Number of clusters formed in an emergency cognitive radio network and upper bound of network simultaneous transmission capacity

In an emergency situation, cognitive radio nodes can be deployed temporarily to form an ad hoc network for data transmission by exploiting available spectrum. Based on some criteria, cognitive radio nodes can form multiple clusters which are connected to form the network. For emergency cognitive radio networks, the number of clusters is an important metric for the network performance evaluation. Hence, in this study, after a clustering scheme is presented briefly, the number of clusters that deployed cognitive radio nodes can form is analysed. First, the maximal number of clusters that can be formed in the given area is studied based on the strict arrangement of nodes. Second, the average number of clusters formed is analysed as the expected value of the number of clusters formed, for which the probability that M clusters are formed is investigated. Thirdly, the upper bound of network simultaneous transmission capacity is derived based on the result of the average number of clusters formed. Finally, simulations are conducted to verify the analytical results.