The served mobile subscriber may invoke the call deflection supplementary service if an incoming call is offered. According to TS 22.072
this may happen as an automatic response from the mobile station if the call is offered or as the result of a subscriber action.
The mobile station shall invoke the call deflection supplementary service by initiating call clearing with a DISCONNECT message including the call deflection request (refer to Figure 4.1
). The call deflection request shall contain the DeflectedToNumber which may be accompanied by a DeflectedToSubAddress.
The MS may invoke the call deflection supplementary service at every time after call confirmation until the call is accepted (refer to TS 24.008
). If the network accepts the call deflection request, it shall continue call clearing. The result indication shall be returned to the mobile station in the RELEASE message.
If the network cannot accept the call deflection request, it shall continue call clearing. The corresponding error indication shall be returned to the mobile station in the RELEASE message. Error values are specified in TS 24.080
During the call deflection request the MS shall run a timer TCD. This timer is started when the call deflection request is sent and stopped when a response is received from the network. If this timer expires the MS shall assume that the call deflection request has failed, locally release the invokeID, inform the user of the failure and continue call clearing as defined in TS 24.008
4.1.2 Deflected-to mobile subscriber side Word‑p. 7
As for the call forwarding supplementary services the deflected-to mobile subscriber will receive a NotifySS operation containing the SS Notification indicating that the incoming call is a forwarded call. When available, the SS Code of the Call Deflection supplementary service is included, see Figure 4.2
When multiple diversions occurs the value of the SS Code shall relate to the last invoked diversion service.
In addition the deflected-to subscriber will receive the redirecting party BCD number and optionally, a redirecting party subaddress.
The redirecting party BCD number information element is made up of a number of information units as defined in TS 24.008
In addition to or instead of the redirecting party's digits, the subscriber may be given the following information:
Indicator values are given in TS 24.008
The redirecting party subaddress information element is made up of a number of information units as defined in TS 24.008
Figure 4.2: Notification to the forwarded to mobile subscriber that the incoming call is a forwarded call
As a subscription option, the served mobile subscriber can request that the calling mobile subscriber receives a NotifySS operation containing the SS Notification indicating that the call has been deflected. When available, the SS Code of the call deflection supplementary service is included, see Figure 4.3
Figure 4.3: Notification to the calling mobile subscriber that the call is forwarded