Within the network the service is activated for the whole subscription period. This supplementary service shall be activated by the service provider as a result of provision.
This supplementary service shall be deactivated by the service provider as a result of withdrawal.
The CD supplementary service shall be invoked by the served mobile subscriber by use of a control procedure as described in TS 22.030
The network offers incoming calls to the served mobile subscriber according to the normal procedure.
The served subscriber can respond to the incoming call offered normally or by invoking the CD supplementary service with an appropriate message. This appropriate message will contain the call deflection request and the deflected-to number. This deflected-to number may be accompanied by a deflected-to subaddress.
Two different cases of the CD invocation can be distinguished:
The invocation can be either an automatic response from the mobile station to the offered call (using pre-programmed information at the mobile station) or
may be the result of an action by the served subscriber.
If the CD supplementary service is invoked and the served mobile subscriber has subscribed to the service, the network performs the call deflection towards the indicated deflected-to number and clears the call to the called (served) mobile subscriber with a positive acknowledgement.
As a subscription option, the served mobile subscriber can request that the subscriber A receives a notification that the call has been deflected.
The deflected-to subscriber shall receive an indication that the CD supplementary service has been invoked on the call, i.e. that call has been deflected. Depending on the value of the served subscribers subscription option, the deflected-to subscriber may also receive the MSISDN of the served subscriber.
When multiple diversions occurs the reason for diversion and the MSISDN given to the deflected-to subscriber should relate to the last diverting subscriber (e.g. the subscriber who has invoked the CD supplementary service).
When calls are diverted once, i.e. due to a single invocation of the CD supplementary service, the following information shall be given to subscriber A based on the value of the served mobile subscriber's subscription option "calling subscriber receives notification that the call has been deflected":
if the value of the subscription option is "no", then no information shall be sent to subscriber A;
if the value of the subscription option is "yes ", then an indication that the call is being deflected shall be sent to subscriber A.