Currency guarantee for read-only transaction in broadcast data delivery environment

Abstract

In recent years, due to the rapid developments of new wireless electronic devices, the broadcast data dissemination has attracted considerable concerns and attentions. In broadcast data delivery environment, people are allowed to obtain any information at any time and place. Moreover, there are lots of update transactions at the server which update data values in the real-time database. As a result, it is important tha t not only the data obtained by clients’ read-only transactions are consistent, but also as recent as possible. It is because data currency of the clients’ read-only transactions can reflect the performance of the broadcast system. Currency guarantee specifies what update transactions at the server are reflected by the data read by read-only transactions. In other words, it simply means how new or update data values the clients can retrieve for their read-only transactions. In this project, currency guarantee on broadcast data delivery environment is studied. A simulation model is built and various broadcasting methods, which provide data consistency and different levels of currency, are implemented. These are multiversioning method, invalidation-only method and multiversioning with invalidation method. From the statistics obtained from the model, the currency guarantee, advantages and limitations of different transmission methods are compared and evaluated.