Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB001 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Wireless sensor networks are being built to facilitate automated information gathering in military, industrial, environmental and surveillance applications. Many such applications of Sensor Networks require improved QoS (packet delivery within a defined deadline) guarantees as well as high reliability. These applications demand high packet delivery ratio and are extremely delay-sensitive. However, certain factors limit the ability of the multihop sensor network to achieve the desired goals. These factors include the delay caused by network congestion, hot regions in the network, limited energy of the sensor nodes, packet loss due to collisions and link failure. In this paper, we propose an energy aware dual-path routing scheme for real-time traffic, which balances node energy utilization to increase the network lifetime, takes network congestion into account to reduce the routing delay across the network and increases the reliability of the packets reaching the destination by introducing minimal data redundancy. This paper also introduces an adaptive prioritized Medium Access Layer (MAC) to provide a differentiated service model for real-time packets. Our claims are well supported by simulation results. <s> BIB002 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Many wireless sensor network applications must resolve the inherent conflict between energy efficient communication and the need to achieve desired quality of service such as end-to-end communication delay. To address this challenge, we propose the Real-time Power-Aware Routing (RPAR) protocol, which achieves application-specified communication delays at low energy cost by dynamically adapting transmission power and routing decisions. RPAR features a power-aware forwarding policy and an efficient neighborhood manager that are optimized for resource-constrained wireless sensors. Moreover, RPAR addresses important practical issues in wireless sensor networks, including lossy links, scalability, and severe memory and bandwidth constraints. Simulations based on a realistic radio model of MICA2 motes show that RPAR significantly reduces the number of deadlines missed and energy consumption compared to existing real-time and energy-efficient routing protocols. <s> BIB003 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Image and video sensing data in the multimedia wireless sensor networks make many requirements in the resource of bandwidth and energy. For the purpose of real-time transmission of multimedia data, this paper proposes a new QoS protocol applied to multimedia wireless sensor networks REAR. In this protocol metadata is used to establish multi-path routing for reducing the energy consumption and a cost function is constructed to evaluate the consumption of the transmission links which trades off the relationship of energy and delay, and then a QoS routing is chosen. The experiments show that the protocol could ensure the real-time transmission of multimedia data and prolong the lifetime of sensor networks. <s> BIB004 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> This paper proposes a power efficient multipath video packet scheduling scheme for minimum video distortion transmission (optimised Video QoS) over wireless multimedia sensor networks. The transmission of video packets over multiple paths in a wireless sensor network improves the aggregate data rate of the network and minimizes the traffic load handled by each node. However, due to the lossy behavior of the wireless channel the aggregate transmission rate cannot always support the requested video source data rate. In such cases a packet scheduling algorithm is applied that can selectively drop combinations of video packets prior to transmission to adapt the source requirements to the channel capacity. The scheduling algorithm selects the less important video packets to drop using a recursive distortion prediction model. This model predicts accurately the resulting video distortion in case of isolated errors, burst of errors and errors separated by a lag. Two scheduling algorithms are proposed in this paper. The Baseline scheme is a simplified scheduler that can only decide upon which packet can be dropped prior to transmission based on the packet's impact on the video distortion. This algorithm is compared against the Power aware packet scheduling that is an extension of the Baseline capable of estimating the power that will be consumed by each node in every available path depending on its traffic load, during the transmission. The proposed Power aware packet scheduling is able to identify the available paths connecting the video source to the receiver and schedule the packet transmission among the selected paths according to the perceived video QoS (Peak Signal to Noise Ratio--PSNR) and the energy efficiency of the participating wireless video sensor nodes, by dropping packets if necessary based on the distortion prediction model. The simulation results indicate that the proposed Power aware video packet scheduling can achieve energy efficiency in the wireless multimedia sensor network by minimizing the power dissipation across all nodes, while the perceived video quality is kept to very high levels even at extreme network conditions (many sensor nodes dropped due to power consumption and high background noise in the channel). <s> BIB005 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB006 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Wireless multimedia sensor network (WMSN) takes more account of dealing with information-intensive data such as audio, image and video, it has much more wide foreground for application than traditional wireless sensor network. It has significance to research topology of WMSN aimed at some characteristic such as the larger media data capacity, limitation on computation, storage & energy and the requirements of transport quality. This paper introduces a novel clustered-control algorithm based on geographic locations, energy, priority of coverage, and multi-layers architecture. Detailed process is proposed including cluster heads’ election method and multimedia data transmission mechanism. The theoretical analysis and simulation experiments indicate that our improved algorithm can strengthen routing function, prolong the lifetime of network and reduce energy consumption. <s> BIB007 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> As a multimedia information acquisition and pro-cessing method, wireless multimedia sensor network(WMSN) has great application potential in military civilian. Compared with traditional wireless sensor network, the routing design of WMSN should obtain more attention on the quality of transmission. This paper proposes a reliable routing based on energy prediction (REP), which includes energy prediction and power allocation mechanism. The introduced prediction mechanism makes the sensor nodes predict the remaining energy of other nodes, which dramatically reduces the overall information needed for balancing energy. based on the predicted result, REP can dynamically balance the energy consumption of nodes by power allocation. The simulation results prove the efficiency on energy equilibrium and reliability of the proposed REP routing. <s> BIB008 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> As a multimedia information acquisition and processing method, wireless multimedia sensor network(WMSN) has great application potential in military and civilian areas. Compared with traditional wireless sensor network, the routing design of WMSN should obtain more attention on the quality of transmission. This paper proposes an adaptive reliable routing based on clustering hierarchy named ARCH, which includes energy prediction and power allocation mechanism. To obtain a better performance, the cluster structure is formed based on cellular topology. The introduced prediction mechanism makes the sensor nodes predict the remaining energy of other nodes, which dramatically reduces the overall information needed for energy balancing. ARCH can dynamically balance the energy consumption of nodes based on the predicted results provided by power allocation. The simulation results prove the efficiency of the proposed ARCH routing. <s> BIB009 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB010 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB011 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Wireless Multimedia Sensor Network(WMSN) is a blooming field due to the development of CMOS cameras and Microphones which are wirelessly interconnected devices that are able to retrieve multimedia content such as video and audio streams, still images and scalar sensor data from the environment. As of today, almost all deployed wireless sensor data networks measure scalar physical parameters like temperature, pressure humidity etc. To capture the image, video Wireless Multimedia Sensor nodes (WMSn) are to be deployed. The node of WMSn is equipped with cameras, microphones, and sensors producing multimedia content. Routing in Wireless Sensor Network is an important issue since WMS nodes that senses the data need to be communicated to the base station. The key issues in design of routing protocol in the WMSN are energy efficiency, adaptive routing, multimedia packet scheduling, Quality of service (QOS) and high bandwidth demand. Many routing protocols have been proposed for the WMSN. The design of more efficient protocols in terms of energy awareness, video packet scheduling and QOS in terms of check point arrangement is still remains a challenge. This paper discuss the design of the routing protocol in wireless multimedia sensor network which is power aware, reliable and has low latency in delivering the sensing data from source or sink node to the destination node. The new proposed architecture called ASARC: ACTUATION SENSOR ADAPTIVE ROUTING WITH CHECK POINT. ASARC provides actuation of sensor on demand basis and selection of path for communication between any two nodes such as sensor or relay node without video distortion. This feature enhances the lifetime of the network and also it supports security and QOS. <s> BIB012 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Automated information gathering in military, industrial, environmental and surveillance applications which requires improved QoS guarantees as well as high reliability is well supported with Wireless Multimedia Sensor Networks (WMSNs). In this paper, we propose a more reliable energy efficient multi-path routing scheme for multimedia-traffic. The proposed protocol quickly chooses partial disjoint paths in case of node failure to minimize routing overhead. Hence increases the reliability of the packets reaching the destination with minimum delay. Extensive simulations are carried out to show that proposed protocol achieves an efficient tradeoff among reliability, energy consumption and end to end delay. It provides higher packet delivery ratios and lower routing overheads compared to the Maximally Radio disjoint Multipath Routing (MR2) and Hop Count Multipath routing (HCMR) protocols. <s> BIB013 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Recently, wireless multimedia sensor networks (WMSNs) have emerged as one of the most important technologies, driven by the development of powerful multimedia device such as CMOS. WMSNs require several factors such as resource constraints, specific QoS, high bandwidth and so on. In this paper, we propose a hierarchical heterogeneous network model based routing protocol for WMSNs. In our proposal, proposed network model is classified into monitoring class, delivery class and aggregation class. Also we define two kinds of the routing path in order to ensure bandwidth and QoS. In simulation results, we illustrate the performance of our proposal. <s> BIB014 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> Wireless Sensor Networks (WSNs) have an ever increasing variety of multimedia based applications. In these types of applications, network nodes should ideally maximize QoS and minimize energy expenditures in video communication. This article presents PEMuR, a novel dual scheme for efficient video communication, which aims at both energy saving and high QoS attainment. To achieve its objectives, PEMuR proposes the combined use of an energy aware hierarchical routing protocol with an intelligent video packet scheduling algorithm. The adopted routing protocol enables the selection of the most energy efficient routing paths, manages the network load according to the energy residues of the nodes and prevents useless data transmissions through the proposed use of an energy threshold. In this way, an outstanding level of energy efficiency is achieved. Additionally, the proposed packet scheduling algorithm enables the reduction of the video transmission rate with the minimum possible increase of distortion. In order to do so, it makes use of an analytical distortion prediction model that can accurately predict the resulted video distortion due to any error pattern. Thus, the algorithm may cope with limited available channel bandwidth by selectively dropping less significant packets prior to their transmission. Simulation results demonstrate the effectiveness of the proposed scheme. <s> BIB015 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB016 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> With the maturity and development of Wireless Sensor Networks, a large body of research is being assembled and several routing protocols have been developed for wireless sensor networks. Routing metric is very important for the performance of wireless sensor networks. But a little attention has been paid by the researchers to the evaluation metrics and design principles for routing protocols that should never be neglected while designing and evaluating routing protocols for wireless sensor networks. This paper depicts some vital evaluation metrics that are essential while designing, developing and evaluating the performance of routing protocols for wireless sensor networks. This research is an effort towards hoarding all the general metrics and guiding the researchers for designing efficient, professional and valuable routing protocols. <s> BIB017 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB018 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB019 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <s> The field of wireless multimedia sensor networks (WMSN) is attracting more and more research community as an interdisciplinary field of interest. This type of network is low-cost, multifunctional due to advances in micro-electromechanical systems, and the proliferation and progression of wireless communications. However transmit multimedia information captured must satisfy the criteria of QoS , which increases energy consumption, fact that should be taken into consideration in the design of any routing protocols for WMSNs. In this paper we present routing protocol which we call an Energy Aware TPGF (EA-TPGF), that improves the Two Phase geographical Greedy Forwarding (TPGF). The basic idea is to take into account the residual energy of the nodes in the identification of pathways. Simulations and statistics produced by the simulator NeTtopo showing a significant contribution with regard to the extension of the life of the network. <s> BIB020 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB021 </s> Survey of QoS routing protocols in Wireless Multimedia Sensor Networks <s> Routing Metrics Associated with Link/Path Cost <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> BIB022
In general, a metric is a system or standard of measurement defined as a parameter or measure for quantitatively assessing a method, event, and entity by using special procedures to perform measurements BIB017 . The performance of any WMSNs routing protocol depends upon limited available resources and the dynamic nature of the sensor network. A routing metric is a parameter or measure used to choose the best next neighbor node or an optimal path between source and destination node. Metric values are affected by environmental factors and network-imminent factors  . Mathematically, metrics can be categorized into static or dynamic, symmetric, or asymmetric and single dimensional or multidimensional. This section briefly outlines a set of routing metrics that are used in combination to find the weight/cost of a link/path. All routing metrics outlined in this section are discussed in the context of the WMSNs QoS protocols surveyed in Section 3. (i) Distance. Distance is the geographical distance from the next forwarding neighboring node to the sink node or is the geographical distance between a current node and subsequent forwarding neighboring node. This is the most widely used basic metric . On its own, the use of this metric may result in suboptimum performance but positively influences performance when used in combination with other metrics. (ii) Residual or Remaining Energy. This metric represents the energy remaining in a sensor node at a specific time after the network is deployed. Residual energy is used extensively in routing decision BIB020 BIB007 BIB002 BIB003 BIB004 BIB012 BIB013 BIB014 BIB001  BIB018 BIB021 . It plays a crucial role in load balancing and extending the lifetime of the network. Certain routing techniques also consider average residual energy of sensor nodes along a single path BIB008 BIB009 . (iii) Expected or Transmission Energy. This metric represents the required energy to route a message between two sequential sensor nodes BIB015 . (iv) Initial Energy. This metric represent the energy in a sensor node at the beginning of the network deployment BIB010 . (v) Bandwidth. Bandwidth indicates bit rate of the available or consumed data capacity that can be used to send data over a link or a path in a given period BIB014 BIB022 BIB005 BIB016 BIB011 BIB006 BIB019 . (vi) Hop Count or Number of Links. This metric represents number of links a packet must travel from the next forwarding neighboring node to the sink or number of links a packet has travelled already to reach the current sensor node or number of links on a path from source to sink [4-26, 26-35, 35-38, 38, 39, 39-43, 50, 55, 60, 61, 63, 67-69] . This metric is independent of the quality and characteristics of the link. (vii) Delay or Latency. The delay metric measures the time to transmit and receive a packet from sender to receiver. The delay is derived from the queuing delay, processing delay, propagation delay, and transmission delay [20, 21, 23, 27, 29-34, 42, 44, 47, 51, 58, 59, 61, 62, 65-67, 69] .