Patent ID: 7274935
Filing Date: 2007-09-25
Classification: H04W

Abstract:
1. A method of reestablishing a packet data session when a mobile station, conducting both a circuit-switched call and a packet data session, is handed over from a serving base transceiver station (BTS) to a target BTS served by the same base station controller (BSC) in a GPRS/EDGE cellular radio telecommunication system, said method comprising: determining by the BSC that a handover of the mobile station from the serving BTS to the target BTS is imminent; sending from the BSC to the mobile station prior to a handover command, information needed by the mobile station to resume the packet data session in the target cell; handing over the mobile station from the serving BTS to the target BTS; sending from the BSC to a serving GPRS service node (SGSN), a pseudo-update message appearing to the SGSN to be a cell update message from the mobile station; reconnecting the circuit-switched call; and reestablishing the packet data session utilizing the information sent to the mobile station prior to the handover command; wherein the step of sending information to the mobile station needed to resume the packet data session in the target cell includes sending from the BSC to the mobile station, an indication that the BSC has sent a pseudo-update message to the SGSN; and wherein the step of reestablishing the packet data session includes reestablishing the packet data session without sending a cell update message from the mobile station.