An efficient routing protocol for cognitive radio networks of energy-limited devices

In the era of Internet-of-things (IoT), the future 5G networks are supposed to provide ubiquitous connectivity, high speed, as well as low latency and energy efficiency at low cost to billions of battery-powered wireless devices. The anticipated tremendous demand for wireless bandwidth in 5G networks calls for efficient usage of the underutilized licensed frequency spectrum that preserves the energy consumption of these energy-limited devices. This is feasible by embracing the cognitive radio concept and making use of its functionalities and capabilities to form 5G-CR incorporation. As a step towards this goal, an efficient routing protocol for cognitive radio (ERCR) networks is proposed in this paper. The proposed protocol is location-based and can fully operate over a single wireless channel using a channel access mechanism that follows the IEEE 802.11 distributed coordination function. It selects the route with the minimum number of forwarding nodes that have sufficient remaining energy. This, in turn, increases the per-node capacity to meet the operational requirements of different IoT applications. Meanwhile, it conserves the limited energy of battery-powered devices. The efficiency of the proposed protocol has been evaluated using extensive network simulator-2 computer simulations for a wide range of performance metrics under different activity levels of licensed users in terms of channel occupancy likelihood and duration. The simulation results reveal that ERCR is capable of providing reliable packet delivery at a low packet transfer latency while saving the energy of the cognitive radio network nodes with a fairly small overhead.