scholarly journals Spectrum Handoff in Cognitive Radio Networks: A Survey

2017 ◽  
Vol 10 (04) ◽  
pp. 765-772 ◽  
Author(s):  
Nisar Lala ◽  
Altaf Balkhi ◽  
G M Mir
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Primary User ◽  
Radio Networks ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Spectrum Handoff ◽  
Suitable Target ◽  
Promising Solution ◽  
Minimum Performance

Cognitive radio (CR) is a promising solution to improve the spectrum utilization by enabling unlicensed users to exploit the spectrum in an opportunistic manner. Spectrum handoff is a different type of handoff in CR necessitated by the reappearance of primary user (PU) in the licensed band presently occupied by the secondary users (SUs). Spectrum handoff procedures aim to help the SUs to vacate the occupied licensed spectrum and find suitable target channel to resume the unfinished transmission. The purpose of spectrum mobility management in cognitive radio networks is to make sure that the transitions are made smoothly and rapidly such that the applications running on a cognitive user perceive minimum performance degradation during a spectrum handoff. In this paper, we will survey the literature on spectrum handoff in cognitive radio networks.

Joint Detection of Spatial-Temporal Spectrum Holes for Cognitive Radio Networks

2014 ◽  
Vol 556-562 ◽  
pp. 2802-2805
Author(s):  
Fu Lai Liu ◽  
Shou Ming Guo ◽  
Rui Yan Du
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Primary User ◽  
Spatial Spectrum ◽  
Radio Networks ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Secondary Network ◽  
Spectrum Holes

Spectrum sensing is a key technology to reliably detect spectrum holes in multi-dimensions for cognitive radio networks. In this paper, a joint spatial-temporal spectrum sensing scheme is proposed. First of all, the secondary users (SUs) located inside the primary exclusive region (PER) perform temporal sensing. When the primary user (PU) is present, the SUs located outside the PER perform spatial spectrum sensing. The proposed method can improve the spectrum utilization by exploiting both temporal and spatial spectrum holes. The achievable throughput for the secondary network of joint spatial-temporal sensing is higher than that of pure temporal sensing. Simulation results demonstrate the effectiveness of the proposed approach.

scholarly journals Intelligent Process of Spectrum Handoff/Mobility in Cognitive Radio Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Prince Semba Yawada ◽  
Mai Trung Dong
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Communication Systems ◽  
Spectral Band ◽  
Spectrum Management ◽  
Radio Networks ◽  
Innovative Technology ◽  
Main Task ◽  
Secondary Users ◽  
Spectrum Handoff

Cognitive radio is an innovative technology in the field of wireless communication systems, aimed at significantly improving the use of the radio spectrum while allowing secondary users to access the spectral band opportunistically. Spectrum management mechanism ensures the transmission of data by controlling the efficiency of operation between the primary and secondary networks. The main task of spectrum management is to ensure that secondary users benefit from the spectrum without interfering with primary users. This paper deals with some of the important characteristics of spectrum mobility in the cognitive radio networks. The new management approaches of the mobility and the connection are designed to reduce the latency and loss of information during spectrum handoff, a list of channel safeguard is maintained in this effect, but the maintenance and update are a challenge. In this paper, we describe the reasons and mechanisms of spectrum handoff. Protocols have been developed to illustrate this handoff mechanism. We also make a comparison between the different methods of spectrum handoff. The simulation results obtained confirm that the protocols developed and the proposed method performed better than the pure reactive handoff method.

scholarly journals A Survey onadvances in security threats and its counter measures in cognitive radio networks

2018 ◽  
Vol 7 (2.8) ◽  
pp. 372 ◽  
Author(s):  
D Ganesh ◽  
T Pavan Kumar
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Dynamic Spectrum Access ◽  
Radio Networks ◽  
Cognitive Networks ◽  
Dynamic Spectrum ◽  
Future Research ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Open Problems

Cognitive radio is a promising wireless communication technology that improves spectrum utilization and offers many benefits for internet users. Cognitive radio networks utilizes the available limited resources in a more efficient and flexible way. The main objective of the Cognitive network is to efficiently utilize the unutilized spectrum and meet the demand of the secondary users. some of the important features of cognitive of Cognitive radio networks are dynamic spectrum access, self organizing  and flexibility. As Cognitive radio networks are flexible in nature, it will be effected by various security attacks which in turn affects the performance of the network. Furthermore Cognitive radio networks transmit the spectrum in several licensed bands and it also performs dynamic spectrum allocation. Cognitive radio and Cognitive radio networks are wireless in nature these face conventional attacks. In this survey we address various  attacks in different layers , new threats and challenges that Cognitive networks face, current available solutions to address layer attacks. In addition applications, open problems and future Research challenges are also specified.

Towards Security Issues and Solutions in Cognitive Radio Networks

2015 ◽  
pp. 813-834
Author(s):  
Saed Alrabaee ◽  
Mahmoud Khasawneh ◽  
Anjali Agarwal
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Radio Networks ◽  
Network Technology ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Security Issues ◽  
Primary Users ◽  
Radio Technology ◽  
Cognitive Radio Technology

Cognitive radio technology is the vision of pervasive wireless communications that improves the spectrum utilization and offers many social and individual benefits. The objective of the cognitive radio network technology is to use the unutilized spectrum by primary users and fulfill the secondary users' demands irrespective of time and location (any time and any place). Due to their flexibility, the Cognitive Radio Networks (CRNs) are vulnerable to numerous threats and security problems that will affect the performance of the network. Little attention has been given to security aspects in cognitive radio networks. In this chapter, the authors discuss the security issues in cognitive radio networks, and then they present an intensive list of the main known security threats in CRN at various layers and the adverse effects on performance due to such threats, and the current existing paradigms to mitigate such issues and threats. Finally, the authors highlight proposed directions in order to make CRN more authenticated, reliable, and secure.

A SURVEY OF IMPLEMENTATION OF OPPORTUNISTIC SPECTRUM ACCESS ATTACK WITH ITS PREVENTIVE SENSING PROTOCOLS IN COGNITIVE RADIO NETWORKS

2015 ◽  
Vol 3 (6) ◽  
pp. 389
Author(s):  
Monisha Ravi ◽  
Nisha Ravi ◽  
N. Ravi
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Primary User ◽  
Radio Spectrum ◽  
Radio Networks ◽  
Spectrum Efficiency ◽  
Network Simulator ◽  
Secondary Users ◽  
Primary User Emulation Attack ◽  
Research Areas

Recently, the expansive growth of wireless services, regulated by governmental agencies assigning spectrum to licensed users, has led to a shortage of radio spectrum. Since the FCC (Federal Communications Commissions) approved unlicensed users to access the unused channels of the reserved spectrum, new research areas seeped in, to develop Cognitive Radio Networks (CRN), in order to improve spectrum efficiency and to exploit this feature by enabling secondary users to gain from the spectrum in an opportunistic manner via optimally distributed traffic demands over the spectrum, so as to reduce the risk for monetary loss, from the unused channels. However, Cognitive Radio Networks become vulnerable to various classes of threats that decrease the bandwidth and spectrum usage efficiency. Hence, this survey deals with defining and demonstrating framework of one such attack called the Primary User Emulation Attack and suggests preventive Sensing Protocols to counteract the same. It presents a scenario of the attack and its prevention using Network Simulator-2 for the attack performances and gives an outlook on the various techniques defined to curb the anomaly.

scholarly journals Primary User Traffic Pattern Based Opportunistic Spectrum Handoff in Cognitive Radio Networks

2020 ◽  
Vol 10 (5) ◽  
pp. 1674 ◽  
Author(s):  
Kaleem Arshid ◽  
Iftikhar Hussain ◽  
Muhammad Khawar Bashir ◽  
Shahid Naseem ◽  
Allah Ditta ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Service Time ◽  
Primary User ◽  
Spectrum Management ◽  
Radio Networks ◽  
Secondary User ◽  
Traffic Pattern ◽  
Spectrum Handoff ◽  
Cognitive Radio User

Through the expeditious expansion of the wireless network, the unlicensed bandwidth-based devices are growing substantially as compared to the present vacant bandwidth. Cognitive radio networks present a proficient solution to the spectrum shortage diminution hitch by allowing the usage of the vacant part of the spectrum that is not currently in use of the Primary User licensed bandwidth to the secondary user or cognitive radio user. Spectrum management procedure in cognitive radio network comprises of spectrum sharing, sensing and handoff. Spectrum handoff plays a vital role in spectrum management and primarily focuses on single handoff strategies. This paper presents a primary user traffic pattern-based opportunistic spectrum handoff (PUTPOSH) approach to use in the cognitive radio networks. PUTPOSH permits a secondary user to sense the arrival of a primary user and use an opportunistic handoff scheme. The opportunistic handoff scheme firstly detects the arrival of the primary users by energy detection sensing and secondly, it allows a cognitive radio user to decide whether to do handoff or not contingent upon the overall service time to reduce the unused handoffs. The handoffs can either be reactive or proactive based on the arrival rate of the primary user. The simulation results show that the presented PUTPOSH approach (a) minimizes the number of handoffs and the overall service time, and (b) maintains the channel utilization and throughput of the system at a maximal point.

Analysis on Communication Performance for Secondary Users Classified in Cognitive Radio Networks

2012 ◽  
Vol 271-272 ◽  
pp. 668-673
Author(s):  
Shan Shan Wang ◽  
Xing Guo Luo ◽  
Bai Nan Li
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Queuing Theory ◽  
First Grade ◽  
Primary User ◽  
Radio Networks ◽  
Theory Model ◽  
Secondary Users ◽  
Communication Performance ◽  
Priority Level

Cognitive Radio Networks is an effective technology and a hot research direction which can solve the problem of deficient resource and revolutionize utilization. In order to enhance the communication efficiency, secondary users are classified by some strategy. We exploit the queuing theory model to research on the communication performance of secondary users, considering primary user as the first grade user and secondary users as other grades users. The research results indicate that the users which have lower priority level are more sensitive than those have higher priority level when primary user appears. Under Primary User Emulation Attack (PUEA), if the number of secondary users reaches 300, the waiting time would larger than 15 minutes. And if the appearance rate of PUEA reaches 4, the break-out rate would be 80%, which is much harmful for CRN.

scholarly journals Performance Analysis of Cooperative Spectrum Sensing under Guaranteed Throughput Constraints for Cognitive Radio Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
H. F. Al-Doseri ◽  
M. A. Mangoud
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
Radio Networks ◽  
Probability Of Detection ◽  
Cooperative Sensing ◽  
Soft Decision ◽  
Secondary Users ◽  
Sensing Time

One of the main challenges in cognitive radio networks is the ability of secondary users to detect the primary user presence with high probability of detection. In previous research, optimizing cooperative sensing in cognitive radio networks is performed for either a targeted probability of detection or a false alarm. After setting one of the probabilities as an optimization constraint, the other is optimized. In this paper, a guaranteed constant throughput at the secondary users is introduced as a target while optimizing probability of detection for cooperative sensing. Both sensing time values and number of cooperated cognitive radio secondary users are investigated to maximize the probability of detection of primary user. AND and OR hard decision schemes are considered and compared with soft decision scheme which is weighted modified deflection coefficient scheme (W-MDC). It is illustrated that cooperation of all users and utilizing full frames for sensing time will not provide maximum probability of detection. A tradeoff between performances of cognitive radio networks with and without optimization is presented. The effects of varying network sizes, normalized target throughput, maximum frame duration times, and received signal-to-noise ratio at the fusion center are investigated for different fusion rules.

scholarly journals Performance Metrics in Cognitive Radio Networks

2021 ◽  
Vol 36 (1) ◽  
pp. 73-79
Author(s):  
Mahmoud Ali Ammar
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Performance Metrics ◽  
Hypothesis Test ◽  
Threshold Value ◽  
Primary User ◽  
Radio Networks ◽  
Malicious Nodes ◽  
Secondary Users ◽  
Primary User Emulation Attack

In Cognitive Radio Networks (CRN), the main aim is to allow the secondary users (SUs) to identify the empty bands and use them to transmit or receive data opportunistically. Primary users (PUs) have the priority to use a channel, while the secondary users must vacant this channel once a primary user requests it. An attack known in cognitive radio networks as a Primary User Emulation Attack (PUEA) aims to prevent the SU from using the empty bands. In this paper, an analytical and experimental approach is presented to mitigate the PUEA. This approach is based on obtaining the Probability Density Functions (PDFs) of the received powers at the secondary users from malicious nodes and also from the primary transmitter in the cognitive network. Then, these obtained PDFs are used in Neyman-Pearson composite hypothesis test to measure the performance metrics (probability of false alarm and miss detection in the network). The results proved that the performance metrics were greatly influenced by the network area, where the secondary user is located, and the threshold value λ used in the decision rule. Also, there are boundaries for the λ choices that cannot be overtaken.

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