Optimization of Radio and Computational Resources for Energy Efficiency in Latency-Constrained Application Offloading

TL;DR

This paper develops an optimization framework for balancing radio and computational resources to improve energy efficiency and reduce latency in mobile offloading to femto-clouds, considering multiple antennas at both ends.

Contribution

It introduces a joint optimization approach for radio and computational resources in femto-cloud offloading, including optimal strategies and conditions for offloading decisions.

Findings

Optimal communication strategies derived (power, rate, precoder)

Conditions for total or no offloading established

Minimum latency for application execution determined

Abstract

Providing femto-access points (FAPs) with computational capabilities will allow (either total or partial) offloading of highly demanding applications from smart-phones to the so called femto-cloud. Such offloading promises to be beneficial in terms of battery saving at the mobile terminal (MT) and/or latency reduction in the execution of applications, whenever the energy and/or time required for the communication process are compensated by the energy and/or time savings that result from the remote computation at the FAPs. For this problem, we provide in this paper a framework for the joint optimization of the radio and computational resource usage exploiting the tradeoff between energy consumption and latency, and assuming that multiple antennas are available at the MT and the serving FAP. As a result of the optimization, the optimal communication strategy (e.g., transmission power, rate, precoder) is obtained, as well as the optimal distribution of the computational load between the handset and the serving FAP. The paper also establishes the conditions under which total or no offloading are optimal, determines which is the minimum affordable latency in the execution of the application, and analyzes as a particular case the minimization of the total consumed energy without latency constraints.