Patent ID: 7236788

Claim:
A cellular communications network comprising: a call setup portion operable, in a call setup process for setting up a call for a mobile station of the network, to allocate respective uplink and downlink channels between the mobile station and a first one of a plurality of base transceiver stations of the network, and to provide the mobile station and at least one further base transceiver station of said plurality, neighboring said first base transceiver station, with call setup information for use by the mobile station and the or each said further base transceiver station to allocate respective uplink and downlink channels between the further base transceiver station concerned and the mobile station; and a hand-off control portion operable initially, upon completion of the call setup process, to set said first base transceiver station to an active state, in which its said uplink and downlink channels are in use, and to set the or each said further base station to a dormant state in which the uplink and downlink channels of the further base transceiver station concerned are not in use, the hand-off control portion also being operable when, during the course of the call, it is determined that the mobile station should communicate with the, or one of the, further base transceiver stations, to employ such call setup information provided in the call setup process to bring about change of that further base transceiver station from said dormant state to said active state; an uplink control message receiving portion operable, when the first base transceiver station is in the active state, to detect, in an uplink signal transmitted by the mobile station to the first base transceiver station, an uplink control message identifying a base transceiver station of the network with which the mobile station requests communication; a comparison portion which compares the identity of the requested base transceiver station specified by the received uplink control message with an own base transceiver station identity of the first base transceiver station; a status control portion which changes the first base transceiver station from said active state to said dormant state if the requested base transceiver station identity is different from said own base transceiver station identity; and a new base transceiver station informing portion operable, when the requested base transceiver station identity is different from said own base transceiver station identity, to send to a base station controller of the network a message specifying the requested base transceiver station identity.