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Serverless computing is a new concept as cloud computing, which dynamically manages the networks and is applied in Serverless Wireless Sensor Networks (SWSN) to help the networks. These networks are becoming famous for monitoring various physical and environmental factors. Serverless computing also facilitates the networks by offering an extensive range of applications. Different applications have been designed for monitoring purposes where the sensor nodes sense the data and transmit it to the base station through single or multi-hop routing. However, existing routing protocols cannot manage the sensor nodes' energy issues because of the complex routing processes and depleted their power before their time. Because of these limitations, the nodes close to BS continuously rely on the network for data forwarding. As a result, these nodes cause energy consumption and lead to a useless state. This paper proposes a serverless architecture and designs an Enhanced Centroid-based Energy Efficient Clustering (ECEEC) protocol for SWSN networks. The proposed serverless architecture provides automated scalability, cost-effective services, and stateless execution. In addition, the proposed protocol offers the cluster head selection and its rotation to maximize the energy efficiency in the network. Furthermore, gateway nodes are chosen in every cluster to overcome the load on the cluster head. Simulation results indicated the excellent performance of the proposed protocol as compared to the existing routing protocols concerning network lifetime and energy consumption. The proposed protocol shows better reliability with nodes failing at 650 rounds compared to 600 rounds, especially with 5 % and 10 % Cluster Heads. The proposed protocol exhibits superior energy efficiency consumption of SNs under varying CH percentages, indicating the protocol's consistent performance across different scenarios. [ABSTRACT FROM AUTHOR]

IEEE 802.15.4 protocol is intended to accomplish the characteristics of low power and low rate Wireless Sensor Network. It employs carrier sense multiple access with collision avoidance (CSMA/CA) protocol to access the network using either unslotted or slotted mode. This paper concentrates on the unslotted CSMA/CA where the node tends to wait for a very limited backoff exponent value, and cannot perform clear channel assessment until backoff procedure is completed. Therefore, the collision probability and the average delay are high. To enhance the unslotted CSMA/CA performance, this paper proposes a modified unslotted CSMA/CA that divides the backoff delay into Main Backoff and Secondary Backoff. The Markov model for the modified CSMA/CA is presented to assess a single hop IEEE 802.15.4 behavior, and derive expressions for average delay, energy consumption and reliability. An optimization problem is also presented to minimize the delay while guaranteeing energy consumption and reliability constraints for the modified CSMA/CA. OPNET simulation tool is applied to compare the modified to the standard unslotted CSMA, and to validate the Markov model proposed. The results demonstrate that the modified CSMA improves the reliability, while reducing the average delay significantly. [ABSTRACT FROM AUTHOR]

As the use of Wireless Sensor Networks grows, many challenging issues with these networks arise. The utilization of power consumption is one of the most significant issue due to the limited energy constraints of the individual sensor nodes. This limitation imposes a challenge to design the best energy-efficient routing mechanism. This work presented an Energy-Efficient Gossiping protocol (EEGossip) that routes data to the sink by choosing the optimal next node. EEGossip uses Chebyshev distance, residual energy and the sink distance as factors when determining the optimal next node. The result of the proposed work has shown that the proposed protocol improves the total energy consumption of the network and leverages the network lifetime since it decreases the computational overhead and ensures that the best next node is chosen. [ABSTRACT FROM AUTHOR]

Wireless sensor networks is made up of many tiny nodes that has the ability to measure physical phenomena and send the collected measurements to the sink node using multiple-hop protocol with short range transmission. One of the main factors that can be considered to increase the sensor network life is routing protocol. The main goal of routing protocol is to select the most optimal path and make decision of sending the gathering data to the sink node. Inefficient routing protocol leads to more re-transmission of data which consume more energy.Thus, a careful and comprehensive performance analysis of the routing protocols used in any wireless sensor network is required. The main goal of this paper is to study the performance of the RPL protocol under three different MAC protocols named; ContikiMac, CXMAC, NullRDC in terms of end-to-end delay, packet delivery ratio and power consumption to find the best behaviour of the RPL routing protocol under the MAC protocols effect. The results show that NullRDC is better in terms of latency while the ContikiMac outperforms the others in terms of power consumption. [ABSTRACT FROM AUTHOR]

WSN became a key technology for ubiquitous living and remains an active research due to wide range of applications. Energy awareness is a critical design issue in WSN. Clustering is the most popular energy efficient technique and provides various advantages like energy efficiency, lifetime, scalability and less delay; but it leads to hot spot problem. To overcome this, unequal clustering is proposed. In unequal clustering, the cluster size varies proportionally to the distance to Base Station (BS). Absence of recent and detailed survey papers in unequal clustering approaches stimulated us to perform this study. In this paper, a comprehensive survey of various unequal clustering approaches with their objectives, characteristics etc., is presented. Also, the classifications of unequal clustering approaches are made and compared based on various cluster properties, Cluster Head (CH) properties and clustering process. [ABSTRACT FROM AUTHOR]

As the use of Wireless Sensor Networks grows, many challenging issues with these networks arise. The utilization of power consumption is one of the most significant issue due to the limited energy constraints of the individual sensor nodes. This limitation imposes a challenge to design the best energy-efficient routing mechanism. This work presented an Energy-Efficient Gossiping protocol (EEGossip) that routes data to the sink by choosing the optimal next node. EEGossip uses Chebyshev distance, residual energy and the sink distance as factors when determining the optimal next node. The result of the proposed work has shown that the proposed protocol improves the total energy consumption of the network and leverages the network lifetime since it decreases the computational overhead and ensures that the best next node is chosen. [ABSTRACT FROM AUTHOR]

Wireless sensor networks is made up of many tiny nodes that has the ability to measure physical phenomena and send the collected measurements to the sink node using multiple-hop protocol with short range transmission. One of the main factors that can be considered to increase the sensor network life is routing protocol. The main goal of routing protocol is to select the most optimal path and make decision of sending the gathering data to the sink node. Inefficient routing protocol leads to more re-transmission of data which consume more energy.Thus, a careful and comprehensive performance analysis of the routing protocols used in any wireless sensor network is required. The main goal of this paper is to study the performance of the RPL protocol under three different MAC protocols named; ContikiMac, CXMAC, NullRDC in terms of end-to-end delay, packet delivery ratio and power consumption to find the best behaviour of the RPL routing protocol under the MAC protocols effect. The results show that NullRDC is better in terms of latency while the ContikiMac outperforms the others in terms of power consumption. [ABSTRACT FROM AUTHOR]

Abstract Mobile sink has been used by many routing algorithms to improve the network lifetime in wireless sensor networks. Sink mobility brings new challenges to the sensor network. It suggests that sink position is continuously propagated through the network area to keep all sensor nodes updated with the direction of forwarding data to the sink. Unfortunately, frequent sink position updates can lead to both high-energy consumption and increased collisions in the network. In this paper, a new routing algorithm for wireless sensor networks is proposed, which uses a virtual multi-ring shaped infrastructure to advertise the mobile sink position to the network. In addition, the proposed algorithm supports several mobile sinks in the network. Simulation results indicate that the proposed algorithm reduces energy consumption and delay, and prolongs the sensor network lifetime when compared with the other similar algorithms. [ABSTRACT FROM AUTHOR]

Abstract The Threshold-based Low-energy Adaptive Clustering Hierarchy (T-LEACH) protocol declares that cluster heads do not have to turn over every round but rather every batch of rounds. In other words, nodes keep serving as cluster heads as long as their energy is higher than a threshold energy. This article imposes upon major drawbacks of T-LEACH protocol and presents a Modified Threshold-based Cluster Head Replacement (MT-CHR) protocol. In the MT-CHR protocol, a new probability of being a cluster head, for any node in any round, has been proposed which agrees fairly with the assumptions introduced in LEACH protocol. Moreover, a new expression for threshold energy is proposed in which delaying the first node death and avoiding any data loss are taken into consideration. The performance of MT-CHR is evaluated using alive nodes, network lifetime, as well as network utilization performance metrics. The results are further compared with those obtained importantly from LEACH and T-LEACH protocols and the contributions of MT-CHR protocol are extremely impressive. As far as the real sensor network is concerned, the MT-CHR protocol is highly applicable and very effective as long-lasting networks are ascertained. [ABSTRACT FROM AUTHOR]

Abstract An important objective of cryptographic schemes is to withstand various attacks, including leakage attacks. Otherwise, leakage of the secret key may cause serious threats to the security of computer systems. However, leakage attacks have not received adequate attention in the literature. For example, most of the existing security protocols in the wireless sensor networks (WSNs) lack the consideration of leakage attacks. Instead, they are only designed in the traditional security model, in which an adversary is assumed not to obtain any information of the internal secret states. Obviously, this is not ideal because partial information of the secret key may be leaked in practice due to side channel attacks or fault injection attack. In this paper, we propose a new construction of secure continuous leakage-resilient certificate-based signcryption (CBS) scheme with access control without using bilinear pairings, and its security can be proved based on the assumptions that solving the classical decisional Diffie-Hellman problem and discrete logarithm problem is infeasible. We then propose a novel certificate-based access control scheme for the WSNs. The analysis shows that our construction not only achieves high computational efficiency in the continuous leakage setting, but also has superior performance regarding communication efficiency and storage requirement. [ABSTRACT FROM AUTHOR]

• There is no collaborative multihop LoRa protocol. Users 'nodes cannot relay each-other's messages. • MauMe assumes users have a home-node with permanent power supply (base-node) acting as a relay for all users. • MauMe is single channel and designed for a controlled flooding of messages. • Messages are acknowledged. Acknowledgments kill lost messages. • Users can activate local Wi-Fi connection to allow sending free emergency SMS using a smartphone. • MauMe has a ready-to-use Github C++ library which allows immediate deployment on ESP32 microcontrollers. • The proposed implementation respects the legal duty-cycle. Low-cost low-power long-distance LoRa radio devices recently made available on the market allow the emerging of a new generation of networking paradigms on the Internet of Things. While the LoRaWan offers an efficient way of connecting LoRa end-point devices to the internet, LoRaWan nodes do not act as peers, but rather as terminals connected to gateways. As such, the current state of the art does not offer a public protocol for easily taking advantage of the fact that individuals and professionals wishing to aggregate data using LoRa devices are likely to run each a "base-node" on a continuous basis. Such permanently-powered base-nodes could potentially offer an increased cumulated area coverage to other nodes if they would behave as relays. In the present study, an Epidemic Delay Tolerant Network messaging protocol is proposed, which allows multi-hops between peer LoRa relay-nodes through a raw-LoRa controlled-flooding approach. This protocol has been implemented on low-cost LoRa-chip-equipped microcontrollers in the form of an open-source library acting as a network transport-layer. The design analysis concluded that MauMe is better suited for networks with reduced connectivity (≤ 9), and that a 4-connectivity redundant network could allow each user to send several tens of messages several tens of hops away. The proposed approach was tested on three different LoRa network topologies, and the totality of the packets and acknowledgments reached their destination. Furthermore, the network's activity ceased after delivery, confirming the ability of the protocol to return the network to rest after the flooding. The proposed library also offers to users a free emergency-messaging system implemented as an http server embedded in each node and accessible via Wi-fi. End-users can readily use our solution to easily deploy a network of sensors at a much lower cost than when using multiple gateways. The MauMe protocol is a first step towards the creation of collaborative and application-friendly extended-range LoRa-peers networks, and is intended for use in remote regions with scattered housings such as in the islands and atolls of Polynesia. [ABSTRACT FROM AUTHOR]

Abstract Wireless Sensor Networks (WSNs) have emerged as one of the prominent area of research in the recent times. Sensor-MAC (S-MAC) protocol is one of the Medium Access Control(MAC)protocols, which follows the idea of periodic listen and sleep. In other words, node is active till the time it receives the data packets, otherwise it goes in sleep mode by turning its radio off. However, this protocol lacks in energy conservation due to unnecessary listening to the channel in idle mode. In this paper, we have proposed a new analytical model in which energy is reduced on the basis of the activities it performs in the active mode. A comparison is made between all the different possibilities which can occur at a node, when it listens unnecessarily to the medium. Various energy consuming modes of S-MAC protocol such as transmission, reception, sensing and listening are considered. The proposed work results in the minimizing the energy and reducing the delay in time as compared to that of basic S-MAC protocol. [ABSTRACT FROM AUTHOR]

In modern era WSN, data aggregation technique is the challenging area for researchers from long time. Numbers of researchers have proposed neural network (NN) and fuzzy logic based data aggregation methods in Wireless Environment. The main objective of this paper is to analyse the existing work on artificial intelligence (AI) based data aggregation techniques in WSNs. An attempt has been made to identify the strength and weakness of AI based techniques. In addition to this, a modified protocol is designed and developed. And its implementation also compared with other existing approaches ACO and PSO. Proposed approach is better in terms of network lifetime and throughput of the networks. In future an attempt can be made to overcome the existing challenges during data aggregation in WSN using different AI and Meta heuristic based techniques. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSNs) are harshly challenged by limited energy. It’s essential to use available energy in efficient manner to maintain sustainability in networks. Sensor nodes once after deployment start depleting their energy in various roles; some may on sensing; some may on communication, some may on aggregating etc. After intense survey its proven fact that communication is the biggest reason of energy consumption. To reduce communication energy requirements clustering plays a very important role. Clustering employs that only cluster heads will participate for communicating aggregated information to far located base station. Challenge comes when cluster heads are managing both roles as heads as well as relay nodes. The role of relay node may require that they are aggregating and communicating their own data as well as other data received due to multi hop communication. This paper focuses on how relay nodes can strengthen clustering. Cluster Heads can save their energy and have prolonged life if sensor networks are optioned with separate relay nodes. This paper has proposed modified Mutual Exclusive Distributive Clustering (MEDC) protocol along relay node. Proposed solution will work to chase relay nodes different from cluster heads and will improve network lifetime further. [ABSTRACT FROM AUTHOR]

In hostile environments where explosives and natural calamities probably occur, wireless sensor networks (WSNs) are susceptible to multiple collocated failures and could be partitioned into disjoint segments. Federating the segments would be essential for restoring connectivity and enabling data sharing in the network. The federation may be achieved by populating relay nodes and providing perpetual inter-segment paths. In this paper, we tackle the federation problem while considering constrained relay availability, i.e., a limited number ( k ) of mobile relays to provide intermittent inter-segment connectivity that makes the problem more challenging. We propose LEEF, a novel algorithm for achieving energy-efficient federation with low inter-segment data delivery latency. LEEF strives to group the segments into k clusters in a star topology where a cluster at the center of the area serves as a hub between each pair of segment-clusters. Each cluster is served by a distinct mobile relay. In addition, LEEF opts to equalize the energy consumed by the k mobile relays due to travel and wireless communication. We analyze the properties of LEEF mathematically and validate its performance through extensive simulation experiments. [ABSTRACT FROM AUTHOR]

Over the next few years, the Industrial Wireless Sensor Network (IWSN), which is a major part of the Industrial Object Internet (IIoT), will play a crucial role in transforming the industrial world by opening a new era of economic and competitive growth in the Industrial Revolution known as "Industry 4.0". IIoT is able to help organizations achieve better benefits in industrial manufacturing markets by increasing productivity, reducing costs and developing new services and products. In this paper we present a wireless industrial communication system based on Node-RED platform using Modbus protocol for smart factories. [ABSTRACT FROM AUTHOR]

In Wireless Sensor Networks (WSNs), sensors are spread over a remote and hardly accessed sensing zone. In this situation, Unmanned Aerial Vehicles (UAVs) allow to facilitate the data gathering from sensors in real time. In the present paper, we consider an optical UAV network that allows the real time data distribution to a base station, based on multiple collection trees and multiple base stations. Each UAV is identified by an optical codeword with adequate structure to reduce the codeword management process implied by the UAV mobility. Using the attributed codewords, each UAV can optically switch the gathered data to reach a base station for processing. Furthermore, we present quality-based attachment and re-attachment procedures allowing to an UAV to attach and re-attach to a tree whether it notices the quality degradation of its link to the collection tree. [ABSTRACT FROM AUTHOR]

Fault diagnosis has been considered as a very challenging problem in wireless sensor network (WSN) research. Faulty nodes having different behavior such as hard, soft, intermittent, and transient fault are called as heterogeneous faults in wireless sensor networks. This paper presents a heterogeneous fault diagnosis protocol for wireless sensor networks. The proposed protocol consists of three phases, such as clustering phase, fault detection phase, and fault classification phase to diagnose the heterogeneous faulty nodes in the wireless sensor networks. The protocol strategy is based on time out mechanism to detect the hard faulty nodes, and analysis of variance method (ANOVA test) to detect the soft, intermittent, and transient faulty nodes in the network. The feed forward probabilistic neural network (PNN) technique is used to classify the different types of faulty nodes in the network. The performance of the proposed heterogeneous fault diagnosis protocol is evaluated using network simulator NS-2.35. The evaluation of the proposed model is also carried out by the testbed experiment in an indoor laboratory environment and outdoor environment. [ABSTRACT FROM AUTHOR]

Many Wireless Sensor Networks (WSN) protocols such as lot of localization protocols rely on the accuracy of the Received Signal Strength Indicator (RSSI). This RSSI metric is sensitive to different factors which lead to its disturbance. Other works have already proved that temperature and humidity have important impact on RSSI in outdoor environment. It is evident that temperature and humidity vary more importantly on outdoor than on indoor. In this paper, we aim to answer at this question: Does the slight modification of temperature and humidity in indoor environment have a significant impact on RSSI value? We have conducted various experiments to study this impact. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) have astounding advantages for monitoring environmental properties and object movement. The small size of sensors in a WSN is used very craftily and is ideal for obscured observations. However, for these observations, the sensor clocks should be synchronized within a few microseconds of each other to accurately determine the point of origin. This paper shows the performance analysis of different time synchronization protocols over different mote platforms. Time synchronization protocols like Reference Broadcast Synchronization (RBS), Timing-Sync Protocol for Sensor Networks (TPSN), Hybrid Energy-Aware protocol and Minimum Distance Clustering Hybrid Synchronization (MDCHS) protocol are simulated over different mote platforms viz., MICA2Dot433, MICA2Dot916, MICAz and TelosB. Different performance metrics like Energy Usage and Synchronization Time are used to analyse the performance of these protocols. The model is simulated using MATLAB. The effects of changes in network topology and node density are also studied. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSNs) are used for environmental monitoring. In recent years, energy constraints have led us to develop sensor nodes that harvest energy from the environment. WSNs improve performances by using techniques such as routing and clustering, by harvesting energy from the environment. These networks are called Energy Harvesting Wireless Sensor Network (EH-WSN). Due to the unique features of EH-WSNs, typical WSN clustering and routing methods are inefficient for EH-WSN. In this paper, we propose a novel hybrid methodology involving static and dynamic clustering operations. It uses a distributed-centralized approach and multi-hop routing and considers criteria, such as the energy level, the amount of harvested energy and the number of neighbors in the clustering process. Simulation results show that the proposed method improves the network stability and efficiency, comparing to other methods. [ABSTRACT FROM AUTHOR]

Congestion control is an extremely important area within wireless sensor networks (WSN), where traffic becomes greater than the aggregated or individual capacity of the underlying channels. Therefore, special considerations are required to develop more sophisticated techniques to avoid, detect, and resolve congestion. The constrained resources of the WSN must be considered while devising such techniques to achieve the maximum throughput. Various approaches have been introduced in the past few years that include routing protocols aided with congestion detection and control mechanism, and dedicated congestion control protocols. In the former schemes, the congestion avoidance is performed by the sink node that causes topology reset and bulk traffic drop. As a consequence, the latter mentioned congestion control protocols addressing the congestion avoidance, detection, and resolution were introduced at the node level. In this paper, we explore mechanisms for controlling congestion in the WSNs and present a comparative study. The congestion control schemes are categorized as centralized with partial congestion control and distributed with dedicated congestion control. [ABSTRACT FROM AUTHOR]

Establishing a unified time reference may be required for the operation of Wireless Sensor Networks (WSNs). Such a requirement may be imposed by the management strategy in the network, e.g., using time based medium access arbitration, or simply due to the dynamic nature of the application, e.g. target tracking. Contemporary clock synchronization protocols introduce significant messaging overhead and thus do not suit the resource-constrained WSNs. In the paper, we propose a novel solution called Synchronization through Piggybacked Reference Timestamps (SPiRT). SRiRT exploits the popularity of two-tier network architectures in WSN, where nodes are grouped into disjoint clusters. Each cluster-head synchronizes its clock to that of a reference node in the network through message exchange. Since cluster members can overhear the cluster-head transmissions, SPiRT takes advantages of such synchronization traffic to adjust the clock of the cluster members. SPiRT calls for appending the reference timestamps in the cluster-head messages so that a cluster member can estimate their clock adjustment. This cuts on energy consumption and increases the synchronization efficiency of SPiRT. We further propose an extension of SPiRT (E-SPiRT) that operates over multi-hop in order to achieve network-wide (global) synchronization. SPiRT and E-SPiRT are validated through simulation and implementation on a Micaz based testbed. The validation results confirm the effectiveness of SPiRT and E-SPiRT and show that they outperform competing schemes in the literature. [ABSTRACT FROM AUTHOR]

In this paper, we propose an efficient and secure key establishment protocol that is tailored for Wireless Mesh Networks. The protocol is based on identity-based key establishment, but without the utilization of a trusted authority for private key generation. Instead, this task is performed by the collaboration of mesh nodes; a number of users exceeding a certain threshold form a coalition to generate private keys for the network users. We performed simulative performance evaluation in order to show the effect of both the threshold value and the network size, i.e., total number of nodes, on the latency of key establishment and on the success percentage of user private key generation. Results reveal a trade-off between resiliency and efficiency; increasing the threshold value also increases the resiliency of the network, but negatively effects its latency and success percentage. For the threshold values that are smaller than 10 and for a minimum of 40 mesh nodes, at least 93% of the user private keys can be computed within at most 2 min. We also discuss the security of our protocol. We show that our protocol is secure against both outsider malicious and insider semi-honest adversaries. [ABSTRACT FROM AUTHOR]

This paper studies the potential of a novel approach to ensure more efficient and intelligent assignment of capacity through medium access control (MAC) in practical wireless sensor networks. Q-Learning is employed as an intelligent transmission strategy. We review the existing MAC protocols in the context of Q-learning. A recently-proposed, ALOHA and Q-Learning based MAC scheme, ALOHA-Q, is considered which improves the channel performance significantly with a key benefit of simplicity. Practical implementation issues of ALOHA-Q are studied. We demonstrate the performance of the ALOHA-Q through extensive simulations and evaluations in various testbeds. A new exploration/exploitation method is proposed to strengthen the merits of the ALOHA-Q against dynamic the channel and environment conditions. [ABSTRACT FROM AUTHOR]

Many applications of Wireless Sensor Networks such as Airborne Ad-hoc Networks (AANETs) or Underwater Wireless Sensor Networks (UWSNs) require the network architecture to be three-dimensional. In this paper, we present a terrestrial three-dimensional network architecture as well as protocol stack deployment for static sensor nodes placed at varying heights. A Dynamic Cluster-Based TDMA MAC (DCB-TDMA MAC) protocol has been developed for this network and simulated using Cooja platform. Cluster-Head nodes are rotated based on residual energy in order to maximize the lifetime of the network. Detailed working of protocol involving Time Synchronization, MAC, Cluster-Head rotation, Dynamic Routing is provided in this paper along with simulation results and analysis. [ABSTRACT FROM AUTHOR]

Digital Signatures are primarily employed to achieve data integrity, data origin authentication and non-repudiation. In comparison to RSA-based digital signatures, the ECC (Elliptical Curve Cryptography) based Signature schemes like ECDSA (Elliptical Curve Digital Signature Algorithm) are more efficient and suited for a resource-constrained network like WSN. In a WSN, proper entity authentication is to be achieved before the sensor data is exchanged. The use of ECDSA is not suitable for achieving mutual authentication between the entities like the base station, cluster heads and nodes. Based on the study of ECDSA, the paper designs a mutual authentication protocol with the help of a computationally low signature scheme. To the best of our knowledge, this is the first digital signature based scheme which achieves mutual entity authentication. The paper also brings out performance parameters of the developed protocol. [ABSTRACT FROM AUTHOR]

In multi-hop routing, cluster heads near the base station act as relays for far cluster heads and thus will deplete their energy very quickly. Thus, hot spots in the sensor field result. This paper introduces a new clustering algorithm named an Unequal Multi-hop Balanced Immune Clustering protocol (UMBIC) to solve the hot spot problem and improve the lifetime of small and large scale/homogeneous and heterogeneous wireless sensor networks with different densities. UMBIC protocol utilizes the Unequal Clustering Mechanism (UCM) and the Multi-Objective Immune Algorithm (MOIA) to adjust the intra-cluster and inter-cluster energy consumption. The UCM is used to partition the network into clusters of unequal size based on distance with reference to base station and residual energy. While the MOIA constructs an optimum clusters and a routing tree among them based on covering the entire sensor field, ensuring the connectivity among nodes and minimizing the communication cost of all nodes. The UMBIC protocol rotates the role of cluster heads among the nodes only if the residual energy of one of the current cluster heads less than the energy threshold, as a result the time computational and overheads are saved. Simulation results show that, compared with other protocols, the UMBIC protocol can effectively improve the network lifetime, solve the hot spot problem and balance the energy consumption among all nodes in the network. Moreover, it has less overheads and computational complexity. [ABSTRACT FROM AUTHOR]

This paper presents Fuzzy and Ant Colony Optimization Based Combined MAC, Routing, and Unequal Clustering Cross-Layer Protocol for Wireless Sensor Networks (FAMACROW) consisting of several nodes that send sensed data to a Master Station. FAMACROW incorporates cluster head selection, clustering, and inter-cluster routing protocols. FAMACROW uses fuzzy logic with residual energy, number of neighboring nodes, and quality of communication link as input variables for cluster head selection. To avoid hot spots problem, FAMACROW uses an unequal clustering mechanism with clusters closer to MS having smaller sizes than those far from it. FAMACROW uses Ant Colony Optimization based technique for reliable and energy-efficient inter-cluster multi-hop routing from cluster heads to MS. The inter-cluster routing protocol decides relay node considering its: (i) distance from current cluster head and that from MS (for energy-efficient inter-cluster communication), (ii) residual energy (for energy distribution across the network), (iii) queue length (for congestion control), (iv) delivery likelihood (for reliable communication). A comparative analysis of FAMACROW with Unequal Cluster Based Routing [33] , Unequal Layered Clustering Approach [43] , Energy Aware Unequal Clustering using Fuzzy logic [37] and Improved Fuzzy Unequal Clustering [35] shows that FAMACROW is 41% more energy-efficient, has 75–88% more network lifetime and sends 82% more packets compared to Improved Fuzzy Unequal Clustering protocol. [ABSTRACT FROM AUTHOR]

The CoRE working group at the IETF has proposed a Resource Directory (RD) solution to facilitate the discovery of the resources provided by constrained wireless sensor and actuator networks. For such a mechanism to be effectively deployable, nodes must first discover the existence of an RD in the network before being able to exploit its functionalities. This paper presents Proactive RD Discovery (PRD); a scalable, reliable, and effective mechanism to discover an RD. To achieve such qualities, the proposed mechanism deploys adaptive Trickle timers. PRD is implemented in Contiki OS and evaluated using emulated sensor/actuator nodes in the Cooja simulator. Simulation results show important performance enhancements in terms of energy consumption, generated traffic, RD discovery time, and reliability when compared with the default discovery mechanism bundled with the RD. [ABSTRACT FROM AUTHOR]

Large scale, duty-cycled, wireless sensor networks provide support for applications ranging from anomaly detection to vehicle tracking. In order meet the requirements of these applications an autonomous configuration and maintenance method that is efficient and effective is required. When selecting a management solution it is important to consider both the direct and indirect costs associated with the different solution. For example, the overhead associated with communication synchronization and scheduling is an example of an indirect cost that can significantly impact the network lifetime. Further, an effective solution needs to recognize that in-network data aggregation and analysis presents significant benefits and should configure the network with a structure that benefits application layer functions. NOA, the proposed network management protocol, utilizes a multi-parent hierarchical logical structure. The multi-parent structure provides application layer functions with significant inherent benefits such as, but not limited to: elimination of the single-parent network divisions, data resolution guarantees when comparisons are performed at data aggregation points, and redundancies for communication as well as in-network data aggregation, analysis and storage. [ABSTRACT FROM AUTHOR]

Though lots of research results about self-healing key management under unreliable links have been proposed, there are still some shortcomings, such as the inefficiency of broadcasts, lack of broadcast authentication, limited sessions for key issues, disastrous risks of access polynomials, and the vulnerability of collusion attacks. In this paper, we propose two modified access polynomial based self-healing key management schemes with broadcast authentication and enhanced collusion resistance. First, two kinds of attacks are introduced to break the security of access polynomials. Then, a modified security model is given, and collusion resistance capability is redefined from the perspective of session interval from node revocation to node addition, which does not depend on the number of collusive nodes. Next, based on sliding window and modified access polynomial, Sch-I and Sch-II are proposed to achieve the security and tolerate packet losses, which allow pairwise keys between member nodes and group manager to be updated dynamically. Finally, theoretical analysis validates that the proposed schemes have δ self-healing capability, any -wise forward security and backward security, and enhanced collusion resistance capability, and can also avoid the flaws of access polynomials and reduce the resource consumption. Compared with existing schemes, they are quite suitable for practical applications. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive and rigorous study of a novel collision resolution algorithm for wireless sensor networks: 2CS-WSN. It is specifically designed to be used during the contention phase of IEEE 802.15.4. This algorithm has been modelled in terms of discrete time Markov chains (DTMCs) and, using the probabilistic symbolic model checker PRISM, correctness properties and different operation modes of the algorithm have been studied. Moreover, different model abstractions have been used in order to identify any inconsistencies or ambiguities, and to prove interesting properties for non-trivial, practical and relevant scenarios. Finally, since the biggest source of energy waste is the collision, this paper conducts a wide study of energy saving in this algorithm. [ABSTRACT FROM AUTHOR]

We consider wireless nodes connected in an ad hoc network where recursion based localization is available and ad hoc routing is deployed. We are interested in studying the possibility to use ad hoc routing to help a mobile (sensor) node in a dense/sparse wireless network to estimate its position by first finding the closest two or three ad hoc reference nodes that are already known their positions then use the position value of the found reference nodes and add the estimated distance using the hop counts of the ad hoc routing to find the estimated position. Our protocol will control which are the nodes that will have to calculate their position using the recursive approach in order to serve as reference points to other nodes in the network. Our proposed algorithm basically includes the improved version of the OLSR protocol mostly about the MPR decision and utilization topics by introducing supplemental selection criteria which are also significant for the localization process. Besides, the first part of the localization is performed with this modified version but at the continuation part, two schemas are used: DV-hop and DV-distance. These two schemas are used in two ways, after finding three anchors to find the position of the related node and if three of the anchors could not be collected then in case of finding anchors. Furthermore, the localized node whose position is detected also assigned as an anchor node in the network. Additionally, we compare our schemas with a recursive position estimation (RPE) algorithm about density, position error and reference point numbers. And t-test is performed in our study for the reference points–densities with p-value of 0.05. [ABSTRACT FROM AUTHOR]

Opportunistic routing is a new paradigm in routing for wireless sensor network which chooses the node closest to the target node for forwarding the data. It uses the broadcasting nature of wireless sensor networks. Opportunistic routing has increased the efficiency, throughput and reliability of sensor networks. Many energy saving techniques has been introduced using opportunistic routing in wireless sensor networks for increasing the network lifetime. In this article we have elaborated the basic concept of Opportunistic routing, different areas in which it has been claimed to be beneficial, some protocols their metrics and their drawbacks. [ABSTRACT FROM AUTHOR]

Overall energy of network is a major issue in current sensor network. This paper proposes (GDCP) GPS (Global Positioning System) based reactive communication protocol for Static WSN (Wireless Sensor Network) to extend the life time of entire network. In GDCP, energy efficient routing is achieved using local communication among sensor nodes. While routing, packets are routed via reliable shortest path from source node to sink node. The shortest path is determined with the help of a Neighbouring Table (NT) of a node. This table stores information such as location, distance to neighbour node and distance to a sink node. If the neighbouring node has sufficient energy and its distance to a sink node is less than other neighbours then it becomes the receiver and packet forwards to neighbour node. After receiving the packet, receiver becomes sender node and it checks its neighbouring table for minimum sink node's distance and sufficient energy. This process continues till the packet reaches the sink node. Sink node is assumed to move from one location to another as its neighbour node's energy becomes less than threshold energy. Energy consumption is analysed on 100 static sensor nodes and one sink node. A simulated result shows that overall energy of network is improved. [ABSTRACT FROM AUTHOR]

A Mobile ad hoc network (MANET) is self organizing, decentralized and infrastructure less wireless network. The successful transmission of data packet is depends on the cooperation of each node in the network. These types of network don’t have permanent base station, so each node in the network acts as a router. Due to openness, decentralized, self organizing nature of MANET, it is vulnerable to various attacks. So security is the main concern in MANET. In this paper, we considered two attacks; Vampire and DDoS attacks. The Vampire attack is not any protocol specific. Single Vampire attack can increase the network-wide energy usage. DDoS attacks exhaust the resources available to a network. Both the attacks drain the energy of nodes. Here, we discuss method to mitigate these attacks. [ABSTRACT FROM AUTHOR]

Energy Harvesting - Wireless Sensor Networks (EH-WSNs) constitute systems of networked sensing nodes that are capable of extracting energy from the environment and that use the harvested energy to operate in a sustainable state. Sustainability, seen as design goal, has a significant impact on the design of the security protocols for such networks, as the nodes have to adapt and optimize their behaviour according to the available energy. Traditional key management schemes do not take energy into account, making them not suitable for EH-WSNs. In this paper we propose a new multipath key reinforcement scheme specifically designed for EH-WSNs. The proposed scheme allows each node to take into consideration and adapt to the amount of energy available in the system. In particular, we present two approaches, one static and one fully dynamic, and we discuss some experimental results. [ABSTRACT FROM AUTHOR]

After more than two decades of their introduction, Wireless Sensor Networks (WSNs) remain an active research topic due to their wide range applications in areas such as healthcare, military, monitoring and surveillance systems. In most applications, sensor nodes are constrained in energy supply and communication bandwidth. Therefore, novel techniques to reduce energy inefficiencies and for efficient use of the limited bandwidth resources are essential. Such constraints combined with dense network deployment pose several challenges to the design and management of WSNs and require energy-awareness at all layers of the networking protocol stack. For instance, at the Data-Link layer, low duty cycle Medium Access Control (MAC) protocols trade off latency for energy efficient operation. In this paper, we present a survey of state-of-the-art low duty cycle MAC protocols. We first outline the design challenges for MAC protocols in WSNs. Then, we present a comprehensive survey of the most prominent and recent MAC protocols. These protocols are classified into synchronous and asynchronous based on their mode of operation. Finally, the paper highlight open research problems in MAC layer for WSNs. [ABSTRACT FROM AUTHOR]

The Internet is used by more than two billion customers around the world and is expected to serve as a global platform for interconnecting cyber-physical objects that form the Internet of Things (IoT). Within the next decade, traffic demands are expected to increase a thousand-fold. This challenge can be addressed by introducing and expanding heterogeneous wireless technologies, which provide higher network capacity, wider coverage and higher quality of service (QoS). However, the heterogeneity and complexity of these networks are a major challenge for traditional control and management systems. Therefore, there is a need for self-manageable and self-configurable networks that support the data produced by the different IoT devices and provide opportunities for data analytics. In this work, a cognitive network framework is proposed, in which the network protocol stack is integrated with a semantic system. The proposed framework provides the bases for building smart networks that observe data from different layers in the network protocol stack and represents it in a hierarchical structure in a knowledge base. The framework employs an ontology that provides an abstraction model for the different heterogeneous wireless devices. The ontology determines the relationships between technology-dependent parameters in the network protocol stack and enables, through the use of inferences, the utilization of the observed data from the network. The use of a cognitive network framework with the network protocol stack allows adding ontologies to describe the data, a solution which could solve the problem of analysing, searching or visualising data. [ABSTRACT FROM AUTHOR]

Wireless sensor networks are formed by a large number of sensor nodes which are commonly known as motes. In the past few years, several reliable, congestion controlled and energy efficient transport layer protocols in wireless sensor networks have been developed and proposed in the literature. In this paper, we have presented a hybrid and dynamic reliable transport protocol which provides the mechanism to dynamically assign the timing parameters to the nodes as well as enhance the protocol performance by using a hybrid Acknowledgement/Negative Acknowledgement scheme. The performance of proposed protocol is tested under TinyOS Simulator varying different parameters and protocol settings and found that proposed protocol is able to program all the nodes when given proper pump/fetch ratios, is able to solve the booting sensor nodes problem by being able to wait till all the nodes finished booting and solves the all-packets-lost problem by acknowledging the receipt of its first packet delivered that is the inform message. [ABSTRACT FROM AUTHOR]

Mobile ad hoc networks (MANETs) are wireless, self-organizing and infrastructure-less networks with nodes that rely on power. Hence, there is a need for an energy-aware and energy-efficient routing protocol. To enhance the lifetime of nodes and network performance, intervals such as the Hello-Interval and TC-Interval of the optimized link state routing (OLSR) protocol are tuned. Additionally, the residue forecast algorithm is incorporated with the protocol, yielding the Hello-Interval 1, TC-Interval 3 residue forecasted optimized link state routing (HTR-OLSR) protocol. In addition, the modified multipoint relay (MPR) selection plays a vital role in energy consideration. In the case of dynamic networks, a gain in throughput of approximately 10% to 15% is obtained. [ABSTRACT FROM AUTHOR]

Designing a lightweight, secure communication protocol for Wireless Sensor Networks (WSNs) remains a challenging issue since sensor networks are resource limited and are left unattended. Sensor nodes in WSNs are subjected to varying forms of attacks. An adversary may destroy or damage the communications done in multi-hop WSNs by means of packet dropping and modification. Hence it is essential to have an efficient cryptographic scheme to protect the communications done in WSNs. This study introduces a Reliable Anonymous Secure Packet forwarding (RASP) scheme that can prevent not only traffic analysis attack but also the attacks done through compromised forwarding nodes. The mechanisms followed here are effective with low computation and communication overhead. The performance of the proposed scheme is evaluated over NS2 with a series of simulation. The simulated results show that the proposed scheme performs better than other comparable schemes. [ABSTRACT FROM AUTHOR]

This paper proposes a cross-layer mobility support scheme for the IPv6 over low-power wireless personal area network (6LoWPAN) wireless sensor network (WSN). This scheme combines the handover in the network layer (L3) with the handover in the link layer (L2) so that the L3 handover and the L2 one can be performed simultaneously. During the L3 handover process, a sensor node neither needs a care-of address nor participates in the handover process. During the L2 handover process, a node uses the channel information to directly achieve the L2 handover without scanning all channels. Finally, this paper analyzes and evaluates the performance of this protocol, and the data results show that this protocol improves the mobility handover performance. [ABSTRACT FROM AUTHOR]

Our research work proposes Multi-hop Communication with Localization (MCL), a strategy to localize and route information to nodes present in such areas by determining angles and distances of consecutive nodes hop by hop towards the Base Station. Based on the application area, Subterranean Wireless Sensor Networks are specifically designed to detect underground abnormal conditions and reported to the base station. Many protocols use distance between the nodes as one of the criteria for multi-hop communication in the network. It is found to be necessary to know the location of the nodes and the distance between the nodes in many power optimization protocols. But the query of how to attain the distance or the location arises in the same. The main objective here is to design a technique to both localize and transmit data efficiently in subterranean areas. Initially there is a group of nodes deployed in the underground areas all of which bond to a sink that is further connected to the Base Station. It is possible to locate all the nodes through GPS which can be used as a reference in the worst case scenario by the Base Station. The sink node has a Node Transmission Area (NTA) within which a node can be directly recognized by the sink node otherwise it finds the target node through the intermediate nodes. Our empirical work proves the computational method on attaining the performance. [ABSTRACT FROM AUTHOR]

In energy constrained wireless sensor networks, maximizing network coverage lifetime while ensuring optimized coverage is important. The challenge is to determine an appropriate duty cycle for the nodes while maintaining sufficient count of active nodes for optimal network coverage. Most of the existing work, for coverage optimization based on duty cycle, does not consider the residual energy of the active nodes. This can result in suboptimal wake-up of sleeping nodes. RBSP considers the residual energy but ignores the active nodes’ battery discharge rate. In this paper, we propose DCBSP ( Discharge Curve Backo ff Sleep Protocol ), which considers the battery discharge curve of the active nodes to determine the duty cycle of the inactive nodes. Thus in DCBSP, inactive nodes wake-up close to death of the active nodes which leads to lesser energy consumption and increased network lifetime. NS-2 simulations show the energy consumption of DCBSP is lesser than that of PEAS by 39% and lesser by 25% and 15% as compared to RBSP and PECAS respectively. Further, the coverage ratio of DCBSP is higher than PEAS by 32% and higher by 17% and 6% as compared to RBSP, PECAS respectively. Hence, DCBSP is effective in ensuring higher coverage while extending the network lifetime. [ABSTRACT FROM AUTHOR]

The Sapienza University Networking framework for underwater Simulation Emulation and real-life Testing (SUNSET) is a toolkit for the implementation and testing of protocols for underwater sensor networks. SUNSET enables a radical new way of performing experimental research on underwater communications. It allows protocol designers and implementors to easily realize their solutions and to evaluate their performance through simulation, in-lab emulation and trials at sea in a direct and transparent way, and independently of specific underwater hardware platforms. SUNSET provides a complete toolchain of pre-deployment and deployment time tools able to identify risks, malfunctioning and under-performing solutions before incurring the expense of going to sea. Novel underwater systems can therefore be rapidly and easily investigated. Heterogeneous underwater communication technologies from different vendors can be used, allowing the evaluation of the impact of different combinations of hardware and software on the overall system performance. Using SUNSET, underwater devices can be reconfigured and controlled remotely in real time, using acoustic links. This allows the performance investigation of underwater systems under different settings and configurations and significantly reduces the cost and complexity of at-sea trials. This paper describes the architectural concept of SUNSET and presents some exemplary results of its use in the field. The SUNSET framework has been extensively validated during more than fifteen at-sea experimental campaigns in the past four years. Several of these have been conducted jointly with the NATO STO Centre for Maritime Research and Experimentation (CMRE) under a collaboration between the University of Rome and CMRE. [ABSTRACT FROM AUTHOR]

Underwater Acoustic Sensor Networks (UWSN) is challenging research area due to limited bandwidth, low data rate, severe multipath, and high variability in the channel conditions. These complicated and non-linear channel characteristics render incorrect most simplifying assumptions used in simulations. We believe that, while researchers have proposed several novel protocols, their use of models and simulations as the only form of validation and intra-protocol comparison remains removed from reality. We argue that research experimentation is hindered by two fundamental constraints: high cost of underwater networking experiments, and lack of a single, easily-replicable platform for evaluation. We present here Underwater Platform to Promote Experimental Research (UPPER): a low-cost and flexible underwater platform designed to enable cost-effective and repeatable experimentation. We utilize commercial off-the-shelf (COTS) components to provide a HW/SW integrated solution that interfaces to two version of our custom hydrophones, from laptops that act as an Software-Defined Radio (SDR)-based physical layer, while allowing higher layer protocols to interact via a flexible API. With a total cost of $25 and $65 for each version of our underwater communication platform, we evaluate the platforms to demonstrate their data rates (50–600 bps) and range (5–10 m for v1, 30–50 m for v2), thus indicating a cost-range tradeoff. We believe our platform removes the barrier to validating simulation results in underwater environments while also allowing a fair comparison between protocols. [ABSTRACT FROM AUTHOR]

The advent of the Internet of Things where billions of devices are able to exchange their data to give a better control to users on their environment has led to the expansion of Wireless Sensor Networks (WSN). To address the specificities of WSN, standards on networking protocols for low power sensors such as 6LoWPAN have been developed. While 6LoWPAN is well suited to fixed- sensor WSN, it must be extended to better address mobile sensors. However, so far little effort has been devoted to the handling of mobile sensor node peculiarities. In this article, generic mobility scenarios are highlighted, existing mobility solutions based in Mobile IPv6 are reviewed and remaining challenges to handle mobile sensors properly are identified. [ABSTRACT FROM AUTHOR]

Cooperative routing is a hybrid approach utilizing routing techniques and cooperative communication to improve the communication quality of single-antenna sensor nodes. It exploits the broadcast nature of wireless medium and transmits cooperatively using nearby sensor nodes as relays. In this research, a cooperative transmission scheme is proposed for UnderWater Sensor Networks (UWSNs) to improve the network performance called ARCUN. The protocol is an energy-efficient and high-throughput routing scheme for UWSN. Potential relays are selected from a group of neighbor nodes that utilize signal-to-noise ratio and distance computation of the underwater channel. Optimal role of cooperation provides load balancing in the network and gives profound improvement in network stability period and packet delivery ratio. [ABSTRACT FROM AUTHOR]