Methods and systems for facilitating a multi-mode multi-pilot hard handoff

A method for a basestation to participate in a handoff of a mobile station, comprising:

• identifying one or more cells which are appropriate for handoff of the mobile station for each of at least two different capabilities;
• outputting one or more messages collectively containing identifiers of each of said cells and said each cell's respective capability;
• wherein said one or more messages are sent to a mobile switching centre and comprise a Handoff_Request message generally in accordance with the CDG IOS A-interface standard except for modifications to allow the inclusion of the multiple cells of differing capability and said each cell's respective capability.

A method for a serving mobile switching centre to participate in a handoff comprising:

• receiving from a source basestation one or more messages collectively containing a group of cell identifiers;
• sending one or more messages to another mobile switching centre comprising cell identifiers of all cells in said group which are served by said another mobile switching center.

A handoff intermediary adapted to participate in handing off a mobile station, comprising:

• a) means for receiving or generating a first group of cell identifiers of potential cells for handoff;
• b) means for sending a second handoff intermediary a second group of cell identifiers, the second group being a subset of the first group which identifies all cells in the first group serviced through any handoff intermediary in a source-to-target direction from the first handoff intermediary;
• whereby the second handoff intermediary is provided with information with which it can participate in multiple attempts at handing off the mobile station to cells identified in the second group of cell identifiers without sending a handoff failure back to the first handoff intermediary after each failed attempt.

A mobile switching centre adapted to participate in a handoff, comprising:

• means for receiving from a source basestation one or more messages collectively containing a group of cell identifiers;
• means for sending one or more messages to another mobile switching centre comprising cell identifiers of all cells in said group which are served by said another mobile switching center.