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While traditional fixed-wired network protocols like 2-Phase-Commit guarantee atomicity, we cannot use them in mobile low bandwidth networks where network partitioning, node failure, and message loss may result in blocking. To deploy traditional database applications easily into a mobile environment, there is a demand for a protocol which guarantees an atomic commit of transactions. This paper introduces a protocol which can guarantee such atomic commitment in mobile environments using a combination of commit and consensus protocols. In addition, it takes advantage of mobile network sub-structures like single-hopenvironments to reduce message transfer costs.

Transaction processing in mobile ad-hoc networks must take network problems like node disconnection, message loss, and network partitioning into consideration. We present a distributed cross-layer atomic commit protocol called CLCP that uses multiple coordinators and makes use of acknowledgement messages to piggyback information. We evaluated transaction processing in mobile ad-hoc networks by using two mobility models (i.e. Attraction Point and Manhattan Geometry), and compared CLCP with both atomic commit protocols, 2PC and Paxos Commit, each implemented in 3 versions, i.e. without acknowledgements, with Relay Routing, and with Nearest Forward Progress Routing. Special to our simulation environment is the use of the quasi-unit-disc model, which assumes a non-binary message reception probability that captures real-world behavior much better than the classical unit-disc-model, often used in theory. Using the quasi-unit-disc model, our evaluation shows the following results. CLCP and "2PC without acknowledement messages" have a significantly lower energy consumption than the other protocols, and CLCP is able to commit significantly more distributed transactions than all the other atomic commit protocols for each of the mobility models.

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