Cognitive Networks: Towards Self-Aware Networks

8.5. Dynamic Spectrum: Scenarios for Cognitive Ad Hoc Networks

The technical challenges of designing cognitive ad hoc networks, which have the type of characteristics that are described in the previous section of this chapter, are vast. The natural question that arises, is whether a need for such complex communications systems will exist. This question is the focus of the final part of the chapter. To answer it we look to dynamic spectrum management and access and explore the proposed roles for cognitive ad hoc networks in this field.

The current spectrum regulatory regime, in the main, takes what is known as a command and control approach to the management of spectrum. Regulators specify which band of frequencies can be used for which services and which technologies should be used to deliver these services. The cycle involved in allocating spectrum for certain usages, specifying the characteristics of the usage and awarding or granting licenses for use can be slow and hence the ability of the command and control approach to keep apace with technological innovation can be quite limited. Added to this there is growing evidence that while on the one hand there is a perceived scarcity of spectrum due to the increasing demand for mobile RF services, on the other hand measurements have shown spectrum usage levels of no more than 10% being common ^[]. Hence there is a need for spectrum management regimes that can keep apace with technology innovation and that facilitate more efficient ...