WiScape: A framework for measuring the performance of wide-area wireless networks
We present WiScape, a framework for benchmarking and understanding the behavior of wide-area wireless networks, e.g., city-wide or nation-wide cellular data networks using active participation from clients. The goal of WiScape is to provide a coarse-grained view of a wide-area wireless landscape that allows operators and users to understand broad performance characteristics of the network. In WiScape, a centralized controller instructs clients to collect minimal measurement samples over time and space in an opportunistic manner. To limit the overheads of this measurement framework, WiScape partitions the world into zones, contiguous areas with relatively similar user experiences, and partitions time into zone-specific epochs over which network statistics are relatively stable. For each epoch in each zone, WiScape takes a minimalistic view-it attempts to collect a small number of measurement samples to characterize the client experience in a zone at a specific epoch, thereby limiting the bandwidth and energy overheads for collecting measurements at client devices. For this effort, we have collected ground truth measurements for three commercial cellular networks across a nation-wide area in USA for a period of more than one year. We justify our design choices of WiScape through collected data, demonstrate that WiScape can provide an accurate performance characterization of the networks over a wide-area (within 4 percent error for more than 70 percent of instances) with a low overhead on the clients, and illustrate multiple applications of this framework through a sustained and ongoing measurement study.