Patent ID: 7376425

Claim:
A method of operating a second network point of attachment in a communications system including a first network point of attachment, the first network point of attachment using signals in a first frequency band to communicate with a mobile node having a communications link with said first network point of attachment over which data can be communicated, the method comprising: transmitting beacon signals having a predetermined frequency into said first frequency band on a periodic basis, said first frequency band being a frequency band into which said second network attachment point does not transmit user data; using a second frequency band which is different from said first frequency band for establishing and maintaining communications links with mobile nodes over which user data can be communicated, said step of using a second frequency band including assigning segments of an uplink communications channel to mobile nodes, the uplink communications channel having a structure that includes a periodic repeating pattern of access segments and traffic segments, access segments being segments into which mobile nodes that do not have an existing wireless communication link established with said second network attachment point can send at least one signal to said network attachment point over the air to establish a wireless communications link with the second network attachment point, each access segment occurring at a fixed time offset from the point at which one of said beacon signals is transmitted into said first frequency band by said second network attachment point, wherein each access segment includes a plurality of tones which can be used for uplink transmissions during at least one symbol transmission time period which occurs during the period of said access segment, said plurality of tones includes at least a first set of tones; receiving a signal from said first network access point indicating that said mobile node is seeking to perform a handoff to said second network point of attachment from said first network point of attachment; dedicating the first set of tones to a first mobile node which is coupled to said first network access point; communicating information to the first mobile node via the first network access point indicating the dedication of said first set of tones to the first mobile node; prior to receiving said access request signal, communicating information to said first mobile node, via the first network access point, indicating the time at which said access segment will occur relative to one of the beacon signals transmitted into said first frequency band; monitoring the first set of tones in the first access segment for a registration signal from the mobile node to which said first access segment was assigned; and receiving a registration signal from the mobile node which was communicated using said dedicated first set of tones.