List of Titles

Provisioning delay sensitive services in cognitive radio networks by opportunistically sharing spectrum from CSMA/CA networks

- Hasan, Rashidul, Murshed, Manzur

Authors: Hasan, Rashidul , Murshed, Manzur
Date: 2010
Type: Text , Conference paper
Relation: 12th IEEE International Conference on High Performance Computing and Communications p. 616-622
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Description: Cognitive radio network (CRN) users are inherently expected to experience widely varied delays and jitters due to the uncertainty in channel availability. Supporting delay sensitive real-time services through CRNs thus remains a challenging task. This paper presents a novel technique to provision QoS guarantee in CRNs by modeling the resultant channel of multiple primary networks and finding the optimum number of primary channels to support a desired level of expected latency. In doing so, this paper introduces a cognitive radio based MAC, which can effectively co-exists with primary CSMA/CA networks by accurately estimating the start of the spectrum holes, reliably modeling channel occupation by the primary users, and using event-driven sensing to adaptively control the sensing frequency and interval. Simulation results with ns-2.33 reveal that a CR network based on the proposed MAC can achieve the targeted service delay time by appropriately selecting optimal WLAN primary channels.

Interference protection in cognitive radio networks

- Shahid, Mohammad, Kamruzzaman, Joarder

Authors: Shahid, Mohammad , Kamruzzaman, Joarder
Date: 2010
Type: Text , Conference paper
Relation: 2010 IEEE 71st Vehicular Technology Conference p. 1-5
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Description: Protection of interference on the primary system is the key requirement for deployment of a cognitive radio system. Typically, spectrum sensing is interleaved in the transmission process of a secondary user to detect the return of primary user for quick evacuation, resulting in frequent stopping of transmission. In this paper, we introduce a novel method of agile spectrum evacuation that ensures continuous transmission by the secondary user until the primary user actually returns. The sensing process goes on simultaneously by a dedicated set of users working in a cooperative manner. The proposed method is evaluated under fading and shadowing conditions and better interference protection and improved utilization of RF spectrum is obtained.

Agile spectrum evacuation in cognitive radio networks

- Shahid, Mohammad, Kamruzzaman, Joarder

Authors: Shahid, Mohammad , Kamruzzaman, Joarder
Date: 2010
Type: Text , Conference paper
Relation: 2010 IEEE International Conference on Communications p. 1-6
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Description: One of the most important aspects of cognitive radio technology is to avoid interference on the primary system. Typically, the interference is avoided by sensing a particular spectrum band for the existence of primary transmitter while all secondary users are kept quiet. Hence, a periodic sensing method is used which incorporates alternate phases of sensing and transmission by all secondary users. In this paper, we introduce a new method of agile spectrum evacuation that allows any secondary user to continue using the band until the return of the primary user is detected through the formation of a set of users that exclusively engages in sensing primary user in a cooperative manner. The proposed method yields better interference protection and enhanced spectrum utilization.

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A comprehensive spectrum trading scheme based on market competition, reputation and buyer specific requirements

- Hassan, Md Rakib, Karmakar, Gour, Kamruzzaman, Joarder, Srinivasan, Bala

Authors: Hassan, Md Rakib , Karmakar, Gour , Kamruzzaman, Joarder , Srinivasan, Bala
Date: 2015
Type: Text , Journal article
Relation: Computer Networks Vol. 84, no. (2015), p. 17-31
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Description: In the exclusive-use model of spectrum trading, cognitive radio devices or secondary users can buy spectrum resources from licensed users or primary users for a short or long period of time. Considering such spectrum access, a trading model is introduced where a buyer can select a set of candidate sellers based on their reputation and their offers in fulfilling its requirements, namely, offered signal quality, contract duration, coverage and bandwidth. Similarly, a seller can assess a buyer as a potential trading partner considering the buyer's reliability, which the seller can derive from the buyer's reputation and financial profile. In our scheme, seller reputation or buyer reliability can be either obtained from a reputation brokerage service, if one exists, or calculated using our model. Since in a competitive market, the price of a seller depends on that of other sellers, game theory is used to model the competition among multiple sellers. An optimization technique is used by a buyer to select the best seller(s) and optimize purchase to maximize its utility. This may result in buying from multiple sellers of certain amount of bandwidth from each, depending on price and meeting requirements and budget constraints. Stability of the model is analyzed and performance evaluation shows that it benefits sellers and buyers in terms of profit and throughput, respectively. © 2015 Elsevier B.V. All rights reserved.

Spectrum allocation framework for multiuser cognitive radio systems

- Shahid, Mohammad, Kamruzzaman, Joarder

Authors: Shahid, Mohammad , Kamruzzaman, Joarder
Date: 2011
Type: Text , Conference paper
Relation: 2011 IEEE International Conference on Communications, ICC 2011; Kyoto, Japan; 5th-9th June 2011 p. 1-6
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Description: One of the most challenging issues in cognitive radio networks is to dynamically access the radio frequency spectrum in an uninterrupted manner. To achieve this, omniscient allocation of spectrum bands among cognitive radio users is crucial. Most of the existing spectrum allocation methods select a band from a pool according to the service requirements of a single user, neglecting the demand of multiple users. In this paper, we introduce a collaborative framework for allocating multiple bands among multiple secondary users. The proposed method defines a capacity of service metric based on the optimal sensing parameters and utilizes this metric to assign distinct bands to all or highest possible number of contending users. Performance evaluation suggests that the proposed method exhibits significant superiority over conventional approaches in terms of improved throughput and spectrum utilization, reduced interference loss and collision, and hence, enhances dynamic spectrum access and sharing capabilities.

Maximizing the concurrent transmissions in cognitive radio ad hoc networks

- Hassan, Md Rakib, Karmakar, Gour, Kamruzzaman, Joarder

Authors: Hassan, Md Rakib , Karmakar, Gour , Kamruzzaman, Joarder
Date: 2011
Type: Text , Conference paper
Relation: 7th International Wireless Communications and Mobile Computing Conference, IWCMC 2011; Istanbul, Turkey; 4th-8th July 2011 p. 466-471
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Description: Spectrum utilization in cognitive radio ad hoc network is a critical task due to the fluctuation of spectrum availability temporally and spatially. Reusing the same channel spatially can effectively improve the spectrum utilization as well as reduce the delay in switching and coordination in different channels. In this paper, a dynamic spectrum sharing method is proposed which allows multiple secondary users to reside in the same channel and use the channel concurrently to maximize the spectrum utilization exploiting variable transmission power and location information, while guaranteeing acceptable level of interference protection to the primary users. Results show that the proposed method successfully outperforms the existing method in maximizing the number of concurrent transmissions as well as the spectrum utilization.

Cognitive AmBC-NOMA IoV-MTS networks with IQI : reliability and security analysis

- Li, Xingwang, Zheng, Yike, Alshehri, Mohammad, Hai, Linpeng, Balasubramanian, Venki, Zeng, Ming, Nie, Gaofeng

Authors: Li, Xingwang , Zheng, Yike , Alshehri, Mohammad , Hai, Linpeng , Balasubramanian, Venki , Zeng, Ming , Nie, Gaofeng
Date: 2023
Type: Text , Journal article
Relation: IEEE Transactions on Intelligent Transportation Systems Vol. 24, no. 2 (2023), p. 2596-2607
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Description: Internet-of-Vehicle (IoV) enabled Maritime Transportation Systems (MTS) communication is anticipated to support ultra-reliable and low latency, diverse quality-of-service (QoS) and large-scale connectivities. To meet such stringent demands, a cognitive ambient backscatter non-orthogonal multiple access (C-AmBC-NOMA) IoV-MTS network is proposed. We explore the reliable and secure performance of the proposed C-AmBC-NOMA IoV-MTS network with in-phase and quadrature phase imbalance (IQI) at radio-frequency (RF) front-ends and the existence of an eavesdropper. In particular, the analytical expressions on the outage probability (OP) and intercept probability (IP) are obtained after a series of calculations. For a deeper understanding, we discuss the asymptotic behavior of OPs in the high signal-to-noise ratio (SNR) region, the diversity orders of OPs, and IPs in the high main-to-eavesdropper ratio (MER) regime. The results of Monte-Carlo simulation and a series of corresponding theoretical analysis show that: i) As the SNR approaches infinity, the OPs tend to be fixed non-negative values, indicating that the diversity orders of the OPs have error floors; ii) When the MER approaches infinity, the IPs of legitimate users decrease continuously, while the IP of backscatter device (BD) increases; iii) Compared with the system performance under ideal condition, the system performance is less reliable under IQI condition, but the security performance is enhanced; iv) By carefully selecting the system parameters, a trade-off can be achieved between reliability and security. © 2000-2011 IEEE.

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