Repeatability for Spatiotemporal Throughput Measurements in LTE

Evaluating mobile broadband in an operational cellular network is a challenging measurement task that depends on many parameters. Throughput is an essential performance indicator in any data network. Particularly in cellular mobile networks, the throughput is very sensitive to the number of active users--the cell load. Nearly every publication discussing throughput measurements in live mobile networks cites that throughput strongly varies in time. However, none of the studies have attempted to remove the impact of the cell load to achieve a more predictable throughput behavior. In this paper, we propose a new throughput-correction technique. Since we have access to the information on the amount of resources scheduled to the measuring device, we can approximate the total throughput that the device would experience if all the resources would get allocated to it. We focus on LTE and analyze several repeated measurements conducted with user equipments mounted in a car. We measured in a live LTE network along a selected highway segment, at different times, on two different days. The results have revealed that the corrected throughput exhibits significantly smaller variations than the raw throughput does. Finally, we discuss possible limitations-especially frequency selective scheduling combined with a low share of resources-and outline further directions of research.