To overcome the limitations of Dedicated Short Range Communications (DSRC) with short range, non-supportability of high-density networks, unreliable broadcast services, signal congestion and connectivity disruptions, vehicle-to-everything (V2X) communication networks, standardized in 3rd Generation Partnership Project (3GPP) Release 14, have been recently introduced to cover broader vehicular communication scenarios including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P) and vehicle-to-infrastructure/network (V2I/N). Motivated by the stringent connection reliability and coverage requirements in V2X, this paper presents the first comprehensive and tractable analytical framework for the uplink and downlink performance of cellular V2X networks, where the vehicles can deliver their information via V2N/cellular network (vehicle-to-base station, V2B communication link) or directly between vehicles in the sidelink, based on their distances, propagation environments and the bias factor. By practically modeling the vehicles on the roads using the doubly stochastic Cox process and the BSs, we derive new association probabilities of V2B and V2V links, new success probabilities of the V2B and V2V communications, and overall success probability of the V2X communication, which are validated by the simulations results. Our results reveal the benefits of V2X communication compared to V2V communication in terms of success probability.

Internet of Medical Things (IoMT) connects different medical devices, health sensors and hospital records to data platforms using wireless communications. Federated Learning (FL) is an emerging collaborative learning technique that can be beneficial for IoMT due to reduced communication overhead and enhanced security. This paper provides an overview of different architectures used in FL and potential approaches for FL based IoMT. We also discuss how Physical Layer Security (PLS) can be used for efficient privacy preservation of data in FL based IoMT. We highlight the recent work in this area and major research challenges related to PLS assisted FL in IoMT. We also provide a case study demonstrating that clustering of IoMT devices (such that a single device in each cluster acts as a cluster head) enhances the secrecy rate of the FL based IoMT network as compared to its non-clustered counterpart. Finally, we also discuss future opportunities and open research questions related to PLS assisted FL in IoMT.

Cybertwin is the intelligent data analytics agent of the future that interacts with the Internet of Vehicles using 6G to make intelligent decisions for automotive application reliability. Intelligent reflecting surface (IRS) is a vital component of future cybertwin-driven 6G networks due to its ability to control unfavorable wireless propagation conditions and achieves higher data rates. In this article, we explain the four major advantages that can be gained by using IRS-enabled cybertwin 6G vehicular networks, including overcoming blockages, Doppler mitigation, enhanced localization, and enhanced security. We also provide a case study showing that IRSs can increase the percentage of vehicles with line-of-sight links by 25% in a high traffic density of 60 vehicles/km, compared to the scenario where no IRS is deployed. Finally, we discuss future opportunities and open challenges to realize IRS-enabled cybertwin 6G vehicular networks.

Physical layer security (PLS) has been shown to hold promise as a new paradigm for securing wireless links. In contrast with the conventional cryptographic techniques, PLS methods exploit the random fading in wireless channels to provide link security. As the channel dynamics prevent a constant rate of secure communications between the legitimate terminals, the outage probability of the achievable secrecy rate is used as a measure of the secrecy performance. This work investigates the secrecy outage probability of a simultaneous wireless information and power transfer (SWIPT) system, which operates in the presence of multiple eavesdroppers that also have the energy harvesting capability. The loss in secrecy performance due to eavesdropper collusion, i.e., information sharing between the eavesdroppers to decode the secret message, is also analyzed. We derive closed‐form expressions for the secrecy outage probability for Nakagami‐m fading on the links and imperfect channel estimation at the receivers. Our analysis considers different combinations of the separated and the integrated SWIPT receiver architectures at the receivers. Numerical results are provided to validate our analysis.

This paper presents a novel method for using full duplex (FD) communication across shared channels in cellular vehicle-to-everything (C-V2X) networks providing an alternate to previously available and widely accepted separate channel framework for side link (PC-5 interface) and cellular link (Uu interface) in vehicular communication. Three modes have been defined in this work for communication in V2X networks. Mode A and Mode B consider already available half duplex (HD) Direct Short Range Communication (DSRC) and C-V2X while Mode C for FD communication in C-V2X has been proposed for the first time. We have derived retractable mathematical model for success probability of FD for C-V2X network while expressions for area spectral efficiency (ASE) have also been formulated based on Shannon Channel Capacity model. Dual connectivity (DC) for simultaneous link of receiving vehicle with nearest transmitting vehicle and base station (BS) has also been analyzed for the first time for HD and FD in C-V2X network over shared channels. It was commonly believed that use of FD in a network will adversely affect performance due to increase in self-interference (SI). Analytical and simulation results have affirmed that utilization of Mode 3 i.e. FD in C-V2X network provides comparable success probability as compared to HD, while ASE for Mode 3 fares better due to enhanced capacity of FD communication. Our network model takes into account vehicles, pedestrians and traffic infrastructure distributed according to Cox Process while 2-Dimensional (2-D) Poisson Point Process (PPP) is used for plotting BSs. Association probability based on distance with nearest neighbor (Nearest Neighbor Criterion - NNC) has been utilized in our network and also compared with DC. Monte Carlo simulations along with analytical results have shown that the success probability of FD remains close to HD in terms of signal to interference noise ratio (SINR) in the range from -40 dBW to 60 dBW. Success probability for different values of self-interference (SIC) in FD network has also been compared to signify importance of achieving perfect self-interference cancellation (SIC). FD in C-V2X network has shown to significantly improve ASE with gain of 2.55 dB over Direct Short Range Communication (DSRC) and 2 dB over HD in CV2X network for specific conditions. Remarkably, no degradation in ASE has been observed in case of DC for HD and FD, accentuating a strong case for adoption of DC with FD broadly across C-V2X networks to improve network reliability. Moreover, it has been shown that ASE for FD improves as compared to HD for DSRC and C-V2X network when evaluated for different density of vehicles, BSs and roads