This TS describes the general aspects on how supplementary services in the GSM system are realized from a technical point of view.
Description of technical realization for specific supplementary services can be found in TS 03.8x and TS 03.9x series.
All supplementary services may require signalling on the radio path. Signalling procedures and messages used are defined in the TS 04.8x and TS 04.9x series.
For some supplementary services information needs to be transferred between the Home Location Register (HLR), the Visitor Location Register (VLR) and the Mobile services Switching Centre (MSC). Signalling procedures for such information transfer are defined in TS 09.02
Definitions and descriptions of supplementary services are given in the TS 02.8x and TS 02.9x series.