3GPP TSG-T2 #7 / ETSI SMG4
Ystad, SWEDEN, 22-26 November 1999	TSGT2#7(99)1060	

Liaison Statement

To:	RAN WG3

CC:	RAN WG2, CN WG1, CN WG2

Source:	TSG-T2 

Subject:	Information on Common Communication Mechanism to be used by the Cell Broadcast Service
___________________________________________________________________________

T2 kindly like to thank RAN3 for their LS on common communication mechanism to be used by the cell broadcast service.

T2 like to answer your questions from the viewpoint of defining requirements for the CBC-RNC protocol:

1. Question of RAN3: Is there a need for dynamic signalling between CN and RNC (i.e. RANAP) to establish the common communication channel or is it foreseen to be pre-configured?

In GSM there is the option either to establish each time a separate connection for each command or to leave the connection open all the time the nodes are running. The operator can choose one option according to the service load or other network requirements (e.g. like minimum number of open connection if the connecting network is provided by a third party).

2. Question of RAN3: Is there a need for a particular Radio Access Bearer and in that case what would be the expected QoS of such a channel ?

The CBS service is combined by two legs. The first leg from the CBC to the RNC has higher QoS requirement (e.g. 1 sec turnaround time, Interactive Class) than the second leg from the RNC to the UE (e.g. maximum delay 10 sec, Background class).

The first leg also needs a reliable and secure transfer over Iu.

This answers are just meant for information and do not require an answer unless RAN3 feels that something is still unclear in handling these items.