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The design of underwater wireless sensor networks (UWSNs) faces many challenges, including power consumption, storage, battery life, and transmission bandwidth. UWSNs usually either use node clustering or multi-hop routing as their energy-efficient optimization algorithms. The cluster optimization technique will organize the sensor nodes into a cluster network, with each cluster led by a cluster head (CH). In contrast, the multi-hop optimization algorithm will create a multi-hop network by sending data to the base station (BS) while switching between different sensor nodes. However, the overburdens of CH nodes impact the performance of the cluster optimization method, whereas the overburdens of nodes close to the BS impact the performance of the multi-hop optimization algorithm. Therefore, clustering and routing procedures can be considered as a simultaneous NP-hard problem that metaheuristic algorithms can address. With this motivation, this paper proposes an energy-efficient clustering and multi-hop routing protocol using the metaheuristic-based algorithm to increase energy efficiency in UWSNs and lengthen the network life. However, the existing metaheuristic-based methods use two separate algorithms for clustering and multi-hop routing, increasing computational complexity, different initialization, and difficulty in hyperparameters' tuning. In order to address the mentioned shortcomings, this paper proposes a novel hierarchical structure called hierarchical chimp optimization (HChOA) for both clustering and multi-hop routing processes. The proposed HChOA is validated using various metrics after being simulated using an extended set of experiments. Results are compared to those from LEACH, TEEN, MPSO, PSO, and IPSO-GWO to validate the impact of the HChOA. According to the findings, the HChOA performed better than other lifespan and energy usage benchmarks. [ABSTRACT FROM AUTHOR]

The location of nodes is critical in underwater wireless sensor networks (UWSNs), which is an ocean monitoring platform. UWSNs are motivated by the popular usage of localization and play a major role in several technologies that depend primarily on innovations and localization of these nodes. Underwater node localization is a critical technology that enables the deployment of a variety of underwater applications. In this study, the underwater nodes are divided into two levels. Firstly, a clock asynchronous localization system (LS-AC) for base layer's node localization is presented. In order to eradicate the original ranging strategy's dependence on active nodes and address the problem of energy consumption, LS-AC performs in-network situation-based monitoring by relying on asynchronous clocks. Secondly, we propose a backtracking search algorithm (OTKL-BSA) based on optimal topology and knowledge learning. It is used to address the issues associated with traditional algorithms' lack of diversity and the imbalance between exploration and exploitation. Thirdly, to solve the problems that the traditional gray wolf optimizer (GWO) is prone to falling into local optimal values and has a low search efficiency, this paper proposes a GWO scheme based on hunting step size (GWO-HSS). Finally, simulation results show that the proposed algorithm outperforms SLMP, MCL-MP, MP-PSO, and MGP in aspects of localization performance. [ABSTRACT FROM AUTHOR]

Wireless multimedia sensor networks (WMSNs) can gather multi-media events such as road traffic accidents, object monitoring, and scalar data. Additionally, multimedia applications have the potential to generate substantial bandwidth congestion leading to greater energy usage. Researchers in WMSNs are constantly interested in designing and developing energy-efficient routing protocols. Numerous clustering routing protocols have been developed in recent years to overcome the limitation of consuming less energy and prolonging the lifetime of sensor nodes in homogeneous and heterogeneous WMSNs. Existing approaches depend on single-hop communication, in which sensor nodes consume more energy and die faster. Inter-communication nodes can play a more important role in reducing energy by transmitting sensing data in a multi-hop fashion to the base station. In this paper, an Energy-Efficient Multipath Clustering with Load balancing routing protocol for WMSNs (EEMCL) was proposed to minimize the energy consumption and prolong the network lifetime. Clustering-based routing with multi-hop would be used to implement the proposed protocol. To analyze and investigate the performance of the proposed protocol, a simulation model utilizing the MATLAB program is used. The simulation results show that the improvement rate for the proposed protocol is 75% when compared with modified-low energy adaptive clustering hierarchy (MODLEACH), and 65% when compared with energy-efficient multistage routing protocol (EE-MRP) in terms of the number of alive nodes and in terms of residual energy of normal sensor nodes, the improvement rate for the proposed protocol is 86% when compared with MODLEACH, and 67% when compared with EE-MRP. [ABSTRACT FROM AUTHOR]

At present, underwater wireless ad hoc networks (UWAN) are widely used in enormous applications. At the same time, UWAN faced many security issues, like energy leaks. The energy hole will make the network lifetime end soon. However, most existing underwater research has not taken security as serious threat. This article aims to provide a new secure data transmission scheme in UWAN, in which the management and deployment of UWAN is typically done by a trusted authority. The proposed Cluster Tree Enhanced Dempster Shafer based Bidirectional Butterfly Optimization algorithm (CT-EDS-BBO) will be divided into three phases. Initially, the cluster-based tree routing protocol designed for cluster formation, CH selection process, and routing process establishment. In the second phase, the Enhanced Dempster Shafer Evidence Theory uses the fusion rule to evaluate the trust value for each node, which is used to determine the security of each node and to detect the Malicious Node. Finally, the Bidirectional Butterfly Optimization algorithm model is designed to avoid the energy hole issue and to allocate a routing channel for secure data transmission over UWAN. The results obtained from simulation analysis demonstrate that the proposed CT-EDS-BBO has observable benefits over the conventional methods with a Packet Delivery Ratio of 90%, energy consumption of 0.14 J, a network lifetime of 732 s for 200 rounds, and an end-to-end delay of 0.12 s. [ABSTRACT FROM AUTHOR]

Wireless sensor network is a group of nodes combined with tiny sensors equipped with transceiver parts used for sensing, monitoring, and data collecting in various environments. It is not possible to support the battery support to the sensors while placed in an unmanned area. Hence, the sensor's energy should be vital, and it is very crucial. Combining the techniques of clustering and proper routing is one of the efficient schemes to save the energy of the sensor nodes. During the clustering process, cluster heads can be chosen with utmost care for load balancing. Along with cluster head selection, this proposed work also focussed on two major things. First, the appropriate relay node can be selected using the fuzzy inference system with sensor energy level as one input and the distance between the relay node and the cluster head node as another input. Secondly, the mobile sink collects the aggregated data from the relay node and sends it to the base station. On combining these two schemes, mobile sink and fuzzy based relay node routing Protocol is proposed. Simulation result shows that the proposed protocol has an improved number of alive nodes and a better network lifetime in terms of energy consumption compared with the existing schemes. [ABSTRACT FROM AUTHOR]

With the development of the internet of things, people pay more and more attention to wireless sensor networks. Designing the energy efficient routing is an essential objective for wireless sensor networks. Cluster routing is one of the most popular routing protocols to enhance the network lifetime. However, hotspot problem always exists in cluster-based routing protocol. The task of this study is designing a cluster routing protocol with mobile base station which aims at balancing the energy consumption and prolonging the network lifetime. In this article, we design a particle swarm optimization and artificial bee colony algorithm for clustering and mobile based software-defined wireless sensor networks. The software defined network architecture is used to reduce the energy overhead and computation overhead in sensor nodes. Particle swarm optimization-based cluster routing algorithm is used to calculate the cluster heads and the sojourn locations of base station. Artificial bee colony algorithm-based traversal path algorithm is used to design the move path of the base station. Comparing with relevant protocols, the proposed protocol reduces the energy consumption, enhances the network lifetime and reduces the control overhead. [ABSTRACT FROM AUTHOR]

Underwater wireless sensor network (UWSN) is a new technolog that can be used for various purposes, including ocean tracking and underwater exploration, military surveillance, disaster management, industrial applications, and scientific research. These applications require the sensed data to be routed to the destination, and this results in making the data routing one of the essential parts in designing such applications. High propagation delay, restricted bandwidth, 3D deployment, and energy constraints are some of the challenges that UWSN faces when developing routing protocols. Therefore, to mitigate these challenges, efficient routing protocols are proposed according to the specific application. This paper surveys recently routing protocols for UWSN. Furthermore, each routing protocol's main idea and essential operation are presented and its merits and demerits. There are two types of routing protocols surveyed: location-based and location-free routing protocols. Each type is divided into two sub-categories: those that take into account node mobility and those that do not. The surveyed protocols are evaluated through the analytical method in which these protocols are compared through a wide range of parameters like packet delivery ratio, end-to-end delay, energy efficiency, and reliability. Some of the surveyed protocols are evaluated through the numerical simulation method by using Aqua-Sim with NS2.30 and are compared through packet delivery ratio, end-to-end delay, and energy consumption. This survey's core goal is to encourage more research into improving UWSN routing protocols for better underwater exploration and monitoring. [ABSTRACT FROM AUTHOR]

As a key enabling technology of underwater acoustic sensor networks, underwater routing feature a variety of unique characteristics, including limited energy supply, high end-to-end delay and low delivery ratio. All these problems pose challenges in the design of efficient and effective routing protocols. To address such challenges, we propose an adaptive multi-zone geographic routing protocol(AMGR). First, AMGR dynamically adjusts the neighbor information acquisition interval according to the topology change speed, which not only reduces the excessive energy consumption of updating information, but also improves the performance of routing in high dynamic underwater environment. Second, according to the characteristics of different forwarding zones, the multi-region cooperative forwarding mechanism is adaptive used to improve the end-to-end delay and increase delivery ratio under the premise of reducing energy consumption as much as possible. Third, in priority calculation, we consider both the impact of packet transmission advancement and energy consumption, which can ensure less hops and avoid some high advancement nodes running out of energy in advance. Simulation results show that the proposed protocol outperforms AHH-VBF, PCR and restrictive flooding in delivery ratio, end-to-end delay and energy tax. [ABSTRACT FROM AUTHOR]

In the vehicular ad hoc network (VANET), due to the particularity of high-speed movement of vehicle nodes, there are higher challenges in link stability and network topology control overhead. In this paper, a new algorithm of clustering AODV based on edge computing strategy is proposed. Considering the vehicle node energy and speed, the AODV routing protocol based on the minimum hop number is optimized, which divided the communication mode into vehicle to vehicle (V2V) and vehicle to road (V2R) mode. Adding edge server in the road side unit (RSU) and using the idea of clustering, that is, the nodes in the cluster use V2V communication mode, and the nodes between clusters use V2V and V2R combined communication mode to select routes. The algorithm improves the routing efficiency in the high-speed mobile. Experiments show that the algorithm is feasible, reducing the network topology control overhead, lowering the end-to-end delay and improving the packet delivery rate comparing with others in different environment. [ABSTRACT FROM AUTHOR]

ZigBee is one of the latest technologies developed by the ZigBee Alliance to enable Wireless Personal Area works. ZigBee technology has better characteristics when compared with other wireless standards such as WI-FI, Bluetooth and WiMAX, and so on. Though the transmission range in ZigBee ranges up to a few meters, the network has several layers, designed to enable interpersonal communication within the network, appropriate routing technique can lead the data to be reached to a longer distance, leading to an increase in the transmission range. Present research emphases on the maximization of the transmission range in the ZigBee network. For the analysis, the Simulink based software called TRUETIME 2.0 in MATLAB tool is used. Energy Efficient ZigBee based AODV routing protocol with incorporated CSMA-CA MAC channel access (EE-ZAODVCSMA) is proposed for maximizing the transmission range in the ZigBee network. To maximize the transmission range, various soft computing techniques such as Fuzzy Logic, Artificial Neural Network, Adaptive Neuro-Fuzzy Inference System, and one more technique which is an integration of ANN and Genetic Algorithm are applied to the network. A small ZigBee network is implemented with four nodes on LPC 2148 to show the data communication based on the proposed algorithm. [ABSTRACT FROM AUTHOR]

This article presents the design, analyses and implementation of the novel routing protocol for energy optimization based on LEACH for WSN. Network Lifetime is the major problem in various routing protocols used in WSN. In order to overcome that problem, our proposed routing protocol is developed, which is a combination of Micro Genetic algorithm with LEACH protocol. Our proposed µGA-LEACH protocol, strengthen the cluster head (CH) selection and also reduce the energy consumption of the network when compared to existing protocols. This paper shows the improvement of network lifetime and energy consumption with the optimal CH selection based on a micro genetic algorithm and also compared the results with an existing hierarchical routing protocol like LEACH, LEACH-C, LEACH GA and GADA LEACH routing protocol with various packet sizes, and initial energy. [ABSTRACT FROM AUTHOR]

Wireless body area network (WBAN) routing protocols are primarily designed for improvement of network performance parameters such as network lifetime, throughput and latency. However, these designs do not take into account the health hazards posed due to WBAN radiation. The focus of implementing IEEE 802.15.6 standards is to develop an energy-efficient, reliable and health-conscious wireless communication system around human body. This paper presents the implementation of a clustering-based routing protocol for WBAN that targets in achieving overall optimization of WBAN performance parameters including network lifetime, throughput, latency, node signal power and specific absorption rate (SAR) of human body for emf radiation. The suggested protocol applies a multi-objective NSGA-II optimization heuristic for cluster formation while taking into account various IEEE 802.15.6 standard constraints. A unique chromosome structure has been proposed for NSGA-II population in which each chromosome represents a random network topology for determining the node clusters, cluster heads and node transmission power. Furthermore, three system-level models for conducting multi-objective fitness evaluation of each chromosome have been proposed. These models predict the global transmission energy consumption; the average received signal strength (RSSI) and end to end network latency respectively. The developed NSGA-II model evolves into a non-dominated set of Pareto-optimal network topologies that renders the desired objectives of minimization of network energy consumption and network latency besides maximization of average RSSI. Enhancement in RSSI further leads to a tremendous improvement in the throughput rate. The node transmission power specifications of Pareto-optimal network topologies meet the standard SAR constraints too. The performance results shows that the suggested protocol strictly meets IEEE 802.15.6 compliance. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are generically self-configuring and organizing networks with constrained communicational ability and energy supply. One of the crucial crises in WSN is the employment of energy effectual routing and load balancing protocol to improve network lifetime. Therefore, this work anticipated an effectual load balancing and routing strategies using the Glowworm swarm optimization approach (LBR-GSO). This LBR-GSO employs a pseudo-random route discovery algorithm and an enhanced pheromone trail-based updating strategy to handle the energy consumption of sensor nodes. It utilizes an effectual heuristic updating algorithm based on cost effectual energy measure to optimize route establishment. At last, to eliminate energy consumption that causes due to control overhead, LBR-GSO cast-off energy-based broadcasting strategy has been proposed. Here, WSNs environment is simulated in MATLAB for various application scenarios to compute LBR-GSO along with metrics such as energy efficiency, energy consumption and prolonging network lifetime. Outcomes derived from this comprehensive analysis determine that LBR-GSO offers an effectual enhancement in contrary to prevailing approaches like ACO, EE-ACO and s-Ant approaches. [ABSTRACT FROM AUTHOR]

In order to mitigate the power consumption issue for the sensor's nodes, an efficient power optimized routing protocol is needed. Therefore, this paper proposes a network coding backpressure routing (NCBPR) routing scheme for a large-scale Internet of Things (IoT) networks, which exploits the backpressure algorithm in order to divert packets flow. In the network, the packets are flowing from the highly congested node to low congested node, which helps to balance the load and optimized the fair use of the battery power of all the participating nodes. It divides the network into the small clusters, where the selection of clusters head depends upon an additional parameter of battery power apart from other optimum path parameters. It also employs an efficient data aggregation mechanism, which improves the throughput of the network by eliminating redundant packets. The network has been designed by considering 300 nodes in a network and the results have been drawn in terms of network throughput, packet delivery ratio and energy consumption. The results are presented in comparison with conventional well-known information-fusion-based role assignment (InFRA) and data routing for in-network aggregation (DRINA) routing schemes. The results prove that the proposed NCBPR scheme delivers significant improvement, such as throughput which increased by 21.38 and 12.13%, packet delivery ratio improved by 24.73 and 11.38%, and sensors node's energy consumption is decreased by 61.46 and 44.35% as compared to conventional InFRA and DRINA schemes, respectively. [ABSTRACT FROM AUTHOR]

Currently, IEEE 802.11 standard for ad-hoc wireless mode is inadequate for multi-hop network. Recent efforts for the advancement of 802.11 standards, such as 11e for QoS support and 11n for high data rates (> 100 Mbps), are still limited as they are dependent on the wired infrastructure backbone and single-hop wireless communication. One major challenge in quality-of-service (QoS) oriented routing in wireless ad-hoc networks is to find a route that satisfies multiple constraints including energy consumption minimization, delay, node failure and throughput maximization. In this paper, we propose a novel Dynamic Energy Efficient Routing (DEER) protocol that guarantees message delivery, maximum network lifetime and message flow. DEER uses those specific nodes on the fly which has maximum residual energy above a defined energy level for relaying message from a source to a destination. Our proposed approach has been evaluated using realistic channel model and it demonstrates improved session lifetime and efficient data flow compared to Probabilistic Energy Profile, Efficient Hop Count Routing, Dijkstra and Random/opportunistic algorithms. In addition, DEER can lend itself easily to battery-based sensor networks or energy-harvested based sensor networks. [ABSTRACT FROM AUTHOR]

The effectiveness of wireless sensor network (WSN) in Internet of Thing (IoT) based large scale application depends on the deployment method along with the routing protocol. The sensor nodes are an important component of WSN-assisted IoT network running on limited and non-rechargeable energy resource. The performance of WSN-assisted IoT is decreased, when network is deployed at large area. So, developing robust and energy-efficient routing protocol is a challenging task to prolong the network lifetime. In contrast to the state-of-the-art techniques this paper introduces Scalable and energy efficient routing protocol (SEEP). SEEP leverages the multi-hop hierarchical routing scheme to minimize the energy consumption. To achieve scalable and energy efficient network, SEEP employs a multi-tier based clustering framework. The network area in SEEP is divided into various zones with the help of proposed subarea division algorithm. The number of zones in the network are increased as the network size increases to avoid long-distance communication. Every zone is divided into certain number of clusters (sub-zones) and the number of clusters are increased towards the base station, whereas the zone width is decreased. In every cluster, some of the optimal nodes are promoted as a Relay Node (RN) and Cluster Head (CH). Normal nodes send their sensed data to the base station via local RN and CH in a multi-hop way. Furthermore, propose protocol provides a trade-off between distance and energy to prolong the network lifetime. In the proposed framework, static and mobile scenarios have been considered by applying Random walk and Random waypoint model for node mobility in simulation to make it more realistic as the various application of WSN-assisted IoT. The effectiveness of SEEP is examined against LEACH, M-LEACH, EA-CRP, TDEEC, DEEC, SEP, and MIEEPB, and result indicates that SEEP performs better for different network metrics: network lifetime, scalability, and energy efficiency. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are one of the key enabling technologies for the internet of things (IoT). WSNs play a major role in data communications in applications such as home, health care, environmental monitoring, smart grids, and transportation. WSNs are used in IoT applications and should be secured and energy efficient in order to provide highly reliable data communications. Because of the constraints of energy, memory and computational power of the WSN nodes, clustering algorithms are considered as energy efficient approaches for resource-constrained WSNs. In this paper, we present a survey of the state-of-the-art routing techniques in WSNs. We first present the most relevant previous work in routing protocols surveys then highlight our contribution. Next, we outline the background, robustness criteria, and constraints of WSNs. This is followed by a survey of different WSN routing techniques. Routing techniques are generally classified as flat, hierarchical, and location-based routing. This survey focuses on the deep analysis of WSN hierarchical routing protocols. We further classify hierarchical protocols based on their routing techniques. We carefully choose the most relevant state-of-the-art protocols in order to compare and highlight the advantages, disadvantage and performance issues of each routing technique. Finally, we conclude this survey by presenting a comprehensive survey of the recent improvements of low-energy adaptive clustering hierarchy routing protocols and a comparison of the different versions presented in the literature. [ABSTRACT FROM AUTHOR]

Sensor node energy constraint is considered as an impediment in the further development of the Internet of Things (IoT) technology. One of the most efficient solution is to combine between compressive sensing (CS) and routing techniques. However, this combination faces many challenges that makes it an attractive point for research. This paper proposes an Efficient Multi-hop Cluster-based Aggregation scheme using Hybrid CS (EMCA-CS) for IoT based heterogeneous wireless sensor networks (WSNs). EMCA-CS efficiently combines between CS and routing protocols to extend the network lifetime and reduces the reconstruction error. EMCA-CS includes the following: a new algorithm to partition the field into various hexagonal cells (clusters) and based on multiple criteria, selects a node from each cluster as cluster head (CH). Each CH will then compress its cluster data using hybrid CS method. Also, a new Grey Wolf based algorithm to create optimal path for CHs to deliver the compressed data to base station (BS) and a CSMO-GWO algorithm to optimize the CS matrix construction process is introduced. Moreover, a new Grey Wolf and reversible Greedy based Reconstruction Algorithm is proposed to recover the actual data. The simulation results indicate that the performance of the proposed work exceeds the existing baseline techniques in terms of prolonging WSN lifetime, reducing the power consumption and reducing normalized mean square error. [ABSTRACT FROM AUTHOR]

Energy conservation is the main issue in wireless sensor networks. Many existing clustering protocols have been proposed to balance the energy consumption and maximize the battery lifetime of sensor nodes. However, these protocols suffer from the excessive overhead due to repetitive clustering resulting in high-energy consumption. In this paper, we propose energy-aware cluster-based routing protocol (ECRP) in which not only the cluster head (CH) role rotates based on energy around all cluster members until the end of network functioning to avoid frequent re-clustering, but also it can adapt the network topology change. Further, ECRP introduces a multi-hop routing algorithm so that the energy consumption is minimized and balanced. As well, a fault-tolerant mechanism is proposed to cope up with the failure of CHs and relay nodes. We perform extensive simulations on the proposed protocol using different network scenarios. The simulation results demonstrate the superiority of ECRP compared with recent and relevant existing protocols in terms of main performance metrics. [ABSTRACT FROM AUTHOR]

In this paper, we propose a data aggregation back pressure routing (DABPR) scheme, which aims to simultaneously aggregate overlapping routes for efficient data transmission and prolong the lifetime of the network. The DABPR routing algorithm is structured into five phases in which event data is sent from the event areas to the sink nodes. These include cluster-head selection, maximization of event detection reliability, data aggregation, scheduling, and route selection with multi attributes decision making metrics phases. The scheme performs data aggregation on redundant data at relay nodes in order to decrease both the size and rate of message exchanges to minimize communication overhead and energy consumption. The proposed scheme is assessed in terms of packet delivery, network lifetime, ratio, energy consumption, and throughput, and compared with two other well-known protocols, namely "information-fusion-based role assignment (InFRA)" and "data routing for in-network aggregation (DRINA)", which intrinsically are cluster and tree-based routing schemes designed to improve data aggregation efficiency by maximizing the overlapping routes. Meticulous analysis of the simulated data showed that DABPR achieved overall superior proficiency and more reliable performance in all the evaluated performance metrics, above the others. The proposed DABPR routing scheme outperformed its counterparts in the average energy consumption metric by 64.78% and 51.41%, packet delivery ratio by 28.76% and 16.89% and network lifetime by 42.72% and 20.76% compared with InFRA and DRINA, respectively. [ABSTRACT FROM AUTHOR]

Solutions for energy hole problem in wireless sensor networks (WSNs) have been excessively explored using mobile sink (MS). Although, MS provides a considerable amount of energy saving and extends network lifetime. However, MS introduces varying degree of data acquisition latency depending on the trajectory followed. Therefore, rendezvous based data acquisition methods are proposed to mitigate this issue which are aimed to provide a trade-off between energy consumption and data acquisition latency. There exists a list of surveys that focus on issues related to sink mobility such as mobility aware energy efficient data acquisition schemes, mobility aware data acquisition and routing, etc. However, none of these surveys concern about the issue of providing a trade-off between energy consumption and data acquisition latency. Therefore, this review addresses the same issue and presents a taxonomy of rendezvous based data acquisition methods along with the design goals and associated designing requirements. The methods are grouped into two categories: rendezvous point (RP) based and rendezvous area (RA) based. Furthermore, a phase-wise comprehensive overview of these methods is provided which clearly unfold the way of resolving the targeted issue. Finally, the research issues and challenges are discussed in pursuit of data acquisition by MS. [ABSTRACT FROM AUTHOR]

With the rapid development in ubiquitous smart sensors, wireless sensor networks have started to evolve into numerous applications including healthcare, medical, agriculture, transportation, industry, internet of things, and smart cities. However, satisfying Quality of Service (QoS) requirements of the diverse application domains remains a challenging issue due to heterogeneous traffic flows, dynamic network conditions, and resource-constrained nature of sensor nodes. In this regard, application-specific QoS provisioning techniques have received considerable research attention at the network layer. This paper presents a systematic review on the QoS mechanisms that have been employed by routing protocols and also highlights the performance issues of each mechanism. Afterwards, the survey presents a comparative analysis of computational intelligence based QoS-aware routing protocols with their strengths and limitations. Finally, this survey discusses various potential directions for future research in the field of QoS provisioning at network layer. [ABSTRACT FROM AUTHOR]

Geographical routing is a prominent area of research in wireless networks where route establishment is based on known locations of wireless nodes. The location may be an exact physical location or virtual location. Many geographical routing protocols based on greedy and face routing approach have been designed for 2D networks, but these protocols may not be suitable in 3D environment like hill area, airborne networks, underground networks, underwater networks and so forth. The objective of this paper is to provide the research issues and challenges of geographical routing in the three-dimensional surface. These routing techniques suffer from many problems like energy efficiency, localization, mobility, load balancing, routing stretch, void node problems, etc. These issues have been addressed in the literature survey. In this paper, the recent research papers related to geographical routing have been discussed, but the main focus is on 3D geographic routing techniques, issues and challenges. [ABSTRACT FROM AUTHOR]

Low-rate wireless sensor networks based on the IEEE 802.15.4 standard are widely used for gathering information from wireless sensors. Such data aggregation requires the deployment of route tree structure for "many-to-one" routing scheme. In this article, we propose energy-saving routing metric, which takes into account both link quality and node initial energy values. For more detailed research, experimental measurements of relationships between packet delivery ratio and link quality have been performed. The results of these experiments were used in simulation and performance analysis of proposed metric. Developed model of WSN allows to simulate network operation at presence of message retransmissions, which can be needed at low quality links. The performance comparison with a number of existing routing metrics (HopCount, ZigBee, ETX, LE-RPL metrics) has been provided. Results of the comparison shows that proposed metric significantly improves network lifetime and average node lifetime in the case of wide dispersed initial energy of sensor nodes. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc networks (VANETs) present an intriguing platform for several applications on e.g., intelligent transportation system (ITS) and infotainment applications aspire to be the main pattern of communication among vehicles while travelling. This can significantly impact on the amount of data exchanged by vehicles, increasing the contention on communication links and thus, degrading the quality of service of these applications. So, discrimination of data becomes imperative and forwarding critical information on suitable routes becomes decisive. Hence, a quality of service (QoS)-driven mechanism is needed to handle and assign network resources according to the stringent application data traffic demands. But, VANETs high node mobility and frequent link failure, stuck a big challenge in implementing an effective policy to meet and enforce these QoS requirements. A promising way to tackle this issue is to enforce QoS at the network layer, since it is the crucial point in VANETs' communication. So, over the years, many QoS-aware routing protocols were specifically conceived for VANETs. In this paper, we present a comprehensive survey of QoS-aware routing protocols in VANETs' literature. We examined the protocols based on their ability to support ITS infotainment services, their multi-constraint path problem (MCP), protocol's functionality and weakness, objectives and design challenges. This way, we outline future directions for VANETs QoS-aware protocol research. [ABSTRACT FROM AUTHOR]

Fault resilient routing is a typical issue for underwater wireless sensor networks ( UWSNs ) due to contact of underwater creatures, mobility of nodes and natural disaster. In the existing studies, most of the researchers introduced routing scheme for routing the packets towards the base station through a cluster head. However, these schemes use static or mobile nodes for deployment, but nodes move from its original position to another position and get stuck in a particular region due to ocean current, natural disaster and environmental interference. Therefore, this leads to high energy depletion, link failure, disjoint path and overloaded data. To resolve this issue, we have proposed fault resilient routing based on moth flame optimization ( MFO ) scheme for transferring the packets towards the base station through autonomous underwater vehicles ( AUVs ). In this scheme, AUVs is used instead of cluster head to avoid the reclustering, overloading problem and it also feasible for large scale networks. There may be a disjoint path issue, so we have deployed additional mobile nodes with the help of AUVs within the network. Further, a novel fitness function is integrated with the MFO scheme to overcome the link failure problem. The proposed scheme is applied to select the best forwarding node for transmitting the packets towards the nearest AUVs using multi-hop acoustic links. In UWSNs , AUVs is placed to move the packets towards the BS from lower level to upper level. Performance evaluation of proposed scheme shows better result in terms of fault resilient, residual energy, network lifetime, packet delivery ratio and convergence rate than the existing scheme under the different network scenario. [ABSTRACT FROM AUTHOR]

In a mobile sensor network with a mobile sink, choosing the next hop depends on the current location of the sink. This necessitates a frequent update of routing paths within the network. In this paper, a link quality indicator (LQI) measured by a sensor when receiving a POLLING packet directly from the sink is employed to acquire the relative position of the sensor to the sink. By doing so, the sensor chooses the next hop with a higher LQI value (alternatively, closer to the mobile sink). Due to the heterogeneity of transmission power and for guaranteeing the reachability of the chosen next hop, an energy-efficient and reliable LQI-based beaconless routing (LQI-BLR) protocol is proposed in this paper. To avoid flooding REPOLLING packets, only the sensors with low LQI values are allowed to broadcast the REPOLLING packet to create a routing path for the sensors outside the transmission range of the sink. Through analytical and simulation approaches, the performance of LQI-BLR and the leader-based routing (LBR) Burgos et al. (Sensors 17(7):1587, 2017. 10.3390/s17071587) is compared. With extensive real-scenario simulations, we successfully show that LQI-BLR outperforms LBR Burgos et al. (Sensors 17(7):1587, 2017. 10.3390/s17071587) and the data-driven routing protocol (DDRP) Shi et al. (Int J Commun Syst 26(10):1341–1355, 2013. 10.3390/s17071587 in terms of packet delivery ratio, energy consumption, and packet delivery delay. [ABSTRACT FROM AUTHOR]

The increasing usage of wireless sensor networks in human life is an indication of the high importance of this technology. Holes in wireless sensor networks are non-operating areas that can happen for a variety of reasons, like natural obstacles and disasters. Detection and packet routing in the presence of holes have always been the main challenges of facing this technology. As a result, most of the research on wireless sensor networks has been concerned with the problem of routing through bypassing routing holes. Considering the fact that the hole detection method for transmitting data in wireless sensor networks has a considerable impact on the energy consumption of the network, this paper attempts to provide a solution in the field of routing with the aim of increasing the network lifetime. In this method, considering networks with a dynamic hole, a distributed algorithm is proposed that can quickly determine and update the hole boundary. According to the hole, the packets are guided along an escape path around the hole which can improve and extend network lifetime. Results of experimental simulation are compared with the well-known and successful routing methods in the wireless sensor networks. This comparison shows that the proposed method reduces the dead nodes by at least 11% and 8% considering the effect of the time and the number of the nodes, in turn. Furthermore, the network lifetime has been improved by 2.71% based on the effect of the time and 1.47% based on the number of the nodes. [ABSTRACT FROM AUTHOR]

Recently, the routing protocol for low power and lossy networks (RPL) was standardized and is considered as the default standard for routing over the low power and lossy networks. However, it has not been optimized to work effectively, especially under mobility, and suffers from frequent disconnections that result in packet loss and increased energy consumption. In this paper, an enhanced mobility routing protocol for wireless sensor network (EM-RPL) that incorporates modules to support the mobility of nodes has been proposed. The main goal of the EM-RPL is to increase network reliability and efficiency by selecting a route that is more stable and reduces the frequency of route discovery process. The performance of the proposed EM-RPL has been evaluated in the Contiki-based Cooja simulator and compared with the performance of other protocols that support mobility in the RPL. The simulation results demonstrated that the EM-RPL improves the packet delivery ratio and minimizes power consumption by allowing the mobile nodes to select a more stable path. [ABSTRACT FROM AUTHOR]

Multimedia transmission in wireless multimedia sensor network requires restricted quality of services (QoS) conditions. Where the resource-constrained nature of wireless multimedia sensor network (WMSNs) adds more challenges. Such a situation demands a routing strategy that can ensure QoS transmission and exploit the resources efficiently. At present, the single-path routing techniques cannot guarantee the end to end QoS requirements of video transmission causing the video quality degradation. Besides, the traditional network layers stack is not suitable for dynamic wireless sensor network environment, where important information is required from nonadjacent layers to enhance the routing decision. This paper proposes the design of cross-layer multipath routing (CLMR) scheme in order to ensure QoS and minimize energy consumption. CLMR is designed to determine the suitable multipath and to send the multimedia packets according to their importance. The cross-layer design between application, network and physical layers is adapted to obtain optimal routing decision. The simulation results show that the CLMR has a significant improvement in performance as compared to other similar existing protocols, where the obtained average delay with high delivery is less than 150 ms, while the energy consumption is reduced, and the PSNR values for the tested clips are more than 30 db. [ABSTRACT FROM AUTHOR]

An efficient routing protocol for a wireless sensor network (WSN) with multiple sinks is proposed. Sensor nodes containing three-sector antennas are deployed randomly in a monitoring area. All sensors discover and record their neighbors' locations, including those of the sink(s), with minimal control overhead. In routing, sensor nodes forward their data to a sink either directly by at most two hops or through a number of intermediate nodes, using their alternative sectors. The sensor nodes that are one or two hops away from a sink may follow the first route, and a major portion of the remaining sensors follow the second route. Each sensor in this case forwards the sensed data to a neighbor through one of the sectors, and the data are further forwarded by alternative sectors of the successive nodes until reaching a sink. An analysis for the proposed routing is provided, focusing on the second routing mechanism, where the success of data reaching a sink with different sector orientations of the sensor nodes is shown. An in-depth analysis of the proposed WSN and simulation using OMNeT++ are performed, and satisfactory results are found. [ABSTRACT FROM AUTHOR]

Enhancing the quality of service is the crucial issue of future wireless networks. In this paper, we propose a new multihop wireless routing protocol inspired by opportunistic resource allocation strategies that take into account the variability of the radio conditions due to path loss, shadowing and multipath fading. Thanks to this knowledge, our proposition dynamically adapts the selected path accross time. The adaptation is function of each link state and the amount of channel information available. This allows to improve system performance in terms of delay and throughput. This solution can be used in all multihop wireless contexts but can have a special interest in wireless coverage zone extension context. Simulation results will show that the proposed routing protocol greatly outperforms the other existing protocols such as ad-hoc on-demand distance vector, optimized link state routing and extremely opportunistic routing protocols reducing mean packet delays by more than 50% in several scenarii. [ABSTRACT FROM AUTHOR]

With the emergence of the Internet of Things (IoT) in recent years, the security has been significantly called more and more people's attention on wireless communication between the devices and the human-beings, as well as the devices to devices. Smart home (SH), as a small-scale example of the smart application-based field, has benefited from the concept of IoT since it uses an indoor data-centric sensor network. In SH, routing schemes are widely utilized for data aggregation purposes. However, there are three main issues, which can considerably affect the current execution of routing protocol in SH: (1) lack of technical methods for precisely regional division of the network, (2) the difficulty of differentiating data among various functional regions, and (3) the vulnerability of network with advanced internal routing attacks. To address the aforementioned issues, in this paper, a two-layer cluster-based network model for indoor structured SH and a novel Beta-based trust management (BTM) scheme are proposed to defend various types of internal attacks by integrating the variation of trust value, threshold, and evaluation. The proposed structure forms a secure hierarchical routing protocol called SH-PCNBTM to effectively support the data transmission service in SH networks. The performance of SH-PCNBTM is thoroughly evaluated by using a set of comprehensive simulations. We will show that the proposed routing protocol not only ensures the even distribution of cluster-heads in each sub-region, but it also identifies and isolates the malicious sensor nodes accurately and rapidly compared with other trust-based hierarchical routing protocols. [ABSTRACT FROM AUTHOR]

In a wireless sensor network, one of the most important constraints on sensor nodes is their power source, which is a battery. Sensor nodes carry a limited and generally irreplaceable battery. When providing a routing protocol for WSNs, it is necessary to take the energy constraint of sensor nodes into consideration. In this paper, a new routing algorithm based on a mobile sink is proposed. In the proposed algorithm, data is forwarded from the sensor nodes to the sink, which moves on four determined paths, by using a virtual cellular structure. In this algorithm when the sink moves from one cell to another, the routing in the network can be updated with minimum energy consumption and delay. The simulation results show that the proposed algorithm is more efficient than similar ones. [ABSTRACT FROM AUTHOR]

This paper proposes an opportunistic routing with data fusion (ORDF) protocol for the widely used multi-source wireless sensor networks in which the spatial-temporal correlation among sensory data is ubiquitous. In the ORDF protocol, a new routing metric, which considers the data fusion and expected any-path transmissions, is presented to select a next-hop forwarding node that could save the maximal amount of energy. A candidate set selection algorithm is proposed to find the optimal candidate set of each node. An ACK-based coordination method among candidates is also given for the design of the ORDF protocol. Simulation results show that the ORDF protocol can greatly improve the network lifetime and reduce the network delay compared to general opportunistic routing protocol, such as ExOR, EEOR and OAPF. With increase of the number of source nodes, the ORDF protocol has more significant advantages in prolonging the network lifetime and reducing the network delay. [ABSTRACT FROM AUTHOR]

Routing protocols in wireless sensor networks are critical as they affect performance, lifetime and scaling. A novel approach to collect data in sensor networks is presented in this paper. The end-user can configure devices to operate for a desired lifetime and achieve reliable operation for that duration—this is the motivation behind the development of this protocol. In the proposed protocol, data routing is controlled by a special packet—the Operator Packet. The Operator Packet circulates through the network (a) allowing nodes to report data when they need to and (b) is circulated such that it preferentially uses nodes with more data and with higher residual battery levels. Time complexity analysis of the the heuristic approach presented in this paper for the circulation algorithm takes O(n) time. The algorithm creates an opportunistic routing condition—the nodes operate only if their battery levels permit. This leads to controllable lifetime, with average lifetimes achieved by the nodes being as high as 99% of the preconfigured targets. If nodes in the network are configured with similar target lifetimes, a highly synchronised network death is possible. Compared to the Low Energy Adaptive Clustering Hierarchy (LEACH) protocol and Hybrid Energy Efficient Distributed clustering protocol (HEED), the proposed protocol achieves higher lifetimes (60 and 165% respectively) and improved Coefficient of Synchronous Death (17 and 102% respectively). A corrective method to achieve reduced data drops in deployments is also suggested and analysed. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc network (VANET), a special type of mobile ad-hoc networks (MANETs), is characterized by a very high mobility. Due to the dynamic nature of vehicle nodes and unstable wireless links, the design of an efficient and effective routing scheme is serious challenging for VANETs. Thus, proposing a reliable routing protocol for important data dissemination is essential for VANETs. In this paper, a clustering-based routing protocol is introduced where nodes are clustered according to movement information such as node degree and velocity of vehicles by means of imperialist competitive algorithm. Then, the cluster head is selected by means of radial basis function neural network algorithm according to amount of free buffer space and expected transmission count. Simulation results indicated that the proposed scheme improves the other related algorithms in terms of the parameters of packet delivery rate, throughput and end-to-end delay. [ABSTRACT FROM AUTHOR]

The advances in hardware manufacturing technologies and wireless communications enabled the evolution of tiny, multi-functional, low-power and resource constrained sensor nodes (SNs) for wireless sensor networks (WSNs). SNs located in sinks vicinity, deplete their batteries quickly because of concentrated data traffic near the sink, leaving the data reporting wrecked and disrupted. In order to mitigate this problem, mobile sinks are introduced that provide uniform energy consumption and load balanced data delivery through the sensor network. However, advertising the mobile sinks position information brings forth additional overhead in terms of energy wastage. Recently, an energy-efficient distributed mobile sink routing protocol named ring routing has been proposed aiming to mitigate the introduced overhead. In this present work, we propose an Energy Efficient Secured Ring Routing ( E 2 S R 2 ) protocol which is an enhancement of existing ring routing protocol [62] that considers rechargeable sensors to be deployed in the sensing region and employs Maximum Capacity Path (MCP), a dynamic load balanced routing scheme for load balancing and prolonging the networks lifetime. Furthermore, we use 2ACK scheme that serves as an efficient mechanism for detecting the routing misbehaviour and simultaneously enhance the security. Finally, the proposed protocol was simulated by varying the sink speed for similar node deployments and the results obtained confirm that the proposed E 2 S R 2 achieves improved performance than the existing protocols such as LBDD (Line Based Data Dissemination), rail road and ring routing. [ABSTRACT FROM AUTHOR]

Wireless nanonetworks are not a simple extension of traditional communication networks at the nano-scale. Owing to being a completely new communication paradigm, existing research in this field is still at an embryonic stage. Furthermore, most of the existing studies focus on performance enhancement of nanonetworks via designing new channel models and routing protocols. However, the impacts of different types of nano-antennas on the network-level performances of the wireless nanonetworks remain still unexplored in the literature. Therefore, in this paper, we explore the impacts of different well-known types of antennas such as patch, dipole, and loop nano-antennas on the network-level performances of wireless nanonetworks. We also investigate the performances of nanonetworks for different types of traditional materials (e.g., copper) and for nanomaterials (e.g., carbon nanotubes and graphene). We perform rigorous simulation using our customized ns-2 simulation to evaluate the network-level performances of nanonetworks exploiting different types of nano-antennas using different materials. Our evaluation reveals a number of novel findings pertinent to finding an efficient nano-antenna from its several alternatives for enhancing network-level performances of nanonetworks. Our evaluation demonstrates that a dipole nano-antenna using copper material exhibits around 51% better throughput and about 33% better end-to-end delay compared to other alternatives for large-size nanonetworks. Furthermore, our results are expected to exhibit high impacts on the future design of wireless nanonetworks through facilitating the process of finding the suitable type of nano-antenna and suitable material for the nano-antennas. [ABSTRACT FROM AUTHOR]

In this article, we propose a novel routing algorithm for wireless sensor network, which achieves uniform energy depletion across all the nodes and thus leading to prolonged network lifetime. The proposed algorithm, divides the Region of Interest into virtual zones, each having some designated cluster head nodes. In the entire process, a node can either be a part of a cluster or it may remain as an independent entity. A non-cluster member transmits its data to next hop node using IRP-Intelligent Routing Process (based on the trade-off between the residual energy of itself as well as its neighbor, and the required energy to transmit packets to its neighbor). If on the transmission path, some cluster member is elected as a next hop, it rejects IRP and transmits the packets to cluster head, which later forwards them to sink (adopting multihop communication among cluster heads). Routing is not solely performed using clusters, rather they aid the overall routing process, hence this protocol is named as Cluster Aided Multipath Routing (CAMP). CAMP has been compared with various sensor network routing protocols, viz., LEACH, PEGASIS, DIRECT TRANSMISSION, CEED, and CBMR. It is found that the proposed algorithm outperformed them in network lifetime, energy consumption and coverage ratio. [ABSTRACT FROM AUTHOR]

With long delays due to sporadic routing links in cognitive vehicular communications systems, relay node selection is one of the key design factors, as it significantly improves end-to-end delay, thereby improving overall network performance. To this end, we propose infrastructure-aided hybrid routing that uses a roadside unit (RSU) to help vehicular nodes to select idle channels and relay nodes. Channel selection is done with a belief propagation algorithm, which aggregates individual beliefs with the help of vehicles and RSUs to make a final belief, providing high accuracy in hypotheses about spectrum availability. The selection of a relay node is determined by calculating the message delivery time—the source/relay node selects the one that has the minimum message delivery time from among all the neighboring nodes. This is a hybrid (vehicle-to-vehicle and vehicle-to-RSU) communications scheme where two nodes can communicate only when they have consensus about a common idle channel. The idea is to combine cognitive capabilities with a routing technique in order to simultaneously overcome spectrum scarcity and network connectivity issues. Therefore, both dense and sparse network conditions are considered in this routing protocol for both highway and city scenarios. To enhance the stability of cognitive routing links, different functions for vehicles and RSUs are considered. We prove better performance in delay, delivery ratio, and overhead by comparing the proposed technique with two existing techniques (one dealing with, and another without, RSUs). [ABSTRACT FROM AUTHOR]

Due to the technological advancement in Low Power and Lossy Networks (LLNs), sensor node mobility becomes a basic requirement for many extensive applications. Routing protocol designed for LLNs must ensure real-time data transmission with minimum power consumption. However, the existing mobility support protocols cannot work efficiently in LLNs as they are unable to adapt to the change in the network topology quickly. Therefore, we propose an Enhanced Routing Protocol for LLNs (ERPL), which updates the Preferred Parent (PP) of the Mobile Node (MN) quickly whenever the MN moves away from the already selected PP. Further, a new objective function that takes the mobility of the node into an account while selecting a PP is proposed. Performance of the ERPL has been evaluated with the varying system and traffic parameters under different topologies similar to most of the real-life networks. The simulation results showed that the proposed ERPL reduced the power consumption, packet overhead, latency and increased the packet delivery ratio as compared to other existing works. [ABSTRACT FROM AUTHOR]

Maintaining durable connectivity during data forwarding in Vehicular Ad hoc Networks has witnessed significant attention in the past few decades with the aim of supporting most modern applications of intelligent transportation systems. Various techniques for next hop vehicle selection have been suggested in the literature. Most of these techniques are based on selection of next hop vehicles from fixed forwarding region with two or three metrics including speed, distance and direction, and avoid many other parameters of urban environments. In this context, this paper proposes a Multi-metric Geographic Routing (M-GEDIR) technique for next hop selection. It selects next hop vehicles from dynamic forwarding regions, and considers major parameters of urban environments including, received signal strength, future position of vehicles, and critical area vehicles at the border of transmission range, apart from speed, distance and direction. The performance of M-GEDIR is evaluated carrying out simulations on realistic vehicular traffic environments. In the comparative performance evaluation, analysis of results highlight the benefit of the proposed geographic routing as compared to the state-of-the-art routing protocols. [ABSTRACT FROM AUTHOR]

Mobile ad hoc networks (MANETs) are becoming an emerging technology that offer several advantages to users in terms of cost and ease of use. A MANET is a collection of mobile nodes connected by wireless links that form a temporary network topology that operates without a base station and centralized administration. Routing is a method through which information is forwarded from a transmitter to a specific recipient. Routing is a strategy that guarantees, at any time, the connection between any two nodes in a network. In this work, we propose a novel routing protocol inspired by the cuckoo search method. Our routing protocol is implemented using Network simulator 2. We chose Random WayPoint model as our mobility model. To validate our work, we opted for the comparison with the routing protocol ad hoc on-demand distance vector, destination sequence distance vector and the bio-inspired routing protocol AntHocNet in terms of the quality of service parameters: packet delivery ratio and end-to-end delay (E2ED). [ABSTRACT FROM AUTHOR]

Recently, Underwater Wireless Sensor Networks (UWSNs) has witnessed significant attention from both academia and industries in research and development, due to the growing number of applications for wide range of purposes including commercial, scientific, environmental and military. Some of the major applications include pollution monitoring, tactical surveillance, tsunami warnings and offshore exploration. Efficient communication among sensors in UWSNs is a challenging task due to the harsh environments and peculiar characteristics of UWSNs. Therefore, design of routing protocol for efficient communication among sensors and sink is one of the fundamental research themes in UWSNs. In this context, this paper proposes a location-free Reliable and Energy efficient Pressure-Based Routing (RE-PBR) protocol for UWSNs. RE-PBR considers three parameters including link quality, depth and residual energy for balancing energy consumption and reliable data delivery. Specifically, link quality is estimated using triangle metric method. A light weight information acquisition algorithm is developed for efficient knowledge discovery of the network. Multi-metric data forwarding algorithm is designed based on route cost calculation which utilizes residual energy and link quality. Simulations are carried out in NS-2 with Aqua-Sim package to evaluate the performance of RE-PBR. The performance of the proposed protocol is compared with the stat-of-the-art techniques: DBR and EEDBR. The comprehensive performance evaluation attests the benefit of RE-PBR as compared to the state-of-the-art techniques in terms of network lifetime, energy consumption, end-to-end delay and packet delivery ratio. [ABSTRACT FROM AUTHOR]

The improvement of sensor networks’ lifetime has been a major research challenge in recent years. This is because sensor nodes are battery powered and may be difficult to replace when deployed. Low energy adaptive clustering hierarchical (LEACH) routing protocol was proposed to prolong sensor nodes lifetime by dividing the network into clusters. In each cluster, a cluster head (CH) node receives and aggregates data from other nodes. However, CH nodes in LEACH are randomly elected which leads to a rapid loss of network energy. This energy loss occurs when the CH has a low energy level or when it is far from the BS. LEACH with two level cluster head (LEACH-TLCH) protocol deploys a secondary cluster head (2CH) to relieve the cluster head burden in these circumstances. However, in LEACH-TLCH the optimal distance of CH to base station (BS), and the choicest CH energy level for the 2CH to be deployed for achieving an optimal network lifetime was not considered. After a survey of related literature, we improved on LEACH-TLCH by investigating the conditions set to deploy the 2CH for an optimal network lifetime. Experiments were conducted to indicate how the 2CH impacts on the network at different CH energy levels and (or) CH distance to BS. This, is referred to as factor-based LEACH (FLEACH). Investigations in FLEACH show that as CHs gets farther from the BS, the use of a 2CH extends the network lifetime. Similarly, an increased lifetime also results as the CH energy decreases when the 2CH is deployed. We further propose FLEACH-E which uses a deterministic CH selection with the deployment of 2CH from the outset of network operation. Results show an improved performance over existing state-of-the-art homogeneous routing protocols. [ABSTRACT FROM AUTHOR]

Single-path routing is widely used in wireless networks due to low resource consumption. However, it is vulnerable to link failure because such a failure may adversely affect an entire path. To overcome this, multipath routing has been proposed providing fault-tolerance. In this paper, we propose a novel multipath routing protocol called traffic-aware stateless multipath routing (TSMR) based on an overlaid tree topology comprising two topologies, namely, bounded degree tree (BDT) and root-oriented directional tree (RODT). BDT is strong on reducing routing overhead, and RODT is resilient against lossy links. By synergistically overlaying them, TSMR dynamically selects the local optimal path according to the given traffic flow and the failure on the primary path. In particular, TSMR enables stateless and low overhead routing despite multipath routing by keeping only one-hop neighbors to maintain multiple paths. To evaluate TSMR, we conducted simulations with a shadowing model reflecting lossy links, and compared with single and multipath routing protocols, such as ZTR, STR, AODV, and RPL. The simulation results show that the overall performance of TSMR surpasses that of others for packet delivery ratio, end-to-end delay, control overhead, memory consumption, and power consumption regardless of network size, number of sessions, and traffic flow. [ABSTRACT FROM AUTHOR]

In this paper, we propose a statistical Call Admission Control (CAC) schemes for single and multi-hop IEEE 802.11 based wireless ad hoc networks. Unlike most papers which consider average end-to-end delay, our algorithm guarantees statistical delay that would be more efficient for real time multimedia applications. We use Effective Bandwidth/Effective Capacity theory to compute delay bound stochastically in each hop. The proposed distributed CAC algorithm is suitable for ad hoc networks. Also, with a few changes, it has been implemented in the AODV routing protocol. Simulation results demonstrate that proposed CAC algorithm works efficiently in both single and multi-hop networks. Moreover, we investigated our algorithm with aggregated traffic and the result shows that the algorithm performed accurately under that condition. [ABSTRACT FROM AUTHOR]

Delay tolerant networks (DTNs) are characterized by delay and intermittent connectivity. Satisfactory network functioning in a DTN relies heavily on co-ordination among participating nodes. However, in practice, such co-ordination cannot be taken for granted due to possible misbehaviour by relay nodes. Routing in a DTN is, therefore, vulnerable to various attacks, which adversely affect network performance. Several strategies have been proposed in the literature to alleviate such vulnerabilities-they vary widely in terms of throughput, detection time, overhead etc. One key challenge is to arrive at a tradeoff between detection time and overhead. We observe that the existing table-based reactive strategies to combat Denial-of-service (DoS) attacks in DTN suffer from two major drawbacks: high overhead and slow detection. In this paper, we propose three secure, light-weight and time-efficient routing algorithms for detecting DoS attacks (Blackhole and Grey-hole attacks) in the Spray & Focus routing protocol. The proposed algorithms are based on use of a small fraction of privileged (trusted) nodes. The first strategy, called TN, outperforms the existing table-based strategy with 20-30 % lesser detection time, 20-25 % higher malicious node detection and negligible overhead. The other two strategies, CTN_MI and CTN_RF explore the novel idea that trusted nodes are able to utilize each others' information/experience using their long range connectivity as and when available. Simulations performed using an enhanced ONE simulator reveals that investing in enabling connectivity among trusted nodes (as in CTN_RF) can have significant performance benefits. [ABSTRACT FROM AUTHOR]

A mobile ad-hoc network (MANET) is composed of mobile nodes without any infrastructure where member nodes easily can leave or join the network. This issue provides a dynamic topology network such that providing quality of service and multicast services are very challenging tasks. The majority of applications of MANETs are in rapid deployment and dynamic reconfigurations. For these reasons, in this paper, we present an efficient fuzzy logic based multicast routing scheme to adaptively manage the network resources without any prior knowledge about network traffic. Every source node self-organizes the multicast session by using average end to end delay and packet delivery ratio parameters in order to dynamically adjust its own sending rate. The proposed method is a novel framework for multicast services such that it can be deployed by both tree-based and mesh-based multicast routing protocols. In addition, The proposed method uses a cross-layer technique to efficiently manage the congestion. The results show high improvement in terms of number of the retransmissions, delay, packet delivery ratio and overhead compared to the existing multicast schemes. [ABSTRACT FROM AUTHOR]