Combining dual tessellation and temporal opportunities for spectrum reuse in cellular systems

Cellular network operators usually have to maintain networks of different generations (2G, 3G, 4G, ...) simultaneously. The progressive upgrade of users´ terminals makes the spectrum of the legacy networks become gradually underused. An operator can enable cognitive radio techniques at its newest generation terminals to reuse the spectrum of its own legacy networks. We propose an hybrid access scheme for cellular networks combining secondary access over temporal and spatial opportunities. We show that, when considering a cell structure with frequency reuse, the spatial opportunities are characterized by a dual tessellation. Our results show that a randomized access strategy maximizes the capacity of the secondary network.