Abstract

Cognitive Radio (CR) technology is a promising enabler towards a more efficient and dynamic use of the frequency spectrum. The challenges related to using the vacant frequencies in an opportunistic manner put extra constraints on the system if it is going to provide reliable services to the end user. When, in addition, we want a system to provide managed quality of service (QoS) and mobility, the challenges are even more demanding. There are two major challenges for cognitive radio systems based on opportunistic spectrum access: the need to keep track of the spectrum; and the aim of providing managed QoS and mobility. Both these are external constraints generally not present for licensed wireless operation and they call for additional functionality and flexibility in the system as well as the need for additional interfaces to handle the new information. The EU-project QoSMOS has addressed this in defining the overall requirements for the system and we show how these responds to the challenges.