On the throughput and energy benefits of network coded cooperation

Cooperative techniques in wireless mobile networks typically leverage short-range communication technologies, e.g., WiFi, to allow data exchange between devices forming a mobile cloud. These mobile clouds have been considered as a key to reduce the cost of multicast services for the network operators as well as a means to deliver a better quality to the users. In fact, LTE-A includes Device-to-Device communication capabilities to enable such a direct communication between devices. The underlying assumption for attaining the throughput gains in mobile clouds is that the communication rate between devices is typically larger than the data rate from the base station to a receiver. However, while the data rates on cellular technologies have been steadily increasing, short-range communication speeds have remained largely unchanged calling into question these assumptions. This work's goal is to assess the operating regions where the use of cooperation results in a higher throughput and/or energy saving. We consider a multicasting and a cooperative scheme with network coded mechanisms, as they typically outperform uncoded approaches. Our analysis and numerical results show that gains of several fold can be attained even if the data rate of the short-range technologies is moderately larger, e.g., 2x larger, than the cellular link data rate.