1 Scope

04.653GPPGeneral Packet Radio Service (GPRS)Mobile Station (MS) - Serving GPRS Support Node (SGSN)Release 1999Subnetwork Dependent Convergence Protocol (SNDCP)TS

The present document provides the description of the Subnetwork Dependent Convergence Protocol (SNDCP) for the General Packet Radio Service (GPRS).

The user of the services provided by SNDCP is a packet data protocol (PDP) at the mobile Station (MS) or the Relay at the Serving GPRS Support Node (SGSN). Additionally, a control entity, e.g., AT command interpreter, may be an SNDCP user. SNDCP uses the services provided by the Logical Link Control (LLC) layer 4 and the Session Management (SM) sub-layer 2.

The main functions of SNDCP are:

– Multiplexing of several PDPs.

– Compression / decompression of user data.

– Compression / decompression of protocol control information.

– Segmentation of a network protocol data unit (N‑PDU) into Logical Link Control Protocol Data Units (LL‑PDUs) and re-assembly of LL‑PDUs into an N‑PDU.

3GPP TS 04.65 is applicable to GPRS MS and SGSN.