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In the cognitive radio ad hoc networks (CRAHNs), the spectrum availability may change from time to time and hop by hop. Thereby, the performance analysis and optimization for CRAHNs become so intricate that pure divide-and-conquer strategies by layered principles strand. Focusing on the five-layer involved performance analysis of CRAHNs, we set up a cross-layer design framework mathematically and...
The exploitation of spectrum opportunities in the dimension of height will bring another transmission degree of freedom for wireless networks. Besides, the modern wireless networks are deployed in the three dimensional (3D) space, which need cognitive radio technologies to enhance their performances. With these motivations, the capacity of 3D cognitive radio networks (CRNs) is addressed in this paper...
Cognitive radio (CR) networks are becoming an increasingly important part of the wireless networking landscape due to the ever-increasing scarcity of spectrum resources throughout the world. Nowadays CR media is becoming popular wireless communication media for disaster recovery communication network. Although the operational aspects of CR are being explored vigorously, its security aspects have gained...
The emergence of cognitive radio network technology provides network nodes with abundant licensed and unlicensed channels to select for routing. Traditional routing methods that minimize hop count often do not leverage the full capabilities of cognitive radio users. They may select high lossy links or choose arbitrarily among the different paths of the same minimum length, regardless of the often...
In this paper, we investigate the connectivity of random cognitive radio networks with different routing schemes. Two coexisting ad hoc networks are considered with m primary users (PUs) and n secondary users (SUs) randomly distributed in a unit area. The relation between n and m is assumed to be n = mβ. We show that with the HDP-VDP routing scheme, which is widely employed in the analysis of throughput...
We propose a distributed routing scheme for cog- nitive radio ad hoc networks which, besides the awareness of the dynamic behavior of the primary users, also considers that some primary users may be hidden to secondary nodes, thus creating asymmetry in the spectrum opportunity availability. We identify this "Hidden Primary User" problem and we introduce in our distributed protocol a mechanism...
This paper deals with the routing in cognitive mobile ad hoc networks. We propose to modify the widely adopted Ad-hoc On-demand Distance Vector (AODV) protocol in order to assure its functionality in the considered scenario. The resulting protocol, referred to as the Cognitive Ad-hoc On-demand Distance Vector (CAODV) protocol, has been designed according to three guidelines: i) to avoid regions of...
The topology of a cognitive radio Ad Hoc network is highly influenced by the behavior of both licensed (primary) and unlicensed (secondary) users. In fact, the network connectivity could be impaired by the activity of primary users. This aspect has a significant impact on the design of routing protocols. We design a routing scheme for cognitive radio Ad Hoc networks, named Gymkhana, which is aware...
Cognitive radio networking is a promising approach to fulfill the future's need for intelligent, high-performance communication and improve the efficiency of overall spectrum utilization. Testbed evaluation of protocols and algorithms is a must for the development of cognitive radio networks. In this paper, we present an integrated testbed framework for cognitive radio networks. The framework includes...
We study two distinct, but overlapping, networks which operate at the same time, space and frequency. The first network consists of n randomly distributed primary users, which form either an ad hoc network, or an infrastructure supported ad hoc network in which l additional base stations support the primary users. The second network consists of m randomly distributed secondary or cognitive users....
In this paper, an ultra-wideband waveform that is designed for optimum power and communication protocol that utilizes cognitive processing to make intelligent communication parameter decisions is proposed for wireless sensor application. Due to multiple objectives such as adaptive data rate, power control and quality-of-service, the message transmission becomes a non-deterministic polynomial computation...
Due to their potential capabilities, cognitive radios have recently been creating a significant interest for researchers to develop new techniques that take advantage of their use to increase spectrum utilization. Albeit generally these researchers proposed solutions that address issues related to cognitive radios, they mainly relied on either analytical or simulation tools to evaluate their proposed...
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