Method for performing a handoff in an ALL-IP network

A method for performing a handoff in an ALL-IP network including at least one MS (Mobile Station) for transmitting a signaling frame including a header and a voice frame to an old BTS (Base Transceiver System), which includes a header information storage for storing overhead information for the MS in association with a unique code of the MS, and an RNC (Radio Network Controller), the method comprising the steps of:

• transmitting measurement information to a new BTS and the RNC by the MS to start a handoff;
• upon receipt of the measurement information, the RNC requesting the new BTS to set up a radio link with the MS that has transmitted the measurement information;
• deleting header information for the MS, stored in the header information storage of the old BTS, by the RNC upon setup of the radio link between the MS and the new BTS;
• transmitting a message including traffic overhead information from the MS to the new BTS;
• and
• upon receipt of the message including the traffic header information, transmitting a binding update message from the new BTS to the MS.