Cognitive radio systems specific for IMT systems: Operator’s view and perspectives

Cognitive radio (CR) is still an emerging and disruptive communication technology which is expected to improve the overall efficiency of the spectrum use. It is envisaged that cognitive radio systems (CRS) could impact many aspects of communications and in particular could facilitate accommodation of the increasing amount of services and applications in wireless networks. Intensive research on CR aims at maximising the utilisation of the limited radio spectrum resource. There have been many advances in CR regarding the technology development aspects; however supplementary research on regulation, policy and market structure reforms in relation with application specific deployment is still required before any CR-based spectrum access could be implemented for specific broadband mobile applications. Indeed, mobile community is still at an early stage of understanding and development of CR capabilities and it is premature to envisage wide deployment of CRS without careful consideration of regulatory and business issues. Therefore, this paper gives a classification of CR-based network and application scenarios, and investigates the feasibility of them from a regulatory perspective at a global level (ITU-R). Main part of this paper presents the wireless network operator’s approach to CRS specific for International Mobile Telecommunications (IMT) systems and proposes the radio environment map (REM) concept as a cognitive tool that increases environmental awareness in wireless network operator’s networks. Studies, which the authors performed internally and within the framework of a collaborative European project as well as within ITU-R yield the conclusion that, at shorter term, only intra-operator based CRS maximises the possibility for CR capabilities to be implemented.

► Intra-operator CRS on IMT bands maximizes the short-term deployment possibility of CR features. ► A novel concept called as radio environmental maps brings cognition to IMT systems. ► Implications of CRS deployment in IMT systems in the long term need to be fully understood.