In emergency scenarios such as earthquakes and floods, Internet-of-Things (IoT) systems composed of heterogeneous devices—including wearable medical sensors, ground gateways, and unmanned aerial vehicles (UAVs)—are increasingly used to collect and relay real-time vital signs to edge nodes for rapid analytics and to cloud services for long-term storage. Although clustering is widely adopted to organize UAV ad hoc networks for efficient IoT data routing, the failure of a cluster head (CH) can fragment the network and result in severe data loss. Existing routing protocols often prioritize latency reduction while overlooking CH continuity and reliability, which are critical in crisis-driven e-health applications. To address these challenges, this work proposes a multi-agent redundant clustering strategy that enhances CH availability while maintaining efficient data delivery. A weighted clustering metric is introduced, incorporating distance stability, reward-based stability, velocity stability, and energy stability to improve cluster formation. In addition, a redundant CH is pre-designated to seamlessly assume routing responsibilities in the event of a CH failure, ensuring uninterrupted data transmission. The proposed protocol is implemented and evaluated through MATLAB simulations and compared against the LEACH protocol. Simulation results demonstrate that the proposed approach improves packet delivery ratio and throughput by approximately 0.7-1.0% and enhances forwarding efficiency by about 0.8%, indicating more reliable and effective data forwarding. While a marginal increase in average end-to-end delay is observed, the delay remains within acceptable limits for e-health monitoring scenarios. Overall, the proposed redundant clustering strategy significantly improves routing reliability and data delivery performance, thereby enhancing the dependability of emergency e-health communication systems.

A swarm of unmanned aerial vehicles (UAVs) is a wireless network made up of UAVs cooperating to upload data to the internet. During critical scenarios like earthquakes, one or more UAV could get damaged. Clustering is one of the most dependable routing systems since the network is divided into clusters with a cluster head (CH) and cluster members (CM). Having a damaged CH results in a disconnected cluster and loss of valuable data. Ensuring a functional CH is a crucial topic that is rarely covered in routing schemes. Our proposed scheme targets ensuring a functional CH through multiple redundancies while redeucing the delays. This paper suggests an enhanced redundant routing scheme based on three weighted parameters, which are the distance stability, the rewarding stability, and the energy stability. The weighted calculation will result in a new metric named cluster index which will be utilized in CH and CMs selection. To guarantee connection stability, whenever the primary CH is not operating, a redundant CH handles the routing responsibilities. The proposed protocol was simulated using MATLAB. The results obtained demonstrated that our proposed scheme is promising in optimizing the cluster formation while reducing total delays and ensuring a functional CH and data delivery.

A UAV-based wireless network is made up of UAVs working together to upload data to the internet. During crisis scenarios like earthquakes or floods, UAVs are highly used in transmitting valuable health-related data. Basic physiological life-saving parameters like blood pressure, temperature, and respiration rate can be tracked by sensors built into UAVs. One of the most reliable routing techniques in UAVs is clustering, where the network is separated into clusters, each of which has a cluster head (CH) and cluster members (CM). Having a damaged CH results in a disconnected cluster and loss of data. Several routing schemes target reducing delays, but ensuring a functional CH is a topic rarely discussed. Our proposed scheme targets both reducing delays and ensuring a functional$\mathbf{C H}$through multiple redundancy and node type variation to ensure health data transmission. This paper suggests an enhanced redundant routing scheme based on four weighted parameters, which are the distance stability, the rewarding stability, the velocity stability, and the energy stability. The network will be formed of UAVs and vehicles to maximize the likelihood of a functional$\mathbf{C H}$. The weighted calculation will result in a customized metric utilized in cluster formation. To guarantee connection stability, whenever the primary$\mathbf{C H}$is not operating, a redundant$\mathbf{C H}$handles the routing responsibilities. The proposed protocol was simulated using MATLAB. The results obtained demonstrated that our proposed scheme is promising in optimizing the cluster formation while reducing total delays and ensuring a functional CH.

Swarm of UAVs (S-UAVs) is the term used to describe an unplanned gathering of un-manned aerial vehicles (UAVs) that collaborate to complete predefined missions. Any UAV has a risk of being damaged in crisis situations like fire. Clustering is one of the most often used routing algorithms in S-UAVs. The clustering scheme divides the UAVs into clusters, with a cluster head (CH) and cluster members (CM) in each cluster. The CH plays a critical role within inter-cluster communication, and because of this, its selection is an ongoing area of study. A clustered weighted scheme with redundancy and dynamic weight adjustment is proposed in this paper. The selection of the principal CH, redundant CHs, and CMs is based on a weighted formula composed of distance, speed, and rewarding index. Whenever the primary CH is damaged, the redundant CH takes its place immediately. After the first clustering process, the proposed scheme dynamically and autonomously adjusts the weights to optimize the UAV role selection. According to the outcomes of the carried-out simulation, this is a promising scheme that reduces data loss in a crisis-case scenario and optimizes the time delay through the dynamic adjustments of the weights.

A swarm of unmanned aerial vehicles (S-UAVs) consists of UAVs flying together with the target of accomplishing a certain task in a faster and more reliable way as compared to a single UAV. In a crisis scenario, UAVs have been widely used in rescue missions. Clustering is one of the most reliable routing schemes for S-UAVs. The UAVs are grouped into clusters with a cluster-head (CH) and cluster-members (CM). The CH plays a major role in clustering schemes as it handles all inter-cluster communication. In a crisis case, any UAV is at risk of getting non-functional, thus resulting in a disconnected cluster. This paper proposes a new clustering scheme based on K-means and weighted formulas. The K-means protocol is applied to generate pilot phase clusters. Afterward, whenever the metrics of the networks are established, the weighted formula is applied for cluster formation and CH selection. The weighted formula is based on the performance index, the relative movement, and the remaining energy. To ensure end-to-end communication despite CH non-functionality, our proposed protocol selects a redundant CH for every CH. This protocol had been simulated using MATLAB. The results obtained and analyzed towards the end of this paper demonstrate that the proposed scheme is very promising.

A spontaneous group of unmanned aerial vehicles (UAVs) is denoted as a swarm of UAVs (S-UAVs). The UAVs communicate wirelessly and cooperate to accomplish tasks. In crisis scenarios such as flooding or earthquakes, all UAVs are at risk of getting damaged and thus non-functional. A non- functional UAV will result in a disconnected network, especially if that UAV is highly responsible for packet forwarding. S- UAV s are dynamic networks; clustering is one of the most adopted routing schemes in S-UAVs. The clustering scheme groups the UAVs into clusters where each cluster is formed of a cluster head (CH) and cluster members (CMs). Only the CH can handle inter-cluster communication. Due to the crucial role played by the CH, its selection is a continuous field of research. This paper proposes an enhanced clustered weighted scheme with redundancy to ensure end-to-end communication. The proposed scheme is based on a weighted formula for the primary CH, redundant CH, and CMs selection. The weighted formula calculates a cluster index based on the distance, the speed, and the reward index. A new component is added to the reward index which is performance. The redundant CH is selected to automatically replace the primary CH whenever it is damaged. If the redundant CH becomes inoperable, the second redundant CH will take over. Each cluster is formed of n CMs and will have n-2 redundant CHs. The results obtained from the conducted simulation experiments concluded that this promising scheme decreases data loss in a crisis case scenario.

A swarm of UAVs (S-UAVs) is a spontaneous wireless network composed of unmanned aerial vehicles (UAVs) cooperating together to upload data to the internet. In crisis cases such as flooding or earthquakes, one or more UAVs might be non-functional, resulting in a disconnected network. Due to the continuous changes in S-UAVs, one of the most reliable routing schemes is clustering. Clustering scheme splits the network into clusters with a cluster head and cluster members. The cluster head is responsible for all intra-cluster communication, which consists of communication between the clusters. The selection of the cluster head has a high impact on the performance of the routing scheme. This paper proposes a new clustered weighted scheme with redundancy to ensure end-to-end communication even with some non-functional UAVs. The proposed protocol has a new weighted formula for the primary cluster head selection. In addition, the proposed protocol selects the secondary cluster heads based on an elimination process. The parameters of the weighted formula are the distance, the speed, and the rewarding index. The rewarding index is calculated based on the latency. This protocol proposes the presence of a secondary cluster head that automatically replaces the primary cluster head whenever it is non-functional, thus ensuring the stability of the connection. The proposed scheme is simulated using MATLAB. The results obtained are discussed towards the end of this paper. The obtained results conclude that this is a promising protocol to decrease data loss in a crisis case scenario.

Unmanned aerial vehicles (UAVs) which are commonly known as drones are highly reliable in data transportation, especially whenever terrestrial access is unavailable due to geographical limitations. Several UAVs might collaborate to perform tasks in several applications such as rescue, military, and others. This collection of UAVs is known as a swarm of unmanned aerial vehicles. Drones can be used as aerial relays in complex communication scenarios thus establishing a reliable end-to-end transmission. Wireless Sensor Network (WSN) consists of sensor nodes and base stations. The sensors of WSN are widely dispersed in predefined geographical fields. These sensors might be used for continuous monitoring for example temperature or might be used for event triggers example whenever the temperature exceeds a certain threshold an alarm is fired. In a crisis case scenario, the base station which acts as a relay to upload the sensed data to the internet might be nonfunctional thus resulting in a disconnected network and loss of sensed data. This paper proposes the usage of a swarm of UAVs to upload data from the WSN network to the internet whenever the base station is nonfunctional. This paper will study the mathematical correlation between the parameters of this network taking into consideration the constraint to avoid collisions between the UAVs. A simulation using MATLAB studies the effect of the number of levels in the WSN, the range of communication, UAV’s velocity, and UAv’s trajectory on the network performance.

Flying Ad hoc Network (FANET) is the result of Unmanned Aerial Vehicles (UAVs) that collaborate to perform tasks in several applications such as rescue, military, and others. The unmanned aerial vehicle which is also known as a drone improves routing as the line-of-sight probability is increased due to its three-dimensional movement capability. Drones can be used as aerial relays in complex communication scenarios. Routing protocols are necessary for FANETs to establish communication between UAVs. Various routing protocols have been reported for FANETs targeting to find the routing protocol with minimal overhead while establishing a reliable end-to-end transmission. Wireless Sensor Network (WSN) consists of sensor nodes and base stations. The wireless sensors collect different types of information for their surroundings. Then, this information is uploaded to the internet through the base station. In a crisis case scenario, the base station might be nonfunctional resulting in a data upload failure. This paper proposes to use the UAV as an aerial base station to compensate for the nonfunctional terrestrial base station. As delay is one of the major metrics in routing protocols this paper targets to study theoretically the transmission time of packets traveling from the sensors in the WSN to the UAV. Besides, a simulation had been carried using MATLAB to study the total transfer time with respect to several network variables such as the coverage radius, the number of levels in WSN, the angle of propagation of the UAV, and the UAV's speed.

Breakdown or interruption of communication infrastructure is one of the most immediate and significant impacts of natural disasters. This paper is devoted to the modeling of the successful uplink in Vehicular ad-hoc networks (VANET) in disaster cases where vehicles encounter disrupted communication. The packets' size to be transmitted, the vehicles' speed, the infrastructure coverage range, the disconnected distance, and the number of copies sent have a strong influence on the probability of success for uploading the packets. A simple connectionless retransmission scheme is proposed where several copies of the same packet are transmitted to make sure that the vehicle will upload successfully at least one copy of the packet. The optimum number of retransmission and the choice of inter-frame gap required between successive copy packets are also found. In this respect, this paper studies the mentioned parameters' effect on the probability of success for the uplink and the throughput. MATLAB was used to run a simulation and validate the theoretical analysis.

VANET is a spontaneous creation of a wireless network among vehicles to exchange data. Clustering is one of the most common networking protocols for data propagation in those networks. The application of the clustering algorithm is effective in VANET because the algorithm makes it a more robust and scalable network. However, due to the high mobility of nodes, it is difficult to obtain stable clusters. One of the major challenges in clustering is the cluster head (CH) election since the CH has a critical role in data routing. For stable cluster formation in VANET, some constraints such as vehicles' velocity and vehicles' separation distance must be considered while selecting the CH. This paper proposes a new clustering algorithm based on a weighted formula for calculating the probability of cluster head selection. The weighted formula is based on three parameters: the trust, the distance, and the velocity. The trust is a newly added metric that is calculated by each vehicle and broadcasted to all neighbors. Whereas, the distance and the velocity are previously treated by other papers.