On the role of base station in fault-tolerant mobile networks

Fault-tolerance in mobile networks presents unique challenges because of scarce wireless resources, limited storage, limited battery power at the mobile host (MH), and host mobility. Checkpointing and rollback techniques can be used to provide fault-tolerance in a distributed application consisting of a set of cooperating processes running on MHs. Most of the checkpointing protocols proposed for general distributed systems are not efficient for wireless mobile networks with respect to the use of scarce resources. The paper introduces a new technique in which the base station is given certain roles to assist in the provision of the fault-tolerance process. The technique requires the base stations to keep a record of interactions among various MHs, and to use a "filtering" process to reduce the number of unnecessary checkpoints and other control message exchanges. The technique can be applied to any existing checkpointing algorithm. It is shown that the technique reduces the checkpointing overhead substantially for some representative algorithms.