An Efficient Quorum-Based Fault-Tolerant Approach for Mobility Agents in Wireless Mobile Networks

In this paper, we propose an efficient quorum-based mechanism to the fault-tolerance problem in mobile IP protocol. In a network with N HAs, all the HAs are grouped into N quorums with logical circular structure. Every HA has lceilradic(N)rceil backup quorums and divides the network that it manages into lceilradic(N)rceil equal parts. According to the home address of the MN, each HA finds out the backup quorum in the network segment and stores the mobility bindings of the MN in lceilradic(N)rceil-1 backup HAs. When a HA crashes, the system will select the HA with minimum load from each backup quorum to take over the bindings of the faulty HA. In comparison with previous related works, our experimental results show that the proposed fault-tolerant protocol has many advantages: better system load balance, less latency for registration process, less system resource requirements, and no extra hardware cost.