CONTROLLING THE SET-UP OF CALLS BETWEEN SUBSCRIBER STATIONS

摘要

The invention relates to a control apparatus (AGNT), a telecommunication system (SYS), a control method and a subscriber sttion (SS1, TE, MT; SS2, TE, MT; SS3, TE, MT) wherein a call set-up request issued by a first subscriber station (SS1) is blocked from a transfer to a telecommunication network (NET) as long as the second subscriber station (SS2) to which a call should be set-up is in a busy state. The control apparatus (AGNT) only transfers the call set-up request to the exchange means (MSC/VLR, GMSC, HLR) of the telecommunication network (NET) when the called second subscriber station (SS2) changes from a busy state into an idle state. Thus, the network resources are not occupied by call set-up requests which would be rejected due to the second subscriber station (SS2) being in a busy state. The invention is particularly advantageous when the calling subscriber station (SS1) uses a re-dial function to repeat a call set-up request. After several retries further retries will be blocked and the call will only be set-up when the second subscriber station becomes free. A particular advantageous application of the invention is to combine the blocking of call set-up requests by the control apparatus (AGNT) with a CCBS service implemented in the network (NET).