The invention concerns a telecommunication network using the W-CDMA protocol comprising a variety of base stations (BS) communicating with each other via a central Radio Network Controller (RNC) by an ATM based data connection via an IUB interface, whereby at least one of the base stations (BS) is comprising a variety of radio sectors (1, 2, 3, ...n) with physically distributed AAL-2 based termination points (TP), each termination point having an AAL-2 over ATM structure where different call IDs are mapped into respective ATM virtual connections (ATM/VC) under the control of a control unit timer (CU-timer) having a determined delay time, all AAL cell streams being sent parallel to each other to an ATM switching unit (AXU) via a UTOPIA interface. In order to increase the efficiency of the system without a reduction of the maximum allowed delay, the ATM switching unit comprises a multiplexing unit (AAM CPS MUX) for multiplexing AAL-2 connections of the different termination points (TP) into one single ATM virtual connection to be processed by the ATM switch.