The Smart Grid (SG) as an intelligent power network, depends on a reliable and efficient communication network to provide two-way communication, which is a prime feature of the smart grid. Many researchers have proposed cognitive radio (CR) as a viable wireless communication technology that can be adapted for smart grid communication in order to improve spectrum utilisation and address communication challenges being faced by conventional wireless communication technologies. A major issue to address in the use of cognitive radio is spectrum handoff. This is because cognitive radio uses the spectrum of a licensed user as its main operating channel and must handoff to another spectrum hole when the licensed user returns. Multiple spectrum handoff degrades the cognitive radio user communication and spectrum handoff schemes are employed to mitigate this negative effect. In this work, a spectrum handoff scheme is proposed for cognitive radio communication in the smart grid neighbourhood area network. The proposed handoff scheme using backup channel scenario is modelled as an overflow system with mixed renewal and Poisson inputs from the perspective of a teletraffic loss system. The performance of the proposed scheme is evaluated in terms of blocking probability, link failure probability and link maintenance probability and compared to that of an existing scheme. Simulation results obtained showed that it is possible to improve the performance of cognitive radio operating in a classical situation by up to 22.8%, 83.2% and 45.2% respectively, for the above performance metrics, depending on selected network parameters. A comparison be tween the proposed and existing scheme showed that the proposed scheme outperformed the existing scheme with respect to the above spectrum handoff performance parameters.

Thesis (MEng Engineering in Telecommunications Engineering) --Botswana International University of Science and Technology, 2020