Reference Broadcast Synchronization
Reference Broadcast Synchronization (RBS) is a synchronization method in which the receiver uses the physical layer broadcasts for comparing the clocks. This slightly differs from traditional methods which synchronize the sender's with the receiver's clock. RBS allows nodes to synchronize their clocks to the resolution necessary for example for wireless sensor network applications. Rather than broadcasting a timestamp in a synchronization packet as in protocols such as Network Time Protocol, RBS allows the nodes receiving the synchronization packets to use the packet's arrival time as a reference point for clock synchronization. Because most of the non-deterministic propagation time involved in transmitting a packet over a wireless channel lies between the construction of the packet and the sender's transmitter (e.g., sender's queue delay, MAC contention delay, etc.