66 research outputs found
Optimal Scanning Bandwidth Strategy Incorporating Uncertainty about Adversary's Characteristics
In this paper we investigate the problem of designing a spectrum scanning
strategy to detect an intelligent Invader who wants to utilize spectrum
undetected for his/her unapproved purposes. To deal with this problem we model
the situation as two games, between a Scanner and an Invader, and solve them
sequentially. The first game is formulated to design the optimal (in maxmin
sense) scanning algorithm, while the second one allows one to find the optimal
values of the parameters for the algorithm depending on parameters of the
network. These games provide solutions for two dilemmas that the rivals face.
The Invader's dilemma consists of the following: the more bandwidth the Invader
attempts to use leads to a larger payoff if he is not detected, but at the same
time also increases the probability of being detected and thus fined.
Similarly, the Scanner faces a dilemma: the wider the bandwidth scanned, the
higher the probability of detecting the Invader, but at the expense of
increasing the cost of building the scanning system. The equilibrium strategies
are found explicitly and reveal interesting properties. In particular, we have
found a discontinuous dependence of the equilibrium strategies on the network
parameters, fine and the type of the Invader's award. This discontinuity of the
fine means that the network provider has to take into account a human/social
factor since some threshold values of fine could be very sensible for the
Invader, while in other situations simply increasing the fine has minimal
deterrence impact. Also we show how incomplete information about the Invader's
technical characteristics and reward (e.g. motivated by using different type of
application, say, video-streaming or downloading files) can be incorporated
into scanning strategy to increase its efficiency.Comment: This is the last draft version of the paper. Revised version of the
paper was published in EAI Endorsed Transactions on Mobile Communications and
Applications, Vol. 14, Issue 5, 2014, doi=10.4108/mca.2.5.e6. arXiv admin
note: substantial text overlap with arXiv:1310.724
Coordinated Dynamic Spectrum Management of LTE-U and Wi-Fi Networks
This paper investigates the co-existence of Wi-Fi and LTE in emerging
unlicensed frequency bands which are intended to accommodate multiple radio
access technologies. Wi-Fi and LTE are the two most prominent access
technologies being deployed today, motivating further study of the inter-system
interference arising in such shared spectrum scenarios as well as possible
techniques for enabling improved co-existence. An analytical model for
evaluating the baseline performance of co-existing Wi-Fi and LTE is developed
and used to obtain baseline performance measures. The results show that both
Wi-Fi and LTE networks cause significant interference to each other and that
the degradation is dependent on a number of factors such as power levels and
physical topology. The model-based results are partially validated via
experimental evaluations using USRP based SDR platforms on the ORBIT testbed.
Further, inter-network coordination with logically centralized radio resource
management across Wi-Fi and LTE systems is proposed as a possible solution for
improved co-existence. Numerical results are presented showing significant
gains in both Wi-Fi and LTE performance with the proposed inter-network
coordination approach.Comment: Accepted paper at IEEE DySPAN 201
The role of Signal Processing in Meeting Privacy Challenges [an overview]
International audienceWith the increasing growth and sophistication of information technology, personal information is easily accessible electronically. This flood of released personal data raises important privacy concerns. However, electronic data sources exist to be used and have tremendous value (utility) to their users and collectors, leading to a tension between privacy and utility. This article aims to quantify that tension by means of an information-theoretic framework and motivate signal processing approaches to privacy problems. The framework is applied to a number of case studies to illustrate concretely how signal processing can be harnessed to provide data privacy
Jamming Sensor Networks: Attack and Defense Strategies
Wireless sensor networks are built upon a shared medium that makes it easy for adversaries to conduct radio interference, or jamming, attacks that effectively cause a denial of service of either transmission or reception functionalities. These attacks can easily be accomplished by an adversary by either bypassing MAC-layer protocols or emitting a radio signal targeted at jamming a particular channel. In this article we survey different jamming attacks that may be employed against a sensor network. In order to cope with the problem of jamming, we discuss a two-phase strategy involving the diagnosis of the attack, followed by a suitable defense strategy. We highlight the challenges associated with detecting jamming. To cope with jamming, we propose two different but complementary approaches. One approach is to simply retreat from the interferer, which may be accomplished by either spectral evasion (channel surfing) or spatial evasion (spatial retreats). The second approach aims to compete more actively with the interferer by adjusting resources, such as power levels and communication coding, to achieve communication in the presence of the jammer
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