A study of autonomous data coherency protocol for mobile devices

An optimistic consistency scheme has been established with respect to data consistency and availability in distributed systems. Wireless networks are becoming popular in data communication and suitable for data sharing among users using multicast capability, but have hidden node problems. This paper proposes a simple data coherency protocol for mobile devices that has less data traffic in data collaboration using a multicast communication feature and is capable of automatic recovery from unpredictable disconnection, such as hidden node problems, by a data versioning scheme using a version vector and update log management. We evaluated the efficiency of data sharing over multicast communication and the recovery cost from failure caused by hidden nodes and confirmed the efficiency of the protocol.