Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Sensor networks are meant for sensing and disseminating information about the environment they sense. The criticality of a sensed phenomenon determines its importance to the end user. Hence, data dissemination in a sensor network should be information aware. Such information awareness is essential firstly to disseminate critical information more reliably and secondly to consume network resources proportional to the criticality of information. In this paper, we describe a protocol called RelnForM to deliver packets at desired reliability at a proportionate communication cost. RelnForm sends multiple copies of each packet along multiple paths from source to sink, such that data is delivered at the desired reliability. It uses the concept of dynamic packet state in context of sensor networks, to control the number of paths required for the desired reliability, and does so using only local knowledge of channel error rates and topology. We show that for uniform unit disk graphs, the number of edge-disjoint paths between nodes is equal to the average node degree with very high probability. RelnForm utilizes this property in its randomized forwarding mechanism which results in use of all possible paths and efficient load balancing. <s> BIB001 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Many new routing protocols have been proposed for wireless sensor networks in recent years. Almost all of the routing protocols considered energy efficiency as the ultimate objective since energy is a very scarce resource for sensor nodes. However, the introduction imaging sensors has posed additional challenges. Transmission of imaging data requires both energy and QoS aware routing in order to ensure efficient usage of the sensors and effective access to the gathered measurements. In this paper, we propose an energy-aware QoS routing protocol for sensor networks which can also run efficiently with best-effort traffic. The protocol finds a least-cost, delay-constrained path for real-time data in terms of link cost that captures nodes' energy reserve, transmission energy, error rate and other communication parameters. Moreover, the throughput for non-real-time data is maximized by adjusting the service rate for both real-time and non-real-time data at the sensor nodes. Such adjustment of service rate is done by using two different mechanisms. Simulation results have demonstrated the effectiveness of our approach for different metrics with respect to the baseline approach where same link cost function is used without any service differentiation mechanism. <s> BIB002 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> As a novel information acquiring and processing technology, compared to other traditional sensor networks, wireless multimedia sensor networks pay more attention to the information-intensive data (e.g. audio, video, image). Potential applications of wireless multimedia sensor networks span a wide spectrum from military to industrial, from commercial to environmental monitoring. This paper discusses QoS routing problem model with multiple QoS constraints, which may deal with the delay, delay jitter and bandwidth, and presents QoS routing algorithm with multiple constraints based on genetic algorithm, and gives the algorithm idiographic flow. Simulating results show that higher routing successful ratio and faster convergence is achieved in the algorithm. <s> BIB003 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless Multimedia Sensor Networks (WMSNs) are composed of small devices that are able to capture video or audio information and to transmit it over wireless channels. The development of wireless technologies, such as: WiFi, Bluetooth, Zigbee, and UWB, encourages the emergence of heterogeneous networks. However, only a few existing solutions take into account the constraints of multi-tier and multi-MAC wireless sensor networks. In this paper, we propose a cost function coupled to a new generic (i.e. independent from any MAC protocol) cross-layer routing protocol adapted to multimedia traffic over hierarchical and heterogeneous networks. The goal of our proposed protocol is to dynamically assess the routing process cost and the requirement of the multimedia application in order to ensure a sufficient quality of service (Soft QoS). Furthermore, the cross-layer approach is needed to use the physical and MAC parameters on the routing operation. Simulation results show that our solution is efficient and gives better results than classical protocols. <s> BIB004 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> The Wireless Multimedia Sensor Networks (WMSNs) consist of nodes that are capable of sensing, computing, communication, actuation, and power components. Some of the applications of the Wireless Sensor Multimedia Networks include habitat monitoring, target tracking, environmental monitoring, and traffic management systems, these applications require effective communication of event features in the form of multimedia such as audio, image, and video. Routing in Wireless Multimedia Sensor Network is an important issue since the WMSN nodes that sense the data need to be communicated to the base station, to take necessary decision. The key issues in the design of routing protocol in the WMSN are energy consideration, multimedia consistency, tight QoS expectations, and high bandwidth demands. Although many routing protocols have been proposed for the WMSNs, the design of a more efficient protocol in terms energy awareness and QoS still remain a challenge. This work involves the design of the routing protocol in wireless multimedia sensor networks which is power aware, reliable and has low latency in delivering the data from source node that is sensing the data to the destination node/sink node. The proposed new algorithm called MPDT: Multipath Data Transfer protocol provides simultaneous multiple paths for communication between any two nodes. This feature prolongs the lifetime of the network. Also from the data security point of view, MPDT is immune to some specific attacks. Simulation results show that the proposed protocol surpasses the conventional protocol in terms of energy consumption and network lifetime. <s> BIB005 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> in this paper we investigate multi-path transmission of video over Wireless Multimedia Sensor Networks (WMSNs). Our objective is to provide a transmission mechanism to improve the video quality perceived at the receiver while considering energy, bandwidth and delay constraints of the network. Our approach is based on packet and path priority scheduling in multipath video transmission over WMSN. Video packets are classified according to their types and more important packets are transmitted through paths with better conditions. Path conditions are evaluated by a score mechanism using variant parameters such as free buffer size, energy, hop count and packet loss. Since path conditions are changed over time, our proposed scheme updates path conditions and adapting packet scheduling accordingly. Simulation analysis of the proposed video transmission scheme shows its efficiency in increasing perceived video quality at the receiver. <s> BIB006 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless multimedia sensor networks (WMSN) emerges as an important category of Wireless Sensor Networks, which retrieves real-time information such as video and audio streams, still images etc. One of the prominent characteristics of WMSN is severe bandwidth limitation which has great impact on design of routing algorithm. In traditional routing protocols, path(s) are selected aiming at providing optimal transmission performance for the current flow while little attention is paid to bandwidth efficiency. This greedy strategy results in the existence of large amounts of bandwidth fragments which can’t be fully used so that the networks capability to carry real-time flows is degraded. In this paper, bandwidth efficient Collaborative Quality of service Routing (CQR) is proposed. The defining aspect of CQR is to collaboratively optimize the path selections of multiple flows over the networks. The CQR problem is formulized as linear programming. Resource allocation vector is constructed to decouple the inherently dependent path selections between different flows and sub-gradient based searching algorithm is proposed to get the optimal solution. Simulation results show that CQR achieves higher call admission rate for real-time flow comparing to existed algorithm, under heavy load CQR outperforms traditional algorithms about 40% in call admission rate and has similar transmission cost. <s> BIB007 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> As a novel information acquiring and processing technology, wireless multimedia sensor networks (WMSNs) pose new challenges on the routing protocol. IEEE 802.11s-based WMSN that integrate with MAC-layer mesh networking protocol is an innovative implementation for WMSN which can offer high coverage, self-organization and good reliability. In this paper, we present a new routing metric based on airtime proposed in IEEE 802.11s draft standard, referred to as load balanced airtime with energy awareness (LBA-EA), for IEEE 802.11s-based WMSNs. LBA-EA not only captures the link quality, but also takes into account the load balancing and energy consumption. Simulation results prove the effectiveness of the proposed routing metric in terms of average network throughput and overall lifetime of WMSNs. <s> BIB008 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> The increase in the usefulness of WSNs, have lead to the transmission of multimedia content over these networks. This has escorted to the concept of Wireless Multimedia Sensor networks (WMSNs). Due to resource constrained structure of WSNs, special attention is required to route data in these networks. In this paper, we propose a novel routing protocol for WMSNs which establishes paths on the basis of traffic load, hop count and node energy. The protocol aims to find completely or partially disjoint paths for routing multimedia traffic with relatively minimum distance. Simulation results have shown that the proposed protocol is capable of finding intelligent path such that it increases throughput and avoid creation of network holes near the sink. <s> BIB009 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> As a new multimedia information acquisition and processing method, wireless multimedia sensor network (WMSN) has great application potential and attracts more and more attentions. Compared to traditional wireless sensor networks, the routing design of WMSN has higher requirements on the quality of service (QoS). This paper systemically analyzes the similarity between social network and WMSN, then designs a QoS trust estimation model based on social network analysis, which enables each sensor node measuring the service quality by monitoring the behaviors of neighbor nodes. An energy efficient QoS assurance routing based on cluster hierarchy (EEQAR) is proposed to achieve energy efficiency and meet the requirement of QoS. To obtain a better performance, EEQAR routing adopts cellular topology to form the cluster structure and balance the energy consumption by structure movement. The simulation results show the high performance of EEQAR routing in lifetime and quality of service. <s> BIB010 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> The transmission of video and imaging data in Wireless Multimedia Sensor Networks (WMSN) requires both energy efficiency and QoS assurance, in order to ensure the efficient use of sensor resources, an Ant Colony Optimization based QoS routing model is proposed to improve the routing protocol of WMSN. Firstly, a routing model for WMSN QoS was presented and then a routing algorithm ACOWMSN was brought forward, which uses the network restrict condition to update the pheromone concentration. The forward ants collects QoS parameters, and the backward ants carry QoS information to update the local node status during returning to source node. The simulation results show that the algorithm has better performance than the traditional QoS routing protocol and can significantly improve the network lifetime. <s> BIB011 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless Multimedia Sensor Networks (WMSN) have an increasing variety of multimedia based applications including image and video transmission. In these types of applications, multimedia sensor nodes should ideally maximize perceptual quality and minimize energy expenditures in communication. To obtain the required perceptual quality, quality of service (QoS) support is needed at the network level. However, mapping the network parameters to the end-user's perceptual quality measures during building paths is a challenging task due to incomplete identification metrics. In this paper, we propose Image Quality Aware Routing (IQAR) for WMSN that introduces the concept of image quality awareness by considering energy issue. The proposed approach employs intra-image prioritization and an adaptive path selection scheme that adjusts reliability level during image transmission using a distortion prediction model. <s> BIB012 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> This paper presents an Adaptive Greedy-compass Energy-aware Multipath protocol (AGEM), a novel routing protocol for wireless multimedia sensors networks (WMSNs). AGEM uses sensors node positions to make packet forwarding decisions. These decisions are made online, at each forwarding node, in such a way that there is no need for global network topology knowledge and maintenance. AGEM routing protocol performs load-balancing to minimize energy consumption among nodes using twofold policy: (1) smart greedy forwarding, based on adaptive compass and (2) walking back forwarding to avoid holes. Performance evaluations of AGEM compared to GPSR (Greedy Perimeter Stateless Routing) show that AGEM can: (a) maximize the network lifetime, (b) guarantee quality of service for video stream transmission, and (c) scale better on densely deployed wireless sensors network. <s> BIB013 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless Multimedia Sensor Networks (WMSNs) is a novel information acquiring and processing technology which is more competent than traditional sensor networks in transferring and processing of huge amount of multimedia information data, such as audio, video, images and so on. It plays critical role in application in civil, military and commercial fields. In this paper, a Non-control sorting method is used to construct the Pareto optimal routing path set and the multiple attribute decision making method is adopted to search for the best routing path from the Pareto optimal routing path set. The simulation experiment result shows that our method can increase the probability of finding the optimal routing path, the TOPSIS method which is based on the Multiple Attribute Decision Making method obtains the best routing path from the Pareto Optimal routing set. <s> BIB014 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless Multimedia Sensor Networks (WMSN) are new and emerging networks of wirelessly connected devices, which consist of cameras, microphones, infra-red sensors, scalar sensors and others. These networks are fast gaining popularity due to their potential to be incorporated in various applications, such as, traffic monitoring, border surveillance, smart homes, environment and habitat monitoring, to retrieve heterogeneous data from the environment. However, these networks present many challenges as they are highly sensitive to delay and errors. The paper presents a Cross-layer QoS Routing protocol for WMSNs (CR-WMSN) that is aimed at providing soft end-to-end delay guarantees. Evaluation of this protocol shows that it provides better delay guarantees as compared to minimum hop routing protocol. <s> BIB015 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> In Wireless Multimedia Sensor Networks (WMSN), routing is essential to promote high data rate accommodation. During the query and data dissemination phases, optimal routing is a vital role since the multimedia content is conditional to strict QoS requirements. But the existing works on Multipath routing rarely consider losses and delay at the sink leading to energy degradation, involve unnecessary additional paths which cause high overhead. To overcome these issues, in this paper, we proposed an adaptive multi constraint Multipath routing protocol which minimizes loss rate, energy consumption and delay. We consider a cluster based architecture where inter cluster routing is performed based on a weighted cost function. The cost function is based on the parameters such as loss rate, residual energy and delay. In order to save energy, nodes which don't take part in routing are put to sleep mode. The simulation results prove that the proposed protocol is efficient in terms of energy efficiency, delay and packet delivery ratio when compared to the QoS aware routing from the literature. <s> BIB016 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Abstract Wireless Multimedia Sensor Networks (WMSN) have been drawing considerable attention and discussion in recent years due to its potential applications in various fields. For WMSN, how to increase the throughput in constrained environments has become the main challenge. Multipath routing is a promising solution because it can improve the channel utilization rate, reduce transmission delay and balance the transmission load. To pursue high efficiency for a multipath routing scheme, we need to take the characteristics of wireless environments and sensor networks into careful considerations. Based on such considerations, this paper introduces a Geographic Energy-Aware non-interfering Multipath (GEAM) routing scheme which divides the whole network topology into many districts and simultaneously forwards data through these districts without interfering with each other – to achieve interference-free transmissions. Our scheme will adjust the load of each district according to the energy status of their nodes; it does not establish fixed paths in advance and will hence maintain high performance even when the topology changes rapidly. We meanwhile employ a simple way to deal with the hole problem. Simulation results show that, when compared with related routing schemes, our GEAM can achieve higher performance at real-time transmission and meanwhile distribute transmission loads more evenly to most of the nodes in the network. <s> BIB017 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Meeting quality of service(QoS) is a challenging task in Wireless Multimedia Sensor Networks(WMSNs). In this paper, a new power-aware QoS routing protocol for WMSNs is proposed, which uses local information in choosing the next hop. For real-time communication, we consider both delay at the sender node and queuing delay at the receiver, and try to reach the latency requirements by minimizing the hop counts for a packet needed to be transferred towards the sink. In order to achieve reliability requirements and energy efficiency, each node dynamically adjusts it's transmission power and chooses nodes which have less remaining hops towards the sink. We consider the history of the packet in order to update these requirements at each hop. A load balancing approach is used to increase lifetime and avoid congestion. Simulation results shows that our protocol can support QoS with less energy consumption. <s> BIB018 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> In Wireless multimedia sensor networks (WMSNs), new metrics are required in order to accurately measure and evaluate link quality of nodes residing along a routing path comprehensively considering end-to-end delay, throughput and radio interference. Moreover, it is important to develop a routing algorithm that can find an optimal path to meet a QoS requirement based on the metrics. This study presents a QoS routing method taking into account congestion, which is aimed at minimizing end-to-end delay and increasing throughput. With a use of congestion control technique and least cost-based routing mechanism, the proposed routing method increases packet transmission rate whereas it reduces packet loss and delay. Ultimately, it contributes to longer network lifetime of sensor networks, which could result to offering better reliability of the network. <s> BIB019 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Multimedia sensors are attracting the attention of the researchers increasingly, and have shifted the focus from traditional scalar sensors to sensors equipped with multimedia devices. The characteristics of multimedia services impose more resource constraints that involve energy consumption, memory, buffer size, bandwidth, and processing capabilities. Existing routing solutions used in wireless multimedia sensor networks suffer from limitations in term of QoS and energy efficiency. In this paper, we propose a new QoS routing solution to increase the energy efficiency while guaranteeing the QoS requirements of the multimedia services over the wireless sensor networks. <s> BIB020 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> “MAEE Routing Protocol for WMSNs”, routes image packets to the sink optimally, utilizing less energy of the node. MAEE uses MMRE+AOMDV protocol to build the multiple paths and then score them using path conditions based on availability of resources. Simulation is performed using ns-2.27 platform and results evaluated in the simulation demonstrate a significant performance parameter improvement. <s> BIB021 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Technological developments in the micro-electronics and wireless communications, in addition to obtain ability of cheap CMOS cameras and micro phones, have led to appearance of next generation networks known as Wireless Multimedia Sensor Networks (WMSNs). WMSN can retrieve image, video, audio and scalar sensor data from the physical environment. Wireless multimedia sensor networks will not only enhance existing sensor network applications like tracking, home automation, and environmental monitor, but they will also enable several new applications such as: Advanced Health Care Delivery, Industrial Process Control, Traffic Congestion Avoidance Systems. In this paper a technique called EEQAR is used to select energy efficient QoS routing which is based on cluster hierarchy. To achieve a enhanced performance, EEQAR routing implements cellular topology to form the cluster structure and balance the energy consumption by structure movement. The simulation results shows that EEQAR performs high efficiency on network lifetime and QoS in wireless multimedia sensor network. <s> BIB022 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> The increasing availability of low-cost hardware along with the rapid growth of wireless devices has enabled the development of Wireless Multimedia Sensor Networks (WMSNs). Multimedia content such as video and audio streaming is transmitted over a WMSN which can easily be deployed with low cost. However, enabling real-time data applications in those networks demands not only Quality of Service (QoS) awareness, but also efficient energy management. Sensor network devices have limited energy resources. The limited energy poses significant threats on the QoS of WMSNs. In this paper, to improve the efficiency of QoS-aware routing, we examine an angle-based QoS and energy-aware dynamic routing scheme designed for WMSNs. The proposed approach uses the inclination angle and the transmission distance between nodes to optimize the selection of the forwarding candidate set and extend network lifetime. Simulation results indicate that considerable lifetime values can be achieved. <s> BIB023 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Multipath routing in wireless multimedia sensor network makes it possible to transfer data simultaneously so as to reduce delay and congestion and it is worth researching. However, the current multipath routing strategy may cause problem that the node energy near sink becomes obviously higher than other nodes which makes the network invalid and dead. It also has serious impact on the performance of wireless multimedia sensor network (WMSN). In this paper, we propose a pair-wise directional geographical routing (PWDGR) strategy to solve the energy bottleneck problem. First, the source node can send the data to the pair-wise node around the sink node in accordance with certain algorithm and then it will send the data to the sink node. These pair-wise nodes are equally selected in 360° scope around sink according to a certain algorithm. Therefore, it can effectively relieve the serious energy burden around Sink and also make a balance between energy consumption and end-to-end delay. Theoretical analysis and a lot of simulation experiments on PWDGR have been done and the results indicate that PWDGR is superior to the proposed strategies of the similar strategies both in the view of the theory and the results of those simulation experiments. With respect to the strategies of the same kind, PWDGR is able to prolong 70% network life. The delay time is also measured and it is only increased by 8.1% compared with the similar strategies. <s> BIB024 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Wireless Multimedia Sensor Networks (WMSNs) consist of networks of interconnected devices involved in retrieving multimedia content, such as, video, audio, acoustic, and scalar data, from the environment. The goal of these networks is optimized delivery of multimedia content based on quality of service (QoS) parameters, such as delay, jitter and distortion. In multimedia communications each packet has strict playout deadlines, thus late arriving packets and lost packets are treated equally. It is a challenging task to guarantee soft delay deadlines along with energy minimization, in resource constrained, high data rate WMSNs. Conventional layered approach does not provide optimal solution for guaranteeing soft delay deadlines due to the large amount of overhead involved at each layer. Cross layer approach is fast gaining popularity, due to its ability to exploit the interdependence between different layers, to guarantee QoS constraints like latency, distortion, reliability, throughput and error rate. The paper presents a channel utilization and delay aware routing (CUDAR) protocol for WMSNs. This protocol is based on a cross-layer approach, which provides soft end-to-end delay guarantees along with efficient utilization of resources. Extensive simulation analysis of CUDAR shows that it provides better delay guarantees than existing protocols and consequently reduces jitter and distortion in WMSN communication. <s> BIB025 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> (x) Current Traffic Load or Number of Active Paths. <s> Graphical abstractDisplay Omitted HighlightsA new multi-objective approach for the routing problem in Wireless Multimedia Sensor Networks (WMSNs) is proposed.Classical approximations optimize a single objective or Quality of Service (QoS) parameter.Classical approximations do not take into account the conflicting nature of QoS parameters which leads to sub-optimal solutions.The proposed approach takes into account multiple QoS requirements such as delay and the Expected Transmission Count (ETX).The case studies applying the proposed approach shows clear improvements on the QoS routing solutions. In this paper, a new multi-objective approach for the routing problem in Wireless Multimedia Sensor Networks (WMSNs) is proposed. It takes into account Quality of Service (QoS) requirements such as delay and the Expected Transmission Count (ETX). Classical approximations optimize a single objective or QoS parameter, not taking into account the conflicting nature of these parameters which leads to sub-optimal solutions. The case studies applying the proposed approach show clear improvements on the QoS routing solutions. For example, in terms of delay, the approximate mean improvement ratios obtained for scenarios 1 and 2 were of 15 and 28 times, respectively. <s> BIB026
During new route establishment, the next forwarding node is selected based on the number of active paths through the neighboring node BIB005 BIB009 . (xi) History. History reports the history of packets belonging to the same flow on which the next routing decision is made  BIB013 BIB020 . (xiv) Jitter. Jitter represents packet delay variation or latency variation over time, which results in fluctuating packet interarrival times BIB003 BIB014 . A network with a consistent delay will have no jitter; however, with variable delay, it will have high jitter. Jitter is a paramount factor in multimedia routing. (xv) Buffer Size or Queue Length. Every sensor node maintains queues for incoming packets and outgoing packets BIB021 BIB006 . The state of these queues decide the performance of the routing protocol. (xvi) Trust Value. Based on this value, every node will have a trust or confidence in another node. In addition, it is based on level of service provided by its neighbors BIB022 BIB010 . Trust value can be computed directly or indirectly from neighboring nodes. (xvii) Data Correlation. To reduce traffic redundancy and to optimize energy consumption a data fusion technique is used. The data correlation coefficient is used to characterize the fusion technique BIB022 BIB010 . (xviii) Traffic Priority. In multipath routing, multiple paths are found between source and sink. These paths can be shortest paths in terms of hop count or energy efficient paths or high throughput reliable paths. Based on the requirement of application data traffic can be prioritized to be distributed along different paths BIB019 BIB020 . (xix) Inclination Angle. Inclination angle is the angle formed by the line that connects the current node and the neighbor node and the line that connects the current node and the sink node BIB023 . (xx) Path Contract Angle. This angle is computed from deviation angle, number of hops from source to sink, and current hop number. Deviation angle is defined as the angle that specifies how much a path is expected to deviate from the reference line at the origin point. Reference line is defined as the straight line between the origin of the virtual coordinate system and the sink BIB024 . (xxi) Included Angle. Included angle is defined as the angle between the current node and the pairwise node with respect to -axis. Pairwise node is a node in the 360 ∘ scope around sink node BIB024 . (xxii) Transmission Radius. The communication range of a sensor node depends on transmission radius BIB017 BIB007 . This metric is directly responsible for Link Interference. Although interference is associated with the MAC and physical layers, it plays a significant role in the routing process. Interflow interference and intraflow interference are two types of interferences. Interflow interference is interference among neighboring nodes contending for the same busy channel. Intraflow interference is interference between intermediate nodes sharing the same flow path. (xxiii) Channel Utilization. Channel utilization indicates the contention level around a node BIB025 BIB015 . (xxiv) Packet Loss Rate. Packet loss rate represents the number of packets lost with respect to the number of packets sent. Packets are lost due to congestion or due to a damaged link BIB002 BIB016 BIB006 BIB011 BIB004 BIB014 . Packet loss rate is an important metric for measuring the performance of routing protocol. (xxv) Expected Transmission Count (ETX). To deliver packets effectively over a specific wireless link, number of transmission attempts are required; this number of attempts is called ETX and is based on the forward delivery ratio and reverse delivery ratio BIB021 BIB026 . ETX is an important metric that directly affects throughput but is independent of link data rate. A summation of the ETX value of each link along a path is the ETX value of the path. (xxvi) Packet Delivery Ratio. The link quality is determined by the Packet Delivery Ratio (PDR) based on both data and control packets. PDR is the ratio of the number of transmitted packets to the number of acknowledged packets BIB012 . (xxvii) Bit Error Rate. Bit Error Rate (BER) metric is used to access the performance of the link BIB018 BIB001 . It is defined as the rate at which errors occur in a particular link. (xxviii) Link Quality Identifier (LQI). This metric characterizes the quality and strength of the received packet on a specific link BIB019 . LQI value ranges from 0 to 255, indicating lowest and highest quality of the link. (xxix) Signal-to-Noise Ratio (SNR). The signal-to-noise ratio is used to measure the quality of the channel and quality of the link BIB004 . The presence of noise will determine how much information can be transferred on the channel. (xxx) Airtime Link Metric. Airtime link metric is default link metric used by Hybrid Wireless Mesh Protocol (HWMP)  to discover the efficient radio-aware path BIB008 . It reflects the amount of channel resources utilized during frame transmission over a particular link.