Twin-Transactions - Delayed Transaction Synchronisation Model

In a mobile computing environment, mobile hosts are not available all the time. Due to this reason, mobile computers are usually considered as clients who can connect to different servers and ask for certain services (client-server). To reduce the contention on the narrow bandwidth of the wireless channel, it is suggested to cache part of a database on mobile computers [1]. When a mobile computer also hosts data (or a portion of a data), the data on such hosts will not be available all the time. Replication of such data will make the data available, but will create certain concurrency and consistency problems. The twin-transaction model (TTM) proposes to replicate transaction-processing flow along with data items stored on mobile hosts.