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The Internet of Vehicles (IoV) has evolved from the classic Vehicular Ad-hoc NETworks (VANETs) as a result of the emergence of the Internet of Things (IoT). IoV is used for communication among vehicles in real-time with their drivers, other vehicles, pedestrians, fleet management systems, and roadside infrastructure. High vehicular speeds and frequent network topology changes make vehicle communication extremely difficult on the IoV network. More constraints are imposed on IoV communication performance in a huge network environment due to the difficult road conditions and the enormous quantity of vehicles. A promising approach to improve the IoV communication performance is through vehicle clustering. Minimizing the number of clusters and identifying a reliable Cluster head (CH) are some of the most challenging tasks. In this paper, we propose a Swarm optimization-based and mobility-aware clustering method termed SOMACA. SOMACA consists of two phases clustering phase and the routing phase. During the clustering phase, we combine mobility measures and cluster distance to generate the minimum number of clusters having stable CHs and employ the Sparrow Search algorithm (SSA) for CH selection. The routing phase consists of two steps (1) Route Formation and (2) Route Upkeep. The main target for route formation step is to build a secure routing path between IoV nodes and base station (BS) by establishing an optimal list of links that are ordered from high to low, and in each round, it selects the best one. Moreover, the Upkeep step aims to update and maintain the existing connection. The performance of SOMACA is assessed using simulation experiments with various metrics including average cluster lifetime, transmission range, and network grid size. The simulation results show that SOMACA reduces the average number of clusters by $42\%, 48\%, 47\%, 9\%$ , 22%,31%, 16%, and 43% less than CAVDO, GOA, GWOCNET, MFCA-IOV, MOGA-AWCP, HHOCNET, AMONE, and p-WOA algorithms respectively when the transmission ranges vary between 200 and 500. Moreover, SOMACA increases the average network lifetime by $11\%, 12\%, 9\%, 6\%$ , 7%, 9%, 3%, and 13% longer than the mentioned above compared algorithms, respectively.

Mobile ad hoc networks are a group of random mobile nodes which does not have a pre-existing base stations or infrastructure. In order to make communications effective over these networks a security scheme is essential. This can be achieved by establishing some shared random bits generated with fundamental secret key generation techniques. This paper presents a secret key generation scheme suitable for networks adapted to dynamic source routing protocol. Investigations were carried out for the possibility of using a system metadata like routing information for randomness extraction. Using routing tables maintained by the nodes as backbone, we are extracting a set of common secret random data for key generation. The secret key generation starts with random source extraction followed by information reconciliation to reduce errors and privacy amplification to increase the confidentiality. The main advantage of this technique is that it utilizes the sources of randomness inherent in the system itself without increasing the computational complexity. It also helps to identify the presence of an adversary in the network. The results of the system are evaluated to analyze the efficiency of the technique in terms of packet loss and packet overhead. [ABSTRACT FROM AUTHOR]

Energy-proportional optical interconnections are enabled by semiconductor optical amplifiers (SOAs) remaining off (or idle) when not routing data. In this letter, the physical layer scalability of SOA-based optical space switches configured with different gain and loss is assessed using an experimental recirculating loop. Results show that for a gain/loss configuration of 13.0 dB, optical multichannel packets successfully propagate through a series of 14 SOAs with a bit-error-rate <; 10-9, which indicates that a single-stage space switch can scale up to 109 ports. Scalability improves for lower gain/loss configuration at the cost of more SOAs per routing path. As expected, scalability is limited by cross-gain modulation and optical signal-to-noise ratio degradation, but their detrimental impact depends on the architecture configuration. [ABSTRACT FROM PUBLISHER]