special values in the PDU, the number of length indicating fields is equal to the number of inserted PDUs; or one or more of the PDUs The length indication field of the reserved special value, the number of length indication fields is equal to the number of inserted PDUs; or the length indication field of the PDU whose value is undefined special value, and different undefined special values indicate different insertions The number of PDUs; or the length indication field of one or more PDUs that take the same undefined special value, the number of length indication fields is equal to the number of inserted PDUs; or the length indication of one or more different undefined special values in the PDU The number of the length indication field is equal to the number of inserted PDUs; or the length indication field in which the value in the PDU is a combination of a reserved special value and an undefined special value.

The method further includes: setting, in the PDU, a number of interruptions indicating the number of PDUs assembled by the SDU to be inserted, wherein the special identifier is a length indication field and a broken number field of the PDU. The special value of the length indication field is a special value reserved by the length indication field in the PDU; or a special value that is not defined by the length indication field in the PDU.

In the above solution, the reserved special value is 1111101 or 111111111111101.

In the foregoing solution, the encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in the PDU after the PDU into which the SDU to be inserted is assembled; or encapsulating the special identifier into the PDU assembled by the SDU to be inserted In the previous PDU.

In the above solution, the method further includes:

The receiving party determines whether the currently received PDU carries a special identifier. If it carries, determines the PDU required to reassemble the SDU according to the special identifier, and completes the reorganization of the SDU according to the determined PDU; otherwise, the data in the received PDU is The SDUs are reorganized in order.

The encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in the PDU after the PDU into which the SDU needs to be inserted; or the encapsulating the special identifier in the PDU, specifically: It is encapsulated in the PDU before the PDU into which the SDU needs to be inserted.

The invention also provides a method for data recombination, the method comprising:

The receiver determines whether the currently received PDU carries a special identifier, and if it is carried, The SDU is determined to determine the SDU irrelevant to the current PDU, and then the PDU is ignored to complete the reassembly of the SDU corresponding to the current PDU; otherwise, the data in the received PDU is reassembled out of the SDU in order.

The special identifier is a length indication field in which one or more PDUs of the PDU take a special value; the receiver determines the number of the domain according to the length of the special value in the PDU, and determines the PDUs that are irrelevant to the SDU corresponding to the current PDU. Or a length indicating field of a special value in the PDU; then the receiver takes the special value of the length indication field in the M-based PDU, and determines the number of PDUs unrelated to the SDU corresponding to the current PDU; or in the PDU The combination of the length indication field and the interruption number field of the special value is taken; then, the receiver determines the number of PDUs unrelated to the SDU corresponding to the current PDU according to the value of the interruption number field in the PDU. The special value of the length indication field is a special value reserved by the length indication field, or a special value not defined by the length indication field, or a combination of the two. The reserved special value is 1111101 or 111111111111101.

In the above solution, the SDU unrelated to the reassembly of the current PDU is located before the current PDU or after the current PDU.

According to the data segment cascading and recombining method provided by the present invention, the sender indicates, by means of a special identifier, whether the adjacent PDU before the current PDU or the subsequent adjacent PDU is a segment containing other SDUs after or before the inserted PDU; When the receiver reorganizes the data, it determines whether each PDU carries a special identifier, and if so, determines how to perform data reorganization according to the indication of the special identifier. The invention can ensure that the receiver correctly recognizes and reorganizes the data, and avoids the problem that the correctly received PDU cannot be reorganized because the inserted PDU is not received, thereby improving the reliability of the information transmission.

The method of the present invention may adopt a special value of the LI in the PDU format as a special identifier, and the special value may directly use a special value reserved by the LI, or may use a special value not defined in the LI; the special identifier may be carried before the PDU is inserted. The special identifier may also be carried after the PDU is inserted; the special identifier may further indicate the number of inserted PDUs. In short, the method of use is various. Therefore, the method of the present invention is flexible, convenient, and simple to implement.

In addition, the method of the present invention is not limited to the transmission of MBMS information as long as RLC UM is required. The environment in which the entity completes the data transmission can adopt the above implementation scheme, and the scope of application is wider. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a wireless network structure supporting broadcast/multicast services;

Figure 2 is a schematic diagram of the business process of the MBMS multicast mode;

Figure 3 is a schematic diagram of the business process of the MBMS broadcast mode;

4 is a schematic diagram of transmission scheduling of MCCH information;

Figure 5 is a structural diagram of a protocol stack of the MCCH;

6 is a mapping diagram of a logical channel of a MAC layer and a FACH channel of a physical layer; FIG. 7 is a transmission mode diagram of MBMS control information;

8 is a schematic diagram of transmission of a PDU containing different information in the prior art;

9 is a flowchart of processing of a sender in a transmission method according to the present invention;

FIG. 10 is a flowchart of processing of a receiver in a transmission method according to the present invention. Mode for carrying out the invention

The core idea of the present invention is to indicate whether the SDU of the current segmentation is interrupted by carrying a special identifier in the PDU. For the sender, if the SDU of the current segment cascade is interrupted, it carries a special identifier for indication; for the receiver, it is detected whether each PDU contains a special identifier to determine how to reorganize the segmented level. Associated SDU.

The special identifier may be a length indication field that takes a special value in the PDU format, and the special identifier may be carried in the PDU before the inserted PDU, or may be carried in the PDU after the inserted PDU. When using the special value of LI, you can directly use the special value reserved by LI, or use a special value not defined in LI, or use a combination of reserved special value and undefined special value; if more than one PDU is inserted, the special identifier It is also possible to further indicate the number of inserted PDUs.

Based on the above idea, the processing flow of the sender is as shown in FIG. 9, and includes the following steps: Steps 901 to 904: The sender RLC UM entity receives the SDU sent by the upper layer, and receives the received SDU. W

In the process of assembling the sPDU into the PDU by the SDU, it is determined whether there is currently an SDU that needs to be inserted, such as a non-criteria information SDU, and if so, interrupts the segmentation cascading of the SDU currently being processed, and will need The inserted SDUs are assembled into PDUs by segmentation and concatenation processing. After the PDUs that need to be inserted into the SDUs are sent, the remaining data of the SDUs that are interrupted by the segmentation are segmented and cascaded, and assembled into PDUs. And, in the process of interrupting the insertion, the sender RLC UM entity indicates that the current SDU is interrupted by a special identifier, specifically: the special identifier indicating that the current SDU is interrupted is encapsulated in the PDU and sent to the receiver; if there is no SDU If the insertion is required, the sender RLC UM entity performs normal segmentation concatenation of the received SDUs and assembles them into PDUs for transmission, that is, the received SDUs are sequentially segmented and cascaded, and assembled into PDUs for transmission. Here, the PDU into which the inserted SDUs are assembled may be referred to as an inserted PDU.

The processing flow of the receiver is as shown in Figure 10, including the following steps:

Steps 1001 to 1003: determining whether the currently received PDU carries a special identifier, and if yes, determining, according to the special identifier, which PDUs are irrelevant to reassembling the current SDU, and then ignoring the determined PDU, and completing the current SDU with the relevant PDU. Reorganize; otherwise, the data in the received PDU is reassembled out of the SDU in order. Here, the number of inserted PDUs may be determined according to the special identifier, thereby determining which PDUs are PDUs that are unrelated to reassembling the current SDU.

In the process of the receiver of the present invention, the receiver may determine, according to the special identifier, whether the data in the unreceived PDU belongs to the SDU that needs to be reassembled. Specifically, if a PDU is not received, it can be determined whether a PDU carries a special identifier. If there is a special identifier indicating that there is an inserted PDU, then it is further determined according to the special identifier whether the PDU that is not received belongs to If the PDU to be reassembled is not affected, the SDU can be reorganized. If it does not belong, the SDU that needs to be reassembled has some data lost, and the corresponding SDU cannot be reorganized. If there is no special identifier, it needs to be reorganized. Some data is lost in the SDU, and the corresponding SDU cannot be reorganized.

The specific implementation of the method of the present invention will be further described below by taking a special value of LI reserved in the PDU format. Embodiment 1:

In this embodiment, the special identifier is located in the PDU after the inserted PDU, where the special identifier is a length indication field in the UMD PDU, and the value of the length indication field is a reserved special value 1111101 or 111111111111101, to indicate that the length is included. The previous PDU of the indicated PDU contains segments inserted into other SDUs, that is, the PDU carrying the special identity does not need to be reassembled with its previous PDU. Here, the previous PDU refers to a PDU whose sequence number is one less than the current PDU.

When the sender encapsulates the UMD PDU, if the previous PDU is found to be a segment inserted into another SDU, the first length indication field value of the current PDU is set to 1111101 or corresponding, and the receiver reassembles the UMD PDU. In the SDU, if the value of the first length indication field of a received PDU is found to be 1111101 or 111111111111101, the previous PDU of the PDU is considered to be reorganized.

For a specific example, the 7-bit LI is used in this example. The RLC sends a maximum of one UMD PDU per TTI. The UMD PDU size is 128 bits. The RLC first receives a 200-bit SDU1. In the first TTI, a PDU is assembled and the first segment of the SDU1 is sent. The serial number (SN) The PDU has an E field of 0, indicating that there is no length indication field, and the Data field contains the first segment of the SDU1, and the length is 120 bits. The PDU format is as shown in Table 4.

SN = ' Ε='0'

Data ( 120bits ) Table 4

In the second TTI, due to the arrival of a new high-priority SDU2, the transmission of SDU1 needs to be interrupted, and SDU2 is sent first. Assume that the size of the SDU2 is 48 bits, and the content of the PDU with the sequence number 11 sent in the second port is as shown in Table 5. The E field is 1 and the next field is the length indicator field.

SN = Ό00101 Γ Ε=' 1 '

LI = '0000110'Ε=' 1 ' LI = 'Ε='0'

Data ( 48bits )

PAD ( 56bits ) Table 5

In the third case, the content of SDU1 is continuously sent. Since the PDU with sequence number 11 is the inserted PDU, the contents of the PDU with sequence number 12 are shown in Table 6.

According to the above transmission method, even if the receiver does not receive the PDU with sequence number 11, as long as the PDU with sequence number 10 and serial number 12 is correctly received, the field value 1111101 is indicated according to the length of the PDU with sequence number 12, 'It can be judged that the PDU with sequence number 11 is an inserted PDU, regardless of its reassembly with the PDU with sequence number 10 and serial number 12, so the 120 bits of the Data portion of the PDU with sequence number 10 will be The 80 bits of the Data part of the PDU with sequence number 12 are reassembled into an SDU to obtain SDU1.

The size of the SDU inserted in this embodiment is limited to an SDU that can be accommodated by the data domain portion of one UMD PDU.

Embodiment 2:

The implementation of the present embodiment is basically the same as that of the first embodiment, except that the values in the length indication field are different. In this embodiment, the value of the length indication field is a reserved special value 1111110 or 111111111111110 to indicate the PDU including the length indication. The previous PDU contains segments that are inserted into other SDUs. Alternatively, other special LI values, such as the currently undefined value 0000001 or 000000000000001, are used to indicate that the previous PDU of the PDU containing the length indication contains a segment inserted into another SDU. Embodiment 3:

This embodiment is based on the first embodiment and the second embodiment. The limitation of expanding the inserted SDU size is: an SDU that can be accommodated by the data domain part of two UMD PDUs.

In this embodiment, the special values of the two LIs are used to indicate that the previous PDU of the PDU including the length indication includes a segment inserted into another SDU, and the second PDU of the PDU containing the length indication includes It is the segment that inserts other SDUs. That is to say, in the embodiment, the special identifier is two length indication fields respectively taking the two special values. Specifically: For a 7-bit LI, the 1111101 indicates that the previous PDU of the PDU containing the special identifier contains a segment inserted into another SDU, and the 1111110 indicates that the second PDU of the PDU containing the special identifier contains an insertion. Segmentation of other SDUs; for a 15-bit LI, the previous PDU indicating the PDU containing the special identifier is contained in 111111111111101, and the segment containing the other SDU is included, and the first PDU containing the PDU containing the special identifier is indicated by 111111111111110. It is the segment that inserts other SDUs.

For the receiver, it is known from the two special values of LI that two PDUs containing other SDUs are inserted before the currently received PDU, and the two PDUs in front of the current PDU are ignored during reassembly.

Still taking the specific example in the first embodiment as an example, if the size of the SDU2 exceeds the length that can be accommodated in the data field of one PDU, but the length range that can be accommodated in the data fields of the two PDUs, the serial number 11 and the sequence The PDU of No. 12 is used to transmit the segment of SDU2, and the sequence number 13 starts to continue to send the segment of SDU1. Then, the content of the PDU with sequence number 13 is as shown in Table 7.

SN =,0001101, Ε=' Γ

Π = Ί 111101 ' Ε='

LI = '1111110'Ε=' 1 ' LI = '0001010, E=,l,

Π = Ί 111111 ' E=, 0,

Data ( 80bits )

PAD ( 24bits ) Table VII

Correspondingly, the receiver knows that the PDUs of sequence number 11 and sequence number 12 should be ignored according to the special identifier, and only the PDUs of sequence number 10 and sequence number 13 are reassembled to obtain SDU1.

Embodiment 4:

The implementation principle of this embodiment is basically the same as that of the third embodiment, except that the values in the length indication domain used have different meanings. In this embodiment, for the 7-bit LI, the previous PDU indicating that the PDU containing the special identifier is included in 1111110 includes a segment inserted into another SDU, and 1111101 indicates that the second PDU included in the front of the PDU containing the special identifier is included. Is a segment into which other SDUs are inserted; for a 15-bit LI, the previous PDU indicating the PDU containing the special identifier is contained in 111111111111110, which is a segment into which other SDUs are inserted, and the first PDU in front of the PDU containing the special identifier is indicated by 111111111111101. The PDU contains segments that are inserted into other SDUs.

Or, using any other two special length indication field values, such as a special value that is not currently defined, to indicate that the previous PDU of the PDU containing the special identifier respectively includes a segment inserted into another SDU, and a part that includes the special identifier. The second PDU in front of the PDU contains the segments that are inserted into other SDUs.

Of course, it is also possible to use both a special value reserved by LI and an undefined special value. Embodiment 5:

Since the SDUs that need to be inserted are likely to be segmentally assembled into two or more PDUs, that is, the number of inserted PDUs is two or more. For this situation, in this embodiment, the reserved special value or the undefined special value of a certain length indication field may be directly used to indicate the number of PDUs inserted before the current PDU. For example: Use 1111101 to indicate that a PDU is inserted before the current PDU; Use 1111110 to indicate that two PDUs are inserted before the current PDU; three PDUs are inserted before the current PDU is indicated by 0000001, and so on. In this embodiment, the special identifier is a length indication field whose value is a reserved special value, or a length indication field whose value is an undefined special value, and different special values indicate the number of different inserted PDUs. Example 6:

Since the SDUs that need to be inserted are likely to be segmentally assembled into two or more PDUs, that is, the number of inserted PDUs is two or more. For this situation, in this embodiment, the number of PDUs inserted before the current PDU can be represented by repeatedly using the length indication field of a reserved special value. In this embodiment, the special identifier is a plurality of length indication fields that take the same reserved special value. For example, the value of the length indication field is a reserved special value 1111110, and there are four insertion PDUs. Then, in the format of the current PDU, After the serial number SN, repeat LI 4 "1111101".

Of course, you can also reuse special values that are reserved in other length indication fields, such as: 1111110 or 111111111111110. Or, reuse any undefined special value in the length indication field.

Then, after receiving the current PDU, the receiver determines the number of PDUs that can be ignored before the current PDU according to the reserved special value or the number of undefined special values used in the length indication field. Example 7:

Since the SDUs that need to be inserted are likely to be segmentally assembled into two or more PDUs, that is, the number of inserted PDUs is two or more. For this case, in this embodiment, a special value that is not defined in two or more length indicating fields, or a combination of special values reserved in two or more length indicating fields and undefined special values, each special value may be used. Used to indicate a PDU inserted before the current PDU. In this embodiment, the special identifier is a plurality of length indication fields that take different undefined special values, or a plurality of length indication fields that take different undefined special values and retain special value combinations.

Then, after receiving the current PDU, the receiver determines the number of PDUs that can be ignored before the current PDU according to the reserved special value or the number of undefined special values used in the length indication field. Example / Since the SDUs that need to be inserted are likely to be segmentally assembled into two or more PDUs, that is, the number of inserted PDUs is two or more. In this case, the new domain is added to the UMD PDU, and the new domain is used to identify the number of previously inserted PDUs, and the newly added domain and the length indication domain whose value is a reserved special value form a special identifier. The special identifier is located in the PDU behind the inserted PDU. For example: If you add an Interrupt number field, the modified UMD PDU format is as shown in Table 8:

Octl

( Optional )

Last Ocetet

Eight

The meaning of the modified E domain is shown in Table IX:

Table IX

At the same time, a special length indication value is needed to indicate that the next field is the interrupted number field. For example: Use 1111101 or 111111111111101 to indicate that the next field is the interrupted number field.

When the sender encapsulates the UMD PDU, if it finds that there is a segment containing the inserted other SDU The PDU sets the first length indication field value of the current PDU to 1111101 or 111111111111101. At the same time, the packet is interrupted by the number field, and the value of the field is equal to the number of previously inserted PDUs.

Correspondingly, when the receiver reassembles the SDU according to the UMD PDU, if it finds that the first length indication field of the received PDU is 1111101 or 111111111111101, the next domain is read at the same time, that is, the number field is interrupted, and the determination is performed. How many inserted PDUs are in front, and the PDU inserted in front of the PDU is ignored when the current PDU is reorganized.

Example 9:

The implementation principle of this embodiment is basically the same as that of the eighth embodiment, except that the reserved special value in the different length indication fields indicates that the next domain is the interrupted number domain.

Alternatively, any other special length indication field value, such as a currently undefined value, is used to indicate that the next field is the interrupted number field.

Example 10:

The implementation principle of this embodiment is basically the same as that of the first embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 11:

The implementation principle of this embodiment is basically the same as that of the second embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 12:

The implementation principle of the embodiment is basically the same as that of the third embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 13:

The implementation principle of the embodiment is basically the same as that of the fourth embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Embodiment 14: This embodiment is basically the same as the implementation principle of the fifth embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 15:

The implementation principle of the embodiment is basically the same as that of the sixth embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 16:

The implementation principle of the embodiment is basically the same as that of the seventh embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example 17:

The implementation principle of the embodiment is basically the same as that of the eighth embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same. Example ten

This embodiment is basically the same as the implementation principle of the ninth embodiment, except that the special identifier for inserting the PDU is located in the PDU before the inserted PDU, and other settings and processing procedures are completely the same.

The above solution is applicable to GPRS, EDGE, WCDMA, TD-SCDMA and other wireless communication systems, and is applicable to many processes, such as: ordinary UMD PDU transmission process, UMD PDU transmission process with out-of-order transmission function, and the like. The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A data segment cascading method, characterized in that: a special identifier encapsulated in a current SDU of a current service data unit SDU is encapsulated and sent in a PDU, the method comprising: interrupting a segmentation cascade of a current SDU The SDUs to be inserted are segmentally cascaded into PDUs, and then the remaining data of the interrupted current SDUs are segmentally concatenated and assembled into PDUs for transmission.

The method according to claim 1, wherein the special identifier is a length indication field in the PDU whose value is a reserved special value, and different reserved special values indicate different number of inserted PDUs.

The method according to claim 1, wherein the special identifier is a length indication field in which one or more PDUs take the same reserved special value, and the number of length indication fields is equal to the number of inserted PDUs.

The method according to claim 1, wherein the special identifier is a length indication field in which one or more PDUs take different reserved special values, and the number of length indication fields is equal to the number of inserted PDUs.

The method according to claim 1, wherein the special identifier is a length indication field in the PDU whose value is an undefined special value, and different undefined special values indicate different number of inserted PDUs. .

The method according to claim 1, wherein the special identifier is a length indication field in which one or more PDUs take the same undefined special value, and the number of length indication fields is equal to the number of inserted PDUs.

The method according to claim 1, wherein the special identifier is a length indication field in which one or more PDUs take different undefined special values, and the number of length indication fields is equal to the number of inserted PDUs.

8. The method according to claim 1, wherein the special identifier is in a PDU A value is a length indication field that holds a combination of a special value and an undefined special value.

The method according to claim 1, wherein the method further comprises: setting, in the PDU, a number of interruptions indicating the number of PDUs assembled by the SDU to be inserted, and the special identifier is in the PDU Take the length of the special value to indicate the domain and the number of breaks.

The method according to claim 9, wherein the special value of the length indication field is a special value reserved by the length indication field in the PDU; or a special value not defined by the length indication field in the PDU.

A method according to claim 2, 3, 4, 8 or 10, characterized in that said reserved special value is 1111101 or 111111111111101.

The method according to any one of claims 1 to 10, wherein the encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in a PDU after the PDU into which the SDU to be inserted is assembled.

The method according to any one of claims 1 to 10, wherein the encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in a PDU before the PDU into which the SDU to be inserted is assembled.

The method according to any one of claims 1 to 10, characterized in that the method further comprises:

The method of claim 14, wherein the encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in a PDU after the PDU into which the SDU to be inserted is assembled.

The method according to claim 14, wherein the encapsulating the special identifier in the PDU is specifically: encapsulating the special identifier in a PDU before the PDU into which the SDU to be inserted is assembled.

17. A method of data recombination, characterized in that the method comprises:

The receiving party determines whether the currently received PDU carries a special identifier, and if so, determines, according to the special identifier, a PDU unrelated to the SDU corresponding to the current PDU, and then ignores the determined PDU to complete the reorganization of the SDU corresponding to the current PDU; otherwise, The data in the received PDU is reassembled out of the SDU in order.

The method according to claim 17, wherein the special identifier is a length indication field in which one or more PDUs take a special value; and the receiver indicates the number of domains according to the length of the special value in the PDU. And determining the number of PDUs unrelated to the SDU corresponding to the current PDU.

The method according to claim 17, wherein the special identifier is a length indication field of a special value in the PDU; and the receiver determines and reorganizes according to the special value taken by the length indication field in the PDU. The number of PDUs unrelated to the SDU corresponding to the current PDU.

The method according to claim 17, wherein the special identifier is a combination of a length indication field and a break number field of a special value in the PDU; and the receiver determines the value according to the number of interruption domains in the PDU. The number of PDUs unrelated to the SDU corresponding to the current PDU.

The method according to claim 18, wherein the special value of the length indication field is a special value reserved by the length indication field, or a special value not defined by the length indication field, or a combination of the two.

The method according to claim 19, wherein the special value of the length indication field is a special value reserved by the length indication field, or a special value not defined by the length indication field.

23. Method according to claim 21 or 22, characterized in that said reserved special value is 1111101 or 111111111111101.

The method according to any one of claims 17 to 22, wherein the PDU unrelated to the SDU corresponding to the current PDU is located before the current PDU or after the current PDU.