Cognitive Ad-hoc Networks under a Cellular Network with an Interference Temperature Limit

We propose an efficient deployment scenario for cognitive ad-hoc networking under a cellular network with a pre-defined interference temperature limit (ITL). Using this scenario, a cellular radio spectrum can be reused efficiently without disturbing the existing cellular network. It uses a relaxed ITL concept in which the pre-defined ITL is satisfied at the target receiver only instead of all around the cellular service coverage. In this scenario, a cognitive radio (CR)-enabled secondary user (also, called as a cognitive ad-hoc user), equipped with the cellular signal strength monitoring device measures the pathloss from the nearest cellular base station (CBS) (also, called as the target CBS) in a cellular downlink channel. Then, using the measured pathloss, each secondary user computes its allowable maximum transmit power level (AMTPL) for a cellular uplink channel. In this scenario, secondary users farther from the target CBS can transmit more power than nearer users can do, thus making the cellular uplink resource reused more efficiently. Therefore, the proposed scenario can reduce the routing overhead and associated delay, and the infrastructure cost because this secondary user power flexibility can decrease the number of required nodes for cognitive ad-hoc networking, or can increase the utilization efficiency of the cellular radio spectrum.