Description

Widely accepted flow control methods in wireline networks, such as TCP for data and TCP Friendly Rate Control (TFRC) for multimedia, assume that packet loss is primarily due to congestion. As such, they fail to apply to wireless networks, in which the bulk of packet loss is due to errors at the physical layer. This often results in serious wireless bandwidth underutilization. In this work, we propose the use of multiple connections within the application layer as a way to improve the throughput and to reduce underutilization in wireless networks. It differs from existing work as follows. First, it is theoretically guaranteed to be optimal, stable and scalable. Second, it end-to-end and requires modifications to neither infrastructure nor transport protocol stack, making it easy to deploy in practice. This work implicitly provides a general framework for flow control. In this framework, it is sufficient to control users' rates and their number of connections independently in two separate timescales, in order to guarantee convergence to a desired equilibrium of the network. This two timescale approach allows modification of the control law in one timescale without affecting the one in the other timescale, or the system's convergence.