A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends

This paper examines the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient defense mechanisms for improving the wireless network security. We first summarize the security requirements of wireless networks, including their authenticity, confidentiality, integrity and availability issues. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provide a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term evolution (LTE) systems. Then, we discuss the state-of-the-art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. We also introduce the family of various jamming attacks and their counter-measures, including the constant jammer, intermittent jammer, reactive jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, some technical challenges which remain unresolved at the time of writing are summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201

Adaptive Multi-Channel Offset Assignment for Reliable IEEE 802.15.4 TSCH Networks

International audienceMore and more IoT applications require low-power operations and high reliability (close to 100%). Unfortunately, radio transmissions are unreliable by nature since they are prone to collision and external interference. The IEEE 802.15.4-2015 TSCH standard has been recently proposed to provide high-reliability through radio channel hopping and by appropriately scheduling all the transmissions. Since some of the radio channels still suffer from external interference, blacklisting techniques consist in detecting bad radio channels, and in privileging the good ones to transmit the packets. MABO-TSCH is a centralized scheduling algorithm which allocates several channel offsets to allow each radio link to apply a localized blacklist. However, such strategy is inefficient for large blacklists. In this study, we propose to allocate the channel offsets dynamically at each timeslot according to the number of parallel transmissions, while still avoiding collisions. We evaluate the performance of our solution relying on a real experimental dataset, highlighting the relevance of dynamic and per timeslot channel offset assignment for environments with high external interference, such as a smart building

Frequency hopping in wireless sensor networks

Wireless sensor networks (WSNs) are nowadays being used to collectively gather and spread information in different kinds of applications, for military, civilian, environmental as well as commercial purposes. Therefore the proper functioning of WSNs under different kinds of environmental conditions, especially hostile environments, is a must and a lot of research currently ongoing. The problems related to the initialization and deployment of WSNs under harsh and resource limited conditions are investigated in this thesis. Frequency hopping (FH) is a spread spectrum technique in which multiple channels are used, or hoped, for communications across the network. This mitigates the worst effects of interference with frequency agile communication systems rather than by brute force approaches. FH is a promising technique for achieving the coexistence of sensor networks with other currently existing wireless systems, and it is successful within the somewhat limited computational capabilities of the sensor nodes hardware radios. In this thesis, a FH scheme for WSNs is implemented for a pair of nodes on an application layer. The merits and demerits of the scheme are studied for different kinds of WSN environments. The implementation has been done using a Sensinode NanoStack, a communication stack for internet protocol (IP) based wireless sensor networks and a Sensinode Devkit, for an IPv6 over low power wireless personal area network (6LoWPAN). The measurements are taken from the developed test bed and channel simulator for different kinds of scenarios. The detailed analysis of the FH scheme is done to determine its usefulness against interference from other wireless systems, especially wireless local area networks (WLANs), and the robustness of the scheme to combat fading or frequency selective fading

A Survey on the Communication Protocols and Security in Cognitive Radio Networks

A cognitive radio (CR) is a radio that can change its transmission parameters based on the perceived availability of the spectrum bands in its operating environment. CRs support dynamic spectrum access and can facilitate a secondary unlicensed user to efficiently utilize the available underutilized spectrum allocated to the primary licensed users. A cognitive radio network (CRN) is composed of both the secondary users with CR-enabled radios and the primary users whose radios need not be CR-enabled. Most of the active research conducted in the area of CRNs has been so far focused on spectrum sensing, allocation and sharing. There is no comprehensive review paper available on the strategies for medium access control (MAC), routing and transport layer protocols, and the appropriate representative solutions for CRNs. In this paper, we provide an exhaustive analysis of the various techniques/mechanisms that have been proposed in the literature for communication protocols (at the MAC, routing and transport layers), in the context of a CRN, as well as discuss in detail several security attacks that could be launched on CRNs and the countermeasure solutions that have been proposed to avoid or mitigate them. This paper would serve as a good comprehensive review and analysis of the strategies for MAC, routing and transport protocols and security issues for CRNs as well as would lay a strong foundation for someone to further delve onto any particular aspect in greater depth

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

A distributed approach to underwater acoustic communications

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2003A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically clustered in a distributed manner based on the estimated position of one-hop neighbor nodes within a shallow water environment. The spatial dynamic cellular clustering scheme allows scalable communication resource allocation and channel reuse similar in design to land-based cellular architectures, except devoid of the need for a centralized controlling infrastructure. Simulation results demonstrate that relatively high degrees of interference immunity, network connectivity, and network stability can be achieved despite the severe limitations of the underwater acoustic channel

Design of an Adaptive Frequency Hopping Algorithm Based On Probabilistic Channel Usage

Dealing with interference in the 2.4 GHz ISM band is of paramount importance due to an increase in the number of operating devices. For instance systems based on Bluetooth low energy technology are gaining lots of momentum due to their small size, reasonable cost and very low power consumptions. Thus the 2.4 GHz ISM band is becoming very hostile. Bluetooth specification enables the use of adaptive frequency hopping to improve performance in the presence of interference. This technique avoids the congested portions of the ISM band, however as the number of interferers increases for a given geographical environment, a greater number of bad channels are removed from the adapted hopping sequence. This results in longer channel occupancy, and consequently higher probability of collisions with coexisting devices, degrading their operation. At CoSa Research Group a novel algorithm, based on probabilistic channel usage of all channels (good and bad), is developed. The scheme is named Smooth Adaptive Frequency Hopping (SAFH) and uses an exponential smoothing filter to predict the conditions of the radio spectrum. Based on the predicted values, different usage probabilities are assigned to the channels, such as good channels are used more often than bad ones. The discrete probability distribution generated is then mapped to a set of frequencies, used for hopping. MATLAB/SIMULINK was used to investigate the performance of SAFH, in the presence of different types of interfering devices such as 802.11b , 802.15.4 and 802.15.1. Simulation study under different scenarios show, that our developed algorithm outperforms the conventional random frequency hopping as well as other adaptive hopping schemes. SAFH achieves lower average frame error rate and responds fast to changes in the channel conditions. Moreover it experiences smooth operation due to the exponential smoothing filter

Medium usage model for the design of dynamic spectrum management in ISM bands

This paper presents a new approach for dynamic spectrum management for heterogeneous wireless devices. Local congestion degrades the reliability of wireless applications in the License Exempt bands. This leads to the research questions: (1) how to realize equal spectrum sharing between dissimilar systems, and (2) how to improve the collective spectrum efficiency. A solution is in dynamic distribution of the available spectrum between contesting devices. Politeness mechanisms embedded in the individual devices are considered as building blocks for the creation of a distributed dynamic spectrum management system. Medium Usage defines the medium occupied by each transmitter and receiver. A regulatory view is chosen, favoring technology neutrality and including receiver parameters

A General Framework for Analyzing, Characterizing, and Implementing Spectrally Modulated, Spectrally Encoded Signals

Fourth generation (4G) communications will support many capabilities while providing universal, high speed access. One potential enabler for these capabilities is software defined radio (SDR). When controlled by cognitive radio (CR) principles, the required waveform diversity is achieved via a synergistic union called CR-based SDR. Research is rapidly progressing in SDR hardware and software venues, but current CR-based SDR research lacks the theoretical foundation and analytic framework to permit efficient implementation. This limitation is addressed here by introducing a general framework for analyzing, characterizing, and implementing spectrally modulated, spectrally encoded (SMSE) signals within CR-based SDR architectures. Given orthogonal frequency division multiplexing (OFDM) is a 4G candidate signal, OFDM-based signals are collectively classified as SMSE since modulation and encoding are spectrally applied. The proposed framework provides analytic commonality and unification of SMSE signals. Applicability is first shown for candidate 4G signals, and resultant analytic expressions agree with published results. Implementability is then demonstrated in multiple coexistence scenarios via modeling and simulation to reinforce practical utility