System and method to facilitate inter-frequency handoff of mobile terminals in a wireless communication network

Claim 1

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; determining that it is to associate with the second access point; initiating a handoff process in response to determining the association of the mobile node with the second access point by sending a request message including a quality of service requirement at a second frequency at which the second access point communicates for receipt by the second access point; and changing its communication frequency back to the first frequency after sending the request message, thereby continuing communication with the first access point; within the second access point: receiving the request message including the quality of service requirement; determining if it can meet the quality of service requirement; and sending a reply message indicating if the second access point can meet the quality of service requirement to the mobile node via the first access point; and within the mobile node: receiving the reply message sent by the second access point in response to the request message, wherein the reply message includes a performance characteristic of the second access point, wherein the performance characteristic relates to a quality of service desired by the mobile node; and when the performance characteristic meets a desired criteria, operating the mobile node to change its frequency to the second frequency and become associated with the second access point.

Claim 2

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; determining that it is to associate with the second access point; initiating a handoff process in response to determining the association of the mobile node with the second access point by sending a request message including a quality of service requirement at a second frequency at which the second access point communicates for receipt by the second access point; and changing its communication frequency back to the first frequency after sending the request message, thereby continuing communication with the first access point; within the second access point: receiving the request message including the quality of service requirement; determining if it can meet the quality of service requirement; and sending a reply message indicating if the second access point can meet the quality of service requirement to the mobile node via the first access point; and within the mobile node: receiving the reply message sent by the second access point in response to the request message, wherein the reply message includes a performance characteristic of the second access point, wherein the performance characteristic relates to a quality of service desired by the mobile node; and when the performance characteristic meets a desired criteria, operating the mobile node to change its frequency to the second frequency and become associated with the second access point.

Claim 8

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; periodically receiving one or more information associated with a list of neighboring access points from the first access point, wherein the one or more information includes one or more information selected from a group of information comprising an identity, an operating frequency and a quality of service level; determining to handoff from the first access point to another access point; selecting the second access point from the list of neighboring access points; initiating a handoff process in response to selecting the second access point by sending a request message at a second frequency at which the second access point communicates for receipt by the second access point; and changing its communication frequency back to the first frequency after sending the request message, thereby continuing communication with the first access point; and within the second access point: receiving the request message, wherein the request message includes a communication requirement; and sending a reply message indicating if the second access point can meet the communication requirement to the mobile node via the first access point.

Claim 9

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; periodically receiving one or more information associated with a list of neighboring access points from the first access point, wherein the one or more information includes one or more information selected from a group of information comprising an identity, an operating frequency and a quality of service level; determining to handoff from the first access point to another access point; selecting the second access point from the list of neighboring access points; initiating a handoff process in response to selecting the second access point by sending a request message at a second frequency at which the second access point communicates for receipt by the second access point; and changing its communication frequency back to the first frequency after sending the request message, thereby continuing communication with the first access point; and within the second access point: receiving the request message, wherein the request message includes a communication requirement; and sending a reply message indicating if the second access point can meet the communication requirement to the mobile node via the first access point.

Claim 11

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; determining to handoff from the first access point to another access point; receiving contention period from the first access point, the contention period corresponding to a plurality of access points; within the first access point: determining quality of service provided and time slot availability based upon a MAC algorithm from the plurality of access points; and selecting the second access point from the plurality of access points for the mobile node to transmit a handoff request message to the second access point; and within the second access point: receiving a handoff request message from the mobile node, wherein the handoff request message includes a communication requirement; and sending a reply message indicating if the second access point can meet the communication requirement to the mobile node via the first access point.

Claim 12

A method for changing association of a mobile node in a wireless communication network from a first access point to a second access point, the method comprising: within the mobile node: communicating at a first frequency with the first access point with which the mobile node is associated; determining to handoff from the first access point to another access point; receiving contention period from the first access point, the contention period corresponding to a plurality of access points; within the first access point: determining quality of service provided and time slot availability based upon a MAC algorithm from the plurality of access points; and selecting the second access point from the plurality of access points for the mobile node to transmit a handoff request message to the second access point; and within the second access point: receiving a handoff request message from the mobile node, wherein the handoff request message includes a communication requirement; and sending a reply message indicating if the second access point can meet the communication requirement to the mobile node via the first access point.