Apparatus for and method of synchronization and beaconing in a WLAN mesh network

摘要

A novel and useful synchronization mechanism that functions to provide a uniform time base for mesh points in a WLAN mesh based network. The invention enables timing synchronization to a common reference clock base by advertising the common TSF within beacon transmissions. All MPs in a mesh share a common DTIM interval. The synchronization mechanism enables the mesh points to avoid collisions in the generation and transmission of beacons. The TBTT offsets of the current MP and its neighbors are advertised in beacons so that neighboring MPs that hear the beacons can select non-overlapping TBTT offsets. Each MP receives one or more beacons from its neighbors and compares the timing of its neighbors to that of itself and adopts the highest TSF (i.e. the fastest) in the mesh. Eventually, all MPs in the mesh will adjust their timing to that of the MP with the fastest clock. The reception of beacons by MPs from its neighbors is also advertised. This allows for MPs to verify that the beacons they send are actually heard and are not in collision with beacon transmissions of other MPs.