A Hashing Scheme for Multi-channel Wireless Broadcast

The rapid development of wireless communication technology and battery-powered portable devices is making mobile information services increasingly popular. Since the bandwidth resource of wireless networks is scarce and the mobile devices have a limited battery capacity, any solution for information access must be devised in such a way that time and power consumption for the devices are minimized. Data broadcast is a promising technique to improve the bandwidth utilization and conserve the power consumption in a mobile computing environment. This paper proposes a hashing scheme for information access via wireless broadcast through multiple channels in which hash functions are used to index broadcast information across multiple channels. In this scheme, two different hash functions called Primary Hash Function (PHF) and Secondary Hash Function (SHF) are used, where PHF is used to determine the channel in which the desired data item is to be broadcasted and SHF is used to locate the data item within that channel. The proposed hashing scheme reduces both the access latency and tuning time and shortens the broadcast length. Moreover, Access Probabilities of data items and User Profiles that indicate the client behavior in the environment at any given time are considered in this system to construct an efficient broadcast schedule. This broadcast schedule is a non-flat data broadcast that further reduces the average access latency. Finally, Caching techniques are also implemented to further improve the access latency and tuning time.