SGSN handover in a GPRS Network

A Serving GPRS Support Node (SGSN) handover procedure, for use in a GPRS network, reduces the need for resequencing in the SGSN. This is achieved in that the old SGSN sends a message to the Gateway GPRS Support Node (GGSN), requesting that it stop transmission of data. At that time, the old SGSN transfers to the new SGSN any data which it needs to transmit to the mobile station. The GGSN resumes transmission of data, this time to the new SGSN, when the handover is complete. This reduces the requirement for the new SGSN to resequence the received data. The signal from the old SGSN to the GGSN, requesting it to stop transmission, can be initiated when the old SGSN receives a message from the new SGSN, informing it that the mobile station has moved to a cell served by the new SGSN. Alternatively, the signal can be sent from the old SGSN to the GGSN, on receipt by the old SGSN of a message from the serving base station, informing it that the mobile station has changed to a cell served by another SGSN.