The reference-broadcast infrastructure synchronization protocol

In this paper the RBIS synchronization protocol is presented, which has been specifically conceived for industrial infrastructure WLANs. It combines the concepts of the sender/receiver and receiver/receiver approaches: similarly to RBS, timestamps are recorded only on received frames while, like IEEE 1588, it permits slaves to synchronize to the same master clock. Compared to RBS, RBIS has several advantages. Every single wireless sub-network, in fact, can be easily synchronized with an external time source located on the wired backbone. Moreover, when software implementations are considered that rely on unmodified conventional WiFi equipment, RBIS is able to feature noticeably better timing accuracy than IEEE 1588.