Protocols For Wireless Mesh Networks Research Articles

PA-SHWMP: a privacy-aware secure hybrid wireless mesh protocol for IEEE 802.11s wireless mesh networks

Wireless mesh networks (WMNs) have emerged as a key technology for next generation wireless networks and provide a low-cost and convenient solution to the last-mile problem. Security and privacy issues are of paramount importance to WMNs for their wide deployment and for supporting service-oriented applications. Moreover, to support real-time services, WMNs must also be equipped with secure, reliable, and efficient routing protocols. Therefore, a number of research studies have been devoted to privacy-preserving routing protocols in WMNs. However, these studies cannot defend against inside attacks effectively, often take it for granted that every internal node is cooperative and trustworthy, and rarely consider dividing the user privacy information into different categories according to the security requirements. To address these issues, we propose a Privacy-Aware Secure Hybrid Wireless Mesh Protocol (PA-SHWMP), which combines a new dynamic reputation mechanism based on subject logic and uncertainty with the multi-level security technology. PA-SHWMP can defend against the internal attacks caused by compromised nodes and achieve stronger security and privacy protection while maintaining reasonable balances between security and performance. We analyze the PA-SHWMP protocol in terms of security, privacy, and performance. The simulation results show that the packet delivery ratio of the proposed PA-SHWMP becomes better than that of the existing HWMP and SHWMP protocols, when the number of malicious nodes and the percentage of lossy links increase. Moreover, the convergence time of PA-SHWMP is smaller than HWMP and SHWMP with any percentage of malicious mesh routers.

ASSM: Agent Based Source Specific Multicast Routing Protocol for Wireless Mesh Networks

ASSM: Agent Based Source Specific Multicast Routing Protocol for Wireless Mesh Networks

APPLICATION OF THE FUZZY LOGICAL APPARATUS FOR ROUTING IN WIRELESS MESH NETWORKS

A new routing protocol for wireless mesh networks based on fuzzy logic that allows taking into account several parameters of the route state for selecting an optimal route is proposed. Simulation modeling results confirming the proposed protocol efficiency are presented.

A routing protocol suitable for backhaul access in wireless mesh networks

This work proposes the Wireless-mesh-network Proactive Routing (WPR) protocol for wireless mesh networks, which are typically employed to provide backhaul access. WPR computes routes based on link states and, unlike current routing protocols, it uses two algorithms to improve communications in wireless mesh networks taking advantage of traffic concentration on links close to the network gateways. WPR introduces a controlled-flooding algorithm to reduce routing control overhead by considering the network topology similar to a tree. The main goal is to improve overall efficiency by saving network resources and avoiding network bottlenecks. In addition, WPR avoids redundant messages by selecting a subset of one-hop neighbors, the AMPR (Adapted MultiPoint Relay), needed to reach all two-hop ones. We first analyze the proposed algorithms compared with the algorithms used by OLSR for the same tasks in terms of running time, optimality, and number of routing messages. Results show that the algorithms proposed by WPR are more efficient than the algorithms used by OLSR in running time and number of routing messages. In addition, we also perform simulations to evaluate the performance of WPR. Results reveal that the aggregated throughput of WPR outperforms OLSR by up to 27% using a combination of web and backbone internal traffic despite our design assumption of traffic convergence toward gateways.

Secure Routing for Wireless Mesh Networks

This paper describes a Security Enhanced AODV routing protocol for wireless mesh networks (SEAODV). SEAODV employs Blom's key pre-distribution scheme to compute the pairwise transient key (PTK) through the flooding of enhanced HELLO message and subsequently uses the established PTK to distribute the group transient key (GTK). PTK and GTK are used for authenticating unicast and broadcast routing messages respectively. In wireless mesh networks, a unique PTK is shared by each pair of nodes, while GTK is shared secretly between the node and all its one-hop neighbors. A message authentication code (MAC) is attached as the extension to the original AODV routing message to guarantee the message's authenticity and integrity in a hop-by-hop fashion. Security analysis and performance evaluation show that SEAODV is more effective in preventing identified routing attacks and outperforms ARAN and SAODV in terms of computation cost and route acquisition latency.

Responsive on-line gateway load-balancing for wireless mesh networks

We propose an adaptive online load-balancing protocol for multi-gateway Wireless Mesh Networks (WMNs) which, based on the current network conditions, balances load between gateways. Traffic is balanced at the TCP flow level and, as a result, the aggregate throughput, average flow throughput and fairness of flows improves. The proposed scheme (referred to as Gateway Load-Balancing, GWLB) is highly responsive, thanks to fast gateway selection and the fact that current traffic conditions are maintained up-to-date at all times without any overhead. It also effectively takes into account intra-flow and inter-flow interference when switching flows between gateway domains. We have found the performance achievable by routes used after gateway selection to be very close to the performance of optimal routes found by solving a MINLP formulation under the protocol model of interference. Through simulations, we analyze performance and compare with a number of proposed strategies, showing that GWLB outperforms them. In particular, we have observed average flow throughput gains of 128% over the nearest gateway strategy.

An Integrated Metrics Based Routing Protocol for Wireless Mesh Networks

Providing users with high-quality,high-performance communication links is one of the most important challenges in wireless mesh networks.However,experiments and applications show that the routing protocols in Ad Hoc networks cannot fully satisfy the performance requirements of wireless mesh networks.Combining optimized link state routing protocol with cross-layer design theory,a novel routing protocol based on integrated metrics is proposed for Infrastructure/Backbone wireless mesh networks.The new protocol greatly optimized routing performance by making use of a brand-new routing metric,which takes into account two factors in route selection:link length and link communication efficiency.The simulation results show that the proposed routing protocol improves the packet delivery ratio,reduces the end-to-end delay,and achieves load balance in the route selection process.

Secure High-Throughput Multicast Routing in Wireless Mesh Networks

Recent work in multicast routing for wireless mesh networks has focused on metrics that estimate link quality to maximize throughput. Nodes must collaborate in order to compute the path metric and forward data. The assumption that all nodes are honest and behave correctly during metric computation, propagation, and aggregation, as well as during data forwarding, leads to unexpected consequences in adversarial networks where compromised nodes act maliciously. In this work, we identify novel attacks against high-throughput multicast protocols in wireless mesh networks. The attacks exploit the local estimation and global aggregation of the metric to allow attackers to attract a large amount of traffic. We show that these attacks are very effective against multicast protocols based on high-throughput metrics. We conclude that aggressive path selection is a double-edged sword: While it maximizes throughput, it also increases attack effectiveness in the absence of defense mechanisms. Our approach to defend against the identified attacks combines measurement-based detection and accusation-based reaction techniques. The solution accommodates transient network variations and is resilient against attempts to exploit the defense mechanism itself. A detailed security analysis of our defense scheme establishes bounds on the impact of attacks. We demonstrate both the attacks and our defense using ODMRP, a representative multicast protocol for wireless mesh networks, and SPP, an adaptation of the well-known ETX unicast metric to the multicast setting.

Probing-based anypath forwarding routing algorithms in wireless mesh networks

Existing routing protocols for Wireless Mesh Networks (WMNs) are generally optimized with statistical link measures, without focusing on the intrinsic uncertainty of wireless links. We show evidence that, with the transient link uncertainties at PHY and MAC layers, a pseudo-deterministic routing protocol that relies on average or historic statistics can hardly explore the full potentials of a multi-hop wireless mesh.We study optimal WMN routing using probing-based anypath forwarding, with explicit consideration of transient link uncertainties. Starting from a two-state link capacity model, we show the underlying connection between WMN routing and the classic Canadian Traveller Problem (CTP) [1]. Inspired by a stochastic recoverable version of CTP (SRCTP), we develop an practical SRCTP-based online routing algorithm under link uncertainties. We study how dynamic next-hop selection can be done with low cost, and derive a systematic selection order for minimizing transmission delay. We further extend our solution to a general multi-rate link model, and present a Stopping Theory (ST) based solution, which naturally degrades to the SRCTP algorithm in the two-state link model. We conduct simulation studies to verify the effectiveness of the SRCTP and ST algorithms under diverse network configurations. In particular, compared to deterministic routing, reduction of end-to-end delay (51.15–73.02% for two-state links, 5.16% for multi-rate links) and improvement on packet delivery ratio (99.76% for two-state links, 94.44% for multi-rate links) are observed. By using RTS/CTS as the online probing tool in ns3 simulator, we observed both significant goodput improvements (29.9% than EXOR, 61.8% than HWMP) and much less packet arriving jitter (14.27 times less than EXOR, 45% less than HWMP) as compared to EXOR and HWMP routing protocols.

The WICKPro protocol with the Packet Delivery Ratio metric

Wireless mesh networks (WMNs) with chain topologies are very useful in road and railroad transportation or in tunnel and mine applications. The proposed protocols for WMNs usually support best-effort traffic or some kind of Quality of Service (QoS). However, some applications such as remote-controlled machines in industrial control networks have hard real-time (HRT) requirements, i.e., strict deadlines. For this reason, this paper incorporates the Packet Delivery Ratio (PDR) metric into the WICKPro (WIreless Chain networK Protocol) protocol, a HRT protocol for WMNs with chain topologies which uses a token-passing approach. WICKPro is a Medium Access Control (MAC) protocol based on the ideas of the Timed-token protocol and the cyclic executive. The incorporation of the PDR metric lets calculate the needed time to be reserved where packet retransmissions can be accommodated while satisfying HRT traffic constraints. Moreover, the feasibility of using the PDR metric in a token-passing protocol is shown. Since WICKPro has been designed to work on top of IEEE 802.11, we made a testbed using commercial 802.11 wireless cards and compared the WICKPro’s performance with the 802.11 protocol and three specific protocols for WMNs with chain topologies.

Splitting algorithm for DMT optimal cooperative MAC protocols in wireless mesh networks

A cooperative protocol for wireless mesh networks is proposed in this paper. The protocol implements both on-demand relaying and a selection of the best relay terminal so only one terminal is relaying the source message when cooperation is needed. Two additional features are also proposed. The best relay is selected with a splitting algorithm. This approach allows fast relay selection within less than three time-slots, on average. Moreover, a pre-selection of relay candidates is performed prior to the splitting algorithm. Only terminals that are able to improve the direct path are pre-selected. So efficient cooperation is now guaranteed. We prove that this approach is optimal in terms of diversity-multiplexing trade-off. The protocol has been designed in the context of Nakagami- m fading channels. Simulation results show that the performance of the splitting algorithm does not depend on channel statistics.

Towards benchmarking routing protocols in wireless mesh networks

Wireless mesh networks (WMNs) establish a new, quick and low-cost alternative to provide communications when deploying a fixed infrastructure that could result prohibitive in terms of either time or money. During last years, the specification of multi-hop routing protocols for WMNs has been promoted, leading to their recent exploitation in commercial solutions. The selection of routing protocols for integration in WMNs requires the evaluation, comparison and ranking of eligible candidates according to a representative set of meaningful measures. In this context, the development of suitable experimental techniques to balance different features of each protocol is an essential requirement. This paper copes with this challenging task by proposing a benchmarking methodology to experimentally evaluate and compare the behaviour of these protocols. The feasibility of the proposed approach is illustrated through a simple but real (non-simulated) case study and reflects to what extent this methodology can be useful in increasing our knowledge on how real WMNs behave in practice.

Link quality analysis and measurement in wireless mesh networks

Protocols and applications in wireless mesh networks often optimize their performance by measuring the quality of wireless links. However, measuring and characterizing link-quality is a challenging task due to the nature of wireless channel and device-specific properties of radios. The paper proposes two aspects of link-quality measurement and estimation in realistic networks that benefit higher-layer protocols. First, we analyze the statistical properties of link-quality metrics, such as received signal strength and packet error rates, in an indoor IEEE 802.11 mesh network. We show that the statistical distribution and memory properties vary across different links, but are predictable. The next contribution of the paper is a real-time measurement framework that enables higher-level protocols in wireless mesh networks. We discuss the architectural requirements and our implementation experiences of a measurement framework. In addition, we provide three concrete applications that use the measured link-quality and statistical inference to better adapt their behavior.

Release-time-based multi-channel MAC protocol for wireless mesh networks

The wireless mesh network (WMN) has been considered one of the most promising techniques for extending broadband access to the last mile. In order to utilize multiple channels to increase the throughput in WMNs, a variety of multi-channel MAC (MMAC) protocols have been proposed in the literature. In particular, the dedicated control channel ( DCC) approach can greatly simply many design issues in multi-channel environments by using a common control channel to exchange control signals. On the other hand, it allows each sender–receiver pair to dynamically select a data channel for their data transmission in an on-demand matter. However, the common control channel would become a bottleneck of the overall performance. Besides, the selection of data channels would be highly related to the final throughput. In this paper, we propose a new MMAC protocol, named the release-time-based MMAC ( RTBM) to overcome the control channel bottleneck and data channel selection problems in the DCC approach. The RTBM consists of three major components: (1) Control initiation-time predication ( CIP); (2) Dynamic data-flow control ( DDC); (3) Enhanced channel selection ( ECS). The CIP can predict a proper initiation time for each control process to reduce control overhead. The DDC can dynamically adjust the flow of each data transmission to fully exploit the channel bandwidth. The ECS can achieve a higher reusability of data channels to further enhance the throughput. Simulation results show that the RTBM can substantially improve the throughput in both single-hop and multi-hop networks.

Architectures and protocols for wireless mesh, ad hoc, and sensor networks

Welcome to this special issue of the Wiley’s Wireless Communications and Mobile Computing Journal. This special issue is devoted to the topic of the latest research and development in the field of wireless communications and networking. During the last few years, we have witnessed a tremendous interest from academia, industry, and standardization bodies in wireless mesh, ad hoc, and sensor networking. With several appealing characteristics, such as dynamic self-configuration, self-organization, self-healing, easy maintenance, and high scalability, wireless mesh networks have been prodded as a cost-effective approach to support high-speed last mile connectivity and ubiquitous broadband access in the context of home, enterprise, and community networking. Wireless ad hoc networks have also shown applications in a variety of situations, such as battlefields, disaster recovery/rescue operations, and entertainment. At the same time, wireless sensor networks are being deployed and actively researched for various forms of environmental monitoring, home automation, military, and civilian applications. Despite recent advances, and the technical accumulations from more than a decade’s research effort in wireless networking, many research issues remain open in all protocol layers of wireless mesh, ad hoc, and sensor networks. For example, the foreseen multi-channel, multi-radio, and multi-antenna hybrid architectures (infrastructure and ad hoc) have brought new challenges in the design of physical, MAC, and routing protocols. New application scenarios are urging researchers to address enhanced quality of service support and various security issues in the design of different protocol layers for wireless mesh, ad hoc, and sensor networks. This special issue is dedicated to various aspects of wireless mesh, ad hoc, and sensor networks. We selected eight papers to show the recent advances in architectures and protocols. The papers cover both topical and innovative areas. A detailed overview of the selected papers is given below. In “Radio resource management of self-organizing OFDMA wireless mesh networks,” Chu et al. present a cognitive resource management system for wireless mesh networks with self-organizing base stations to optimize the available spectrum. The authors first present the concept of radio resource management based on an extensive literature survey and then highlight the challenges to achieve the best performance of such systems in future wireless mesh networks. In “IP address assignment in wireless mesh networks,” extending a work that received a best paper award in LCN 2008, Zimmermann et al. introduce and evaluate a novel auto-configuration protocol for wireless mesh networks, dubbed DWCP for Dynamic WMN Configuration Protocol. The proposed protocol deals with assigning unique addresses, managing the free and assigned addresses, reacting autonomously to failures and features support of conventional Dynamic Host Configuration Protocol (DHCP) clients. The proposed protocol has been deployed and evaluated in a real testbed and showed a good potential. In “CORE: centrally optimized routing extensions for efficient bandwidth management and network coding in the IEEE 802.16 MeSH mode,” Mogre et al. propose CORE, a new system that targets the optimization of routing, scheduling and bandwidth savings via network coding. Based on new heuristics, CORE has been evaluated through simulations and the obtained results demonstrated its performance. In “Study of Patching-based and Caching-based videoon-demand in mutli-hop WiMax mesh networks,” Xie et al. provide a study of two cross layer techniques, the Patching-based scheme and the Caching-based scheme, to provide video-on-demand in multi-hop WiMax mesh networks. Both approaches employ a novel joint solution of admission control and channel scheduling for video streams in the lower layers. This joint solution guarantees the data rate for the admitted video streams, which is crucial for real-time video streaming application. Their extensive simulations showed a good performance of this joint solution under real system settings. In “A security framework for wireless mesh networks,” Mogre et al. develop a holistic approach toward securing the wireless mesh networks with a particular focus on the network layer. They provide a set of solutions that guarantee the integrity and authenticity of routing messages, detect misbehaviors in forwarding data or routing messages, and dynamically manage reputation of nodes throughout the network. The combination of these building blocks enables a secure and self-organizing wireless mesh networks as they demonstrated it through their implementation and tests of a realistic IEEE 802.16 mesh network.

IP address assignment in wireless mesh networks

AbstractIn recent years cheap Internet access has become increasingly popular within the industrialized countries. Especially in the age of Web 2.0, where popular Internet applications begin to dominate computer use, ubiquitous network access is more important than ever. A new class of networks aim to satisfy the demand for high bandwidth, low‐cost, and ubiquitous Internet access: wireless mesh networks (WMNs). However, in order to reach a greater market penetration a fundamental factor must yet to be addressed: the ease of use. Except for small networks, manual configuration is infeasible, so robust autoconfiguration mechanisms are needed. To address this shortcoming of complicated setup procedures we introduce and evaluate a novel autoconfiguration protocol for WMN: the Dynamic WMN Configuration Protocol (DWCP). It deals with the assignment of unique addresses, the management of free and assigned addresses, the autonomous reaction to failures, and features support of conventional Dynamic Host Configuration Protocol (DHCP) clients. It is specifically suitable for large installations and was deployed and evaluated in a real testbed. Copyright © 2010 John Wiley & Sons, Ltd.

Design and Performance Analysis of Mobility Management Schemes Based on Pointer Forwarding for Wireless Mesh Networks

We propose efficient mobility management schemes based on pointer forwarding for wireless mesh networks (WMNs) with the objective to reduce the overall network traffic incurred by mobility management and packet delivery. The proposed schemes are per-user-based, i.e., the optimal threshold of the forwarding chain length that minimizes the overall network traffic is dynamically determined for each individual mobile user, based on the user's specific mobility and service patterns. We develop analytical models based on stochastic Petri nets to evaluate the performance of the proposed schemes. We demonstrate that there exists an optimal threshold of the forwarding chain length, given a set of parameters characterizing the specific mobility and service patterns of a mobile user. We also demonstrate that our schemes yield significantly better performance than schemes that apply a static threshold to all mobile users. A comparative analysis shows that our pointer forwarding schemes outperform routing-based mobility management protocols for WMNs, especially for mobile Internet applications characterized by large traffic asymmetry for which the downlink packet arrival rate is much higher than the uplink packet arrival rate.

QuRiNet: A wide-area wireless mesh testbed for research and experimental evaluations

Research in wireless mesh networks has been growing in recent years. Many testbeds have been created to study networking protocols in wireless mesh networks. In this work, we describe QuRiNet, an outdoor wide-area wireless mesh network deployed in a natural reserve. QuRiNet comprises of over 30 wireless nodes, spread over 2000 acres of wilderness. QuRiNet provides the backbone infrastructure for transporting ecological and environmental data from the natural reserve to the on-campus laboratories. Mesh nodes in QuRiNet are powered by solar energy, and comprise of multiple radios per node. Physical link distances in QuRiNet range from hundreds to thousands of meters. A parallel goal of deploying QuRiNet is to create a novel platform for advanced research in wireless mesh networks. In this report, we share our experiences in the deployment and maintenance of QuRiNet in its unique setting. We also describe various research efforts that have been leveraging the QuRiNet testbed. Several interesting measurement results are reported, along with the impact of various network configurations and technological variations on the functionality of the testbed. QuRiNet has been used for a variety of experimental studies including: channel assignment, network monitoring, and mobility studies. Current and future study plans include experimental evaluations of various security and reliability research.

Extra back-off flow control in multi-hop wireless networks

CSMA is the predominant distributed access protocol for wireless mesh networks. Originally designed for single-hop settings, CSMA can exhibit severe performance problems in multi-hop networks in terms of stability and end-to-end throughput. To ensure a smoother flow of packets, we examine an enhancement referred to as Extra Back-off (EB) flow control. In this enhanced scheme a node remains silent for a certain extra back-off time (imposed on top of the usual back-off time that is part of CSMA) after it has transmitted a packet, to give both the downstream and upstream neighbors the opportunity to transmit. EB flow control entails only a small modification to CSMA, preserving its distributed character. In order to examine the performance of EB flow control, we analyze a novel class of Markov models at the interface between classical tandem queues and interacting particle systems. The results demonstrate that EB flow control provides an effective mechanism for improving the end-to-end throughput performance.

A 2-MAKE: An efficient anonymous and accountable mutual authentication and key agreement protocol for WMNs

Multi-hop hybrid wireless mesh networks (WMNs) have recently attracted increasing attention and deployment. For easy acceptance and wide deployment of WMNs, security, privacy, and accountability issues have to be addressed by providing efficient, reliable, and scalable protocols. The fact that regular users, which may be resource-constrained wireless devices, are involved in routing activities highlights the need for efficiency and compactness. However, the said objectives, i.e., security, privacy, accountability, efficiency etc., are, most of the time, not compatible. So far no previous work has adequately reconciled these conflicting objectives in a practical framework. In this paper, we design and implement such a framework named as A 2-MAKE, which is a collection of protocols. The framework provides an anonymous mutual authentication protocol whereby legitimate users can connect to network from anywhere without being identified or tracked unwillingly. No single party (or authority, network operator, etc.) can violate the privacy of a user, which is provided in our framework in the strongest sense. Our framework utilizes group signatures, where the private keys and corresponding credentials of the users are generated in a secure three-party protocol. User accountability is implemented via user identification and revocation protocols that can be executed by two semi-trusted authorities, one of which is the network operator. The assumptions about the trust level of the network operator are relaxed with respect to similar protocols. Our framework makes use of more efficient signature generation and verification algorithms in terms of computational complexity than their counterparts in literature, where signature size is almost the same as the shortest signatures proposed for similar purposes so far.