Scheduling Of Concurrent Transactions in Broadcasting Environment

Mobile computing environment is subject to the constraints of bounded network bandwidth,
frequently encountered disconnections, insufficient battery power, and system asymmetry. To
meet these constraints and to gain high scalability, data broadcasting has been proposed on
data transmission techniques. However, updates made to the database in any broadcast cycle
are deferred to the next cycle in order to appear to mobile clients with lower data currency. The
main goal of this paper is to enhance the transaction performance processing and database
currency. The main approach involves decomposing the main broadcast cycle into a number of
sub-cycles, where data items are broadcasted as they were originally sequenced in the main
cycle while appearing in the most current versions. A concurrency control method
AOCCRBSC is proposed to cope well with the cycle decomposition. The proposed method
exploits predeclaration and adapts the AOCCRB method by customizing prefetching, back-off,
and partial backward and forward validation techniques. As a result, more than one of the
conflicting transactions is allowed to commit at the server in the same broadcast cycle which
empowers the processing of both update and read-only transactions and improves data
currency.