Energy saving in content-oriented networks

By allowing in-network caching, content-oriented networks may significantly decrease the network congestion, shorten the access delays, and reduce latency when delivering contents. On the other hand, a massive deployment of caches may subsequently increase the operational expenditures (OPEX), and particularly the energy bill of telecommunication operators. In this paper, we address the energy saving problem in content-oriented networks. This consists in determining which caches and which links could be switched off to minimize energy consumption in such a way that all demands are met while respecting capacity constraints. We propose a novel Mixed Integer Linear Programming (MILP) Formulation of the problem to solve the related object caching and traffic routing problem on arbitrary graph-based network topologies. We use CPLEX to solve our model to optimality. Then, we assess several network performance metrics. After all, we develop a routing on shortest path-based heuristic in order to compare our solutions with those given by the standard shortest path-based routing. Finally, we discuss the numerical results. We show that: 1) The metrics of interest provide additional insights on the impact and/or gain of introducing energy-aware caches in a real telecommunication network; 2) The benefits of our model compared to a routing on shortest path-based model: 38.72 % of energy saving is reached using our MILP model.