This TS describes the point to point Short Message Service (SMS) of the GSM PLMN system. It defines:
the services and service elements;
the network architecture;
the Service Centre functionality;
the MSC functionality (with regard to the SMS);
the SGSN functionality (with regard to the SMS);
the routing requirements;
the protocols and protocol layering;
for the Teleservices 21 and 22, as specified in TS 02.03
The use of radio resources for the transfer of short messages between the MS and the MSC or the SGSN is described in TS 04.11
, and is dealt with in that specification.
The network aspects of Short Message Service provision are outside the scope of this TS (i.e. the provision of network connectivity between the PLMN subsystems). There is no technical restriction within this TS for the transfer of short messages between different PLMN's. Any such restriction is likely to be subject to commercial arrangements and PLMN operators must make their own provision for interworking or for preventing interworking with other PLMN's as they see fit.
The required and assumed network service offered to the higher layers is defined in this TS.