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New Cross-Layer Processing and Routing Strategies for Cognitive Radio Networks

Supervisors: Prof. Laurence Dooley, Dr. Patrick Wong

Student: Mr. John Martin

Most of today’s radio systems are unaware of their spectral environment and operate in a specific frequency band using a dedicated spectrum access system. Extensive investigations into spectrum utilisation reveal that not all the spectrum is used either spatially (geographic location) or in time. A radio able to both sense and understand its local radio spectrum environment by identifying and exploiting temporarily vacant spectrum therefore has the exciting potential to increase spectrum efficiency, provide higher bandwidth services, and minimise the need for centralised spectrum management. This can be achieved by a system able to make fast autonomous decisions about how best to access vacant spectrum, which is one of the key characteristics of Cognitive Radio Networks (CRN).

Key research questions this research will investigate include:

• Cross Layer Processing – how best to share information between Layers 1, 2, 3, 4 & 5 of the Open System Interconnection (OSI) model to optimise throughput and maintain minimum Quality of Service (QoS) provision in CRN. Exploit cross-layer information to make optimal channel, power and modulation allocations to minimise disruption to the spectrum environment while allocating the requisite resources to satisfactorily fulfil all application and network requirements.

• Routing Strategies – Design and develop new techniques to optimise features such as, end-to-end (E2E) QoS i.e. choosing the route to obtain the best results for users application, and rapid and flexible routing in multi-hop ad hoc networks to mitigate fast changing wireless conditions.