Optimal Wake-up Scheduling for PSM Delay Minimization in Mobile Wireless Networks

In this work, we propose a Lloyd-Max based Sleep interval Determination (LMSD) algorithm towards optimal wake-up schedule computation to minimize the delay between data arrival and mobile device wake-up time, termed as the ON-OFF delay, for the Power Saving Mode in wireless networks. The proposed algorithm employs the probability distribution of the request-response time to compute the optimal sleep interval lengths for average wake-up delay minimization. Analytical results are derived to demonstrate convergence of the proposed LMSD algorithm. We also derive a novel information-theoretic bound to characterize the minimum average wake-up delay for a maximum threshold on the energy consumption for any generic wake-up schedule determination scheme. The LMSD algorithm is also seen to be computationally efficient due to the convexity of the average delay optimization objective. We compare the proposed approach with the existing schemes that improve the delay performance of the standard Binary Truncated Exponent algorithm and demonstrate that it achieves a lower average wake-up delay for a given average energy consumption while asymptotically achieving the delay bound.