Design and implementation of a rate-scalable wireless local area network

Future wireless local area networks are to support a wide spectrum of devices that run different applications with widely different traffic characteristics. For example, a motion sensor may generate traffic at a rate of a few bytes every second while a video player may transmit a few Mbps. Considering the fact that data packets are transmitted in bursts at the peak transmission rate, different devices should have different peak transmission rates as long as the rate is sufficient to ensure the packets can be delivered within a reasonable delay. The main advantages of making different devices to have different peak transmission rate are: (a) devices with a low data rate can be built for a lower peak transmission rate at a lower cost, and (b) device with a lower battery capacity can be built for a lower peak transmission rate to converse power. We call this type of networks that is capable of supporting the co-existence of different peak transmission rates, the rate-scalable wireless local area networks. In this paper, we first propose an architecture for such a rate-scalable network. Next, we describe the hardware implementation of a test-bed based on the proposed architecture. Despite incompleteness of our implementation, a few experiments on the test-bed indicate that a scalable system throughput is achievable.