Reliable data transfer and energy efficiency are the essential considerations for network performance in resource-constrained underwater environments. One of the efficient approaches for data routing in underwater wireless sensor networks (UWSNs) is clustering, in which the data packets are transferred from sensor nodes to the cluster head (CH). Data packets are then forwarded to a sink node in a single or multiple hops manners, which can possibly increase energy depletion of the CH as compared to other nodes. While several mechanisms have been proposed for cluster formation and CH selection to ensure efficient delivery of data packets, less attention has been given to massive data communication processes with sink node. As such, failure in communicating nodes would lead to a significant network void-holes problem. Considering the limited energy resources of nodes in UWSNs along with the heavy load of CHs in the routing process, this paper proposes a void-holes aware and reliable data forwarding strategy (VHARD-FS) in a proactive mode to control data packets delivery from CH nodes to the sink in UWSNs. In the proposed strategy, each CH node is aware of its neighbor’s performance ranking index to conduct a reliable packet transmission to the sink via the most energy-efficient route. Extensive simulation results indicate that the VHARD-FS outperforms existing routing approaches while comparing energy efficiency and network throughput. This study helps to effectively alleviate the resource limitations associated with UWSNs by extending network life and increasing service availability even in a harsh underwater environment.

With the recent growth of global populations, main roads in cities have witnessed an evident increase in the number of vehicles. This has led to unprecedented challenges for authorities in managing the traffic of ambulance vehicles to provide medical services in emergency cases. Despite the high technologies associated with medical tracks and advanced traffic management systems, there is still a current delay in ambulances’ attendance in times of emergency to provide patients with vital aid. Therefore, it is indispensable to introduce a new emergency service system that enables the ambulance to reach the patient in the least congested and shortest paths. However, designing an efficient algorithm to plan the best route for an ambulance is still a global goal and a challenge that needs to be solved. This article introduces an Internet of Things emergency services system based on a real-time node rank index (NR-index) algorithm to find the best route for the ambulance to reach the patient and provide the required medical services in emergency cases. The proposed system design copes with the dynamic traffic conditions to guarantee the shortest transport time. For this purpose, a vehicular ad hoc network is employed to collect accurate real-time traffic data. In this article, we suggest two parameters to compromise distance and congestion level. The first is the distance between the patient and the surrounding ambulance vehicles, and the second determines the congestion level to avoid the path with high congestion traffic. The system employs a developed real-time NR-index algorithm to select a suitable ambulance vehicle to respond to emergency cases at a low travel cost with the fastest journey. Finally, our system makes it easier for ambulance vehicles to use the best route and avoid heavy traffic. This allows them to make their way to the patient quickly and increases the chance of saving lives. The simulation results show significant improvements in terms of average travel time, average travel speed, and normalized routing load.

Underwater Wireless Sensor Networks (UWSNs) play a vital role in ocean monitoring and exploration. However, harsh underwater conditions and frequent topology changes caused by node and sink mobility pose significant challenges for reliable routing. Conventional routing protocols that depend on global route reconstruction and static paths generate excessive control overhead and degrade performance in large-scale underwater environments. In this paper, we propose an energy-efficient virtual cell-based mobile-sink adaptive routing (VC-MAR) protocol for UWSNs. The sensing field is logically partitioned into a three-dimensional grid of virtual cells, where a cell-gateway is elected in each cell to construct a low-overhead routing backbone. To support sink mobility, VC-MAR introduces a localized route-adjustment mechanism that updates only the affected backbone segments rather than reconstructing the entire routing structure. By confining routing updates to neighboring cells influenced by sink movement, the proposed protocol significantly reduces control packet exchanges while ensuring stable and reliable data delivery. Simulation results show that the proposed VC-MAR improves the packet delivery ratio by up to 20% and reduces routing control overhead by about 34% compared with traditional grid-based routing methods. These results confirm the suitability of VC-MAR for dynamic and realistic underwater sensing scenarios.

Electric vehicles are emerging as a sustainable alternative to conventional transportation. However, route planning in Internet of Vehicles environments remains challenging because conventional routing algorithms based on travel distance or time do not adequately consider electric vehicle-specific constraints. Existing routing strategies often overlook the combined effects of battery energy, traffic congestion, and charging requirements, resulting in inefficient routing decisions. This paper proposes an adaptive Energy, Congestion, and Charging-Aware Routing (ECCAR) protocol that uses energy-feasibility verification, cost-based charging-station selection, and route re-optimization for electric vehicles in Internet of Vehicles environments. ECCAR integrates residual battery energy, traffic congestion, travel time, charging station availability, and charging delay into a unified routing decision framework. It first evaluates whether the remaining battery energy is sufficient to reach the destination. Otherwise, it identifies all reachable charging stations and selects the one that minimizes the routing cost rather than the nearest station. After charging, the route is recalculated using traffic and charging information obtained through V2V and V2I communications. Simulation results demonstrate that ECCAR reduces total energy consumption by up to 19.4%, travel time by up to 25.3%, and charging waiting time by up to 39.1% compared with existing routing schemes. These results demonstrate the benefits of integrating energy, traffic, and charging information for reliable electric vehicle routing in dynamic Internet of Vehicles environments.