677 research outputs found
On the Security of the Automatic Dependent Surveillance-Broadcast Protocol
Automatic dependent surveillance-broadcast (ADS-B) is the communications
protocol currently being rolled out as part of next generation air
transportation systems. As the heart of modern air traffic control, it will
play an essential role in the protection of two billion passengers per year,
besides being crucial to many other interest groups in aviation. The inherent
lack of security measures in the ADS-B protocol has long been a topic in both
the aviation circles and in the academic community. Due to recently published
proof-of-concept attacks, the topic is becoming ever more pressing, especially
with the deadline for mandatory implementation in most airspaces fast
approaching.
This survey first summarizes the attacks and problems that have been reported
in relation to ADS-B security. Thereafter, it surveys both the theoretical and
practical efforts which have been previously conducted concerning these issues,
including possible countermeasures. In addition, the survey seeks to go beyond
the current state of the art and gives a detailed assessment of security
measures which have been developed more generally for related wireless networks
such as sensor networks and vehicular ad hoc networks, including a taxonomy of
all considered approaches.Comment: Survey, 22 Pages, 21 Figure
REBUF: Jam Resistant BBC based Uncoordinated Frequency Division
One of the central tenants of information security is availability. One common form of attack against the availability of information in wireless networks is jamming. Currently, the most common techniques to provide jam-resistant communication, such as frequency-hopping spread spectrum (FHSS), are based on the use of a symmetric shared secret. However, there are theoretical approaches to jam resistance without a pre-shared secret. One theoretical approach using concurrent codes, called the BBC algorithm, was developed at the United States Air Force Academy.
We developed and tested the effectiveness of REBUF, a Jam Resistant BBC based Uncoordinated Frequency Division Multiplexing (FDM) system. REBUF is the first known implementation of the BBC algorithm in a simultaneous frequency division multiplexing system. The contributions of this paper include: demonstrating the practical use of a BBC based FDM system, the ability of such a system to jam traditional orthogonal frequency division multiplexing (OFDM) systems, and the resilience of such a system to some common forms of jamming
Goodbye, ALOHA!
©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The vision of the Internet of Things (IoT) to interconnect and Internet-connect everyday people, objects, and machines poses new challenges in the design of wireless communication networks. The design of medium access control (MAC) protocols has been traditionally an intense area of research due to their high impact on the overall performance of wireless communications. The majority of research activities in this field deal with different variations of protocols somehow based on ALOHA, either with or without listen before talk, i.e., carrier sensing multiple access. These protocols operate well under low traffic loads and low number of simultaneous devices. However, they suffer from congestion as the traffic load and the number of devices increase. For this reason, unless revisited, the MAC layer can become a bottleneck for the success of the IoT. In this paper, we provide an overview of the existing MAC solutions for the IoT, describing current limitations and envisioned challenges for the near future. Motivated by those, we identify a family of simple algorithms based on distributed queueing (DQ), which can operate for an infinite number of devices generating any traffic load and pattern. A description of the DQ mechanism is provided and most relevant existing studies of DQ applied in different scenarios are described in this paper. In addition, we provide a novel performance evaluation of DQ when applied for the IoT. Finally, a description of the very first demo of DQ for its use in the IoT is also included in this paper.Peer ReviewedPostprint (author's final draft
Uncoordinated access schemes for the IoT: approaches, regulations, and performance
Internet of Things (IoT) devices communicate using a variety of protocols,
differing in many aspects, with the channel access method being one of the most
important. Most of the transmission technologies explicitly designed for IoT
and Machine-to-Machine (M2M) communication use either an ALOHA-based channel
access or some type of Listen Before Talk (LBT) strategy, based on carrier
sensing. In this paper, we provide a comparative overview of the uncoordinated
channel access methods for IoT technologies, namely ALOHA-based and LBT
schemes, in relation with the ETSI and FCC regulatory frameworks. Furthermore,
we provide a performance comparison of these access schemes, both in terms of
successful transmissions and energy efficiency, in a typical IoT deployment.
Results show that LBT is effective in reducing inter-node interference even for
long-range transmissions, though the energy efficiency can be lower than that
provided by ALOHA methods. The adoption of rate-adaptation schemes,
furthermore, lowers the energy consumption while improving the fairness among
nodes at different distances from the receiver. Coexistence issues are also
investigated, showing that in massive deployments LBT is severely affected by
the presence of ALOHA devices in the same area
Secret Key Generation in Rayleigh Block Fading AWGN Channels under Jamming Attacks
Jamming attacks have been shown to disrupt secret key generation (SKG) in systems that exploit the reciprocity of the wireless medium to generate symmetric keys at two remote locations through public discussion. In this study, the use of frequency hopping/spreading in Rayleigh block fading additive white Gaussian noise (BF-AWGN) channels is investigated as a means to counteract such attacks. The competitive interaction between a pair of legitimate users and a jammer is formulated as a zero-sum game and the corresponding Nash equilibria (NE) are characterized analytically and in closed form. It is found that the jammer's optimal strategy is to spread its power across the entire spectrum. On the contrary, the pair of legitimate users should use frequency spreading only in favorable transmission conditions, and frequency hopping otherwise (e.g., low signal to jamming power ratio). Numerical results show that frequency hopping/spreading in BF-AWGN channels is an effective technique for combating jamming attacks in SKG systems; a modest increase of the system bandwidth can substantially increase the SKG rates
On adaptive frequency hopping to combat coexistence interference between bluetooth and IEEE 802.11b with practical resource constraints
In contrast to traditional frequency hopping techniques, Adaptive Frequency Hopping (AFH) is a low cost and low power solution to avoid interference dynamically. While each AFH algorithm proposed previously is shown to be efficient, a detailed performance analysis of various AFH mechanisms under realistic resource constraints is yet to be done. In particular, based on our performance study on Bluetooth systems presented in this paper, we have found that the AFH mechanism adopted by IEEE 802.15 Task Group 2 (TG2) is very sensitive to memory and power limitations. We then propose a novel Interference Source Oriented Adaptive Frequency Hopping (ISOAFH) approach based on a cross-layer design, in which the baseband layer of Bluetooth considers not only the instantaneous channels condition but also the physical layer transmission characteristics of potential interference sources in determining the hop sequence. In our simulations using detailed MATLAB Simulink modeling, we find that our proposed method is much more robust in that it is insensitive to memory and energy constraints. Indeed, our approach generally achieves a lower collision rate and higher ISM spectrum utilization.published_or_final_versio
Interference Mitigation in Frequency Hopping Ad Hoc Networks
Radio systems today exhibit a degree of flexibility that was unheard of only a few years ago. Software-defined radio architectures have emerged that are able to service large swathes of spectrum, covering up to several GHz in the UHF bands. This dissertation investigates interference mitigation techniques in frequency hopping ad hoc networks that are capable of exploiting the frequency agility of software-defined radio platforms
Survey of Spectrum Sharing for Inter-Technology Coexistence
Increasing capacity demands in emerging wireless technologies are expected to
be met by network densification and spectrum bands open to multiple
technologies. These will, in turn, increase the level of interference and also
result in more complex inter-technology interactions, which will need to be
managed through spectrum sharing mechanisms. Consequently, novel spectrum
sharing mechanisms should be designed to allow spectrum access for multiple
technologies, while efficiently utilizing the spectrum resources overall.
Importantly, it is not trivial to design such efficient mechanisms, not only
due to technical aspects, but also due to regulatory and business model
constraints. In this survey we address spectrum sharing mechanisms for wireless
inter-technology coexistence by means of a technology circle that incorporates
in a unified, system-level view the technical and non-technical aspects. We
thus systematically explore the spectrum sharing design space consisting of
parameters at different layers. Using this framework, we present a literature
review on inter-technology coexistence with a focus on wireless technologies
with equal spectrum access rights, i.e. (i) primary/primary, (ii)
secondary/secondary, and (iii) technologies operating in a spectrum commons.
Moreover, we reflect on our literature review to identify possible spectrum
sharing design solutions and performance evaluation approaches useful for
future coexistence cases. Finally, we discuss spectrum sharing design
challenges and suggest future research directions
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