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Trust Modelling and Management (TMM) techniques are frequently applied in ad-hoc Distributed Wireless Networks (DWNs) to stimulate and improve cooperation between network nodes. TMM facilitate DWNs in building a trust network that assures reliability of communication channels, offers an additional layer of security, and enables group decision making processes. Likewise, TMM became in the past decades an attractive solution for solving problems in cooperative ad hoc DWN. The proposed solutions focus on modelling trust in a social-centric approach to maintain a system where nodes trust each other, and detect untrustworthy (malicious) neighbours. The work at hand considers a time span of three years, from 2020 to 2022, where the scientific research in the domain of TMM and DWN is analysed. Our survey aggregates over 130 research papers and investigates the quality of experimental assessment done by each work. Additionally, we establish an indication on the level of experimental analysis done by each study from a TMM security perspective. Lastly, the survey offers a trust ontology, a general overview of a trust models, together with a concise description of trust threats to facilitate the reader’s understanding of TMM.

Localization is one of the major problems in mobile wireless sensor networks, since it provides the location of an event occurrence. This paper evaluates the performance of range-based localization algorithms: the multilateration algorithm, the weighted multilateration algorithm, the maximum likelihood algorithm and the multilateration algorithm with a correcting factor. We also propose the weighted multilateration algorithm with a correcting factor through which the localization error is decreased through the addition of a factor that corrects the distance between the node of interest and the reference nodes. Our proposal includes the analysis of noise in the environment due to the time of arrival and the analysis of node of interest’s mobility in the calculation of the correlation matrix of the weighted multilateration algorithm and the calculation of the correcting factor. The localization algorithms analyzed in this study are evaluated in a single-hop scenario and a multi-hop scenario considering a well-defined distribution of the reference nodes and a random distribution of these in both scenarios. The results we obtained varying the number of reference nodes and noise proportion prove that the algorithm we propose yields a better performance than the other analyzed algorithms do, according to the normalized root mean squared error.

Nowadays vehicles on the roads can communicate using a special type of wireless network called Vehicular Ad-hoc Networks (VANETs). It has been demonstrated by the researchers that because of the unique features such as high density of vehicles and frequent change of network topology, VANETs are not supported by the traditional routing protocols. The routing consistency of such highly dynamic networks must be taken into account in VANETs as communication links are disintegrated in VANETs more often than Mobile ad-hoc Networks (MANETs). The nature of VANET communication can bring extreme routing overhead to the network, therefore to increase network performance, the overhead issue must be tackled. The proposed protocol is focused on reducing the overhead to get the improved PDR performance of the network. The improvement is achieved by permitting communication amongst only those nodes which are considered reliable in terms of availability and geographical position. The reliability factor simply reduces unnecessary nodes from the communication process and selects a set of reliable nodes that are discovered with the help of clustering technique throughout the routing process. Simulation experiments using the network simulator are presented to demonstrate the efficacy of the proposed protocol. The results show that the proposed protocol has enhanced network performance effectively compared to prior approaches.

Infrastructure-less (sometimes known as ad-hoc) networking paradigm is very appealing and potentially shaping its future into almost all emerging networks (i.e., IoT, wireless sensor networks, vehicular ad-hoc networks, emergency, and tactical radio networks, etc.). However, when conventional networking protocols are used, such networks often perform poorly, mainly because of interference within the network and limited network throughput. Recent advancements in wireless communications have enabled full-duplex (FD) operation by suppressing self-interference, which can theoretically double the network throughput. However, conventional medium access control (MAC) protocols like carrier-sense multiple access with collision avoidance (CSMA/CA) favor half-duplex (HD) operation and fail to benefit from FD transmission opportunities. This article proposes a novel hybrid MAC protocol for full-duplex ad-hoc networks. The proposed MAC combines time division multiple access (TDMA) and IEEE 802.11 distributed coordination function (DCF) strengths in chains of time-slotted contention-based control frames and collision-free data frames. The aim is to fully utilize FD transmission opportunities to increase network throughput. The proposed protocol modifies request-to-send (RTS) and clear-to-send (CTS) frames in IEEE 802.11 DCF MAC to form FD-RTS/CTS frames. These frames are used to enable collision-free FD communications among neighbors. The proposed scheme mitigates conventional MAC issues like hidden-node problem (HNP) and exposed-node problem (ENP). It also allows concurrent FD data transmissions in a collision-free manner. The model is generic and can be applied to any ad-hoc wireless network. In this article, the design is applied to a single channel ad-hoc network with FD transceivers. We compared the proposed design with IEEE 802.11 CSMA/CA protocol with both HD and FD transceivers. The simulation results show a 30% gain in throughput, reduced latency, and fairness among participating wireless nodes.

Despite the surge in a vehicular ad-hoc network (VANET) and volunteer computing research, future high-end vehicles are expected to under-utilize the onboard computation, storage and communication resources. Therefore, this research envisions the next paradigm shift by merging VANET and volunteer computing, which we call VANET based volunteer computing (or VBVC). To date, the potential design system for VBVC has not been characterized. To fill up this gap, we first set forth the scientific classification of VBVC, which uses the automobiles alongside roadside units (RSU) to give computational administrations to different vehicles on the road. We propose a potential framework for different VBVC scenarios. Moreover, we provide an experimental evaluation of VBVC by comparing it with the traditional model in terms of job completion, latency, and throughput. The proposed VBVC performs better when compared with traditional approaches.

Localization is one of the main problems in Mobile Wireless Sensor Networks, since it provides the location of an event occurrence. This paper presents a performance evaluation of the localization algorithms: Multilateration Algorithm, Weighted Multilateration Algorithm and Probabilistic Multilateration Algorithm (PMA). In addition, we propose an Improved Probabilistic Multilateration Algorithm that decreases the localization error of the interest node by using an approach that computes iteratively the position of a node of interest until it reaches the solution that minimizes the localization error. The proposed approach regards the noisy environment by its impact on a correlation matrix that involves the variance of the separation distance between the node of interest and the respective reference nodes (RNs). Furthermore, we also introduce a constant parameter called damping factor; which enhances the convergence of the localization algorithm providing the solution that minimizes the localization error. In this study, we evaluate localization algorithms in a single-hop and multi-hop scenarios considering a distribution with solid geometry of the RNs and randomly distributed RNs in both scenarios. The results we obtained show that our proposed algorithm Improved PMA presents a better performance according to the Normalized Root Mean Squared Error varying the number of reference nodes and noise proportion.

A planar multifunctional four-port antenna system integrated on one substrate applied in the suburban mobile tablet is presented in this paper. The types of these antennas are selected based on different functions and the interactions between them are analyzed and reduced. Two identical T-shaped printed monopole antennas are designed for the MIMO mobile ad-hoc networks (MANET) application. The mutual coupling between the ports of these two MANET antennas is decreased by introducing a decoupling metal strip loaded with an inductor. Two horizontal printed dipoles with parasitic strips are developed to operate in the satellite navigation and communication frequency bands. Through the analysis of the interaction between the MANET antenna and satellite antennas, the satellite antennas with improved broadside radiation patterns are obtained. The performance stability of the proposed antenna system is verified by the investigation of the performances in different gestures. A prototype of the antenna system is fabricated and the measured results show that the proposed antenna system can cover the frequency bands of MANET communication, satellite navigation, and satellite communication with good performances. This proposed multifunctional antenna system is a good choice for the sub-urban mobile terminal systems.

Autonomous vehicles are becoming a reality in places with advanced infrastructure to support their operations. In crowded places, harsh environments, missions that require these vehicles to be aware of the context in which they are operating, and situations requiring continuous coordination with humans such as in disaster relief, advanced-vehicle systems (AVSs) need to be better contextually aware. The vast literature referring to “context-aware systems” is still sparse, focusing on very limited forms of contextual awareness. It requires a structured approach to bring it together to truly realize contextual awareness in AVSs. This paper uses a human-AVSs (HAVSs) lens to polarize the literature in a coherent form suitable for designing distributed HAVSs. We group the relevant literature into two categories: contextual-awareness related to the vehicle infrastructure itself that enables AVSs to operate, and contextual-awareness related to HAVSs. The former category focuses on the communication backbone for AVSs including ad-hoc networks, services, wireless communication, radio systems, and the cyber security and privacy challenges that arise in these contexts. The latter category covers recommender systems, which are used to coordinate the actions that sit at the interface of the human and AVSs, human-machine interaction issues, and the activity recognition systems as the enabling technology for recommender systems to operate autonomously. The structured analysis of the literature has identified a number of open research questions and opportunities for further research in this area.

This paper proposes a spectRum Aware cRoss-layEr (RARE) medium access control protocol for cognitive radio ad-hoc networks. The RARE protocol initially splits the network into clusters, where cluster formation is defined as maximum edge biclique problem. Besides, in order to maintain the integrity of the cluster-based network, super-frame structure, and topology maintenance protocols are also presented in this paper. Moreover, RARE also integrates a delay-aware routing protocol, where the routing protocol is defined as a weighted graph problem. It is anticipated that clusters in RARE adapt themselves dynamically with respect to spectrum availability and nodes mobility. Furthermore, the routing protocol in RARE is expected to select stable paths while ensuring faster data delivery from a source node to the destination. Simulation is conducted to evaluate the performance of the proposed RARE protocol, where it is found that RARE outperforms existing approaches by maintaining a lesser number of clusters and a steady number of common channels. The simulation results also show that route selection in RARE proves to be more stable with the lowest packet transmission delay compared with the other approaches.