The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Sang-yoon Chang - One of the best experts on this subject based on the ideXlab platform.
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securemac securing Wireless Medium access control against insider denial of service attacks
IEEE Transactions on Mobile Computing, 2017Co-Authors: Sang-yoon ChangAbstract:Wireless network dynamically allocates channel resources to improve spectral efficiency and, to avoid collisions, has its users cooperate with each other using a Medium access control (MAC) protocol. However, MAC assumes user compliance and can be detrimental when a user misbehaves. An attacker who compromised the network can launch more devastating denial-of-service (DoS) attacks than a network outsider by sending excessive reservation requests to waste bandwidth, by listening to the control messages and conducting power-efficient jamming, by falsifying information to manipulate the network control, and so on. We build SecureMAC to defend against such insider threats while retaining the benefits of coordination between the cooperative users. SecureMAC is comprised of four components: channelization to prevent excessive reservations, randomization to thwart reactive targeted jamming, coordination to counter control-message aware jamming and resolve over-reserved and under-reserved spectrum, and power attribution to determine each node's contribution to the received power. Our theoretical analyses and implementation evaluations demonstrate superior performance over previous approaches, which either ignore security issues or give up the benefit of cooperation when under attack by disabling user coordination (such as the Nash equilibrium of continuous wideband transmission). In realistic scenarios, our SecureMAC implementation outperforms such schemes by 76-159 percent.
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Securing Wireless Medium Access Control Against Insider Denial-of-Service Attackers
2016Co-Authors: Sang-yoon Chang, Zhuotao LiuAbstract:Abstract—In a Wireless network, users share a limited resource in bandwidth. To improve spectral efficiency, the network dynam-ically allocates channel resources and, to avoid collisions, has its users cooperate with each other using a Medium access control (MAC) protocol. In a MAC protocol, the users exchange control messages to establish more efficient data communication, but such MAC assumes user compliance and can be detrimental when a user misbehaves. An attacker who compromised the network can launch a two-pronged denial-of-service (DoS) attack that is more devastating than an outsider attack: first, it can send excessive reservation requests to waste bandwidth, and second, it can focus its power on jamming those channels that it has not reserved. Furthermore, the attacker can falsify information to skew the network control decisions to its favor. To defend against such insider threats, we propose a resource-based channel access scheme that holds the attacker account-able for its channel reservation. Building on the randomization technology of spread spectrum to thwart outsider jamming, our solution comprises of a bandwidth allocation component to nullify excessive reservations, bandwidth coordination to resolve over-reserved and under-reserved spectrum, and power attribution to determine each node’s contribution to the received power. We an-alyze our scheme theoretically and validate it with WARP-based testbed implementation and MATLAB simulations. Our results demonstrate superior performance over the typical solutions that bypass MAC control when faced against insider adversary, and our scheme effectively nullifies the insider attacker threats while retaining the MAC benefits between the collaborative users. I
Nitin H Vaidya - One of the best experts on this subject based on the ideXlab platform.
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token dcf an opportunistic mac protocol for Wireless networks
arXiv: Networking and Internet Architecture, 2012Co-Authors: Ghazale Hosseinabadi, Nitin H VaidyaAbstract:IEEE 802.11 DCF is the MAC protocol currently used in Wireless LANs. 802.11 DCF is inefficient due to two types of overhead; channel idle time and collision time. This paper presents the design and performance evaluation of an efficient MAC protocol for Wireless networks, called Token-DCF. Token-DCF decreases both idle time and collision time. In Token-DCF, each station keeps track of neighboring links' queue length by overhearing of transmitted packets on the Wireless Medium. The result is then used to assign privileges to the network stations. A privileged station does not follow the backoff mechanism and transmits immediately after the channel is sensed idle. Our simulation results show that Token-DCF can significantly improve channel utilization, system throughput and channel access delay over 802.11 DCF.
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explicit and implicit pipelining for Wireless Medium access control
Vehicular Technology Conference, 2003Co-Authors: Xue Yang, Nitin H VaidyaAbstract:In Wireless networks, multiple stations contend for access to the shared channel. In the cases of collisions, the associated collision cost is much higher than wired networks since stations cannot detect the collision without explicit feedback from the receiver. For this reason, more efficient contention resolution algorithms are desired for Wireless networks to reduce the collision probability among backlogged stations. With distributed multiple access control, each station usually goes through a contention resolution stage before initiating its transmission. As contention resolution stage consumes channel bandwidth without producing any goodput, ideally, we desire it to be as short as possible while reducing the possibility of collisions to as small as possible. However, in general, it is difficult to achieve an optimum tradeoff between these two desired features. In this paper, we propose to use pipelining techniques to resolve such conflicts and improve the performance of multiple access control in terms of channel utilization. We discuss several pipelining MAC schemes and present their advantages and disadvantages accordingly.
John O. Limb - One of the best experts on this subject based on the ideXlab platform.
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Wireless Medium access control protocols
IEEE Communications Surveys & Tutorials, 2000Co-Authors: Ajay Chandra V. Gummalla, John O. LimbAbstract:Technological advances, coupled with the flexibility and mobility of Wireless systems, are the driving force behind the Anyone, Anywhere, Anytime paradigm of networking. At the same time, we see a convergence of the telephone, cable and data networks into a unified network that supports multimedia and real-time applications like voice and video in addition to data. Medium access control protocols define rules for orderly access to the shared Medium and play a crucial role in the efficient and fair sharing of scarce Wireless bandwidth. The nature of the Wireless channel brings new issues like location-dependent carrier sensing, time varying channel and burst errors. Low power requirements and half duplex operation of the Wireless systems add to the challenge. Wireless MAC protocols have been heavily researched and a plethora of protocols have been proposed. Protocols have been devised for different types of architectures, different applications and different media. This survey discusses the challenges in the design of Wireless MAC protocols, classifies them based on architecture and mode of operation, and describes their relative performance and application domains in which they are best deployed.
Eduardo Tovar - One of the best experts on this subject based on the ideXlab platform.
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WiDom: A Dominance Protocol for Wireless Medium Access
IEEE Transactions on Industrial Informatics, 2007Co-Authors: Nuno Pereira, Björn Andersson, Eduardo TovarAbstract:Wireless networks play an increasingly important role in application areas such as factory-floor automation, process control, and automotive electronics. In this paper, we address the problem of sharing a Wireless channel among a set of sporadic message streams where a message stream issues transmission requests with real-time deadlines. For this problem, we propose a collision-free Wireless Medium access control (MAC) protocol, which implements static-priority scheduling and supports a large number of priority levels. The MAC protocol allows multiple masters and is fully distributed; it is an adaptation to a Wireless channel of the dominance protocol used in the CAN bus, a proven communication technology for various industrial applications. However, unlike that protocol, our protocol does not require a node having the ability to receive an incoming bit from the channel while transmitting to the channel. The evaluation of the protocol with real embedded computing platforms is presented to show that the proposed protocol is in fact collision-free and prioritized. We measure the response times of our implementation and find that the response-time analysis developed for the protocol indeed offers an upper bound on the response times
Yang Xiao - One of the best experts on this subject based on the ideXlab platform.
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robust medical ad hoc sensor networks masn with wavelet based ecg data mining
Ad Hoc Networks, 2008Co-Authors: Meng Jiang, Laura Celentano, Yang XiaoAbstract:Heart disease is the top elder killer in the world. To reduce the healthcare cost, it is a necessary tendency to deploy self-organized, Wireless heart disease monitoring hardware/software systems. Telemedicine platform based on ad hoc interconnection of tiny ECG sensors, called medical ad hoc sensor networks (MASN), can provide a promising approach for performing low-cost, real-time, remote cardiac patient monitoring at any time. The contribution of this research is the design of a practical MASN hardware/software platform to perform real-time healthcare data collections. It has reliable, cluster-based communication scheme. Due to the radio broadcasting nature of Wireless networks, a MASN has the risk of being attacked. This research also designs a low overhead medical security scheme to achieve confidential ECG data transmission in the Wireless Medium. Finally, our MASN system has the capability of keeping track of cardiac patients and extracting ECG features based on wavelet theories. Our MASN platform is very useful to practical medical monitoring applications.
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performance analysis of priority schemes for ieee 802 11 and ieee 802 11e Wireless lans
IEEE Transactions on Wireless Communications, 2005Co-Authors: Yang XiaoAbstract:The IEEE 802.11 distributed coordination function (DCF) enables fast installation with minimal management and maintenance costs, and is a very robust protocol for the best effort service in Wireless Medium. However, the current DCF is unsuitable for real-time applications. This paper studies backoff-based priority schemes for IEEE 802.11 and the emerging IEEE 802.11e standard by differentiating the minimum backoff window size, the backoff window-increasing factor, and the retransmission limit. An analytical model is proposed to derive saturation throughputs, saturation delays, and frame-dropping probabilities of different priority classes for all proposed priority schemes. Simulations are conducted to validate analytical results. The proposed priority schemes can be easily implemented, and the results from this paper are beneficial in designing good priority parameters.
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protection and guarantee for voice and video traffic in ieee 802 11e Wireless lans
International Conference on Computer Communications, 2004Co-Authors: Yang Xiao, Sunghyun ChoiAbstract:In order to support multimedia applications such as voice and video over the Wireless Medium, a contention-based channel access function, called enhanced distributed coordination function (EDCF), is being developed in the emerging standard IEEE 802.11e. In EDCF, differentiated services are provided for different traffic classes. In this paper, we propose a two-level protection and guarantee mechanism for voice and video traffic in IEEE 802.11e Wireless LANs. In the first-level protection, the existing voice and video flows are protected from the new and other existing voice and video flows. In the second-level protection, the voice and video flows are protected from the best-effort data traffic. For each protection level, a couple of protection mechanisms are proposed. Extensive simulation results show that the proposed two-level protection and guarantee mechanism is very effective in terms of protecting and guaranteeing existing voice and video flows as well as fully utilizing the channel capacity
