First Mile Access Networks and Enabling Technologies

Contention Resolution

The BS controls assignments on the uplink channel through the UL-MAP messages and resolves which minislots are subjected to collisions. Collisions occur during initial maintenance and request intervals defined by their respective IEs. The contention resolution is based on a truncated binary exponential backoff scheme, where the BS controls the initial backoff window (how much do we retransmit based on the available window) and maximum backoff window. Backoff means the BS backs off from sending more data when it sees a collision in the channel. When an SS is ready to send data, it enters the contention resolution process. It sets its initial backoff window equal to the request backoff (initial window set up for communication). ...