prefetching policies for energy saving and latency reduction in a wireless broadcast data delivery system
Periodic data broadcasting on a wireless channel has been proposed as an effective data dissemination technique for mobile users. With this technique, users access data by simply monitoring the channel until the required data appear in the broadcast. Hence, this access mode may be advantageous in a wireless environment with respect to the traditional client-server access mode, since it consumes less bandwidth and avoids energy-expensive requests sending. Potential drawbacks of this access mode are the latency caused by the wait for the required data in the broadcast, and the energy consumption caused by active listening on the wireless channel. Some techniques have been proposed to alleviate these two drawbacks. In particular, the use of prefetching has been proposed to reduce the latency experienced by a user. However, prefetching could have a negative effect on energy consumption, since it could actually increase the number of channel accesses. We define a general analytical model to investigate the impact of prefetching on both latency and energy consumption in a wireless broadcast data delivery system, with the goal of determining policies characterized by a good tradeoff between the two goals of reducing latency and saving energy, and then compare by simulation two policies derived from the model results with a policy proposed in the literature.
prefetching energy saving latency data broadcasting analytical model simulation caching mobile computing wireless network