Energy-Aware Cooperative Content Distribution over Wireless Networks: Design Alternatives and Implementation Aspects

This paper presents a comprehensive overview on the area of energy-aware common content distribution over wireless networks with mobile-to-mobile cooperation. It is assumed that a number of mobile terminals (MTs) that are geographically close to each other are interested in downloading the same content from a server via a base station using a long-range wireless technology. Selected MTs download the content directly from the base station and transmit it to other MTs using a short-range wireless technology. This cooperation can lead to significant performance gains since short-range wireless technologies are energy efficient and provide higher data rates due to the geographical proximity among the MTs. In this paper, we highlight the main alternatives that shape the design of cooperative content distribution architectures with focus on energy efficiency. These include content segmentation, long-range and short-range distribution strategies, grouping of the MTs into cooperating clusters, single hop and multihop communications among the MTs, resource allocation, fairness considerations, and network dynamics. We also discuss various methods commonly utilized for developing content distribution algorithms and evaluating network performance. Finally, we present sample results for selected network scenarios, discuss related standardization activities, and highlight future research directions.