scholarly journals A Novel Multi-radio Rendezvous Algorithm for Cognitive Radio Networks

10.29007/4lkq ◽  
2019 ◽  
Author(s):  
Michael Fischer ◽  
Jonathan Backens
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Cognitive Radio Networks ◽  
Ad Hoc ◽  
Radio Networks ◽  
Secondary Users ◽  
Multiple Users ◽  
Heterogeneous Nature ◽  
Hoc Networks ◽  
Short Time

Channel Rendezvous between secondary users remains a key challenge to the development of cognitive ad-hoc networks. The decentralized and heterogeneous nature of ad-hoc CRNs makes guaranteeing rendezvous across multiple users within a short time difficult. Current research focuses on single hop networks or on multi-radio platforms to reduce the Time To Rendezvous (TTR). This work presents a Novel Multi-radio Rendezvous algorithm that leverages increasing availability of multi-radio secondary users to reduce TTR in heterogeneous and anonymous CRNs with multiple users.

scholarly journals Analysis of Channel Selection and Heterogeneous Spectrum Handoff in Cognitive Radio Ad Hoc Networks

2012 ◽  
Vol 6-7 ◽  
pp. 1122-1128
Author(s):  
Hai Tao Lin ◽  
Gan Liu ◽  
Wei Min Wu
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Performance Improvement ◽  
Ad Hoc ◽  
Markov Chain Model ◽  
Channel Selection ◽  
Chain Model ◽  
Secondary Users ◽  
Probability Of Collision ◽  
Hoc Networks

This paper addresses the priority of channel selection and switch over heterogeneous spectrum in cognitive radio ad hoc networks, which is not addressed carefully in the literature, with the aid of a novel 3-D structured Markov-chain model analysis. Our analysis indicates that the performance of the capacity, the probability of collision or switch of the Secondary Users (SUs) will be improved if the new SUs select available channels to initialize a session with a proper priority of Secondary Channels (SCs). Moreover, our work indicates that the same performance improvement would be gained if the active SUs interrupted by the PUs switch their working spectrum to available secondary channels with a proper priority. Extensive numerical analysis results verify the effectiveness of the proposed models and analysis methods.

scholarly journals Spectrum aware clustering in cognitive radio ad hoc networks

2018 ◽  
Vol 7 (2.30) ◽  
pp. 27
Author(s):  
Aishwarya Sagar Anand Ukey ◽  
Meenu Chawla
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Cluster Formation ◽  
Clustering Algorithms ◽  
Radio Spectrum ◽  
Dynamic Nature ◽  
Secondary Users ◽  
Hoc Networks ◽  
Maintenance Process

Cognitive radio (CR) is an emerging technology developed for efficient utilization of the radio spectrum. CRN utilizes CR technology and enables the unlicensed users also referred as secondary users (SUs) to access free portions of the licensed spectrum in an opportunistic manner. To support scalability and stability in distributed CRNs also referred as cognitive radio ad hoc networks (CRAHNs), SUs are often organized into smaller groups known as clusters. Spectrum aware clustering is considered as the key technique to overcome numerous is-sues associated with the dynamic nature of CRAHNs. This article focuses on clustering in CRAHNs and presents a comprehensive review of various spectrum aware clustering algorithms presented in the literature. The article highlights notable clustering metrics and includes the description of cluster formation and maintenance process. The article also renders potential research gaps in existing research works and discusses open challenges and issues that need to be addressed for efficient clustering in CRAHNs. 

scholarly journals Ranked Sense Multiple Access Control Protocol for Multichannel Cognitive Radio-Based IoT Networks

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1703 ◽  
Author(s):  
Muhammad Shafiq ◽  
Pankaj Singh ◽  
Imran Ashraf ◽  
Maqbool Ahmad ◽  
Amjad Ali ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Multiple Access ◽  
Ad Hoc ◽  
Markov Chain Model ◽  
Low Cost ◽  
Chain Model ◽  
Secondary Users ◽  
Hoc Networks ◽  
Cr System

The widespread growth of the Internet-of-Things (IoT) and its dependence on the license-exempt Industrial, Scientific, and Medical (ISM) bands have made spectrum resources scarce. IoT can nonetheless get advantage from the Cognitive Radio (CR) technology to resolve the spectrum shortage issue. Since in CR networks the unlicensed Secondary Users (SUs) can exploit the white spaces in licensed channels of Primary Users (PUs) opportunistically. CR ad hoc networks are more useful in IoT due to ease of installation, low cost, and less complexity. However, CR ad hoc networks are prone to the rendezvous issue and hidden primary terminal problem. Moreover, the available channels in the CR system are not identical, PUs’ and SUs’ activities can diversify them as well. In this connection, channel selection by SUs is a complex balancing act since the transmission opportunities are space, frequency and time bounded. In this paper, we hence proposed a new Ranked Sense Multiple Access with Collision Avoidance (RSMA/CA) protocol for multichannel CR-based IoT networks. Our proposed RSMA/CA protocol not only resolves the hidden primary terminal problem but also avoids hidden and exposed terminal problems at the same time by mutual spectrum sensing. We suggest a new channel ranking mechanism to rank the available channels based on the long term qualities of the channels, PUs’ return rate, and SUs’ activities and tailor-made the algorithms in an existing scheme to make the rendezvous process more efficient. We analyze the performance of our proposed RSMA/CA in terms of normalized throughput through the Markov chain model and compared with that of the existing scheme. Simulation results show that our RSMA/CA protocol outperforms the existing scheme due to efficient rendezvous and access mechanisms.

scholarly journals Quorum Systems towards an Asynchronous Communication in Cognitive Radio Networks

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Sylwia Romaszko ◽  
Petri Mähönen
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Ad Hoc ◽  
Difference Set ◽  
Radio Networks ◽  
Asynchronous Communication ◽  
Quorum Systems ◽  
Common Control ◽  
Central Controller ◽  
Hoc Networks

This paper reviews quorum systems (QS) from the perspective of cognitive radio networks. Quorum systems were originally developed for and widely used in the scope of operating systems. Recently, quorum systems have been also started to be applied to wireless communications. The objective of this paper is threefold. First, the paper provides survey and guidance on the use of quorum systems. Second, it shows that QS properties provide an interesting alternative towards an asynchronous communication in cognitive radio ad hoc networks (CRANs). Due to properties of quorum systems it is possible to establish CRANs without employing a common control channel (CCC), perfect synchronization, or central controller architecture. QS properties can be efficiently utilized to handle the rendezvous (RDV) problem in CRANs. New RDV protocols must be designed in such a way that there is a guarantee that all nodes meet periodically within reasonable periods of time. Since pseudorandom solutions do not provide this guarantee, systematic approaches are needed such as QSs. Third, we also propose a novel distributed RDV protocol, MtQS-DSrdv, which is based on mirror torus QS and difference set concepts. The proposed protocol guarantees RDVs on all available channels while CR nodes have the same channel set.

scholarly journals Connectivity Analysis of Cognitive Radio Ad-Hoc Networks with Multi-Pair Primary Networks

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 565 ◽  
Author(s):  
Le Dung ◽  
Seong-Gon Choi
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Simulation Analysis ◽  
Secondary Users ◽  
Mathematical Expressions ◽  
Primary Network ◽  
Secondary Network ◽  
Interference Range ◽  
Hoc Networks

In this paper, we study the connectivity of cognitive radio ad-hoc networks (CRAHNs) where primary users (PUs) and secondary users (SUs) are randomly distributed in a given area following a homogeneous Poisson process. Moreover, for the sake of more realistic CRAHNs, contrary to previous works in the literature, we consider the case that primary network is comprised of multiple communication pairs which are spatial-temporal distributed in the network area. We also take into consideration the differences in transmission range and interference range of both PUs and SUs. The connectivity of such CRAHN is studied from three viewpoints. First, we mathematically analyze the probability of isolated secondary transmitter and secondary receiver. Second, we derive the approximation expression of the link probability between two adjacent SUs. Third, we investigate the path connectivity between two arbitrary SUs by using the simulation analysis approach. The correctness of our mathematical expressions is confirmed by comparing analytical results with simulation results. The results in this paper provide insights into how multiple communication pairs in primary network affect the connectivity of secondary network, which can be useful guidelines for the design of CRAHNs.

scholarly journals A Sensitive Secondary Users Selection Algorithm for Cognitive Radio Ad Hoc Networks

Sensors ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 445 ◽  
Author(s):  
Aohan Li ◽  
Guangjie Han ◽  
Liangtian Wan ◽  
Lei Shu
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Selection Algorithm ◽  
Secondary Users ◽  
Hoc Networks

Improved frog leap inspired protocol (IFLIP) – for routing in cognitive radio ad hoc networks (CRAHN)

2018 ◽  
Vol 15 (2) ◽  
pp. 306-311 ◽  
Author(s):  
Ramkumar J. ◽  
Vadivel R.
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Multicast Routing ◽  
Research Work ◽  
Service Rate ◽  
Secondary Users ◽  
Content Type ◽  
End To End ◽  
Hoc Networks

Purpose End-to-end latency in network affects the overall performance in number of ways. It is one of the major tasks to minimize the end-to-end latency in cognitive radio ad hoc networks (CRAHN), as the transmission of packets passes through every hop of the routing path. This paper aims to propose a new reactive multicast routing protocol, namely, improved frog leap inspired protocol (IFLIP) to reduce the overall end-to-end latency in CRAHN. Design/methodology/approach It is difficult to solve the problems that emerge in optimization. Routing is the procedure for choosing the best network path. This paper proposes a novel algorithm by improving the FLIP to use an ideal route, which progressively reduces the congestion level on various routing path by considering the spectrum accessibility and the service rate of each hop in CRAHN. Findings Result of this research work concludes that IFLIP significantly outperforms other baseline schemes (namely, TIGHT and Greedy TIGHT) in minimizing the end-to-end latency in CRAHN. Originality/value It is proved that IFLIP gives a better ratio of packet delivery under varying primary users and secondary users. IFLIP results in increased packet deliver ratio, reduced end-to-end latency and better throughput.

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