"Simple rules" for mobile network operators\´ strategic choices in future cognitive spectrum sharing networks

Spectrum sharing is becoming a necessity in future cellular networks due to the increasing traffic demand and challenges of getting exclusive spectrum. This article reviews the spectrum sharing framework that consists of regulatory, technology, and business domains. For future mobile network operators, sharing of spectrum with other operators or with other radiocommunication services - especially when using cognitive radio system technologies - is a disruptive change. Building on alternative spectrum sharing scenarios, this article discusses a set of Simple Rules for mobile network operators, both dominators and challengers, regarding spectrum sharing in future cognitive cellular networks. The Simple Rules provide a dynamic framework for both dominating and challenger mobile network operators for developing their sharing-based business models.