Routing Metrics Research Articles

A Survey on Routing Protocols for Delay and Energy-Constrained Cognitive Radio Networks

The ever-growing demand for higher network data rates, lower delay, and conservative energy consumption at reduced costs, to support Internet-of-things (IoT) communications, has pushed wireless technologies into a new frontier. The growing demand for such technologies can be attributed to several factors, such as the massive number of the upcoming bandwidth-hungry IoT applications and the enormous number of - often battery-powered - devices expected to connect to the network. Cognitive Radio Networks (CRNs) can play a significant role in future generations of mobile-communication technologies by providing dynamic access to underutilized licensed bands. However, battery-operated devices, which communicate delay-sensitive data over multihop links, impose serious energy-delay limits. In such CRN-based IoT communications, as one device depletes its energy, network disconnectivity may arise, which can degrade the network efficiency. Therefore, building a reactive routing protocol to recover from any sudden link breakage is necessary to maintain prolonged network connectivity. This paper provides a comprehensive survey of CRN routing protocols that are based on two essential metrics, namely, packet delay, energy consumption, or both, while excluding all other CRN routing protocols. The survey is meant to support the designers of future CRN-based IoT communication frameworks with a detailed comparative survey, which targets the most relevant proposed routing protocols, including the specifics of the routing metrics, implemented spectrum awareness strategy, and employed medium-access control standard along with the simulator tool used for performance evaluation. In addition, this survey finds that the majority of cognitive radio routing protocols address either delay or energy consumption, but only a few consider a joint delay-energy metric, which suits delay-sensitive IoT applications running on energy-constrained devices.

Increased Network Lifetime and Load Balancing Based on Network Interface Average Power Metric for RPL

The technological paradigm of the Internet of Things has attracted the attention of the market, industry, and scientific community. The possibility of integrating wireless sensor network (WSN) devices to the Internet has prompted the Internet Engineering Task Force (IETF) to specify new standards and protocols, such as the Routing Protocol for Low-Power and Lossy Networks (RPL), designed to find stable routing paths via links that have considerable losses. Among the routing metrics, the expected transmission count (ETX) is notable because its implementation in RPL helps choosing reliable paths. However, the rapid exhaustion of battery energy at bottleneck nodes remains a problem. In this context, this study introduces the network interface average power metric (NIAP), a new metric based on the estimated average power consumption of the network interface, which contributes not only to the choice of reliable paths but also to load balancing and lifetime increasing of a wireless sensor network. The results of several experiments conducted in a simulated environment demonstrate that NIAP is a promising alternative to ETX due to its simple implementation without modifications of the RPL standard.

Beaconless Traffic-Aware Geographical Routing Protocol for Intelligent Transportation System

Intelligent Transportation System (ITS) in sustainable smart cities are taking advantage of moving vehicle nodes for data communication. VANETs support many applications related to safety, infotainment, and accident detection. The routing protocols are using for data communication in the presence of high mobility nodes and dynamic topologies. Due to high mobility and unpredictable topologies, the data communication becomes unreliable which causes data loss, delay, and link disconnections among vehicle nodes. To address these routing limitations, various types of routing protocols have developed. In all existing routing protocols types, geographic routing protocols are one of the efficient types due to its low overhead processes. Geographical routing protocols are able to handle vehicular environment constraints. However, with many advantages, geographic routing protocols are not considering many constraints of the vehicular environment. Geographical routing protocols should have well-defined routing metrics to deal with high mobility and other data loss and link disconnection issues. This research designs a Beaconless Traffic-Aware Geographical Routing Protocol (BTA-GRP) by considering traffic density, distance and direction for next forwarder node and route selection. The protocol is feasible for urban dense and sparse traffic conditions and addresses delay, disconnection and packet dropping issues. The proposed protocol has simulated with state of the art routing protocols. The simulation results indicated that the proposed protocol has higher performance in VANETs.

Experimental Performance Evaluation of RPL Protocol for IPv6 Sensor Networks

In this article, the authors propose a new approach to meet various QoS requirements from different kinds of traffic; thus, maximizing network utilization, while improving its performance. The authors design an objective function based on ant colony optimization (ACO). The authors use the delay, energy, packet loss, and memory as the routing metric of the nodes in the preferred parent selection process for the RPL protocol to build the DODAG structure. After, the authors implement it in an experimental testbed deployed in real scenarios, and then the authors compare the results with RPL based on ETX.

Selective-path clustered-based routing protocol for large scale wireless sensor networks

Wireless sensor networks (WSNs) consist of large number of small low-powered electronic sensor devices. Therefore, reliable power saving schemes must be developed in order to manage the energy dissipated and extend the network life and functionality for a meaningful time. Arranging sensor nodes (SNs) into clusters has been viewed as an efficient approach of balancing the energy dissipated in WSNs. Regardless, a clustered WSN needs a robust energy efficient (EE) and energy balanced (EB) routing communication protocol. This paper proposes a selective-path priority table (SPT) EE and EB routing protocol (RP) ideal for most conventional clustering algorithms. The SPT RP forms the priority table by prioritising the k nearest multi-hop paths to the cluster heads (CHs) and/or base station (BS) based on some robust rules. These rules are compiled using a combination of some routing metrics which include the residual energy (RE) and transmission range/power. Firstly, the simulation results indicate that the SPT RP can be combined with most of the conventional clustering algorithm irrespective of the number of deployed SNs. Secondly, the performance of the SPT RP improves as the value of the selected number of routing paths (k) increase. More so, the simulation results show that the SPT RP reduces the energy dissipated and can prolong the network life and throughput as compared to related routing schemes.

Investigation on optimisation, prioritising and weight allocation techniques for load balancing and controlling multimedia traffic in wireless mesh network

Wireless mesh network (WMN) is a type of wireless ad hoc network where radio nodes are wirelessly connected within sizable geographic area through mesh topology. The best path is identified by routing metrics to ensure efficient data transmission from source node to destination node. The performance of routing is concern with set of routing constraints such as bandwidth, network delay, energy consumption, load balancing and communication cost. The routing constraints are needed to be resolved to improve the WMN performance. In WSN, network load balancing plays a significant role to achieve effective routing without traffic. The energy consumption is an additional factor to provide high-quality data delivery at the destination end. Our research work is concentrated on developing the energy efficient and load balanced routing in WMN.

Resilient Routing Mechanism for Wireless Sensor Networks With Deep Learning Link Reliability Prediction

Wireless sensor networks play an important role in Internet of Things systems and services but are prone and vulnerable to poor communication channel quality and network attacks. In this paper we are motivated to propose resilient routing algorithms for wireless sensor networks. The main idea is to exploit the link reliability along with other traditional routing metrics for routing algorithm design. We proposed firstly a novel deep-learning based link prediction model, which jointly exploits Weisfeiler-Lehman kernel and Dual Convolutional Neural Network (WL-DCNN) for lightweight subgraph extraction and labelling. It is leveraged to enhance self-learning ability of mining topological features with strong generality. Experimental results demonstrate that WL-DCNN outperforms all the studied 9 baseline schemes over 6 open complex networks datasets. The performance of AUC (Area Under the receiver operating characteristic Curve) is improved by 16% on average. Furthermore, we apply the WL-DCNN model in the design of resilient routing for wireless sensor networks, which can adaptively capture topological features to determine the reliability of target links, especially under the situations of routing table suffering from attack with varying degrees of damage to local link community. It is observed that, compared with other classical routing baselines, the proposed routing algorithm with link reliability prediction module can effectively improve the resilience of sensor networks while reserving high-energy-efficiency.

Selective-path clustered based routing protocol for large scale wireless sensor networks

Wireless sensor networks (WSNs) consist of large number of small low-powered electronic sensor devices. Therefore, reliable power saving schemes must be developed in order to manage the energy dissipated and extend the network life and functionality for a meaningful time. Arranging sensor nodes (SNs) into clusters has been viewed as an efficient approach of balancing the energy dissipated in WSNs. Regardless, a clustered WSN needs a robust energy efficient (EE) and energy balanced (EB) routing communication protocol. This paper proposes a selective-path priority table (SPT) EE and EB routing protocol (RP) ideal for most conventional clustering algorithms. The SPT RP forms the priority table by prioritising the k nearest multi-hop paths to the cluster heads (CHs) and/or base station (BS) based on some robust rules. These rules are compiled using a combination of some routing metrics which include the residual energy (RE) and transmission range/power. Firstly, the simulation results indicate that the SPT RP can be combined with most of the conventional clustering algorithm irrespective of the number of deployed SNs. Secondly, the performance of the SPT RP improves as the value of the selected number of routing paths (k) increase. More so, the simulation results show that the SPT RP reduces the energy dissipated and can prolong the network life and throughput as compared to related routing schemes.

Efficient Multipath Routing to Increase QoS by Link Estimation and Minimum Interference path in MANET'S

Many significant techniques have been developed for real time transmission to meet stringent QoS for various applications of wireless sensor network. However routing in MANET’s still a challenging issue to achieve QoS due to frequent topology changes and its dynamic nature. For majority MANET applications, on demand multi path data routing protocols have been modelled to transfer data in multiple routes to prove its effectiveness on link disjoints and high packet delivery ratio. However due to mobility and underlying medium, multiple routes are exposed to interference and low power unstable link quality which are essential to guarantee QoS in routing. In this paper we propose link quality estimation and minimum path interference based on Geographic adhoc on demand multi path distance vector (GAOMDV) an adaptation of AOMDV routing protocol. To ensure the reliability of MANET’s this adaptation is done by considering routing metrics. GAOMDV selects forwarding neighbour nodes based on link quality and minimum path interference across multiple paths and ensures high stable links between nodes. Extensive simulation is carried on discrete event simulation tool and performance of GAOMDV is analysed in terms of network QoS parameters.

Routing Schemes in FANETs: A Survey.

Flying ad hoc network (FANET) is a self-organizing wireless network that enables inexpensive, flexible, and easy-to-deploy flying nodes, such as unmanned aerial vehicles (UAVs), to communicate among themselves in the absence of fixed network infrastructure. FANET is one of the emerging networks that has an extensive range of next-generation applications. Hence, FANET plays a significant role in achieving application-based goals. Routing enables the flying nodes to collaborate and coordinate among themselves and to establish routes to radio access infrastructure, particularly FANET base station (BS). With a longer route lifetime, the effects of link disconnections and network partitions reduce. Routing must cater to two main characteristics of FANETs that reduce the route lifetime. Firstly, the collaboration nature requires the flying nodes to exchange messages and to coordinate among themselves, causing high energy consumption. Secondly, the mobility pattern of the flying nodes is highly dynamic in a three-dimensional space and they may be spaced far apart, causing link disconnection. In this paper, we present a comprehensive survey of the limited research work of routing schemes in FANETs. Different aspects, including objectives, challenges, routing metrics, characteristics, and performance measures, are covered. Furthermore, we present open issues.

Toward an understanding of recent developments in RPL routing

The ability to enhance network routing for flexible support of different application requirements is essential to widen the horizon for the Internet of things (IoT) deployments. The Internet protocol (IP) version 6 routing protocol for low-power and lossy networks (RPL) provides an effective routing solution addressing such a challenge. It realises flexible end-to-end IP routing that can be adapted to support different IoT applications. This is based on the concept of customisable objective functions (OFs), which facilitates application-specific routing using a wide range of routing metrics. There are only two default OFs of basic routing metrics, which are specified by the Internet engineering task force for RPL. However, a number of others have been proposed by the network research community to address single- and multi-objective RPL routing enhancement. These research proposals followed different methodological approaches and adopted a variety of routing metrics to achieve different optimisation goals. Up-to-date research efforts to improve RPL routing and topology optimisation have been reviewed, and recent RPL OFs and routing metrics in the literature have been discussed. The major aim is shedding light on relevant contributions to establish a firm understanding of recent RPL developments and outline plausible areas for follow-up researches.

Differential back‐pressure routing for single‐queue time‐varying wireless networks

Dynamic resource control and routing are important for realising the intelligent control of data transmission in wireless multi-hop networks. It is well known that back-pressure routing based on a max-weight policy maximises network throughput and optimises resource allocation in multi-hop wireless networks with time-varying channels. Due to the slow routing convergence and complex control of data queues, however, back-pressure routing also results in large end-to-end delays and a waste of network resources, particularly when the network loads are light or moderate. In this study, a differential back-pressure routing scheme with single-queue management is proposed to improve the packet delay performance and simplify the management of data queues. Unlike in traditional back-pressure routing, the authors use the differences in the rates of change in data queue length to calculate data pressure. Compared with the method of data backlog calculation based on queue length differences, this method achieves faster routing convergence. They also consider the ceiling problem for a single queue and enhance the effect of the queue cap on the routing metric by means of dynamic weighting. Simulation results show that the proposed routing algorithm achieves a 20% decrease in end-to-end delay in grid and random networks.

Fuzzy Logic-Based Directional Location Routing in Vehicular Ad Hoc Network

The vehicular ad hoc network (VANET) is an autonomous system of mobile vehicles where mobile vehicles can transmit or receive data packet over the wireless link. Due to the movable nature and limited communication, range of vehicles causes breaking the link between them very frequently, which in turn causes failure in the data delivery. Therefore, a stable path should be established from the source to the destination node to deliver data packets at the intended destination node. Therefore, for a stable route from source to the destination node selection of the next hop should be appropriate. The proposed work in this paper has been made to discuss how the best next hop node can be selected to deliver data packet successfully at the destination node D. A mathematical model fuzzy logic-based directional location routing (FLDLR) has been proposed to select a remarkable next hop node in the VANET. To select next hop, FLDLR has considered fuzzy logic sets of the routing metrics, i.e., next hop distance, node speed, closeness, the data transmission rate of the node, and node movement direction. To investigate the performance of FLDLR, the simulation work has been done through network simulator-2 and compared with existing LAR and D-LAR protocols. Through simulated results has shown that the FLDLR outperforms existing protocols from the standpoints routing overhead and packet delivery delay.

Classification of Routing Protocols Based on Routing Metrics in Cognitive Radio AD HOC Networks

Cognitive radio ad hoc networks are opportunistic networks, which utilize licensed spectrum. The spectrum assigning authority has divided the spectrum in to two regions: licensed and unlicensed. The unlicensed bands are clogged while licensed bands are underutilized. So unlicensed traffic needs to be shifted to unused licensed portion of the spectrum. Henceforth, Cognitive Radio Networks are proposed. These networks were having an infrastructure just like base station in cellular network. Cognitive radio ad hoc network are special wireless ad hoc networks having cognitive capability. In these networks, devices are able to adapt according to the environment. These devices are designed to operate in different frequency ranges. Routing data in this kind of network is a bit challenging due to its different nature. This paper discusses these challenges in detail. Later a detailed discussion is presented on the existing approaches used to handle these challenges. A clear & concise analysis of every approaches is preformed which leads to identification of merits & demerits of each of these approach. Lastly, identification of various routing metrics which need to be considered while designing a new routing protocol for cognitive radio ad hoc networks has been made.

Extension of Lifespan in WSN

Objectives: Since Wireless Sensor Network has played a crucial role in our life, further research is needed to enhance its performance. For missions to be accomplished successfully, the lifetime span has to be prolonged. The lifetime of WSNs is considered a crucial issue that has to be studied further. Methods/Findings: Thus, numerous researches from different perspectives have been proposed. In this study and research, it has been found that there is a harmful process called sink isolation (hotspot zone) because of neighbor nodes of sink running out of energy more than the others. Our point of view is that these hotspot zones are of more concern than far away zones. Thus, a pioneering Q-metric is studied which tackles the energy consumption at each hotspot zone relative to the dimension of its interconnected nodes at the far away zone. Application: Accordingly, the Q can be manipulated to switch data traffic to alternative routes lead to a more proper hotspot zone and hence an exhausted hotspot zones will be avoided and consequently lifetime of this network will be extended. Keywords: Hotspot, Lifetime, Tree Topology, Route Metric, WSN

A Resource Oriented Route Selection Framework Using Contextual Information Based on Fuzzy Logic

Internet of Things (IoT) is expected to have a significant impact on city’s service provisioning and make a smart city more accessible and pragmatic since the deployment of heterogeneous smart devices in each infrastructure of cities is increasing. So far, the IPv6 routing protocol for low power and lossy networks (RPL) is considered to fit on IoT infrastructure for achieving the expected network requirements. While RPL meets the IoT network requirements quite well, there are some issues that need to be addressed, such as adaptability to network dynamics. This issue significantly limits the use of RPL in many smart city application scenarios, such as emergency alerts with high traffic flows. As part of a smart city vision, IoT applications are becoming more diverse, which requires context-awareness in routing protocols to support the behavior of the network. To address this issue, we design an objective function that performs the route selection based on fuzzy logic techniques while using contextual information from the application. For this, we present a new context-oriented objective function (COOF) that comprises both nodes as well as link metrics. Further, we suggest two new routing metrics, known as queue fluctuation index (QFI) and residual energy index (REI), which consider the status of queue utilization and remaining energy, respectively. The metrics used are designed to respond to the dynamic needs of the network. The proposed approach has been examined and evaluated in different scenarios when compared to other similar approach and default RPL objective functions. Simulation experiments are conducted in Cooja network simulator for Contiki OS. The evaluation results show that COOF can cope with network dynamics and IoT-based smart city application requirements.

Resource oriented topology construction to ensure high reliability in IoT based smart city networks

Today, advanced metering infrastructure (AMI) is a subject that is undergoing intense study in smart city perspective, where the quality of service is the main concern. Hence, data routing is a key challenge in such a network. So far, the routing protocol for low power and lossy network (RPL) is considered to fit on AMI structure for achieving the expected network requirements. However, it is not optimized, as its parent selection mechanism attracts a large number of nodes and constructs the unbalance topology that degrades the network reliability. To overcome this problem, in this paper, we propose an efficient parent selection scheme that avoids the overburdened parent. The scheme combines the multiple routing metrics to calculate the rank, and that results in the balanced topology formation, which ensures the highest reliability in the RPL based AMI network. We evaluate the proposed work by implementing in Contiki OS with Cooja simulator. The simulation results show that the proposed work provides a higher packet delivery ratio, a lower latency, and a higher throughput as compared to default RPL.

Using a New Routing Metric in Paths Discovery Process for MDSR

Mobile Ad-hoc Network (MANET) is infrastructure-less network that consists of a set of mobile nodes. These nodes have limited power based on their batteries. Network lifetime is one of the most important challenges facing this type of networks; motivating many researchers to investigate alternatives that prolong the network lifetime. This paper proposes a new path selection metric that considers the ratio between the minimum residual energy of all route nodes and hop count value to select a rout in MDSR routing protocol. The discovered paths are checked periodically for ensuring their availabilities using special packets called DTC. Glomosim simulator is used to compare the modified MDSR protocol with the traditional MDSR and other existing protocols as well. Simulation results showed that the proposed routing protocol outperformed the traditional MDSR protocol in terms of network lifetime, packet delivery ratio and end to end delay. Moreover, it showed improved performance over other existing protocols in terms of packet delivery ratio and network lifetime.

An Attack-Resistant Trust Inference Model for Securing Routing in Vehicular Ad Hoc Networks

The problem of routing security in vehicular ad hoc networks has become a major concern for researchers. Compared with cryptography-based solutions, trust-based solutions are considered to be more acceptable as a promising approach, which mainly define two operations: trust computing and security application. In this paper we first study trust properties and construct a novel trust inference model, where two trust attributes named subjective trust and recommendation trust, are selected to quantify the trust level of a specific vehicle. The SCGM(1,1)-weighted Markov prediction algorithm based on fluctuation recognition is utilized to calculate the subjective trust accurately, meanwhile a new evaluation method of recommendation credibility based on the feedback mechanism is introduced for the calculation of recommendation trust. We subsequently exploit the advantages of mesh structure and design a light-weight trust-aware multicast routing protocol (i.e., LTMRP), which can establish secure and reliable communication paths by selecting trusted relay vehicles. To further improve the routing efficiency, two mechanisms including forwarding nodes reuse mechanism and trust-aware route handoff mechanism are proposed. Simulation verification and comparison of the relevant trust models and trust-based protocols are accomplished by three simulation platforms (i.e., Netlogo, SUMO, and NS-2).The convincing results show that our trust model obtains strong resistibility to multiple malicious attacks. Moreover, examined in four routing metrics, the experimental results indicate that LTMRP performs better than the other relevant protocols.

Fuzzy-logic-based data-differentiated service supported routing protocol for emergency communication networks in underground mines

Hybrid wireless mesh networks are suitable to construct emergency communication networks after disasters in underground mines. The routing decision in emergency scene is more difficult to give an accurate mathematical description due to the constraints of various data types, different data transmission requirements, and multi-parameters. Based on the fuzzy decision theory, this article has proposed a fuzzy-logic-based data-differentiated service supported routing protocol. Through the use of the adaptive fuzzy decision system, fuzzy-logic-based data-differentiated service supported routing protocol can provide data-differentiated services and make optimized routing decisions to satisfy the transmission requirements of different data types. In addition, a path soft handoff strategy has been proposed to maintain continuous data transmission when the path quality deteriorates. Based on NS2, we set three transmission scenarios (transmitting emergency data, regular data, or mixed data) to test the performances of fuzzy-logic-based data-differentiated service supported routing protocol, ad hoc on-demand distance vector, FUZZY-ad hoc on-demand distance vector, and multi-criteria routing metric. The results show that the fuzzy-logic-based data-differentiated service supported routing protocol has a higher delivery ratio and lower end-to-end delay when transmitting emergency data. When transmitting regular data, fuzzy-logic-based data-differentiated service supported routing protocol has achieved higher throughput and longer network lifetime than that of similar algorithms.