Bit-error-rate and capacity estimation in wireless networks

In this study we examine a scenario where communication over a wireless channel degrades causing applications communicating over this channel to perform poorly. Dynamically adapting protocols, such as forward-error correction (FEC), can mitigate the e ect of the link degradation. To drive these protocols we need to know the current bit-error rate (BER) and capacity of the wireless channel.In some scenarios it is not possible to gain direct access to the wireless radios and calculate the BER and capacity directly. We present a solution that can estimate the BER and capacities of these links to feed into forward error correction (FEC) or other modules using only packet information. We consider, an example scenario where it is not possible for applications to gain direct access to the wireless radios, what happens when an airborne platform communicates with a ground station.Finally we discuss the control problem that arises when multiple applications share the constrained network resource. When FEC, or another adaptive protocol, is employed, it can increase the performance of a single application, but may lower the aggregate performance of all applications sharing the constrained network link. In some scenarios applications need to be controlled (by activating the adaptive protocols) or suspended (by stopping communication of that application) so that the remaining applications can perform adequately. We first present the control problem of managing the throughput of a number of applications. We describe the Channel State (CS) algorithm, which determines how to allocate the available resources by determining which applications are to be to controlled or suspend. Then we demonstrate the operation of the CS algorithm in two scenarios, first in the presence of decreasing capacity and then in the presence of increasing BER.Ph.D., Electrical Engineering -- Drexel University, 201