A measurement based study of TCP protocol efficiency in cellular networks

This paper examines the efficiency of resource utilization with respect to short-lived TCP flows in various cellular networks. The examination is done from the vantage point of an end-user who would like to use as much as possible of the cellular transmission resources that are available at any given time, thus minimizing the delays associated with communication. Based on a comprehensive measurement campaign we first derive network characteristics with regards to base RTT, RTT under load, and average throughput. A protocol efficiency metric is introduced to capture how efficiently short TCP flows are in fact able to use the instantaneously available transmission resources in a cellular network. The measurements show that short TCP connections have low efficiency in 3.5G (HSPA+) and 4G (LTE) mobile broadband networks, and that the improved latency and throughput characteristics of 4G in relation to 3.5G nevertheless results in lower short-flow efficiency for 4G.