Communication-Constrained Mobile Edge Computing Systems for Wireless Virtual Reality: Scheduling and Tradeoff

Mobile edge computing (MEC) is expected to be an effective solution to deliver virtual reality (VR) videos over wireless networks. In contrast to previous computation-constrained MEC, which reduces the computation-resource consumption at the mobile device by increasing the communication-resource consumption, we develop a communications-constrained MEC framework to reduce communication-resource consumption by fully exploiting the computation and caching resources at the mobile VR device in this paper. Specifically, according to a task modularization, the MEC server only delivers the components which have not been stored in the VR device, and then the VR device uses the received components and other cached components to construct the task, yielding low communication cost but high delay. The MEC server also computes the task by itself to reduce the delay, however, it consumes more communication-resource due to the delivery of entire task. Therefore, we propose a task scheduling strategy to decide which computation model should the MEC server operates to minimize the communication-resource consumption under the delay constraint. Finally, the tradeoffs among communications, computing, and caching are also discussed, and we analytically find that given a target communication-resource consumption, the transmission rate is inversely proportional to the computing ability of mobile VR device.