8.19 Short Message Service

3GPP43.318Generic Access Network (GAN)Release 16Stage 2TS

GAN provides support for both Circuit Switched (GSM based) and Packet Switched (GPRS based) SMS services. GAN-attached and GPRS enabled mobile stations will be able to send and receive GSM and GPRS SMS messages via the GAN, regardless of the GPRS class (B or C) with the restriction that the class C mobiles can support only GPRS based SMS.

8.19.1 GSM based SMS

GSM SMS support in GAN is based on the same mechanism that is utilized for GSM mobility management and call control. On the MS side, the SMS layers (including the supporting CM sub layer functions) utilize the services of the MM layer to transfer SMS messages per standard circuit switched GSM implementation. The SM-CP protocol is effectively tunnelled between the MS and the CN, using GA-CSR messages from the MS to the GANC, where the GANC relays the SM-CP to BSSAP DTAP messages for transport over the A interface.

As with GSM mobility management and call control procedures, the secure IPsec tunnel and TCP session are used to provide secure and reliable SMS delivery over the IP network.

8.19.2 GPRS based SMS

GPRS SMS message transfer is based on the same mechanism as the transfer of the GPRS MM/SM signalling messages. On the MS side, the SMS layers (including the supporting CM sub layer functions) utilize the services of the LLC layer to transfer SMS messages per standard packet switched GPRS implementation.

As with GPRS signalling, the secure IPsec tunnel and TCP session is used to provide secure and reliable GPRS SMS delivery over the IP network.