Task Offloading with Network Function Requirements in a Mobile Edge-Cloud Network

Pushing the cloud frontier to the network edge that is close to mobile users has attracted tremendous interest not only from cloud operators of the IT service/software industry but also from network service operators that provide various network services for mobile users. The deployment of cloudlets in metropolitan area networks enables network service providers to provide low-latency network services to mobile users. In this paper, we formulate a novel task offloading problem in a mobile edge-cloud network, where each offloading task requests a specified network function with a tolerable delay. We aim to maximize the number of requests admitted while minimizing the operational cost within a finite time horizon. We first show that the problem is NP-hard. Consider dynamic changes of offloading request patterns over time, we propose an effective prediction mechanism for new VNF instance creations and idle VNF instance releases for operational cost savings. We then develop an efficient algorithm built upon the prediction mechanism. Also, we devise an online algorithm with a competitive ratio for a special case of the problem. We finally evaluate the performance of the proposed algorithms through experimental simulations. Experimental results indicate that the proposed algorithms are promising.