Reducing energy use: Automatic selection of the appropriate communications channel

Energy use for communications and computing equipment has become a major concern. A growing trend is the almost universal access to multiple communications channels such as Wi-Fi and Ethernet. We develop and evaluate a means of automatically selecting a low-speed (and low-power) channel that delivers sufficient level of performance and selecting a high-speed channel only when it is absolutely needed. Specifically, we explore a Dual-Channel, Single-Link (DCSL) concept at the application layer whereby file downloads automatically select a Wi-Fi or Ethernet channel as appropriate for given performance and energy use constraints. We develop a software application that autonomously selects the best channel for a given file download. A performance evaluation shows the application-layer DCSL is feasible and a controlled trade-off of response time performance and energy use is possible. We project that our system can reduce local communications energy costs in many key cases.