Energy-aware optimal cache consistency level for mobile devices

Power consumption in a mobile device is an important performance metric. It is strongly required for the mobile device to access wireless links efficiently because wireless communication expends a significant amount of energy per second. By using cache schemes, we can reduce communication costs and enhance performance by storing and reusing recently used data. However, the cached data on the mobile device should be updated in sync with the original data on the server as they are being modified. With a δ consistency policy, we can provide the energy-efficient cache consistency level by setting δ in accordance with various environmental parameters. This paper proposes a method to determine the optimal δ that minimizes the overhead energy expenditure for mobile devices in wireless web environments. We derive the optimal δ from a mathematical model and conduct a simulation for validation. We also implement a test application for the proposed optimal δ method on a test-bed and assess its performance.