1.4 State transition model

23.0833GPPCall Waiting (CW) and Call Hold (HOLD) supplementary servicesRelease 17Stage 2TS

The following figure shows the successful cases of transition between the applicable logical states of call waiting. The state changes are either caused by actions of the service provider or the mobile user.

Note that error cases are not shown in the diagram as they normally do not cause a state change. Additionally, some successful requests may not cause a state change. Hence they are not shown in the diagram.

The diagram only shows operations on elementary basic service groups.

Figure 1.7: State transition model for call waiting