A Low-Latency Fault-Tolerant Protocol for Mobile IP in Wireless Systems

In wireless systems, mobile IP provides mobile nodes with uninterrupted network connections to correspondent nodes through foreign and home agents. A failure in foreign agent causes the constant network connections of affected mobile nodes to be interrupted, hence increasing latency in packet delivery. Existing proposals to tolerate foreign agent failures impose latency in packet delivery. Hence, we present a fault-tolerant protocol to reduce latency in packet delivery by allocating exactly one primary and one backup foreign agent in a distributed fashion for all mobile nodes in the wireless system prior to registration between mobile nodes and their home agents. When foreign agents fail, affected mobile nodes are not required to re-register with their home agents, thus lowering latency in packet delivery. Through simulation, our results show that the proposed protocol lowers latency in packet delivery by 3.7% to 6.0% for each mobile node as compared to a previously published protocol.