TSG-SA Working Group 2 (Architecture) meeting #4	     TSGS2#4(99)235
19 - 22 April 1999 Yokohama

Source:    NTT COMMUNICATIONWARE
Subject: 	Proposed add to Draft UMTS 23.20, 
Protocol Archtectre of Radio Interface Layer 3 (GMM/SM) between UE and 3G-SGSN
Purpose: 	for decision

1. Introduction

This contribution intends to clarify C plane radio interface protocol architecture in UMTS PS Service Domain.

2. Discussion

In GPRS radio interface protocol architecture, LLC instance is existing per user in order to multiplex Signalling (i.e. GMM/SM), User Packet and SMS for the user.
On the other hand, it is not the case in UMTS, i.e. signalling connection shall be established per user independent of the user data traffic channel.
Accordingly, LLC layer is unnecessary and should not be defined on the protocol stack for radio interface layer 3 in UMTS.

Figure X: Protocol Architecture for radio interface layer 3 towards the IP domain

3. Proposal

It is proposed that the Figure X should be incorporated in chapter 7.x (7.x Structure of radio interface layer 3) of UMTS 23.20 and chapter 9.7 should be removed.

4. Reference

[1]	 UMTS 23.20 Version 1.6.1  
[2]	 GSM 04.60 Version 6.3.0 , Logical Link Control (LLC) Layer specification
[3]	 UMTS TS S3.01 Version 0.0.4, UTRAN Overall Description