Results 1 -
9 of
9
Traffic-Aware Channel Sensing Order in Dynamic Spectrum Access Networks
"... Abstract—In this paper we present new results on the problem of finding the best channel sensing order for multi-channel Dynamic Spectrum Access (DSA) networks. We start with the general assumption that all Secondary Users (SUs) cooperatively sense each Primary User (PU) channel at one time. Then, t ..."
Abstract
-
Cited by 3 (1 self)
- Add to MetaCart
(Show Context)
Abstract—In this paper we present new results on the problem of finding the best channel sensing order for multi-channel Dynamic Spectrum Access (DSA) networks. We start with the general assumption that all Secondary Users (SUs) cooperatively sense each Primary User (PU) channel at one time. Then, the SU sensing results are reported to a DSA base station that schedules SU transmissions in order to maximize DSA network throughput. We then assume that PU traffic parameters are not perfectly known to DSA network and change over time, and propose a novel PU channel sensing order scheme based on the quality of PU traffic estimation. We adopt a maximum likelihood estimator to estimate the traffic statistics of PU channels and derive the Cramér-Rao (CR) bounds for the PU traffic estimation performance. Based on the CR bound and its Gaussian approximation, we analyze the impact of the estimation error on the DSA network throughput by computing a new metric called sensing order confidence, i.e., the probability that the best selected sensing order is not affected by PU traffic estimation errors. Finally, we formulate a convex optimization problem to determine the minimum number of PU channel state samples required for estimating PU traffic parameters after determining a certain constraint on the sensing order confidence metric to achieve the best sensing order. Index Terms—Dynamic spectrum access networks, channel sensing order, throughput maximization, traffic estimation, sens-ing order confidence, convex optimization. I.
Wireless Networks
"... A sensor network consists of a large number of sensor nodes that are densely deployed either inside or close to the phenomenon. In general, the position of sensor nodes need not be engineered or predetermined. This allows for random deployment in inaccessible terrains or disaster relief operations. ..."
Abstract
- Add to MetaCart
(Show Context)
A sensor network consists of a large number of sensor nodes that are densely deployed either inside or close to the phenomenon. In general, the position of sensor nodes need not be engineered or predetermined. This allows for random deployment in inaccessible terrains or disaster relief operations. Sensor networks can be considered as a special type of ad hoc wireless networks, where sensor nodes are, in general, stationary. A unique feature of sensor networks is the cooperative effort of sensor nodes. Sensor nodes are usually fitted with an onboard processor. Instead of sending the raw data to the nodes responsible for the fusion, they use their processing abilities to locally carry out simple computations and transmit only the required and partially processed data. A sensor system normally consists of a set of sensor nodes operated on a limited battery and a base system without any battery constraint. Typically, the base station serves as the gathering point for the collected data (through fusion). The base station also broadcasts different control commands to sensor nodes. The application areas of sensor networks include health, military, and civilian. In military application, the rapid deployment, self-organization, and fault-tolerance characteristics
University of Alberta OPTIMAL OPPORTUNISTIC CHANNEL ACCESS IN WIRELESS COMMUNICATION NETWORKS
"... and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication an ..."
Abstract
- Add to MetaCart
(Show Context)
and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis, and except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatever without the author’s prior written permission. High transmission rates will be demanded in future wireless communication networks. However, we will soon experience a spectrum scarcity problem since almost all available spectrum has been allocated to various wireless applications. A promising solution to this problem is to significantly improve the spectrum utilization efficiency by using opportunis-tic channel access (OCA). In the literature, OCA approaches have been developed in two kinds of networks: cognitive radio networks (CRNs) (in which secondary users, which are unlicensed users, may access the spectrum when primary users, which are licensed users, are not active) and wireless networks exploiting time diversity (in which a user may give
1Delay Analysis of Multichannel Opportunistic Spectrum Access MAC Protocols
"... We provide in this paper a comprehensive delay and queueing analysis for two baseline medium access control (MAC) protocols for multi-user cognitive radio (CR) networks and investigate the impact of different network parameters, such as packet size, Aloha-type medium access probability and number of ..."
Abstract
- Add to MetaCart
We provide in this paper a comprehensive delay and queueing analysis for two baseline medium access control (MAC) protocols for multi-user cognitive radio (CR) networks and investigate the impact of different network parameters, such as packet size, Aloha-type medium access probability and number of channels on the system performance. In addition to an accurate Markov chain, which follows the queue status of all users, several lower complexity queueing theory approximations are provided. Accuracy and performance of the proposed analytical approximations are verified with extensive simulations. It is observed that for CR networks using an Aloha-type access to the control channel, a buffering MAC protocol, where in case of interruption the CR user waits for the primary user to vacate the channel before resuming the transmission, outperforms a switching MAC protocol, where the CR user vacates the channel in case of appearance of primary users and then compete again to gain access to a new channel. The reason is that the delay bottleneck for both protocols is the time required to successfully access the control channel, which occurs more frequently for the switching MAC protocol. We also propose a user clustering approach, where users are divided into clusters with a separate control channel per cluster, and observe that it can significantly improve the performance by reducing the number of competing users per control channel. I.
Impact of Control Channel Design on Cooperative Spectrum Sensing in Opportunistic Spectrum Access Networks
"... Abstract—In Opportunistic Spectrum Access (OSA) networks, Secondary unlicensed Users (SUs) need a common Control Channel (CC) to identify the spectrum opportunities, i.e., com-mon spectrum holes unused by licensed Primary Users (PUs). Typically, an interference-free CC is unrealistically assumed in ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—In Opportunistic Spectrum Access (OSA) networks, Secondary unlicensed Users (SUs) need a common Control Channel (CC) to identify the spectrum opportunities, i.e., com-mon spectrum holes unused by licensed Primary Users (PUs). Typically, an interference-free CC is unrealistically assumed in the literature. In this paper we evaluate the impact of the availability and the characteristics of the CC on the performance of cooperative spectrum sensing. We deal with the dimensioning of an underlay Ultra-wideband (UWB) signalling network for the exchange of sensing data among secondary Cognitive Radio (CR) nodes avoiding harmful interference to PUs. To this aim, we analyse the trade-off between the connectivity degree of a multi-hop underlay UWB signalling network, directly related to the possibility to perform cooperative sensing, and its coexistence with PUs. It is observed that the correct dimensioning of the UWB signalling network allows to achieve high accuracy of PU detection without compromising primary systems.
1 Throughput and Collision Analysis of Multi-Channel Multi-Stage Spectrum Sensing Algorithms
"... ar ..."
(Show Context)
1 When Channel Bonding is Beneficial for Opportunistic Spectrum Access Networks
"... ar ..."
(Show Context)
Les Cahiers du GERAD ISSN: 0711–2440 Delay analysis of multichannel opportunistic spectrum access
, 2014
"... Les textes publiés dans la série des rapports de recherche Les Cahiers du GERAD n’engagent que la responsabilite ́ de leurs auteurs. La publication de ces rapports de recherche est rendue possible grâce au soutien de HEC Montréal, Polytechnique Montréal, Universite ́ McGill, Universite ́ du Que ..."
Abstract
- Add to MetaCart
(Show Context)
Les textes publiés dans la série des rapports de recherche Les Cahiers du GERAD n’engagent que la responsabilite ́ de leurs auteurs. La publication de ces rapports de recherche est rendue possible grâce au soutien de HEC Montréal, Polytechnique Montréal, Universite ́ McGill, Universite ́ du Québec a ̀ Montréal, ainsi que du Fonds de recherche du Québec – Nature et technologies. Dépôt légal – Bibliothèque et Archives nationales du Québec, 2014. The authors are exclusively responsible for the content of their research papers published in the series Les Cahiers du GERAD. The publication of these research reports is made possi-ble thanks to the support of HEC Montréal, Polytechnique Montréal, McGill University, Universite ́ du Québec a ̀ Montréal, as well as the Fonds de recherche du Québec – Nature et tech-nologies. Legal deposit – Bibliothèque et Archives nationales du Québec,
