US Patent 7940790 Multiple request intervals

Methods and apparatuses are presented for communicating using a shared communication medium. A request is sent over the shared communication medium. The shared communication medium is organized to include a request signal space and a scheduled transmission signal space. The request signal space includes a plurality of request segments each having a different location within the request signal space. The scheduled transmission signal space includes a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space. The request occupies more than one request segment. Each of the more than one request segments is randomly selected by the first node. An assignment is received assigning the request to a transmission opportunity in the scheduled transmission signal space. The assignment is made in response to detecting at least one of the more than one request segments. A data transmission is sent using the assigned transmission opportunity.