Abstract
The ever-growing demand for higher network data rates, lower delay, and conservative energy consumption at reduced costs, to support Internet-of-things (IoT) communications, has pushed wireless technologies into a new frontier. The growing demand for such technologies can be attributed to several factors, such as the massive number of the upcoming bandwidth-hungry IoT applications and the enormous number of - often battery-powered - devices expected to connect to the network. Cognitive Radio Networks (CRNs) can play a significant role in future generations of mobile-communication technologies by providing dynamic access to underutilized licensed bands. However, battery-operated devices, which communicate delay-sensitive data over multihop links, impose serious energy-delay limits. In such CRN-based IoT communications, as one device depletes its energy, network disconnectivity may arise, which can degrade the network efficiency. Therefore, building a reactive routing protocol to recover from any sudden link breakage is necessary to maintain prolonged network connectivity. This paper provides a comprehensive survey of CRN routing protocols that are based on two essential metrics, namely, packet delay, energy consumption, or both, while excluding all other CRN routing protocols. The survey is meant to support the designers of future CRN-based IoT communication frameworks with a detailed comparative survey, which targets the most relevant proposed routing protocols, including the specifics of the routing metrics, implemented spectrum awareness strategy, and employed medium-access control standard along with the simulator tool used for performance evaluation. In addition, this survey finds that the majority of cognitive radio routing protocols address either delay or energy consumption, but only a few consider a joint delay-energy metric, which suits delay-sensitive IoT applications running on energy-constrained devices.
Highlights
The rapid expansion of wireless devices has enabled the extensive use of various real-time applications
We provide an insight into the works published in the Cognitive Radio (CR) field in the current decade to highlight the challenges in fulfilling the requirements of IoT-based networks, and in particular, of devices with limited-energy and/or stringent response-delay constraints running information-critical Secondary Users (SUs)’ applications
The other two subsections review the research works focusing on joint delay and energy metrics and the publications addressing IoT applications
Summary
The rapid expansion of wireless devices has enabled the extensive use of various real-time applications. The Internet-of-things (IoT) paradigm [1] [2] enables the interaction between devices from several application domains that include – but not limited to mobile phones, routers, game consoles, printers, pacemakers, telephone systems, refrigerators, and Automatic Teller Machines (ATMs) Applications running on such devices interact with each other using Wireless Sensor Network (WSN) technologies such as Zigbee, LPWAN, LTEM, Wireless HART, Wireless networks for Industrial Automation-Process Automation (WIA-PA). The suitability of future wireless network technologies to work under different environments and provide equal coverage for billions of high-traffic devices sets high expectations to be met in IoT networks. Nodes mobility, Y channel degradation, or spectrum mobility?
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
