WO2013067809A1

WO2013067809A1 - Inter-protocol-layer data segmentation and recombination processing method and device

Info

Publication number: WO2013067809A1
Application number: PCT/CN2012/076101
Authority: WO
Inventors: 朱寰; 郭文丹
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-11-09
Filing date: 2012-05-25
Publication date: 2013-05-16
Also published as: CN103108407A; CN103108407B

Abstract

Provided are an inter-protocol-layer data segmentation and recombination processing method and device, the method comprising: setting the length of an SNDCP layer packet data package, and segmenting an IP packet to form a segmented SN PDU packet; segmenting the segmented SN PDU packet according to the length of an LLC layer packet data package so as to form a segmented LLC PDU packet; obtaining an SN PDU packet after removing the LLC prefix of the segmented LLC PDU packet of the LLC layer; parsing the SNDCP prefix of each SN PDU packet to obtain IP data segments; sequencing and combining the IP data segments; and recombining the IP layer with the combined IP packet. The present invention presets the length of the SNDCP layer packet data package so that the SNDCP layer is no longer limited by the LLC layer, and reduces the coupling degree between the SNDCP layer and the LLC layer, thus maintaining the independence of each layer and ensuring higher flexibility.

Description

协议层间数据分段、重组处理方法和装置技术领域 Protocol layer data segmentation, recombination processing method and device

本发明设计移动通信领域，尤其涉及一种基于 GPRS ( General Packet Radio Service, 通用分组无线业务） ***的协议层间数据分段、重组的处理方法，以及分段 /重组处理装置。背景技术 The present invention is directed to the field of mobile communications, and in particular, to a method for processing data segmentation and reassembly between protocols based on a GPRS (General Packet Radio Service) system, and a segmentation/reassembly processing device. Background technique

GPRS是在现有的 GSM ( Global System for Mobile Communication, 全球移动通信***）基础上发展起来的一种移动分组数据业务。 GPRS通过在 GSM数字移动通信网络中引入分组交换的功能实体，以完成用分组方式进行的数据传输，完成 GPRS业务，原 GSM网络则完成话音功能。 GPRS系统可以看作是对原有的 GSM电路交换***的基础上进行的业务扩充，以支持移动用户利用分组数据移动终端接入 Internet 或其他分组数据网络的需求。 GPRS is a mobile packet data service developed on the basis of the existing GSM (Global System for Mobile Communication). GPRS introduces a packet-switched functional entity in the GSM digital mobile communication network to complete the data transmission in the packet mode to complete the GPRS service, and the original GSM network completes the voice function. The GPRS system can be seen as a service extension based on the original GSM circuit-switched system to support the need for mobile users to access the Internet or other packet data networks using packet data mobile terminals.

GPRS***的基本网络结构如图 1所示。在 GPRS***中， MS ( Mobile Station, 移动台）和 BSS ( Base Station Subsystem, 基站子***）之间的 Urn接口以及 BSS和 SGSN ( Serving GPRS Support Node, GPRS服务支持节点）之间的 Gb接口的无线协议栈结构包含了多种协议， GPRS***的无线数据面协议栈结构如图 2 所示。其中 SNDCP ( Subnetwork Dependent Convergence Protocol , 子网相关汇聚协议 )针对数据面进行数据的分段 /重组、头部和数据部分的压缩 /解压缩等功能，目的在于将不同的网络层协议汇聚到空口进行传输，节约了终端和核心网之间的无线接口的无线带宽资源，提高了数据的传输效率。 The basic network structure of the GPRS system is shown in Figure 1. In the GPRS system, the Urn interface between the MS (Mobile Station) and the BSS (Base Station Subsystem) and the Gb interface between the BSS and the SGSN (Serving GPRS Support Node) The wireless protocol stack structure contains multiple protocols. The wireless data plane protocol stack structure of the GPRS system is shown in Figure 2. The SNDCP (Subnetwork Dependent Convergence Protocol) performs data segmentation/reassembly, header and data compression/decompression for the data plane, and aims to aggregate different network layer protocols into air interfaces. Transmission saves the wireless bandwidth resources of the wireless interface between the terminal and the core network, and improves the data transmission efficiency.

但是在 SNDCP层协议之中，并无指示该层分段具体大小，具体分段大小是由更下一层的 LLC ( Logical Link Control, 逻辑链路控制）分段大小来限制的。如果 LLC为确认帧，即应答模式下，则每段大小不超过 1520 Bytes; 如果 LLC为非确认帧，即无应答模式下，则每段大小不超过 500 Bytes。所以出现了上层协议层受制于下层协议层的情况，上层协议层与下层协议层之间耦合度较大，不能相互独立。发明内容 However, in the SNDCP layer protocol, there is no indication of the specific size of the layer segment, and the specific segmentation is large. The small size is limited by the segmentation size of the LLC (Logical Link Control) layer. If the LLC is an acknowledgment frame, that is, in the acknowledge mode, the size of each segment does not exceed 1520 Bytes; if the LLC is a non-acknowledgement frame, that is, in the no-answer mode, each segment does not exceed 500 Bytes. Therefore, the upper protocol layer is subject to the lower protocol layer, and the coupling between the upper protocol layer and the lower protocol layer is relatively large and cannot be independent of each other. Summary of the invention

本发明的主要目的在于提供一种基于 GPRS***的协议层间数据分段、重组处理方法和装置，以解决协议间耦合过紧的问题。 The main object of the present invention is to provide a method and device for data segmentation and reassembly between protocol layers based on GPRS system, so as to solve the problem of excessive coupling between protocols.

为了解决上述问题，本发明的技术方案是这样实现的： In order to solve the above problems, the technical solution of the present invention is implemented as follows:

一种基于 GPRS***的协议层间数据分段处理方法，包括： A method for inter-layer data segmentation processing based on GPRS system, comprising:

设定 SNDCP层的分组数据包长度，将 IP层的 IP报文传送到 SNDCP 层； Setting the packet data length of the SNDCP layer, and transmitting the IP packet of the IP layer to the SNDCP layer;

按照设定的 SNDCP层分组数据包长度对所述 IP报文进行分段，并将各分段加上 SNDCP字头，构成分段子网协议数据单元 SN PDU报文； The IP packet is segmented according to the set SNDCP layer packet length, and each segment is added with a SNDCP header to form a segment subnet protocol data unit SN PDU packet;

将 SNDCP层的所述分段 SN PDU报文传送到逻辑链路控制 LLC层；各分段加上 LLC字头，构成分段 LLC PDU报文。 The segmented SN PDU message of the SNDCP layer is transmitted to the logical link control LLC layer; each segment is added with a LLC prefix to form a segmented LLC PDU message.

其中，所述 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 The packet data packet length of the SNDCP layer is greater than or equal to the LLC layer packet data packet length.

其中，所述将各分段加上 SNDCP字头为将各分段加上以下内容：空闲比特字段、第一个分段指示符字段、是否为最后一个分段指示符字段、 PDU 编号字段、非应答模式下的分段编号字段、以及分组数据包长度字段。 Wherein, the SNDCP prefix is added to each segment to add the following content to each segment: an idle bit field, a first segment indicator field, a last segment indicator field, a PDU number field, The segment number field in the non-acknowledgement mode, and the packet packet length field.

其中，对于第一个分段 SN PDU报文，所述 SNDCP字头还包括：数据压缩编码字段和协议控制信息压缩编码字段。 The SNDCP header further includes: a data compression coding field and a protocol control information compression coding field, for the first segment SN PDU message.

其中，所述将各分段加上 LLC字头为将各分段加上以下内容：地址域字段、控制域字段和帧校验字段。 Wherein, adding the LLC prefix to each segment is to add the following content to each segment: Address field Fields, Control Domain Fields, and Frame Check Fields.

一种基于 GPRS***的协议层间数据重组处理方法，包括：并将得到的 SN PDU报文发送到 SNDCP层； A method for reorganizing data between protocol layers based on a GPRS system, comprising: sending the obtained SN PDU message to the SNDCP layer;

解析各 SN PDU报文的 SNDCP字头，将各 SN PDU报文去除 SNDCP 字头后得到 IP数据段，并对所述 IP数据段进行排序组合，每个排序组合的大小不超过设定的 SNDCP层分组数据包长度，将组合后的 IP报文传送到 IP层； Parsing the SNDCP header of each SN PDU packet, removing the SNDCP header from each SN PDU packet, obtaining an IP data segment, and sorting and combining the IP data segments, and the size of each sorting combination does not exceed the set SNDCP. Layer packet data packet length, and the combined IP packet is transmitted to the IP layer;

IP层对接收到的 IP报文进行重组。 The IP layer reassembles the received IP packets.

其中，对所述 IP数据段进行排序组合的过程包括：解析 SN PDU报文的字头，获取字头中的报文顺序号，根据所述报文顺序号对所述 IP数据段进行排序组合。 The process of sorting and combining the IP data segments includes: parsing a header of the SN PDU packet, obtaining a sequence number of the packet in the prefix, and sorting the IP data segment according to the sequence number of the packet .

一种基于 GPRS***的协议层间数据分段 /重组处理装置，包括：下层收发模块、上层收发模块、分段 /重组模块；其中， A protocol inter-layer data segmentation/reassembly processing device based on a GPRS system, comprising: a lower layer transceiver module, an upper layer transceiver module, a segmentation/reassembly module;

所述分段 /重组模块，用于设置 SNDCP层的分组数据包长度；并用于通过上层收发模块接收 IP报文，按照设定的 SNDCP层分组数据包长度对 IP报文进行分段处理后通过下层收发模块转发到 LLC层；还用于通过下层收发模块接收 SN PDU报文，按照设定的 SNDCP层分组数据包长度对 SN PDU报文进行重组处理后通过上层收发模块转发到 IP层。 The segmentation/reassembly module is configured to set a packet data packet length of the SNDCP layer, and is configured to receive an IP packet by using an upper layer transceiver module, and process the IP packet according to the set SNDCP layer packet length. The lower layer transceiver module is forwarded to the LLC layer. The SN PDU packet is received by the lower layer transceiver module, and the SN PDU packet is reassembled according to the set SNDCP layer packet length.

其中，所述的 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 The packet data packet length of the SNDCP layer is greater than or equal to the length of the LLC layer packet data packet.

本发明预先设定 SNDCP层分组数据包长度，使 SNDCP层不再受限于 LLC层，降低 SNDCP层与 LLC层的耦合度，从而使各层之间保持独立，保证了较强的灵活性。附图说明 The invention pre-sets the packet data packet length of the SNDCP layer, so that the SNDCP layer is no longer restricted by the LLC layer, and the coupling degree between the SNDCP layer and the LLC layer is reduced, so that the layers remain independent. Guaranteed greater flexibility. DRAWINGS

图 1为现有 GPRS***的基本网络结构示意图； 1 is a schematic diagram of a basic network structure of an existing GPRS system;

图 2为现有 GPRS***的无线数据面协议结构示意图； 2 is a schematic structural diagram of a wireless data plane protocol of an existing GPRS system;

图 3为本发明的 SNDCP PDU分段 /重组示意图； 3 is a schematic diagram of SNDCP PDU segmentation/reassembly according to the present invention;

图 4为本发明实施例一中数据分段处理方法流程图； 4 is a flowchart of a data segmentation processing method according to Embodiment 1 of the present invention;

图 5为本发明实施例二中数据重组处理方法流程图； FIG. 5 is a flowchart of a data reorganization processing method according to Embodiment 2 of the present invention;

图 6为本发明实施例三中分段 /重组处理装置结构示意图。具体实施方式 FIG. 6 is a schematic structural diagram of a segmentation/reassembly processing apparatus according to Embodiment 3 of the present invention. detailed description

下面通过具体实施方式结合附图对本发明作进一步的详细说明。 The present invention will be further described in detail below with reference to the accompanying drawings.

本发明的主要构思是通过增加 SNDCP层的分组数据包的本层分段长度的定义，使得 SN PDU ( Subnetwork Protocol Data Unit , 子网协议数据单元）分段的长度只受限于本层的数据参数制约，而不在受到下层 LLC层的数据参数的反向制约。 The main idea of the present invention is to increase the length of the SN PDU (Subnetwork Protocol Data Unit) segment by only the data of the layer by increasing the definition of the layer segment length of the packet data packet of the SNDCP layer. Parameter constraints, but not subject to the reverse constraints of the data parameters of the lower LLC layer.

按照传统的协议功能描述，上层协议的实现需要下层给其提供相应的服务。 PDU在上下层协议间传输时需要执行分段 /重组流程。 According to the traditional protocol function description, the implementation of the upper layer protocol requires the lower layer to provide corresponding services. The segmentation/reassembly process needs to be performed when the PDU is transmitted between the upper and lower layers.

以太网和 802.3对协议数据单元传输时的长度都有限制，最大值分别是 1500字节和 1492字节。这个最大传输长度称作 MTU ( Maximum Transmit Unit, 最大传输单元）。 Both Ethernet and 802.3 have limitations on the length of the protocol data unit when it is transmitted. The maximum values are 1500 bytes and 1492 bytes, respectively. This maximum transmission length is called MTU (Maximum Transmit Unit).

如果 IP层有一个数据包要传，而且数据的长度比链路层的 MTU还大，那么 IP层就需要把数据包分成若干段，这样每一段都小于 MTU。分组数据在经过 GPRS网络时，同样也需要在各协议层之间进行分段 /重组流程。 If the IP layer has a packet to transmit and the length of the data is larger than the MTU of the link layer, the IP layer needs to divide the packet into segments so that each segment is smaller than the MTU. Packet data When passing through a GPRS network, it is also necessary to perform a segmentation/reassembly process between protocol layers.

实施例一 Embodiment 1

如图 4所示为本发明数据分段处理方法中一实施例流程图，所述具体数据分段处理方法包括： FIG. 4 is a flowchart of an embodiment of a data segmentation processing method according to the present invention, where the specific The data segmentation processing method includes:

步驟 101, 预先对 SNDCP层的分组数据包长度进行设定，并将上层的 IP层的 IP 4艮文发送到 SNDCP层；的 IP报文进行分段，并给 IP报文的每个分段加上 SNDCP字头，构成了分段 SN PDU报文； Step 101: The packet data packet length of the SNDCP layer is set in advance, and the IP packet of the upper layer IP layer is sent to the SNDCP layer; the IP packet is segmented, and each segment of the IP packet is given. Adding the SNDCP header to form a segmented SN PDU message;

LLC层； LLC layer;

步驟 104, LLC层收到所述分段 SN PDU报文后，按照 LLC层的分组数据包长度对其进行分段，并将各分段加上 LLC字头，构成分段 LLCPDU 报文。 Step 104: After receiving the segmented SN PDU message, the LLC layer segments the packet according to the length of the packet data of the LLC layer, and adds the LLC prefix to each segment to form a segment LLCPDU packet.

现有技术中的 SNDCP 字头中增加的字段对于应答模式和非应答模式是不同的（参见 3GPPTS44.065协议）。如表 1所示，对于应答模式，增加的字段包括：空闲比特（X)、第一个分段指示符（F)、 SN PDU报文类型 The added fields in the SNDCP header in the prior art are different for the answer mode and the non-acknowledge mode (see 3GPP TS 44.065 protocol). As shown in Table 1, for the acknowledge mode, the added fields include: idle bit (X), first segment indicator (F), SN PDU message type.

(T)、是否最后一个分段指示符（Μ) 以及 PDU编号（ N-PDU number ); 其中对于第一个分段 SN PDU报文， SNDCP字头还包括：数据压缩编码字段（DCOMP)和协议控制信息压缩编码（PCOMP)字段。如表 2所示，对于非应答模式，增加的字段包括：空闲比特（X)、第一个分段指示符（F)、 SN PDU报文类型（T)、是否最后一个分段指示符（Μ) 以及 PDU编号(T), whether the last segment indicator (Μ) and the PDU number (N-PDU number); wherein for the first segment SN PDU message, the SNDCP header further includes: a data compression coding field (DCOMP) and Protocol Control Information Compression Coding (PCOMP) field. As shown in Table 2, for the non-acknowledgement mode, the added fields include: idle bit (X), first segment indicator (F), SN PDU message type (T), whether the last segment indicator ( Μ) and PDU number

( N-PDU number )、分段编号（ Segment number )；其中对于第一个分段 SN PDU报文， SNDCP字头还包括：数据压缩编码字段（DCOMP)和协议控制信息压缩编码（PCOMP)字段。其中的 SNPDU报文类型字段用来指示为应答模式或非应答模式。

(N-PDU number), segment number (Segment number); wherein for the first segment SN PDU message, the SNDCP header further includes: a data compression coding field (DCOMP) and a protocol control information compression coding (PCOMP) field . The SNPDU message type field is used to indicate the response mode or the non-answer mode.

表 1 Table 1

表 2 如表 3所示，本发明在 SNDCP字头中由于不再区分应答模式和非应答模式，不再需要 SNPDU报文类型字段，在分段 SNPDU报文中的 SNDCP 字头中增加了一个字段 SN-PDU LI, 用来指示本层报文的长度。其中对于第一个分段 SN PDU 报文， SNDCP 字头还包括：数据压缩编码字段 (DCOMP)和协议控制信息压缩编码（PCOMP) 字段。 As shown in Table 3, the present invention does not need to distinguish between the acknowledge mode and the non-answer mode in the SNDCP header, and the SNPDU packet type field is no longer needed, and a SNDCP header is added to the fragmented SNPDU header. The field SN-PDU LI is used to indicate the length of the packet of this layer. For the first segment SN PDU message, the SNDCP header further includes: a data compression coding field (DCOMP) and a protocol control information compression coding (PCOMP) field.

表 3 对于设定 SNDCP层的分组数据包长度的大小，因为 SNDCP层不再以 LLC层分组数据长度作为依据，删除了 SNDCP字头中用来指示应答或无应答模式的 T字段，因此 SNDCP层分组数据长度不再区分模式，即应答模式和无应答模式，所以建议 SNDCP层的分组数据包长度大于等于所述 LLC 层分组数据包长度。又因 LLC层数据分段长度在应答和无应答模式下分别为 1520或 500, 且上述已描述 SNDCP不分模式，所以建议 SN-PDU的分段大小不小于 1520,如表 3所示， SN-PDU LI字段占 11位，可以指示 1520 以上的长度。 Table 3 For setting the size of the packet data packet size of the SNDCP layer, since the SNDCP layer is no longer based on the length of the LLC layer packet data, the T field used to indicate the response or no response mode in the SNDCP header is deleted, so the SNDCP layer The packet data length no longer distinguishes between the mode, that is, the acknowledge mode and the no answer mode, so it is recommended that the packet data packet length of the SNDCP layer is greater than or equal to the length of the LLC layer packet data packet. In addition, since the segment length of the LLC layer data is 1520 or 500 in the response and non-answer modes, respectively, and the SNDCP mode is not described above, it is recommended that the segment size of the SN-PDU is not less than 1520, as shown in Table 3, SN. - The PDU LI field occupies 11 bits and can indicate a length of 1520 or more.

对在 LLC层进行分段的分段 SN PDU报文添加 LLC字头时，所加的字头可以包括：地址域字段、控制域字段和帧校验字段。 When a LLC header is added to a segmented SN PDU message segmented at the LLC layer, the added header may include: an address field field, a control field field, and a frame check field.

实施例二 Embodiment 2

如图 5 所示为数据重组处理方法中一实施例流程图，所述具体数据重组处理方法包括： FIG. 5 is a flowchart of an embodiment of a data reorganization processing method, where the specific data reassembly processing method includes:

步驟 201 ,去除 LLC层的分段 LLC PDU报文的 LLC字头，获得 SN PDU 报文并发送到上层的 SNDCP层； Step 201: The LLC header of the segment LLC PDU packet of the LLC layer is removed, and the SN PDU packet is obtained and sent to the upper SNDCP layer.

步驟 202, 解析 SN PDU报文的 SNDCP字头，将各 SN PDU报文去除 SNDCP字头后得到 IP数据段，并对所述 IP数据段进行排序组合，组合的大小不得超过 SNDCP层设定的分组数据包长度，经过组合后的 IP数据段便是 IP报文，并将 IP报文传送到 IP层； Step 202: Parse the SNDCP header of the SN PDU packet, remove the SNDCP header from each SN PDU packet, obtain an IP data segment, and sort and combine the IP data segments, and the combined size may not exceed the SNDCP layer setting. Packet packet length, the combined IP data segment is an IP packet, and the IP packet is transmitted to the IP layer;

步驟 203， IP层将接收到的 IP报文再次进行重组。同样建议 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 Step 203: The IP layer reassembles the received IP packet again. It is also recommended that the packet data packet length of the SNDCP layer be greater than or equal to the length of the LLC layer packet data packet.

在上述的方法中对 IP数据段进行排列组合可具体用以下方法：首先将收到的 SN PDU报文的 SNDCP字头进行解析，通过解析得到了 SNDCP字头中的报文顺序号，最后根据所获得的报文顺序号对所述 IP数据段进行排列组合。 In the above method, the IP data segments may be arranged and combined in the following manner: First, the SNDCP header of the received SN PDU packet is parsed, and the sequence number of the packet in the SNDCP prefix is obtained through parsing, and finally according to The obtained message sequence number is arranged and combined with the IP data segments.

实施例三 Embodiment 3

如图 6所示为数据分段 /重组处理装置中一实施例结构示意图，本发明装置包括：下层收发模块、上层收发模块、分段 /重组模块。 FIG. 6 is a schematic structural diagram of an embodiment of a data segmentation/reassembly processing device. The device includes: a lower layer transceiver module, an upper layer transceiver module, and a segmentation/reassembly module.

所述分重组模块，用于设置 SNDCP层的分组数据包长度；并用于通过上层收发模块接收 IP报文，按照设定的 SNDCP层分组数据包长度对 IP报文进行分段处理后通过下层收发模块转发到 LLC层；还用于通过下层收发模块接收 SN PDU报文，按照设定的 SNDCP层分组数据包长度对 SN PDU报文进行重组处理后通过上层收发模块转发到 IP层。 The sub-reassembly module is configured to set a packet data packet length of the SNDCP layer, and is configured to receive an IP packet by using an upper layer transceiver module, perform segmentation processing on the IP packet according to the set SNDCP layer packet data packet length, and then send and receive the IP packet through the lower layer. The module is forwarded to the LLC layer. It is also used to receive the SN PDU message through the lower layer transceiver module, reorganize the SN PDU message according to the set SNDCP layer packet length, and then forward it to the IP layer through the upper layer transceiver module.

在本发明装置中，用于设置 SNDCP层的分组数据包长度的分段 /重组模块，其对 SNDCP层的分组数据包长度的设定建议大于等于所述 LLC层分组数据包长度。 In the apparatus of the present invention, the segmentation/reassembly module for setting the packet data length of the SNDCP layer, the setting of the packet data length of the SNDCP layer is suggested to be greater than or equal to the LLC layer packet data packet length.

综上所述可见，本发明的协议层间数据分段处理方法和装置，设定 SNDCP层的分组数据包长度以对 IP报文进行分段以构成分段 SN PDU报分段 LLC PDU报文。还可以将 LLC层的分段 LLC PDU报文去除 LLC字头后得到 SN PDU报文，解析各 SN PDU报文的 SNDCP字头以得到 IP数据段，并对所述 IP数据段进行排序组合， IP层对组合后的 IP报文进行重组。本发明预先设定 SNDCP层分组数据包长度，使 SNDCP层不再受限于 LLC层，降低 SNDCP层与 LLC层的耦合度，从而使各层之间保持独立，保证了较强的灵活性。 In summary, the protocol layer data segmentation processing method and apparatus of the present invention sets the packet data packet length of the SNDCP layer to segment the IP packet to form a segment SN PDU report segmentation LLC PDU message. . The segmented LLC PDU packet of the LLC layer may be removed from the LLC header to obtain an SN PDU packet, and the SNDCP header of each SN PDU packet is parsed to obtain an IP data segment, and the IP data segments are sorted and combined. The IP layer reassembles the combined IP packets. The invention pre-sets the packet data packet length of the SNDCP layer, so that the SNDCP layer is no longer restricted by the LLC layer, and the coupling degree between the SNDCP layer and the LLC layer is reduced, so that the layers remain independent. Guaranteed greater flexibility.

以上所述，仅为本发明的较佳实施例而已并非用于限定本发明的保护范围。 The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

权利要求书 Claim

1、一种基于通用分组无线业务 GPRS***的协议层间数据分段处理方法，包括： 1. A method for inter-layer data segmentation processing based on a general packet radio service GPRS system, comprising:

设定子网相关汇聚协议 SNDCP层的分组数据包长度，将 IP层的 IP报文传送到 SNDCP层； Set the packet data packet length of the subnet-related aggregation protocol SNDCP layer, and transmit the IP packet of the IP layer to the SNDCP layer;

2、根据权利要求 1所述的方法，其中，所述 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 2. The method according to claim 1, wherein the packet data packet length of the SNDCP layer is greater than or equal to the LLC layer packet data packet length.

3、根据权利要求 1或 2所述的方法，其中，所述将各分段加上 SNDCP 字头为将各分段加上以下内容：空闲比特字段、第一个分段指示符字段、是否为最后一个分段指示符字段、 PDU编号字段、非应答模式下的分段编号字段、以及分组数据包长度字段。 The method according to claim 1 or 2, wherein said adding a SNDCP header to each segment is to add the following to each segment: an idle bit field, a first segment indicator field, whether The last segment indicator field, the PDU number field, the segment number field in the non-acknowledgement mode, and the packet packet length field.

4、根据权利要求 3所述的方法，其中，对于第一个分段 SN PDU报文，所述 SNDCP 字头还包括：数据压缩编码字段和协议控制信息压缩编码字段。 The method of claim 3, wherein, for the first segmented SN PDU message, the SNDCP header further comprises: a data compression coding field and a protocol control information compression coding field.

5、根据权利要求 1或 2所述的方法，其中，所述将各分段加上 LLC 字头为将各分段加上以下内容：地址域字段、控制域字段和帧校验字段。 5. The method according to claim 1 or 2, wherein the adding the LLC header to each segment is to add the following to each segment: an address field field, a control field field, and a frame check field.

6、一种基于 GPRS***的协议层间数据重组处理方法，包括：并将得到的 SN PDU报文发送到 SNDCP层； A data processing method for inter-layer data re-establishment based on the GPRS system, comprising: sending the obtained SN PDU message to the SNDCP layer;

解析各 SN PDU报文的 SNDCP字头，将各 SN PDU报文去除 SNDCP 字头后得到 IP数据段，并对所述 IP数据段进行排序组合，每个排序组合的大小不超过设定的 SNDCP层分组数据包长度，将组合后的 IP报文传送到 IP层； Parse the SNDCP header of each SN PDU, and remove the SNDCP for each SN PDU. After the prefix, the IP data segment is obtained, and the IP data segments are sorted and combined, and the size of each sorting combination does not exceed the set SNDCP layer packet data packet length, and the combined IP packet is transmitted to the IP layer;

7、根据权利要求 6所述的方法，其中，所述 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 7. The method according to claim 6, wherein the packet data packet length of the SNDCP layer is greater than or equal to the LLC layer packet data packet length.

8、根据权利要求 6或 7所述的方法，其中，对所述 IP数据段进行排序组合的过程包括：解析 SN PDU报文的字头，获取字头中的报文顺序号，根据所述报文顺序号对所述 IP数据段进行排序组合。 The method according to claim 6 or 7, wherein the process of sorting and combining the IP data segments comprises: parsing a header of the SN PDU packet, and acquiring a sequence number of the packet in the prefix, according to the The message sequence number sorts and combines the IP data segments.

9、一种基于 GPRS***的协议层间数据分段 /重组处理装置，包括：下层收发模块、上层收发模块、分^/重组模块；其中， 9. A protocol inter-layer data segmentation/reassembly processing device based on a GPRS system, comprising: a lower layer transceiver module, an upper layer transceiver module, and a sub/reassembly module; wherein

10、根据权利要求 9所述的装置，其中，所述的 SNDCP层的分组数据包长度大于等于所述 LLC层分组数据包长度。 10. The apparatus according to claim 9, wherein the packet data packet length of the SNDCP layer is greater than or equal to the LLC layer packet data packet length.