Interactions between the physical layer and upper layers in wireless networks

The physical layer in wireless networks has characteristics that profoundly influence the operation of a network and the resulting performance. Interactions between the physical layer and higher layers are complex and intricate, and cannot be understood without taking the details of operation at all layers into account. Furthermore, these interactions often lead to unexpected and undesirable effects. We illustrate these effects by studying four different scenarios: (i) the impact of channel fading on the quality of voice over IP for communication between two devices, (ii) the quality of streaming video in the case of two interfering wireless networks, (iii) the impact of physical layer parameters and path loss on throughput in a multihop scenario, and (iv) the impact of channel variability on the performance of routing and applications in a real test-bed.