CMAP: A Real-Time Prototype for Cognitive Medium Access

Abstract

In this paper we present CMAP, a real-time prototype for Cognitive Medium Access (CMA). We have previously proposed CMA as a protocol that enhances coexistence with a set of independently evolving WLAN bands by constraining collisions. Based on a time-slotted physical layer, the cognitive radio uses a sense-before-transmit strategy to control its medium access. We further employ a model-based design approach to predict the WLAN's transmission behavior and reduce collisions. In this paper we present the implementation of the real-time prototype CMAP. The cognitive radio consists of a high-performance DSP/FPGA board as well as a commercial radio frontend for the 2.4 GHz ISM band. The performance of CMAP shows an excellent fit with analytical and simulation results solidifying our previous work. In addition, we use CMAP to measure its dynamic impact on the WLAN.