Towards spectrum micro-trading

Spectrum trading is an important tool to increase overall spectrum utilization and to open up opportunities for businesses to get access to desired spectrum. It has been implemented in some countries for some spectrum bands. At the same time, systems and architectures for cognitive radio technologies are being developed that are able to dynamically use spectrum bands in more flexible manners including functionalities such as dynamic bandwidth, spectrum band concatenation, sensing, channel switching and cognition. However, the current spectrum trading regimes usually require long times to execute a trade, hence limiting the flexibility over short time scales. In this paper we study spectrum micro-trading as a concept to enable trading of spectrum at the micro scale in at least three dimensions; on the micro-spatial, micro-temporal and micro-frequency scale. The ecosystem required for spectrum micro-trading and the most important metrics are defined; market viability, spectrum utilization, channel quality and social welfare. Furthermore, we propose a model for spectrum micro-trading, the Micro-trading Pixelation Model, which addresses the three dimensions on the micro scale. We then discuss the main challenges and issues that have to be solved for the realization of spectrum micro-trading with the proposed model. Finally, some initial simulation results are provided to demonstrate the performance of spectrum micro-trading.