Design Guidelines for Routing Metrics in Multihop Wireless Networks

Mesh networks, motivated by wireless neighborhood networks are composed of static wireless nodes that have ample energy supply. Each of these wireless nodes can be equipped with multiple radios, called a multiradio/multichannel node, and each of the radios can be configured to a different channel to enhance network capacity. All wireless nodes cooperatively route each otherpsilas traffic to the Internet through one or more Internet Transit Access Points (TAPS), which are gateways to the Internet. Nodes may also communicate with each other directly through the mesh network without going through TAPS. Supporting communication among mesh nodes and TAPS requires the use of routing protocols that must be combined with a routing metric to determine which route among all possible routes between a pair of nodes will be used. The design of effective routing metrics, however, depends on the specific characteristics of the target network. For example, the severe energy constraints of sensor networks demand the design of energy efficient routing, while the mobility of nodes in ad hoc networks demand the design of protocols that can efficiently maintain connectivity. The unique combination of static nodes with the shared nature of the wireless medium in mesh networks also imposes specific requirements for the design of routing metrics. In this paper it was analyzed the proposed IPRA (Intelligent Portal Routing Algorithm) protocol and its performances in comparison with those offered by the AODV (Ad-hoc on Demand Vector) and DSDV (Destination Sequence Distance Vector) protocols.

Routing is an essential mechanism for proper functioning of large networks, and routing protocols make use of routing metrics to determine optimal paths. The design of routing metrics is critical for achieving high throughput and we begin this chapter by proposing the design principles for routing metrics. These design principles are for ensuring the proper functioning of the network and achieving high throughput. We continue by giving a detail analysis of the existing routing metrics. We also look at the pitfalls of the existing routing metrics. We conclude the chapter by outlining the future research directions.

In Wireless Sensor Networks (WSNs), fair utilisation of the network resources is a challenging task. In this regard, one of the determining factors is the routing protocol that plays an important role to route the data traffic from the source to the destination, under limited network resources. Most of the routing protocols and their variants in WSNs replace the routing metric of the prevalent routing protocol with their proposed routing metric and keep the route discovery mechanism intact. However, replacing only the routing metric is insufficient to improve the performance of the entire network as it can generate high End-to-End (ETE) delay in finding the destination as per the routing criteria. In this paper, a novel single path loop-free Distributed On-demand Multi-Optional routing (DOMO) protocol is presented. The DOMO selects the best sensor node based on the routing metric(s) amonst various alternatives at each stage during forward route formation. A simulation has been performed in ns-2.35 and it has been observed that, using the same routing metric(s), DOMO performs better for long-term communication in WSNs as compared to Ad hoc On Demand Distance Vector (AODV). The results have revealed that DOMO improves the average ETE delay by 17% and normalises the routing load by 47% as compared to AODV.

A cross-layer framework for joint routing and rate adaptation in infrastructure Wireless Mesh Networks

A Wireless Mesh Network (WMN) is a multi-hop network that gains the benefits of low deployment cost, fast access speed, expanded service coverage and large network capacity. However, the multi-hop communication in WMNs limits the throughput capacity due to increased number of packet transmissions. As a result, network coding is a recently emerged paradigm that can enhance the throughput capacity (i.e. network throughput) by minimizing the quantity of network workload and at the same time it ensures the data transfer among all the users. Further, with network coding the transmission effectiveness of a node can be improved by encoding (combining) several packets collectively and verifies whether the coding strategies is satisfied or not. Subsequently, if the coding strategies are satisfied then it transmits only the resultant encoded packet to the desired destination. In other words, network coding can improve the network throughput in WMNs by minimizing the transmission counts needed to transfer several packets to the destination. It should be noted that, while employing network coding in WMNs there are several challenges that should be compensated such as (i) identifying packets that can be combined (encoded) collectively and (ii) integrating the coding strategies in routing protocols. In this paper, we proposed a new mesh routing protocol that integrates network-coding called as Network Coding Aware Routing (Net-CART) protocol. Therefore, to enjoy the whole benefit of network coding a Net-CART protocol uses the innovative routing metric called Code-Aware and Load-Aware Routing Metric. Additionally, to identify numerous ‘coding structures’ and to support number of ‘packet encodings’ an improved set of coding strategies known as Enhanced Universal Coding Strategies is also proposed. The proposed Net-CART protocol comprising an improved set of coding strategies and a new routing-metric considers both the coding-opportunities and “network workload”. The simulation study carried out in wide forms of network configurations showed that Net-CART gives more fairness performances than other protocols.

There has been rapid growth in the area of wireless communication by Wireless Mesh Networks (WMNs) where routing metric is the key metric to find the optimized route in WMNs. For obtaining optimal performance, integrating multiple performance metrics into a routing protocol is effective, as single metric will not be able to satisfy the thorough requirement of WMNs. This paper has proposed a new routing metric for Multiple Metric Cost (MMC), WMNs, incorporating three metrics: Residual energy 2) Available Bandwidth and 3) Expected Transmission Count (ETX). MMC results in a better throughput. We evaluated the performance of MMC for proactive, reactive and opportunistic routing protocols using the OMNET++ network simulator. Our evaluation shows that MMC performs well in all three classes of routing protocols.

Mobile ad hoc networks (MANETs) are consists of mobile devices connected wirelessly. Mobile nodes in MANET are applicable of routing functionality, where messages are forwarded in a multi-hop fashion. In such a communication scheme a routing protocol play an important role in the network performances. The wireless connectivity and node mobility in MANET networks contributes in rapid topological changes, which brings the need for a channel aware routing protocol. To overcome this problem, many channel aware routing metrics are proposed in the literature, however these routing metrics are either utilizing the shared bandwidth to measure the link quality, or they implies less awareness to the link quality. This paper proposed a SNR-based routing metric for Dynamic Sequence Distance Vector (DSDV) routing protocol. This paper starts by investigate and compare the performance among common routing protocols in MANET. Secondly a cross layer approach is proposed for the new routing metric. Simulation scenarios are used for the work of the paper. The new metrics is implemented in one of the MANET common routing protocols DSDV module in MONET++. The results show that SNR-based DSVD improves the performance of the MANET in terms of throughput and delay.

We present a new metric for routing in multi-radio, multi-hop wireless networks. We focus on wireless networks with stationary nodes, such as community wireless networks.The goal of the metric is to choose a high-throughput path between a source and a destination. Our metric assigns weights to individual links based on the Expected Transmission Time (ETT) of a packet over the link. The ETT is a function of the loss rate and the bandwidth of the link. The individual link weights are combined into a path metric called Weighted Cumulative ETT (WCETT) that explicitly accounts for the interference among links that use the same channel. The WCETT metric is incorporated into a routing protocol that we call Multi-Radio Link-Quality Source Routing.We studied the performance of our metric by implementing it in a wireless testbed consisting of 23 nodes, each equipped with two 802.11 wireless cards. We find that in a multi-radio environment, our metric significantly outperforms previously-proposed routing metrics by making judicious use of the second radio.

Wireless sensor networks (WSNs) technology is attracting more attention with the emergence of the Internet of Things (IoT). Wireless sensor networks have been intensively studied for optimizing their life time by enhancing their low power operations. Few studies have been developed in order to deal with mobility. In some cases, nodes move around a specific area and the network topology should adapt fast. Routing protocols should react to topology changes and build new routes. Traditionally, control traffic is used to update routing metrics. Each node will then choose a next-hop among its neighbor nodes based on this routing metric. In this paper, we propose an enhancement based on signal strength monitoring and depth updating in order to improve the routing protocol performance in mobility scenarios where all nodes are moving. This enhancement can be integrated into most data collection routing protocols. It helps them to better cope with mobility and to make faster decisions on updating their next-hop neighbors. We also implemented this enhancement in the Routing Protocol for Low-Power and Lossy Networks (RPL). We show that through simulations using our technique allows better performance for different routing metrics.

The impact of interference-aware routing metrics on video streaming in Wireless Mesh Networks

The stationary nature of nodes in a mesh network has shifted the main design goal of routing protocols from maintaining connectivity between source and destination nodes to finding high-throughput paths between them. In recent years, numerous link-quality-based routing metrics have been proposed for choosing high-throughput paths for unicast protocols. In this paper we study routing metrics for high-throughput tree or mesh construction in multicast protocols. We show that there is a fundamental difference between unicast and multicast routing in how data packets are transmitted at the link layer, and accordingly there is a difference in how the routing metrics for each of these primitives are designed. We adapt certain routing metrics for unicast for high-throughput multicast routing and propose news ones not previously used for high-throughput. We then study the performance improvement achieved by using different link-quality-based routing metrics via extensive simulation and experiments on a mesh network testbed, using ODMRP as a representative multicast protocol. Our testbed experiment results show that ODMRP enhanced with linkquality routing metrics can achieve up to 17.5% throughput improvement as compared to the original ODMRP.

Impact of multiple channels and radios on the performance of a TDMA based wireless mesh network

The majority of work in cognitive radio networks have focused on single-hop networks with mainly challenges at the physical and MAC layers. Recently, multi-hop secondary networks have gained attention as a promising design to leverage the full potential of cognitive radio networks. One of the main features of routing protocols in multi-hop networks is the routing metric used to select the best route for forwarding packets. In this paper, we survey the state-of-the-art routing metrics for cognitive radio networks. We start by listing the challenges that have to be addressed in designing a good routing metric for cognitive radio networks. We then provide a taxonomy of the different metrics and a survey of the way they have been used in different routing protocols. Then we present a case study to compare different classes of metrics. After that, we discuss how to combine individual routing metrics to obtain a global one. We end the paper with a discussion of the open issues in the design of future metrics for cognitive radio networks.

Routing metric plays a vital role in path selection process. A variety of routing metrics have been proposed to enhance the performance of routing protocols. Considering the forwarding behavior of neighbor node in the design of a routing metric would address the most generic packet dropping attacks in wireless mesh network (WMN). The existing routing metrics to address packet dropping attack in WMN only consider selfish mesh routers. On the other hand, to the best of our knowledge no such routing metric has been proposed to address the malicious behavior of mesh routers in a network. In this paper, we propose an airtime link metric AFC (Airtime Forwarding Capability), that considers both selfish and malicious behavior of mesh routers. AFC is computed using local station level measurements and does not require direct cooperation from any neighbor node, thereby avoiding neighbor lying attacks. The analysis of proposed metric shows that it satisfies the required design properties of a routing metric. The experimental results confirm the performance enhancement by accounting for the malicious behavior of mesh routers.

This work is situated at the conjunction of the fields of distributed systems, telecommunications, and mathematical modeling, aiming to offer solutions to the problem of people’s overexposure to electro-magnetic fields (EMF) radiation. In this paper, we propose a new routing scheme for wireless multi-hop networks, which seeks a fairer distribution of the exposure to electromagnetic fields, by leveraging a combination of the transmitted power and the accumulated exposure as a routing metric. We carry out a holistic approach, including: (1) an algorithmic study, (2) an analytical model of the aforementioned novel routing metric, and (3) the specification of a routing protocol. We make a performance assessment of our novel routing protocol and the corresponding algorithm, by means of an extensive simulation campaign over the NS-3 simulator. The obtained results yield that the proposed novel solution is able to not only fairly distribute the exposure, but also to reduce its average value, thus enhancing the user experience. We also show that the power consumption using the EMF-aware proposed solution, based on Cycle Canceling Algorithm (CCA), and that observed with an approach seeking power reduction are alike. Indeed, even if there exist key-differences from the user experience’s point of view between both routing approaches, there is no statistically relevant power increase between them. Thus, our solution manages to keep the consumed power at a low level, and at the same time it reduces the overall nodes’ exposure to EMF.