Patent ID: 7715319

Claim:
A method for conducting communications over a shared communication medium involving a plurality of nodes, the method comprising: (a) transmitting a request from a first node in the plurality of nodes, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment that is one of the plurality of request segments; (b) obtaining an assignment, in a first tier of assignments, associating the request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, the assignment taking into account location of the request within the request signal space; (c) from the first node, transmitting a data transmission in the scheduled transmission segment associated with the request in accordance with the assignment; and (d) wherein the plurality of scheduled transmission segments includes at least one default use segment, the at least one default use segment being available for use by a default entity if the at least one default use segment is not assigned in the first tier of assignments.