UC Riverside

Recently, research on the use of ultraviolet light for communication purposes has gained popularity. Analytical models that predict the manner in which UV light propagates and scatters have begun to be designed and developed. Using this information, a high level network protocol can begin to be created that would be able to take advantage of the unique UV channel properties. This thesis explores different aspects that comprise an outdoor UV communication system.

A leadership based neighbor discovery protocol is designed that is able to handle the initial configuration of the communication system. The protocol creates an interference free environment that helps reduce the time required for neighbor discovery. The protocol is based on the sequential discovery of a node's neighbors. At the termination of the protocol, a node is able to know the addresses of the neighbors that surround it and the directions that it can use to communicate with them.

A medium access control protocol is proposed to moderate access to the medium making the communication among devices orderly and efficient. Practical UVOC-MAC is a random access based protocol designed for an outdoor ad hoc network. Practical UVOC-MAC is able to handle deafness and the hidden/exposed node problems that arise with the use of directional antennas. The design of Practical UVOC-MAC is tied to the UV PHY layer properties which allow the use of non-line of sight links for communication. Spatial reuse is achieved by the protocol by allowing it to adaptively choose the direction of the communication.

A test bed is constructed allowing us to analyze the performance of the communication system. A software defined radio is used construct transceivers that exchange information using the UV channel. A software framework is used to implement the neighbor discovery and MAC protocols. Preliminary results on the performance of the communication system tested bed are analyzed. The bit error rate and path loss are used to evaluate the performance of the communication system.