Mobile Multi-hop Wireless Networks Research Articles

Anonymous Authentication and Key Agreement Scheme Combining the Group Key for Vehicular Ad Hoc Networks

Vehicular ad hoc network (VANET) is a multihop mobile wireless communication network that can realize many vehicle-related applications through multitop communication. In the open wireless communication environment, security and privacy protection are important contents of VANET research. The most basic method of VANET privacy protection is anonymous authentication. Even through, there are many existing schemes to provide anonymous authentication for VANETs. Many existing schemes suffer from high computational cost by using bilinear pairing operation or need the assistance of the trust authorities (TAs) during the authentication process or rely on an ideal tamper-proof device (TPD), which requires very strong security assumption. In this study, an anonymous authentication and key negotiation scheme by using private key and group key is proposed, which is based on pseudonym using the nonsingular elliptic curve. In this scheme, there is no third party trust center to participate in the authentication, there is no need to query the database, and there is no need of the local database to save the identity information of many vehicles, which reduce the storage space and the authentication time compared with other schemes. The proposed scheme only needs realistic TPDs. In the proposed scheme, TPDs do not need to preinstall the system key as many other schemes do; hence, the failure of a single TPD does not affect the security of the entire system. The security of the scheme is proved under the random oracle model. Compared with the related schemes using bilinear pairings, the computational cost and communication cost of the proposed scheme are reduced by 82% and 50%, respectively.

Variable-weight topology-transparent scheduling

In this paper, topology-transparent scheduling for mobile multi-hop wireless networks is extended from constant-weight to variable-weight schedules. A construction of variable-weight topology-transparent schedules – the first of its kind – is provided based on transversal designs from the finite field. The schedules are integrated into the VWATT medium access control (MAC) protocol, enabling nodes to dynamically select their schedule weights to accommodate both their local traffic load and local topology while maintaining a guarantee on maximum delay. Simulations show VWATT to increase throughput compared to constant-weight topology-transparent schedules, to reduce both maximum and expected delay relative to schedules whose weights are not constrained to the set of weights, and to adapt rapidly to changes in topology and traffic load. The results suggest variable-weight topology-transparent scheduling as a viable approach to medium access control when a bound on delay is required.

Analytical framework for the characterization of the link properties in multi-hop mobile wireless networks

The maintainability of connectivity in multi-hop mobile wireless networks is a complex task to achieve, for which various factors must be taken into account in order to avoid link failures. In addition to the bandwidth limitation, node mobility and interference are two aspects that impact directly the reliability of the communication link, leading generally to loss of wireless link connectivity. In this paper, we develop an analytical framework which determines the link and path lifetime in multi-hop mobile wireless networks. Through this model, we derive an analytical model of the link and path lifetime by taking into consideration both node mobility and interference. We find that the probability density function (PDF) of the duration of a link in presence of interference can be approximated by an exponential distribution with parameter λ which relies the transmission range R, the average speed V¯, the Signal-to-Interference-Plus-Noise-Ratio (SINR) threshold β, the path loss exponent α, and the maximum number of interfering nodes N. We extend this model to evaluate the PDF of the link lifetime by taking into account both interference and mobility of the linked nodes. We conclude that the PDF of the overall link lifetime can be approximated by a Rayleigh distribution that is in harmony with several previous simulation based-studies. Furthermore, some properties of wireless links and multi-hop paths are evaluated and several simulations are carried out in order to investigate the multi-hop wireless network connectivity and the associated performance.

Research for Network Security Mechanism of Ad Hoc Network

Ad Hoc network is a special kind of mobile multi-hop wireless networks, which has been widely used various occasions. In this paper, the main characters of Ad Hoc network are presented. Meanwhile, based on the inherent defect and security threats of Ad Hoc network, the corresponding security mechanism and strategy are proposed.

Selfish Node Detection in Replica Allocation over MANETs

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost, and average query delay.

Link Stability and Energy Aware routing Protocol for Mobile Adhoc Network

MOBILE ad hoc networks (MANETs) have more popularity among mobile network devices and wireless communication technologies. A MANET is multihop mobile wireless network that have neither a fixed infrastructure nor a central server. Every node in a MANET will act as a router, and also communicates with each other. The mobility constraints in mobile nodes will lead to problems in link stability. Energy saving, path duration and stability will be two major efforts and to satisfy them can be difficult task. A self node which is present in the network may also consume little energy during the transmission. This proposed approach tries to account for link stability and for minimum drain rate energy consumption. In order to verify the correctness of the proposed solution a objective optimization formulation has been designed and a novel routing protocol called Link-Stability and Energy aware Routing protocols is proposed. This novel routing scheme has been compared with other two protocols: PERRA and GPSR. The protocol performance has been evaluated in terms of Data Packet Delivery Ratio, Normalized Control Overhead, Link duration, Nodes lifetime, and Average energy consumption. Keywords-component; Energy Consumption, Link Stability, Routing, Self node

Effect of Packet Size on Various MANET Routing Protocols

MANET is a peer to peer, multi-hop mobile wireless networks in which packets are transmitted in store and forward manner from source to destination. When processing the packets from one node to another node packet size is very important parameter because changing the packet size effect the performance of the MANET network. Aim of this research paper to analyze the effect of packet size in MANET network. We analyze the MANET network for three routing protocols AODV, OLSR & DSR. For this purpose we take 50 nodes MANET network & each node work as MANET station.

Design of zone-based bandwidth management scheme in IEEE 802.16 multi-hop relay networks

IEEE 802.16 Wireless Network technology is a hot research issue in recent years. It provides wider coverage of radio and higher speed wireless access, and Quality-of-Service plays an important part in the standard. For mobile multi-hop wireless network, IEEE 802.16j/MR network not only can supply large area wireless deployment, but also can provide high quality network service to mobile users. Although Mobile QoS supporting has been extensively investigated, Mobile QoS supporting in the IEEE 802.16-MR network is relatively unexplored. In this article, the probability of a mobile user who visits a Relay Station (RS) is known beforehand. With the visiting probability at each RS and the system specified size of the range for bandwidth allocation, Base Station (BS) can calculate the required bandwidth to meet the mobile user's demand and allocate appropriate bandwidth for a mobile user roaming in the range of the bandwidth allocation. The range of bandwidth allocation for mobile users is called the Zone in this article, which includes the user's current RS and the nearby RSs. The proposed scheme is therefore called Zone-based bandwidth management scheme. The simulation results demonstrate that Zone-based bandwidth management scheme can reduce QoS degradation and bandwidth re-allocation overhead.

NAT-MANEMO: Route Optimization for Unlimited Network Extensibility in MANEMO

MANET for NEMO (MANEMO) is a new type of network that integrates multi-hop mobile wireless networks with global connectivity provided by Network Mobility (NEMO). Two factors limit the scalability of MANEMO: the volatility of topologically correct global addresses, and excessive traffic load caused by inefficient use of nested tunnels and the consequent redundant routing of packets. We propose NAT-MANEMO, which solves both problems by applying NAT for some mobile router addresses, bypassing tunnel nesting. This approach retains global addresses for mobile end nodes, preserving application transparency, and requires only minimal modification to existing specifications. Our ideas are evaluated using simulation and a proof of concept implementation. The simulation shows the additional signaling overhead for the route optimization introduced by our proposal is negligible compare to the bandwidth of an IEEE 802.11 link. The implementation confirms that route optimization reduces latency and improves throughput.

Throughput Improvement of Mobile Multi-Hop Wireless Networks

This paper demonstrates the use of some novel cognitive techniques we propose to improve the throughput of a mobile WIMAX network and minimize the packet losses. We propose a novel method called Orthogonal Frequency Division Most Congested Access First (OFDMCAF), to modify the spectrum sharing technique of (Time Division Multiple Access) TDMA and (Orthogonal Frequency Division Multiple Access) OFDMA and to manage the spectrum access. The heavy multimedia traffic is managed by OFDMCAF with novel spectrum sharing and buffer management methods we propose. By use of novel cognitive methods, real time voice and video packet transmissions have been provided with full success and the packet loss rate of data packets has been minimized. The simulation results are confirmed by comparing them with results of other publications and comparing with results of packet loss calculations we made. The results are usable in designing unicast mobile multimedia network with improved system throughput.

AMNP: ad hoc multichannel negotiation protocol with broadcast solutions for multi-hop mobile wireless networks

A multi-hop mobile ad hoc network (MANET) is generally configured as a peer-to-peer network with no centralised hubs or controllers that coordinate channel resources. Nodes in a MANET usually equip one single transceiver for data transmissions. However, the single transceiver architecture will cause a difficulty of being implemented in multichannel environment if the network transmission capacity would be improved by adopting parallel multichannel access. To solve this thorny problem, this study presents a distributed medium access control (MAC) layer protocol called ad hoc multichannel negotiation protocol (AMNP) for multichannel transmissions in the multi-hop MANET. Additionally, two problems, the multichannel hidden terminal problem and the multichannel broadcast transmission problem, caused by single transceiver operations in the multichannel environment, which have not been revealed in academia, is presented and solved in this study. Finally, an enhanced AMNP with channel scheduling (AMNP/s) scheme is introduced to improve the channel utilisation. The author show, via simulations, that AMNP/s provides a higher throughput compared to its single-channel counterpart by promoting simultaneous transmissions in different channels. Simulation results also show that AMNP/s derives higher performance than other multichannel transmission schemes that use multiple transceivers.

Efficient geocasting with multi-target regions in mobile multi-hop wireless networks

Geocasting, a variation on the notion of multicasting, is a mechanism to deliver messages of interest to all nodes within a certain geographical target region. Although several geocasting protocols have already been proposed for multi-hop wireless networks, most of these algorithms consider a "single" target region only. Here, when more than one target regions need to receive the same geocast messages, multiple transmissions need to be initiated separately by the message source. This causes significant performance degradation due to redundant packet transmissions, and it becomes more severe as the number of target regions increase. To solve this problem, we propose a basic scheme and its variations which utilize the geometric concept of "Fermat point" to determine the optimal junction point among multiple geocast regions from the source node. Our simulation study using ns-2 shows that the proposed schemes can effectively reduce the overhead of message delivery while maintaining a high delivery ratio in mobile multi-hop wireless networks.

이동 다중 홉 무선망 모델에 기반한 해양통신망을 위한 경로배정 보안 연구

In recent years, many mobile wireless communication devices and applications have been deployed on the planet. The mobile multi-hop wireless network models appeared to provide means to access to networks where few infrastructure exists. However, the mobile multi-hop wireless networks have weaker points in attacks and intrusions than the wired and one-hop wireless networks. In this paper, the secure routing issues in most mobile multi-hop wireless network models are surveyed in depth. The state-of-the-art technologies and research activities are explained. Finally, the issues and technologies for the secure routing specific to a maritime network model are sufficiently discussed as conclusions.

Cross Layer PHY-MAC Protocol for Wireless Static and Mobile Ad Hoc Networks

Multihop mobile wireless networks have drawn a lot of attention in recent years thanks to their wide applicability in civil and military environments. Since the existing IEEE 802.11 distributed coordination function (DCF) standard does not provide satisfactory access to the wireless medium in multihop mobile networks, we have designed a cross-layer protocol, (CroSs-layer noise aware power driven MAC (SNAPdMac)), which consists of two parts. The protocol first concentrates on the flexible adjustment of the upper and lower bounds of the contention window (CW) to lower the number of collisions. In addition, it uses a power control scheme, triggered by the medium access control (MAC) layer, to limit the waste of energy and also to decrease the number of collisions. Thanks to a noticeable energy conservation and decrease of the number of collisions, it prolongs significantly the lifetime of the network and delays the death of the first node while increasing both the throughput performance and the sending bit rate/throughput fairness among contending flows.

Information-based connection algorithm for supporting QoS in nested mobility network

A multihop mobile wireless network can be a collection of wireless mobile nodes forming a temporary network without the aid of any established infrastructure or centralized administration. Mobile nodes communicate with each other using multihop wireless links. Each mobile node in the network also acts as a router, which forwards data packets to other nodes. A main challenge in the design of this mobile network is the development of dynamic routing protocols that can efficiently find routes between two communicating nodes that often change the network topology drastically and unpredictably. All communications between the nodes inside the mobile network and the global Internet must be maintained, although the mobile router (MR) connecting the other mobile network to the global Internet must change their address; and mobile nodes suffer from end-to-end delay and handoff delay. That is to say, hereafter the packets sailing for the mobile node would not be routed directly for the destination, but will always make a detour by way of HA to the target node. In this paper, we suggest Information-based Connection Algorithm that adds keyword management method in order to resolve such a problem, simulations are carried out with NS-2 for performance evaluation. The results of the simulations show an improvement on throughput and handoff delay, and consequently the QoS improvement.

Intrusion detection for secure clustering and routing in Mobile Multi-hop Wireless Networks

Intrusion detection and secure routing schemes have been proposed for increasing security and reliability in critical wireless scenarios. In this paper we present an integrated secure routing system based on Intrusion Detection Systems (IDS) and Statistically Unique and Cryptographically Verifiable (SUCV) identifiers. The proposed IDS has been used for the support of secure Ad Hoc On Demand Distance Vector (AODV) routing, named IDS-based Secure AODV (IS-AODV), in wireless ad hoc and vehicular network scenarios. Our IDS is based on the detection of behavior anomalies on behalf of neighbor hosts, with passive reactions, aiming to create a cluster whose route paths will include only safe nodes, eventually. Simulation results show that the proposed IDS is effective in isolating misbehaving hosts, and it assists the AODV secure routing scheme to converge in finding safe end-to-end routes.

M obiW orp: Mitigation of the wormhole attack in mobile multihop wireless networks

In multihop wireless systems, the need for cooperation among nodes to relay each other’s packets exposes them to a wide range of security attacks. A particularly devastating attack is the wormhole attack, where a malicious node records control traffic at one location and tunnels it to a colluding node, possibly far away, which replays it locally. This can have an adverse effect on route establishment by preventing nodes from discovering legitimate routes that are more than two hops away. Previous works on tolerating wormhole attacks have focused only on detection and used specialized hardware, such as directional antennas or extremely accurate clocks. More recent work has addressed the problem of locally isolating the malicious nodes. However, all of this work has been done in the context of static networks due to the difficulty of secure neighbor discovery with mobile nodes. The existing work on secure neighbor discovery has limitations in accuracy, resource requirements, and applicability to ad hoc and sensor networks. In this paper, we present a countermeasure for the wormhole attack, called M obiW orp, which alleviates these drawbacks and efficiently mitigates the wormhole attack in mobile networks. M obiW orp uses a secure central authority (CA) for global tracking of node positions. Local monitoring is used to detect and isolate malicious nodes locally. Additionally, when sufficient suspicion builds up at the CA, it enforces a global isolation of the malicious node from the whole network. The effect of M obiW orp on the data traffic and the fidelity of detection is brought out through extensive simulation using ns-2. The results show that as time progresses, the data packet drop ratio goes to zero with M obiW orp due the capability of M obiW orp to detect, diagnose and isolate malicious nodes. With an appropriate choice of design parameters, M obiW orp is shown to completely eliminate framing of a legitimate node by malicious nodes, at the cost of a slight increase in the drop ratio. The results also show that increasing mobility of the nodes degrades the performance of M obiW orp.

Real-time traffic support in heterogeneous mobile networks

Multi-hop mobile wireless networks have been proposed for a variety of applications where support for real-time multimedia services will be necessary. Support for these applications requires that the network is able to offer quality of service (QoS) appropriate for the latency and jitter bounds of the real-time application constraints. In this paper, we analyze the primary challenges of realizing QoS in mobile wireless networks with heterogeneous devices and propose a QoS framework for real-time traffic support. We address the problem in three ways: estimate the path quality for real-time flows, mitigate the impact of node heterogeneity on service performance, and reduce the impact of interfering non-real-time traffic. Specifically, our proposed QoS framework first utilizes a call setup protocol at the IP layer to discover paths for real-time flows, as well as to perform admission control by accurate service quality prediction. The underlying routing protocol also enables transparent path selection among heterogeneous nodes to provide stable paths for real-time traffic delivery. We then use a prioritized MAC protocol to provide priority access for flows with real-time constraints to reduce interference from unregulated non-real-time traffic. We foresee the utility of our proposed solution in heterogeneous mobile networks, such as campus or community-wide wireless networks. In these environments, resource-rich or fixed wireless routers may be leveraged to achieve better service quality when heterogeneity of node capability and movement is significant. Through experimental results, we demonstrate the utility and efficiency of our approach.

Hierarchically-organized, multihop mobile wireless networks for quality-of-service support

MMWN is a modular system of adaptive link- and network-layer algorithms that provides a foundation on which to build mechanisms for quality-of-service provision in large, multihop mobile wireless networks. Such networks are a practical means for creating a communications infrastructure where none yet exists or where the previously existing infrastructure has been severely damaged. These networks provide communications for such diverse purposes as tactical maneuvering and strategic planning on the battlefield, emergency relief in an area afflicted by a natural disaster, and field studies conducted by a team of scientists in a remote location. In this paper, we describe three key components of the MMWN system: the clustering procedures for defining a virtual, hierarchical control structure superimposed on a large network of mobile switches and endpoints; the location management procedures for determining the current locations of mobile endpoints relative to the hierarchical control structure; and the virtual circuit management procedures for setting up and repairing virtual circuits as switches and endpoints move. We also provide simulation results that illustrate the robustness of each of these components with respect to a broad spectrum of transmission ranges and relative mobility of switches and endpoints.

Forwarding Group Multicast Protocol (FGMP) for multihop, mobile wireless networks

In this paper we propose a new multicast protocol for multihop mobile wireless networks. Instead of forming multicast trees, a group of nodes in charge of forwarding multicast packets is designated...