System and method for determining handover at a base station request in a broadband wireless access communication system

A method for performing a handover from a serving base station to one of the at least one target base stations at the serving base station request in a broadband wireless access communication system including the serving base station for providing a service to the subscriber station and a plurality of neighbor base stations being adjacent to the serving base station the method comprises the steps of:

• receiving information on the neighbor base stations from the serving base station;
• measuring carrier-to-interference and noise ratios (CINRs) of frequency bandwidth signals from the neighbor base stations based on the information on the neighbor base stations;
• receiving the handover request message from the serving base station;
• and
• transmitting to the serving base station a handover response message.

A method for performing a handover by a serving base station in a broadband wireless access communication system including the serving base station for providing a service to a subscriber station and a plurality of neighbor base stations being adjacent to the serving base station, the method comprising the steps of:

• (a) transmitting a handover scan request message to the subscriber station, if a handover of the subscriber station is required;
• (b) receiving carrier-to-interference and noise ratios (CINRs) of the neighbor base stations from the subscriber station in response to the handover scan request message;
• (c) sorting the neighbor base stations in order determined by the received CINR levels;
• (d) sequentially sending a handover connection request to the neighbor base stations in the sorted order, and
• (e) transmitting information on a particular neighbor base station to the subscriber station upon receiving a handover connection response including ACK (Acknowledgement) information from the particular neighbor base station in response to the handover connection request.

A broadband wireless access communication system comprising:

• a subscriber station for transmitting a request for a handover to at least one neighbor base station having a carrier-to-interference and noise ratio (CINR) satisfying a handover condition, in response to a handover scan request message, and performing the handover to a particular neighbor base station of the at least one neighbor base stations that transmits a handover response in response to a handover request;
• a serving base station, which is currently in communication with the subscriber station, for receiving the request for the handover, transmitting the handover scan request message to the subscriber station, if handover of the subscriber station is required, sending a handover connection request to the neighbor base stations in an order determined by CINRs reported from the subscriber station, and sending, to the subscriber station, handover information, upon receiving a handover connection response including ACK (Acknowledgement) information;
• and
• a particular neighbor base station from the at least one neighbor base stations for determining whether it can support the handover of the subscriber station, in response to the handover connection request, and sending the handover connection response including the ACK information to the serving base station, if it can support the handover of the subscriber station.