Handover system and method for minimizing service delay due to pingpong effect in a broadband wireless access communication system

A handover method of a mobile subscriber station (MSS) for minimizing a service delay due to a pingpong effect in a Broadband Wireless Access (BWA) communication system having the MSS, a serving base station (BS) in communication with the MSS, and a plurality of neighbor BSs being different from the serving BS, the method comprising the steps of:

• upon detecting a need for performing handover from the serving BS to a target BS selected from the neighbor BSs, changing its connection from the serving BS to the target BS;
• after changing its connection from the serving BS to the target BS, detecting an occurrence of the pingpong effect when performing a network re-entry operation with the target BS;
• sending, to the target BS, a report indicating that the MSS will change its connection from the target BS to the serving BS due to the occurrence of the pingpong effect;
• after sending, to the target BS, the report indicating that the MSS will change its connection to the serving BS, changing its connection from the target BS to the serving BS;
• and
• after changing its connection to the serving BS, connecting a communication service with the serving BS using a contention-free-based ranging resource allocated from the serving BS.

A handover method of a serving base station (BS) for minimizing a serving delay due to a pingpong effect in a Broad band Wireless Access (BWA) communication system having a mobile subscriber station (MSS), the serving BS in communication with the MSS, and a plurality of neighbor BSs being different from the serving BS, the method comprising the steps of:

• upon receiving from the MSS a notification indicating that the MSS will perform handover from the serving BS to a target BS selected from the neighbor BS, deleting connection information for the MSS;
• receiving from the target BS a notification indicating that the MSS will change its connection to the serving BS due to occurrence of the pingpong effect;
• upon receiving from the MSS a notification indicating that the MSS will change its connection to the serving BS, allocating a contention-free-based ranging resource to the MSS;
• and
• connecting a communication service with the MSS using the contention-free-based ranging resource.

A handover system for minimizing a service delay due to a pingpong effect in a Broad band Wireless Access (BWA) communication system, the system comprising:

• a mobile subscriber station (MSS);
• a serving base station (BS);
• and
• a target BS,
• wherein the MSS, upon detecting a need for performing handover from the serving BS to the target BS, which is selected from neighbor BSs, changes its connection from the serving BS to the target BS, sends, to the target BS, a report indicating that the MSS will change its connection from the target BS to the serving BS, upon detecting occurrence of the pingpong effect while performing a network re-entry operation with the target BS, sends, to the target BS, a report indicating that the MSS will change its connection to the serving BS, receives a contention-free-based ranging resource allocated from the serving BS, and connects a communication service with the serving BS using the contention-free-based ranging resource;
• the target BS, upon receiving from the MSS a notification indicating that the MSS will change its connection from the target BS to the serving BS in a process of performing a network re-entry operation with the MSS, sends, to the serving BS, a notification indicating that the MSS will change its connection from the target BS to the serving BS;
• and
• the serving BS, upon receiving from the target BS the notification indicating that the MSS will change its connection from the target BS to the serving BS, allocates a contention-free-based ranging resource to the MSS, and connects a communication service with the MSS using the contention-free-based ranging resource.

A handover method of a serving base station (BS) for minimizing a serving delay due to a pingpong effect in a Broad band Wireless Access (BWA) communication system having a mobile subscriber station (MSS), the serving BS in communication with the MSS, and a plurality of neighbor BSs being different from the serving BS, the method comprising the steps of:

• upon receiving from the MSS a notification indicating that the MSS will perform handover from the serving BS to a target BS selected from the neighbor BS, retaining the connection information for a predetermined time;
• receiving from the target BS a notification indicating that the MSS will change its connection to the serving BS due to occurrence of the pingpong effect;
• upon receiving from the MSS a notification indicating that the MSS will change its connection to the serving BS, allocating a contention-free-based ranging resource to the MSS;
• and
• connecting a communication service with the MSS using the contention-free-based ranging resource.