Energy Efficient Dynamic Content Distribution

Consider a network of prosumers of media content in which users dynamically create and request content objects. The request process is governed by the objects' popularity, which may vary across network regions and over time. In order to meet user requests, content objects can be stored and transported over the network, characterized by the capacity and efficiency of its storage and transport resources. The energy-efficient dynamic content distribution problem aims at finding the evolution of the network configuration, in terms of the placement and routing of content objects over time, that meets user requests, satisfies network resource capacities and minimizes overall energy use. We present 1) an information-centric linear programming formulation for the energy efficient dynamic content distribution problem that captures multicasting and caching over the network, per-object system dynamics, and delivery deadlines; 2) an offline solution that characterizes the minimum energy use achievable with global knowledge of user requests and network resources; and 3) an efficient distributed online solution that allows network nodes to make caching decisions based on their local estimate of the global energy benefit. Using a custom-built content distribution network simulator as well as a real prototype implementation in an information-centric networking testbed, we show the significant energy savings that can be obtained via the efficient and lightweight cache cooperation induced by our service and energy aware distributed online solution with respect to state of the art approaches.