Coexistence Management Algorithms for Cognitive Radio Diversity Networks Using 802.19.1 Standard

Abstract

We study the coexistence management and propose coexistence decision algorithms for assigning TV channels to TV Band Devices considering IEEE 802.19.1 standard specifications. As mandated by 802.19.1, there is a hierarchy of servers providing coexistence mechanisms. Coexistence Managers (CMs) are the central servers serving a specific set of dissimilar networks. We propose that the CM assigns a channel to each Access Point (AP) based on two events (as considered in this paper): a new AP joins/leaves, and channel availability changes. The event in which a new AP joins and needs a channel assignment is contingent upon the spatio-spectral interference index (first introduced in this paper). The event in which a channel becomes unavailable is contingent upon both spatio-spectral interference index as well as switching of the APs involved. These two factors are optimized based on the event and thus two optimization problems are formulated as quadratic integer programming (QIP) problems. These QIP problems are NP hard. To avoid the NPhard complexity, we propose two heuristic algorithms; Least Interference based TSB Scheduling for Diversity Networks (DLITS) algorithm and Least Interference and Switching based TSB Scheduling for Diversity Networks (D-LISTS) algorithm. The results obtained confirm that the two algorithms provide near optimal solutions.