Abstract. The Eager, Lazy and Movement-based strategies are used in mobile computing system when handoff. They result in performance loss while moving the whole checkpoint on fault-free or slow recovery while not moving any checkpoint until recovery. In the paper, a compromise strategy is proposed. The whole recovery information are broken into two parts, which one little part with high-priority should be transferred to the new cell during handoff and another large part with low-priority should be transferred only when the mobile host recovers from a fault. From the view of mobile host, it seems that all recovery information reside on the local mobile support station. The strategy guarantees little performance losing when fault-free and quick recovery when fault occurs. Experiments and analysis show the handoff strategy performance overcomes others. Keywords: mobile computing, fault tolerant, checkpoint, handoff, rollback recovery Checkpointing and rollback-recovery has been an attractive technique for providing fault-tolerance in mobile computing system [1]. Due to the mobility of the hosts, limited bandwidth, highly unreliable wireless link, mobile hosts disconnect from network voluntarily, power restriction and limitation of storage space in mobile devices, conventional checkpointing recovery schemes used in wired distributed network cannot be directly applied to mobile environment [2] When a mobile host (MH) moves from one cell to another, Eager, Lazy and Movement-based strategies are used, which move the whole recovery information to new mobile support station (MSS) or not move any recovery information until a MH recovers [3] . A strategy which moves the whole recovery information in fault-free will depress the performance of system due to transfer useless information and others which not move any recovery information until a fault occurs will delay the system recovers from a fault due to recovery information can not be gotten in time. No one strategy is excellent in every circumstance. A compromise strategy is proposed. Only a few part of recovery information is moved to the new local cell when a MH moves, which little
In REF , a compromising checkpointing data storage strategy is proposed in which high-priority recovery information will be transferred to the cell during handoff and other low-priority recovery information will be transferred while failure recovery.
An efficient handoff strategy for mobile computing checkpoint system
EUC
Computer Science