Results 1 - 10
of
10
Secure Cooperative Sensing in IEEE 802.22 WRANs Using Shadow Fading Correlation
- IEEE Trans. Mobile Computing
, 2011
"... Abstract—Cooperative (or distributed) sensing has been recognized as a viable means to enhance the incumbent signal detection by exploiting the diversity of sensors. However, it is challenging to secure such distributed sensing due mainly to the unique features of dynamic spectrum access networks—op ..."
Abstract
-
Cited by 13 (4 self)
- Add to MetaCart
(Show Context)
Abstract—Cooperative (or distributed) sensing has been recognized as a viable means to enhance the incumbent signal detection by exploiting the diversity of sensors. However, it is challenging to secure such distributed sensing due mainly to the unique features of dynamic spectrum access networks—openness of low-layer protocol stacks in software-defined radio devices and the absence of interactions/coordination between primary and secondary devices. To meet this challenge, we propose an attack-tolerant distributed sensing protocol (ADSP) for DTV signal detection in IEEE 802.22 WRANs, under which sensors in close proximity are grouped as a cluster, and sensors within a cluster cooperate to safeguard the integrity of sensing. The heart of ADSP is a novel filter based on shadow-fading correlation, by which the fusion center cross-validates reports from the sensors to identify and penalize abnormal sensing reports. By realizing this correlation filter, ADSP significantly reduces the impact of an attack on the performance of distributed sensing, while incurring minimal processing and communication overheads. ADSP also guarantees the detectability requirements of 802.22 to be met even with the presence of sensing report manipulation attacks by scheduling sensing within the framework of sequential hypothesis testing. The efficacy of ADSP is validated on a realistic 2D shadow-fading field. Our extensive simulation-based study shows that ADSP reduces the false-alarm rate by 99.2 percent while achieving 97.4 percent of maximum achievable detection rate, and meets the detection requirements of IEEE 802.22 in various attack scenarios. Index Terms—Cognitive radio, cooperative sensing, shadowing correlation, attack tolerance, IEEE 802.22, sensing scheduling. Ç 1
Euclidean Traveling Salesman Tours through Stochastic Neighborhoods
"... Abstract. We consider the problem of planning a shortest tour through a collection of neighborhoods in the plane, where each neighborhood is a disk whose radius is an i.i.d. random variable drawn from a known probability distribution. This is a stochastic version of the classic travel-ing salesman p ..."
Abstract
-
Cited by 2 (0 self)
- Add to MetaCart
(Show Context)
Abstract. We consider the problem of planning a shortest tour through a collection of neighborhoods in the plane, where each neighborhood is a disk whose radius is an i.i.d. random variable drawn from a known probability distribution. This is a stochastic version of the classic travel-ing salesman problem with neighborhoods (TSPN). Planning such tours under uncertainty, a fundamental problem in its own right, is motivated by a number of applications including the following data gathering prob-lem in sensor networks: a robotic data mule needs to collect data from n geographically distributed wireless sensor nodes whose communication range r is a random variable influenced by environmental factors. We propose a polynomial-time algorithm that achieves a factorO(log log n) approximation of the expected length of an optimal tour. In data mule applications, the problem has an additional complexity: the radii of the disks are only revealed when the robot reaches the disk boundary (trans-mission success). For this online version of the stochastic TSPN, we achieve an approximation ratio of O(log n). In the special case, where the disks with their mean radii are disjoint, we achieve an O(1) approx-imation even for the online case. 1
Modeling low-power wireless communications
, 2015
"... Low-power wireless communications have particular characteristics that highly affect the performance of network protocols. However, many of these essential characteristics have not been considered in the existing simulation platforms and analytical performance evaluation models. While this issue i ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
Low-power wireless communications have particular characteristics that highly affect the performance of network protocols. However, many of these essential characteristics have not been considered in the existing simulation platforms and analytical performance evaluation models. While this issue invalidates many of the reported evaluation results, it also impedes pre-deployment performance prediction and parameter adjustment. Accordingly, this paper studies, analyzes and proposes models for accurate modeling of low-power wireless communications. Our contributions are six-fold. First, we investigate the essential characteristics of low-power wireless transceivers. Second, we present a classified and detailed study on modeling signal propagation, noise floor, system variations and interference. Third, we highlight the importance and effects of system variations and radio regularity on the real applications of wireless sensor networks. Fourth, we reveal the inaccuracy of the packet reception algorithms used in the existing simulators. Furthermore, we propose an improved packet reception algorithm and we confirm its accuracy through comparison with empirical results. Fifth, we propose an architecture to integrate and implement the models presented in this paper. Finally, we show that the transitional
Simulation Evaluation Accuracy
, 2014
"... Implementation a b s t r a c t Low-power wireless communications have particular characteristics that highly affect the performance of network protocols. However, many of these essential characteristics have not been considered in the existing simulation platforms and analytical performance evaluati ..."
Abstract
- Add to MetaCart
Implementation a b s t r a c t Low-power wireless communications have particular characteristics that highly affect the performance of network protocols. However, many of these essential characteristics have not been considered in the existing simulation platforms and analytical performance evaluation models. While this issue invalidates many of the reported evaluation results, it also impedes pre-deployment performance prediction and parameter adjustment. Accordingly, this paper studies, analyzes and proposes models for accurate modeling of low-power wireless communications. Our contributions are six-fold. First, we investigate the essential characteristics of low-power wireless transceivers. Second, we present a classified and detailed study on modeling signal propagation, noise floor, system variations and interference. Third, we highlight the importance and effects of system variations and radio regularity on the real applications of wireless sensor networks. Fourth, we reveal the inaccuracy of the packet reception algorithms used in the existing simulators. Furthermore, we propose an improved packet reception algorithm and we confirm its accuracy through comparison with empirical results. Fifth, we propose an architecture to integrate and implement the models presented in this paper. Finally, we show that the transitional
Connectivity of multihop wireless networks with log-normal shadowing
"... Abstract In this paper, we study the connectivity of multihop wireless networks with the log-normal shadowing model by investigating the critical transmission power re-quired by each node for asymptotic vanishing of the isolated nodes, and the precise distribution of the number of isolated nodes. Th ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract In this paper, we study the connectivity of multihop wireless networks with the log-normal shadowing model by investigating the critical transmission power re-quired by each node for asymptotic vanishing of the isolated nodes, and the precise distribution of the number of isolated nodes. The vanishing of isolated nodes is not only a pre-requisite but also a good indication of network connectivity. Most of the known works on network connectivity under such a shadowing model were obtained only based on simulation studies or ignoring the important boundary ef-fect to avoid the challenging technical analysis, and thus hardly applied to practical wireless networks. It is ex-tremely challenging to take the complicated boundary effect into consideration under such a realistic shadowing model because the transmission area of each node is an irregular region other than a circular area. Assume the wireless nodes are represented by a Poisson point process with density n over a unit-area disk. With the boundary effect taken into consideration, we first obtain an explicit formula for the expected number of isolated nodes, we then derive an upper and a lower bounds of the critical transmission power for asymptotic vanishing of the isolated nodes. The tightness of the upper and lower bounds for the critical transmission power are analyzed via numerical analysis by using the software engineering approach. When a wireless network consists of n nodes distributed independently and uniformly over a unit-area disk, we derive the precise distribution of the number of the isolated nodes under such a realistic shadowing model with the linear power assignment, taking the boundary effect into consideration.
1 An Efficient Clustering Algorithm for Device-to-Device Assisted Virtual MIMO
"... ar ..."
(Show Context)
Efficient and Robust Spectrum Management for Cognitive Radio Networks
"... The recent advent of cognitive radio (CR) technology has potential for making a significant improvement in spectrum efficiency by allowing secondary (unlicensed) devices or users (SUs) to opportunistically utilize unused portions of the licensed spectrum bands. Such opportunistic spectrum access has ..."
Abstract
- Add to MetaCart
The recent advent of cognitive radio (CR) technology has potential for making a significant improvement in spectrum efficiency by allowing secondary (unlicensed) devices or users (SUs) to opportunistically utilize unused portions of the licensed spectrum bands. Such opportunistic spectrum access has drawn considerable attention for its ability to alleviate the spectrum scarcity problem that we may soon face due to the rapid increase in wireless spectrum demand and also due to the inefficiency of the current static spectrum-allocation policies. We identify and address two main challenges that hinder the realization of dynamic spectrum access (DSA): (i) primary users’ (PUs’) fear of interference that can lead to potential loss of customers, and (ii) lack of economic incentives to PUs for spectrum sharing. We provide novel approaches and comprehensive solutions to these challenges to fully exploit the benefits of DSA. In order to meet these challenges from a comprehensive perspective, we first address the problem of detecting large-scale primary signals (e.g., TV signals) and present a frame-work that minimizes the sensing overhead while achieving the detectability requirements
RESEARCH Open Access
"... Multi-antenna spectrum sensing by exploiting spatio-temporal correlation Sadiq Ali1,2*, David Ramírez3, Magnus Jansson4, Gonzalo Seco-Granados1 and José A López-Salcedo1 In this paper, we propose a novel mechanism for spectrum sensing that leads us to exploit the spatio-temporal correlation present ..."
Abstract
- Add to MetaCart
(Show Context)
Multi-antenna spectrum sensing by exploiting spatio-temporal correlation Sadiq Ali1,2*, David Ramírez3, Magnus Jansson4, Gonzalo Seco-Granados1 and José A López-Salcedo1 In this paper, we propose a novel mechanism for spectrum sensing that leads us to exploit the spatio-temporal correlation present in the received signal at a multi-antenna receiver. For the proposed mechanism, we formulate the spectrum sensing scheme by adopting the generalized likelihood ratio test (GLRT). However, the GLRT degenerates in the case of limited sample support. To circumvent this problem, several extensions are proposed that bring robustness to the GLRT in the case of high dimensionality and small sample size. In order to achieve these sample-efficient detection schemes, we modify the GLRT-based detector by exploiting the covariance structure and factoring the large spatio-temporal covariance matrix into spatial and temporal covariance matrices. The performance of the proposed detectors is evaluated by means of numerical simulations, showing important advantages over existing detectors.
1Secure Cooperative Sensing in IEEE 802.22 WRANs Using Shadow Fading Correlation
"... Abstract—Cooperative (or distributed) sensing has been recognized as a viable means to enhance the incumbent signal detection by exploiting the diversity of sensors. However, it is challenging to secure such distributed sensing due mainly to the unique features of dynamic spectrum access networks—op ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—Cooperative (or distributed) sensing has been recognized as a viable means to enhance the incumbent signal detection by exploiting the diversity of sensors. However, it is challenging to secure such distributed sensing due mainly to the unique features of dynamic spectrum access networks—openness of low-layer protocol stacks in software-defined radio devices and the absence of interactions/coordination between primary and secondary devices. To meet this challenge, we propose an attack-tolerant distributed sensing protocol (ADSP) for DTV signal detection in IEEE 802.22 WRANs, under which sensors in close proximity are grouped as a cluster, and sensors within a cluster cooperate to safeguard the integrity of sensing. The heart of ADSP is a novel filter based on shadow-fading correlation, by which the fusion center cross-validates reports from the sensors to identify and penalize abnormal sensing reports. By realizing this correlation filter, ADSP significantly reduces the impact of an attack on the performance of distributed sensing, while incurring minimal processing and communication overheads. ADSP also guarantees the detectability requirements of 802.22 to be met even with the presence of sensing report manipulation attacks by scheduling sensing within the framework of sequential hypothesis testing. The efficacy of ADSP is validated on a realistic two-dimensional shadow-fading field. Our extensive simulation-based study shows that ADSP reduces the false-alarm rate by 99.2 % while achieving 97.4 % of maximum achievable detection rate, and meets the detection requirements of IEEE 802.22 in various attack scenarios. Index Terms—Cognitive radio, cooperative sensing, shadowing correlation, attack tolerance, IEEE 802.22, sensing scheduling. 1
EFFICIENT AND SECURE NETWORK SERVICES IN WIRELESS SENSOR NETWORKS
, 2009
"... First of all, I would like to express my gratitude to my advisor, Professor Kang G. Shin. Without his continuous guidance and encouragement, I could never have completed my dissertation. I would also like to thank my other committee members, Professors Atul Prakash, Sugih Jamin, and Mingyan Liu. Tha ..."
Abstract
- Add to MetaCart
(Show Context)
First of all, I would like to express my gratitude to my advisor, Professor Kang G. Shin. Without his continuous guidance and encouragement, I could never have completed my dissertation. I would also like to thank my other committee members, Professors Atul Prakash, Sugih Jamin, and Mingyan Liu. Thanks to their invaluable comments, I could significantly improve the quality of my dissertation. I thank great colleagues at the Real-Time Computing Laboratory including Songkuk
