Routing security in wireless ad hoc networks

A mobile ad hoc network consists of a collection of wireless mobile nodes that are capable of communicating with each other without the use of a network infrastructure or any centralized administration. MANET is an emerging research area with practical applications. However, wireless MANET is particularly vulnerable due to its fundamental characteristics, such as open medium, dynamic topology, distributed cooperation, and constrained capability. Routing plays an important role in the security of the entire network. In general, routing security in wireless MANETs appears to be a problem that is not trivial to solve. In this article we study the routing security issues of MANETs, and analyze in detail one type of attack-the "black hole" problem-that can easily be employed against the MANETs. We also propose a solution for the black hole problem for ad hoc on-demand distance vector routing protocol.     

A routing protocol for mobile ad‐hoc networks using the profit optimization model

Recently, wireless networks have become one of the major development trends in computer network technology. Because there is no more need of the wired transmission medium, applications have thus diversified. One such growing field of wireless networks is the mobile ad‐hoc network (MANET). A MANET consists of mobile hosts (such as portable laptops, vehicles, etc.), and no fixed infrastructure is required. MANETs provide ease of self‐configuration and can extend coverage at a low cost. Numerous applications have therefore been proposed under this network environment for daily life use. Because MANETs nodes are capable of moving, MANET network topology changes frequently. Thus, the traditional routing protocols fail to fit such an environment. In this paper, we propose an efficient routing protocol for MANETs, which integrates the mathematical model of profit optimization (the Kelly formula) from the field of economics to cope with the routing problem caused by node mobility. Some numerical simulations have been conducted to evaluate the performance of the proposed method using the network simulator NS‐2. The results show that our proposed method outperforms conventional routing protocols in packet delivery ratio comparisons; and the average end‐to‐end delays are within a tolerable range. Copyright © 2013 John Wiley & Sons, Ltd.     

The Effects of Physical Layer on the Routing Wireless Protocol

Mobile ad hoc networks (MANETs) are characterized by multiple entities, a frequently changing network topology and the need for efficient dynamic routing protocols. In MANETs, nodes are usually powered by batteries. Power control is tightly coupled with both the physical and medium access layers (MACs). However, if we increase the transmission power, at the same time we increase the interference to other nodes which diminish the transport capacity of wireless systems. Thus, the routing protocols based on hop count metric suffer from performance degradation when they operate over MANET. Routing in ad hoc wireless networks is not only a problem of finding a route with shortest length, but it is also a problem of finding a stable and good quality communication route in order to avoid any unnecessary packet loss. Cross-layer design of ad hoc wireless networks has been receiving increasing attention recently. Part of these researches suggests that routing should take into account physical layer characteristics. The goal of this paper is to improve the routing reliability in MANET and to reduce power consumption through cross-layer approach among physical, MAC and network layers. The proposed cross-layer approach is based on signal to interference plus noise ratio (SINR) and received signal strength indication (RSSI) coming from the physical layer. This solution performs in one hand the ad hoc on-demand distance vector routing protocol by choosing reliable routes with less interferences using SINR metric and in another hand; it permits to reduce the power transmission when sending the data packets by using RSSI metric.     

Friend-assisted intrusion detection and response mechanisms for mobile ad hoc networks

Nowadays, a commonly used wireless network (i.e., Wi-Fi) operates with the aid of a fixed infrastructure (i.e., an access point) to facilitate communication between nodes. The need for such a fixed supporting infrastructure limits the adaptability and usability of the wireless network, especially in situations where the deployment of such an infrastructure is impractical. Recent advancements in computer network introduced a new wireless network, known as a mobile ad hoc network (MANET), to overcome the limitations. Often referred as a peer to peer network, the network does not have any fixed topology, and through its multi hop routing facility, each node can function as a router, thus communication between nodes becomes available without the need of a supporting fixed router or an access point. However, these useful facilities come with big challenges, particularly with respect to providing security. A comprehensive analysis of attacks and existing security measures suggested that MANET are not immune to a colluding blackmail because such a network comprises autonomous and anonymous nodes. This paper addresses MANET security issues by proposing a novel intrusion detection system based upon a friendship concept, which could be used to complement existing prevention mechanisms that have been proposed to secure MANETs. Results obtained from the experiments proved that the proposed concepts are capable of minimising the problem currently faced in MANET intrusion detection system (IDS). Through a friendship mechanism, the problems of false accusations and false alarms caused by blackmail attackers in intrusion detection and response mechanisms can be eliminated.     

Integrating Mobile Ad Hoc Network to the Internet

A novel scheme is presented to integrate mobile ad hoc networks （MANETs） with the lnternet and support mobility across wireless local area networks （WLANs） and MANETs. The mobile nodes, connected as a MANET, employ the optimize d link state routing （OLSR） protocol for routing within the MANET. Mobility management across WLANs and MANETs is achieved through the hierarchical mobile IPv6 （HMIPv6） protocol. The performance is evaluated on a HMIPv6 based test-bed composed of WLANs and MANETs. The efficiency gain obtained from using HMIPv6 in such a hybrid network is investigated. The investigation result shows that the use of HMIPv6 can achieve up to 27% gain on reducing the handoff latency when a mobile roams within a domain. Concerning the reduction of the signaling load on the lnternet, the use of HMIPv6 can achieve at least a 54% gain and converges to 69%.     

Performance Modeling of MANET Interconnectivity

The proliferation of mobile wireless computing devices and the increasing usage of wireless networking have motivated substantial research in mobile ad hoc networks (MANETs). In addition, much has also been done to link autonomous MANETs to the Internet, and as MANETs become more prevalent, the need to interconnect multiple MANETs becomes increasingly important too. However, direct interconnection of MANETs has rarely been studied. In this paper, we first report an experimental study on the performance of interconnected MANETs running two different routing protocols, viz., the Ad hoc On-Demand Distance Vector (AODV) and Optimized Link State Routing (OLSR) protocols, which represent the two major categories, and show that with the use of multiple gateways, it is possible to viably interconnect multiple networks running different MANET routing protocols. We then follow with a simulation study to evaluate the performance in large networks, which not only validates the scalability of the proposed scheme, but also helps to identify various problems that were not apparent in small experimental networks.     

Using group mobility and multihomed mobile gateways to connect mobile ad hoc networks to the global IP Internet

Connecting multihop mobile ad hoc wireless networks (MANETs) to the Internet would enable MANET nodes to share wireless Internet access with mobile hosts that are one‐hop away from their foreign networks. The integration of MANETs and the global Internet, however, faces an obstacle due to their network architectural mismatches regarding their infrastructure, topology, and mobility management mechanisms. Solutions to the integration problem should introduce an intermediate facility with hybrid mechanism, enabling it to connect to both networks. The quality of the multihop wireless Internet access service provided to MANET nodes depends on the design quality of this facility in order for MANET nodes to enjoy their Internet connectivity anywhere and anytime without much disconnections. In this paper, we propose hierarchical architecture that uses group mobility and multihomed mobile gateways, and present and analyse different simulations results. A multihomed mobile gateway can simultaneously connect to multiple Mobile IP foreign agents, provided it is located within their overlapping coverage area. It runs updated versions of the destination‐sequenced distance vector (DSDV) and Mobile IP protocols, and is responsible for providing MANET nodes with wireless Internet access though they are multiple wireless hops away from the edge of the Internet. The rationale behind using multihoming is to increase reliability of the Internet access service and enhance performance of the integrated network. Copyright © 2006 John Wiley & Sons, Ltd.     

Constructing secure group communication over wireless ad hoc networks based on a virtual subnet model

Recently, more and more people have begun using mobile devices such as PDAs and notebooks. Our lives have been profoundly affected by such devices. A MANET, a mobile ad hoc network, is an effective networking system facilitating an exchange data between mobile devices, without the support of wireless access points and base stations. A MANET is not restricted to unicast or multicast communication, but can also provide "many-to-many" transmission, which can be treated as a group communication. Until recently, however, the way in which such groups are formed had not drawn much attention. Because communication in wireless networks is broadcast and a certain amount of devices can receive transmitted messages, the risk of unsecured sensitive information being intercepted by unintended recipients is a real concern. Consequently, efforts to ensure the security of group communications in MANETs are essential. This article proposes a virtual subnet model to construct secure group communication over a MANET. With the model, the composition of groups is established as the forming of group keys. Our results show that this approach can completely satisfy the needs for both security and efficiency.     

Load balanced routing protocols for ad hoc mobile wireless networks - [Topics in ad hoc and sensor networks]

Mobile ad hoc networks are collections of mobile nodes that can dynamically form temporary networks without the need for pre-existing network infrastructure or centralized administration. These nodes can be arbitrarily located and can move freely at any given time. Hence, the network topology can change rapidly and unpredictably. Because wireless link capacities are usually limited, congestion is possible in MANETs. Hence, balancing the load in a MANET is important since nodes with high loads will deplete their batteries quickly, thereby increasing the probability of disconnecting or partitioning the network. This article discusses the various load metrics and summarizes the principles behind several existing load balanced ad hoc routing protocols. Finally, a qualitative comparison of the various load metrics and load balanced routing protocols is presented.     

A survey of current architectures for connecting wireless mobile ad hoc networks to the Internet

Connecting wired and wireless networks, and particularly mobile wireless ad hoc networks (MANETs) and the global Internet, is attractive in real‐world scenarios due to its usefulness and praticality. Because of the various architectural mismatches between the Internet and MANETs with regard to their communication topology, routing protocols, and operation, it is necessary to introduce a hybrid interface capable of connecting to the Internet using Mobile IP protocol and to MANETs owing to an ad hoc routing protocol. Specifically, the approaches available in the literature have introduced updated versions of Mobile IP agents or access points at the edge of the Internet to help MANET nodes get multi‐hop wireless Internet access. The main differences in the existing approaches concern the type of ad hoc routing protocol as well as the switching algorithm used by MANET nodes to change their current Mobile IP agents based on specific switching criteria. This paper surveys a variety of approaches to providing multi‐hop wireless Internet access to MANET nodes. Copyright © 2006 John Wiley & Sons, Ltd.     

Genetic Algorithms With Immigrants and Memory Schemes for Dynamic Shortest Path Routing Problems in Mobile Ad Hoc Networks

In recent years, the static shortest path (SP) problem has been well addressed using intelligent optimization techniques, e.g., artificial neural networks, genetic algorithms (GAs), particle swarm optimization, etc. However, with the advancement in wireless communications, more and more mobile wireless networks appear, e.g., mobile networks [mobile ad hoc networks (MANETs)], wireless sensor networks, etc. One of the most important characteristics in mobile wireless networks is the topology dynamics, i.e., the network topology changes over time due to energy conservation or node mobility. Therefore, the SP routing problem in MANETs turns out to be a dynamic optimization problem. In this paper, we propose to use GAs with immigrants and memory schemes to solve the dynamic SP routing problem in MANETs. We consider MANETs as target systems because they represent new-generation wireless networks. The experimental results show that these immigrants and memory-based GAs can quickly adapt to environmental changes (i.e., the network topology changes) and produce high-quality solutions after each change.      

Relay-based deployment concepts for wireless and mobile broadband radio

In recent years, there has been an upsurge of interest in multihop-augmented infrastructure-based networks in both the industry and academia, such as the seed concept in 3GPP, mesh networks in IEEE 802.16, and converge extension of HiperLAN/2 through relays or user-cooperative diversity mesh networks. This article, a synopsis of numerous contributions to the working group 4 of the wireless world research forum and other research work, presents an overview of important topics and applications in the context of relaying. It covers different approaches to exploiting the benefits of multihop communications via relays, such as solutions for radio range extension in mobile and wireless broadband cellular networks (trading range for capacity), and solutions to combat shadowing at high radio frequencies. Furthermore, relaying is presented as a means to reduce infrastructure deployment costs. It is also shown that through the exploitation of spatial diversity, multihop relaying can enhance capacity in cellular networks. We wish to emphasize that while this article focuses on fixed relays, many of the concepts presented can also be applied to systems with moving relays.     

Rate-Adaptive MAC Protocol for Wireless Multicast Over OFDMA-Based MANETs

Unlike in unicast transmissions, a feedback channel has not been implemented for multicast transmission over Mobile ad hoc networks (MANET), due to the increase in the overhead with increasing group member size. As a result, rate-adaptation for wireless multicast has not been considered either. In this paper, a novel rate-adaptive Medium Access Control protocol is proposed to allow dynamic rate-adaptation for wireless multicast transmission over MANETs by utilizing the orthogonality of the subcarriers in an Orthogonal Frequency-Division Multiplexing system. In the proposed rate-adaptation method, each member station is assigned a unique subcarrier and by using this subcarrier, its preferred data rate in the current channel condition is reported to the multicast source. Due to their orthogonality, the feedbacked packets simultaneously transmitted by the group members can be distinguished at the source. Therefore, the source chooses the most appropriate data rate for all member stations. By using this method, the data rate for wireless multicast is able to be adaptively changed, so that the overall network performance is improved.     

Topology control for service-oriented wireless mesh networks - [Service-oriented broadband wireless network architecture]

Topology control is one of the most critical design issues in multihop wireless networks. Topology control has been investigated extensively in the literature. Nevertheless, it is noted that most existing studies do not consider the requirements on upper layer applications or services. In this article we address the topology control issues on service-oriented wireless mesh networks. In particular, we provide a comprehensive survey of existing works on topology control from a service- oriented perspective. We then propose a general framework for topology control in service- oriented WMNs. To demonstrate the effectiveness of the framework, we conduct a case study in which the main objective is to maximize the overall throughput in a network with random unicast traffic. The performance of this topology control scheme is evaluated by numerical results. In addition, it is illustrated that the generated topology can support advanced technologies, including network coding and physical-layer network coding, which can significantly improve the throughput capacity of a network.     

IoT energy efficiency routing protocol using FHO-based clustering and improved CSO model-based routing in MANET

Many protocols, services, and electrical devices with built-in sensors have been developed in response to the rapid expansion of the Internet of Things. Mobile ad hoc networks (MANETs) consist of a collection of autonomous mobile nodes that can form an ad hoc network in the absence of any pre-existing infrastructure. System performance may suffer due to the changeable topology of MANETs. Since most mobile hosts operate on limited battery power, energy consumption poses the biggest challenge for MANETs. Both network lifetime and throughput improve when energy usage is reduced. However, existing approaches perform poorly in terms of energy efficiency. Scalability becomes a significant issue in large-scale networks as they grow, leading to overhead associated with routing updates and maintenance that can become unmanageable. This article employs a MANET routing protocol combined with an energy conservation strategy. The clustering hierarchy is used in MANETs to maximize the network's lifespan, considering its limited energy resources. In the MANET communication process, the cluster head (CH) is selected using Fire Hawk Optimization (FHO). When choosing nodes to act as a cluster for an extended period, CH election factors in connectivity, mobility, and remaining energy. This process is achieved using an optimized version of the Ad hoc On-Demand Distance Vector (AODV) routing protocol, utilizing Improved Chicken Swarm Optimization (ICSO). In comparison to existing protocols and optimization techniques, the proposed method offers an extended network lifespan ranging from 90 to 160 h and reduced energy consumption of 80 to 110 J, as indicated by the implementation results.     

Message Complexity Analysis of Mobile Ad Hoc Network Address Autoconfiguration Protocols

This paper proposes a novel method to perform a quantitative analysis of message complexity and applies this method in comparing the message complexity among the mobile ad hoc network (MANET) address autoconfiguration protocols (AAPs). The original publications on the AAPs had incomplete parts, making them insufficient to use on practical MANETs. Therefore, the first objective of the research was to complete the AAPs by filling in the missing gaps to make them operational. The missing procedures that were filled in have been developed based on the most logical procedures being accurate to the original protocol publications. The research in this paper finds applications in wireless networks that apply reduced addresses to achieve less memory usage, smaller overhead, and higher throughput (for example, the IPv6 low-power wireless personal address network (6LoWPAN)), but, as a result, possess a high address duplication probability. This research consists of two cases, where the first case deals with the message complexity analysis of the single-node joining case (SJC) and the second case deals with the complexity analysis of the MANET group merging case (GMC).     

A virtual multiple message ferry backbone routing scheme for mobile ad-hoc networks

A MANET (Mobile Ad-Hoc Network) consists of relocating wireless communication devices without infrastructure installed in its network environment. Due to the mobility of the devices, the network topology changes frequently and consequently results in poor network performance. When the density of nodes in a MANET is sparse, the performance becomes even worse due to the intermittent connected routing problem arising. To cope with this problem, this paper integrates mechanisms of Virtual Multiple Message Ferry Routing (VMMFR) and Virtual Multiple Message Ferry Dispatch Scheduling (VMMFDS) into the routing protocol design of MANETs and proposes a Virtual Multiple Message Ferry Backbone Routing (VMMFBR) scheme for MANETs. Several simulations have been conducted using the network simulator NS-2 to evaluate the performance of the proposed VMMFR mechanism. Due to the VMMFR mechanism providing a reliable and predictable backbone routing for MANETs communications. The results show that the proposed method has a higher packet delivery ratio, low bandwidth consumed, and that there is greater precision of packet delivery time, compared to the traditional MANETs routing protocols (AOMDV and DSR). In addition, some theoretical results for the proposed VMMFDS mechanism to minimize the transfer waiting time are also given in this paper.     

Stochastic Geometry and Random Graphs for the Analysis and Design of Wireless Networks

Wireless networks are fundamentally limited by the intensity of the received signals and by their interference. Since both of these quantities depend on the spatial location of the nodes, mathematical techniques have been developed in the last decade to provide communication-theoretic results accounting for the network?s geometrical configuration. Often, the location of the nodes in the network can be modeled as random, following for example a Poisson point process. In this case, different techniques based on stochastic geometry and the theory of random geometric graphs ? including point process theory, percolation theory, and probabilistic combinatorics ? have led to results on the connectivity, the capacity, the outage probability, and other fundamental limits of wireless networks. This tutorial article surveys some of these techniques, discusses their application to model wireless networks, and presents some of the main results that have appeared in the literature. It also serves as an introduction to the field for the other papers in this special issue.     

Understanding interference and carrier sensing in wireless mesh networks [Accepted from Open Call]

Wireless mesh networks aim to provide high-speed Internet service without costly network infrastructure deployment and maintenance. The main obstacle in achieving high-capacity wireless mesh networks is interference between the mesh links. In this article, we analyze the carrier sensing and interference relations between two wireless links and measure the impact of these relations on link capacity on an indoor 802.11a mesh network testbed. We show that asymmetric carrier sensing and/or interference relations commonly exist in wireless mesh networks, and we study their impact on the link capacity and fair-channel access. In addition, we investigate the effect of traffic rate on link capacity in the presence of interference.     

Exploring mesh and tree-based multicast. Routing protocols for MANETs

Recently, it became apparent that group-oriented services are one of the primary application classes targeted by MANETs. As a result, several MANET-specific multicast routing protocols have been proposed. Although these protocols perform well under specific mobility scenarios, traffic loads, and network conditions, no single protocol has been shown to be optimal in all scenarios. The goal of this paper is to characterize the performance of multicast protocols over a wide range of MANET scenarios. To this end, we evaluate the performance of mesh and tree-based multicast routing schemes relative to flooding and recommend protocols most suitable for specific MANET scenarios. Based on the analysis and simulation results, we also propose two variations of flooding, scoped flooding and hyper flooding, as a means to reduce overhead and increase reliability, respectively. Another contribution of the paper is a simulation-based comparative study of the proposed flooding variations against plain flooding, mesh, and tree-based MANET routing. In our simulations, in addition to "synthetic" scenarios, we also used more realistic MANET settings, such as conferencing and emergency response.