Coral Cognitive WiFi Networking System
John Sydor · 2015
Modern radio standards provide a means to create cognitive radio but provide little guidance as to its implementation. In this chapter, we provide a design and implementation example for a low-cost cognitive WiFi radio designed specifically for economically challenged environments such as those found in the rural parts of India. In such environments, one of the greatest challenges is to ensure that a network can function on its own with a minimum of technical adjustment and oversight, simply because this is either impossible to provide or creates expenses that make the network economically unviable. Our solution to the problem was to take commercially available WiFi radio chip sets and router cards that provided access to their electronic subsystems governing (IEEE 802.11) MAC and PHY layer performance and by adding customized circuits and signal processing subsystems allowed construction of a WiFi-based cognitive radio. The resulting radio platform called "CORAL 3_P" is a wireless building block that allows the creation of 3-sector WiFi cells that can be assembled into networks spanning rural villages and towns. The resulting technology is scalable and allows cognitive radio designers to program it with adaptive and learning algorithms that can direct the network to undertake dynamic channel selection (DCS), implement priority access, and allow optimization of throughput and other wireless performance metrics in an autonomous manner. This chapter provides a general overview of the cognitive radio platform that was built and tested in numerous field trials and provides insight into the factors that impact the design of the cognitive engines and the networks they control.