With a rapid advance of wireless communication technology such as celluar communication, packet radio network and satellite communication, the importance of wireless information systems has been increasingly recognized. Wireless information systems can provide dynamic information to mobile users in timely and efficient manner.
In this work we address data management issues in data broadcasting. Data broadcasting in wireless networks has many applications because it has an excellent energy-efficiency and bandwidth-efficiency characteristics. We propose a divergence caching scheme for mobile clients in wireless information systems. In this scheme we incorporate cache control information into the index broadcasted with data. By utilizing cache control information, data tuning costs are considerably reduced when the variations of information are not significant. We can also reduce index tuning overhead when the information services are not relocated. In addition to divergence caching scheme, we propose a method for data stream construction for further improvement of energy-efficiency. We perform simulation experiments for our proposed scheme and show that the proposed scheme works better than those proposed earlier. The performance characteristics are evaluated and analysed through statistical techniques.
