Information sharing in mobile networks: a survey on replication strategies
João Barreto, Inesc-Id Lisboa · 2003
The emergence of more powerful and resourceful mobile devices, as well as new wireless communication technologies, is turning the concept of ad-hoc networking into a viable and promising possibility for ubiquitous information sharing. In such context, replication is a key issue in order to achieve acceptable performance and availability levels. However, the inherent characteristics of ad-hoc networks bring up new challenges for which most conventional replication systems don’t provide an appropriate response. Namely, the lack of a preexisting infrastructure, the high topological dynamism of these networks, the relatively low bandwidth of wireless links, as well as the limited storage and energy resources of mobile devices are issues that strongly affect the efficiency of any distributed system intended to provide ubiquitous information sharing. Such aspects demand solutions that are able to offer high availability, in spite of the expected frequent network partitions and device suspension periods. Pessimistic approaches for replication are usually too restrictive solutions to achieve such requirement. On the other hand, optimistic replication strategies offer weak consistency guarantees which may not reflect the expectations of users and applications. This paper aims at exposing the main challenges of a replicated system operating in the particular environment of mobile ad-hoc networks, with the goal of providing general guidelines for an effective