A stable weight-based on-demand routing protocol for mobile ad hoc networks

A mobile ad hoc network (MANET) consists of a set of mobile hosts that can communicate with each other without the assistance of base stations. In MANETs, the high mobility of mobile nodes is a major reason for link failures. In this paper, we propose a stable weight-based on-demand routing protocol (SWORP) for MANETs. The proposed scheme uses the weight-based route strategy to select a stable route in order to enhance system performance. The weight of a route is decided by three factors: the route expiration time, the error count, and the hop count. Route discovery usually first finds multiple routes from the source node to the destination node. Then the path with the largest weight value for routing is selected. Simulation results show that the proposed SWORP outperforms DSR, AODV, and AODV-RFC, especially in a high mobility environment.     

Performance comparison of OLSR and BATMAN routing protocols by a MANET testbed in stairs environment

A Mobile Ad-hoc Network (MANET) is a set of mobile terminals, which move in different directions with different speeds. MANETs are found very useful in real applications such as time-lacking implementations and indoor environments. In this paper, we analyze the behavior of Optimized Link State Routing (OLSR) and Better Approach To Mobile Ad-hoc Network (BATMAN) routing protocols, in stairs environment, based on real data from our MANET testbed. We evaluate the performance considering three metrics: throughput, delay and packet loss. We design and implement two experimental scenarios: static stairs scenario and shifting stairs scenario. From our experiments, we show that as the number of hops increases to three or more hops, the performance of the communication decreases. The performance decreases further when the nodes are mobile. However, OLSR shows a better performance than BATMAN.     

TCP Issues in Mobile Ad Hoc Networks: Challenges and Solutions

Mobile ad hoc networks （MANETs） are a kind of very complex distributed communication systems with wireless mobile nodes that can be freely and dynamically self-organized into arbitrary and temporary network topologies. MANETs inherit several limitations of wireless networks, meanwhile make new challenges arising from the specificity of MANETs, such as route failures, hidden terminals and exposed terminals. When TCP is applied in a MANET environment, a number of tough problems have to be dealt with. In this paper, a comprehensive survey on this dynamic field is given. Specifically, for the first time all factors impairing TCP performance are identified based on network protocol hierarchy, i.e., lossy wireless channel at the physical layer; excessive contention and unfair access at the MAC layer; frail routing protocol at the network layer, the MAC layer and the network layer related mobile node; unfit congestion window size at the transport layer and the transport layer related asymmetric path. How these factors degrade TCP performance is clearly explained. Then, based on how to alleviate the impact of each of these factors listed above, the existing solutions are collected as comprehensively as possible and classified into a number of categories, and their advantages and limitations are discussed. Based on the limitations of these solutions, a set of open problems for designing more robust solutions is suggested.     

The performance impact of traffic patterns on routing protocols in mobile ad hoc networks

As mobile ad hoc network (MANET) systems research has matured and several testbeds have been built to study MANETs, research has focused on developing new MANET applications such as collaborative games, collaborative computing, messaging systems, distributed security schemes, MANET middleware, peer-to-peer file sharing systems, voting systems, resource management and discovery, vehicular computing and collaborative education systems. The growing set of diverse applications developed for MANETs pose far more complex traffic patterns than the simple one-to-one traffic pattern, and hence the one-to-one traffic pattern widely used in previous protocol studies has become inadequate in reflecting the relative performance of these protocols when deployed to support these emerging applications.As a first step towards effectively supporting newly developed and future diverse MANET applications, this paper studies the performance impact of diverse traffic patterns on routing protocols in MANETs. Specifically, we propose a new communication model that extends the previous communication model to include a more general traffic pattern that varies the number of connections per source node. We study the performance impact of traffic patterns on various routing protocols via detailed simulations of an ad hoc network of 112 mobile nodes. Our simulation results show that many of the conclusions drawn in previous protocol comparison studies no longer hold under the new traffic patterns. These results motivate the need for performance evaluation of ad hoc networks to not only include rich and diverse mobility models as has been done in the past but also include diverse traffic patterns that stress a wide set of protocol design issues.     

Standardisation advancements in the area of routing for mobile ad-hoc networks

Mobile Ad hoc Networks (MANETs) are self-organized and fully distributed networks that rely on the collaboration of participating devices to route data from source to destination. The MANET paradigm is expected to enable ubiquitous mobile communication and thus the proliferation of pervasive applications. The MANET Working Group (WG) of the Internet Engineering Task Force (IETF) is responsible for standardizing an appropriate Internet Protocol (IP) based routing protocol functionality for both static (mesh) and dynamic (mobile) wireless ad hoc network topologies. In this paper, we provide a background on the possibility to use MANETs for enabling future pervasive internet and innovative ubiquitous services. We also describe the work achieved by the MANET WG thus far on the area of secure unicast and multicast routing for MANETs. We also examine non-IETF work on this area, chiefly based on adaptive and hybrid routing. The paper then presents comparative performance evaluations of discussed routing protocols. It is mainly observed that there is a need for adaptive hybrid routing approaches in order to support future innovative and pervasive applications. Consequently, we present our conclusions.     

Research on multicast routing protocols for mobile ad-hoc networks

A mobile ad-hoc network (MANET) is composed of mobile nodes without any infrastructure. Mobile nodes self-organize to form a network over radio links. The goal of MANETs is to extend mobility into the realm of autonomous, mobile and wireless domains, where a set of nodes form the network routing infrastructure in an ad-hoc fashion. The majority of applications of MANETs are in areas where rapid deployment and dynamic reconfiguration are necessary and wired network is not available. These include military battlefields, emergency search, rescue sites, classrooms and conventions, where participants share information dynamically using their mobile devices. These applications lend themselves well to multicast operations. In addition, within a wireless medium, it is crucial to reduce the transmission overhead and power consumption. Multicasting can improve the efficiency of the wireless link when sending multiple copies of messages by exploiting the inherent broadcast property of wireless transmission. Hence, reliable multicast routing plays a significant role in MANETs. However, to offer effective and reliable multicast routing is difficult and challenging. In recent years, various multicast routing protocols have been proposed for MANETs. These protocols have distinguishing features and employ different recovery mechanisms. To provide a comprehensive understanding of these multicast routing protocols and better organize existing ideas and work to facilitate multicast routing design for MANETs, we present the taxonomy of the multicast routing protocols, their properties and design features. This paper aims to aid those MANETs researchers and application developers in selecting appropriate multicast routing protocols for their work.     

A survey of data replication techniques for mobile ad hoc network databases

A mobile ad hoc network (MANET) is a network that allows mobile servers and clients to communicate in the absence of a fixed infrastructure. MANET is a fast growing area of research as it finds use in a variety of applications. In order to facilitate efficient data access and update, databases are deployed on MANETs. These databases that operate on MANETs are referred to as MANET databases. Since data availability in MANETs is affected by the mobility and power constraints of the servers and clients, data in MANETs are replicated. A number of data replication techniques have been proposed for MANET databases. This paper identifies issues involved in MANET data replication and attempts to classify existing MANET data replication techniques based on the issues they address. The attributes of the replication techniques are also tabulated to facilitate a feature comparison of the existing MANET data replication works. Parameters and performance metrics are also presented to measure the performance of MANET replication techniques. In addition, this paper also proposes criteria for selecting appropriate data replication techniques for various application requirements. Finally, the paper concludes with a discussion on future research directions.     

Robust and secure routing scheme for wireless multihop network

Mobile ad hoc network (MANET) is an appealing technology that has attracted lots of research efforts. On-demand routing protocol such as AODV may suffer from frequent topological changes. Due to frequent communication failures, multipath MANET is preferred than single-path MANET in many applications as former is used for achieving robustness and load balancing and improving reliability. Although multipath MANET is attractive solution, there are still some major flaws that prevent commercial growth. Security is one of these main barriers; MANETs are known to be particularly vulnerable to security attack. The paper presents a design of robust and secure framework for multipath MANET. In this paper, we propose not only a robust multipath routing protocol but also an extended security scheme. We discuss security analysis for proposed security scheme. And we also conduct simulation to evaluate such a framework through different performance metrics. Results show that the proposed routing protocol achieves better performance in terms of various metrics than other protocols.     

基于博弈的MANETs信任模型研究

移动Ad-Hoc网络(MANET)是由一组带有无线收发装置的移动节点组成的无须固定设置支持的临时性的通信网络.MANETs具有开放的媒质、动态的拓扑结构、分布式的合作和受限的网络能力等基本特点.在MANETs中,节点之间相互信赖路由和转发数据包,节点间的合作是非常重要的.但是由于自私节点为了储存能量和其他资源,而不参与转发数据.由于MANETs通信没有第3方的中心认证,所以集中于强制合作是不适应的.基于博弈研究MANETs中的节点行为,根据节点的信誉度来获得资源,刺激节点共享资源和转发数据.提出了基于博弈理论的信任模型,鼓励包转发,约束自私节点.仿真结果表明该信任模型能够识别自私节点并且能在信任节点之间建立信任,提高了整个网络效率.     

Protocol interoperability in mobile IP enabled mobile ad hoc networks

A trend in future 4G wireless networks is the integration of MANETs into all-IP systems, which may enhance the flexibility and pervasiveness of 4G networks. One of the most crucial challenges in this field is the design of Protocol Interoperability to achieve the integration of MANET routing protocols and Mobile IP into the IP routing systems. This problem has not been effectively addressed by researches published thus far. This paper contributes solutions to solving this challenge. The protocol architecture and protocol interfaces are designed, which are suitable for gateways and mobile nodes in such Internet integrated MANETs supporting Mobile IP. Propagation methods of Mobile IP signalling messages with MANET routing information piggybacking are designed. Finally, an enhanced Mobile IP protocol suitable for MANET system is contributed. In summary, the contribution of this paper is a thorough scheme for establishing an IP/MIP/MANET integrated system.     

Influence of mobility models on the performance of data dissemination and routing in wireless mobile ad hoc networks

Many routing protocols are proposed in the literature on mobile ad hoc networks (MANETs). Some of those protocols which have been investigated under different assumptions are unable to capture the actual characteristics of MANETs. Therefore, there is a necessity to investigate the performance of MANETs under a number of different protocols with various mobility models. This paper evaluates the performance of the single path routing protocols (AODV, DSR, and DSDV), in the presence of different network loads and differing mobility models. Our findings show that DSR routing protocol has a better performance compared to other protocols with respect to various metrics.     

Behavior of Ad Hoc routing protocols,analyzed for emergency and rescue scenarios,on a real urban area

A mobile Ad Hoc network (MANET) is a collection of wireless mobile nodes that can dynamically configure a network without a fixed infrastructure or central administration. This makes it ideal for emergency and rescue scenarios, where sharing information is essential and should occur as soon as possible. This article discusses which of the routing strategies for mobile MANETs: proactive, reactive or hierarchical, has a better performance in such scenarios. By selecting a real urban area for the emergency and rescue scenario, we calculated the density of nodes and the mobility model needed for the validation study of AODV, DSDV and CBRP in the routing model. The NS2 simulator has been used for our study. We also show that the hierarchical routing strategies are better suited for this type of scenarios.     

基于OPNET的MAODV协议仿真实现及分析

移动Ad Hoc网络(MANET)的路由协议对网络的性能有较大影响,尤其在多播的场景下,好的多播路由协议可以节省大量无线传输带宽。MAODV路由协议是在AODV路由协议的基础上进行的多播扩展,也是目前MANET网络多播路由协议的研究热点。通过使用OPNET网络仿真软件,对MAODV协议进行仿真建模,使OPNET在MANET场景下支持多播路由协议的仿真,为其它需要MANET网络多播路由协议的场景提供支持。对仿真建模的结果进行了多方面的验证,以保证建模的正确性和有效性。     

Link stability based multicast routing scheme in MANET

The group-oriented services are one of the primary application classes that are addressed by Mobile Ad hoc Networks (MANETs) in recent years. To support such services, multicast routing is used. Thus, there is a need to design stable and reliable multicast routing protocols for MANETs to ensure better packet delivery ratio, lower delays and reduced overheads. In this paper, we propose a mesh based multicast routing scheme that finds stable multicast path from source to receivers. The multicast mesh is constructed by using route request and route reply packets with the help of multicast routing information cache and link stability database maintained at every node. The stable paths are found based on selection of stable forwarding nodes that have high stability of link connectivity. The link stability is computed by using the parameters such as received power, distance between neighboring nodes and the link quality that is assessed using bit errors in a packet. The proposed scheme is simulated over a large number of MANET nodes with wide range of mobility and the performance is evaluated. Performance of the proposed scheme is compared with two well known mesh-based multicast routing protocols, i.e., on-demand multicast routing protocol (ODMRP) and enhanced on-demand multicast routing protocol (EODMRP). It is observed that the proposed scheme produces better packet delivery ratio, reduced packet delay and reduced overheads (such as control, memory, computation, and message overheads).     

Dynamic backup routes routing protocol for mobile ad hoc networks

Mobile Ad Hoc Networks (MANETs), which provide data networking without infrastructure, represent one kind of wireless networks. A MANET is a self-organizating and adaptive wireless network formed by the dynamic gathering of mobile nodes. Due to the mobility of mobile nodes, the topology of a MANET frequently changes and thus results in the disability of originally on-the-fly data transmission routes. The dynamic properties of MANETs are therefore challenging to protocol design. To cope with the intrinsic properties of MANETs, Dynamic Backup Routes Routing Protocol (DBR²P), a backup node mechanism for quick reconnection during link failures, is proposed in this paper. DBR²P is an on-demand routing protocol and it can set up many routes to reach a destination node in a given period. Even when a link fails, those routes from the source node to the destination node can be analyzed to obtain backup routes to sustain quick reconnection. The information of backup routes can be saved in a specific on-the-route node and enables backup routes to be found immediately in situation regarding disconnection. As a result, DBR²P could more thoroughly improve the quality of routing protocol than those proposed in the past.     

An anonymous distributed routing protocol in mobile ad-hoc networks

This paper proposes an efficient anonymous routing protocol for mobile ad hoc networks (MANETs). This protocol considers symmetric and asymmetric links during the wireless communication of MANETs. A MANET is one type of self-organized wireless network that can be formed by several wireless devices such as laptops, tablet PCs, and smartphones. Different wireless transmission ranges of different mobile devices lead to a special communication condition called an asymmetric link. Most research on this topic focuses on providing security and anonymity for the symmetric link without considering the asymmetric link. This paper proposes a novel distributed routing protocol beyond the symmetric and asymmetric links. This protocol guarantees the security, anonymity, and high reliability of an established route by avoiding unreliable intermediate nodes. The routes generated by the proposed protocol are shorter than previous research. The proposed protocol enhances MANET performance in assuring security and anonymity.     

基于Ad Hoc的QoS多播路由协议研究

近年来,随着计算机网络和无线通信技术的迅速发展,无线移动AdHoc网络在军事和民用方面获得了大量应用。多媒体业务的引入对AdHoc网络提出了多播和QoS服务的需求,如何在AdHoc网络中实现有效的多播和QoS服务是一项十分困难和具有挑战性的工作。论文介绍了当前几种比较典型的QoS多播路由协议,并且从多个方面对它们的特性进行了比较分析,最后对AdHoc网络的QoS多播路由协议的进一步研究提出了预测和展望。     

Uncertainty analysis framework for trust based routing in MANET

MANET (Mobile Ad hoc Network) has distinctive characteristics like node mobility, broadcast nature of wireless communication, and peer to peer data transfer. Due to these characteristics uncertainty is an integral part of MANET behavior. Uncertainty quantification is important for performance evaluation and better decision making in MANET. Packet dropping is a serious issue in MANET which degrades the performance of the network to a great extent. The packet dropping attack increases uncertainty in the network communication and eventually of the MANET. Trust based routing mechanisms are useful for neutralizing packet dropping attack. There are many existing trust based routing protocols which uses uncertainty for precise trust calculations. Thus, trust and uncertainty are closely related to each other. The paper proposes Uncertainty Analysis Framework (UAF) for MANET, it calculates the network Belief, Disbelief, and Uncertainty (BDU) values. The UAF framework integrated into different trust variants of AODV protocol which use direct trust, indirect trust, and global trust. The research work discovers impact of different trust models on MANET BDU using various mobility models. Experimental analysis shows that, trust based routing protocols show average 3 % gain in packet delivery ratio and at least 5 % increase in the network belief.     

A novel mobility model based on semi-random circular movement in mobile ad hoc networks

When simulating a mobile ad hoc network (MANET), it is important to use a realistic mobility model to reflect the actual performance of a mobile system. The spatial distribution of node locations in a mobile model plays a key role when investigating the characteristics of a MANET. However, most existing mobility models with random and simple straight line movement lead to unrealistic scenarios and non-uniform distributions, and can not describe the actual movement of Unmanned Aerial Vehicles (UAVs) connected via a MANET. To address this issue, a novel mobility model based on semi-random circular movement (SRCM) is presented. The approximate node distribution function in SRCM is derived within a 2D disk region. The relationship between application performance and node distribution is investigated for a UAV MANET, with focus on scan coverage and network connectivity. A simulation using the NS2 tool is conducted. It is shown that the presented model with a uniform distribution performs better than the popular Random Waypoint mobility model. The SRCM model with the NS2 simulator provides a realistic way for simulation and performance evaluation of UAV MANETs.     

Efficient energy conservation in MANET using Energy Conserving Advanced Optimised Link State Routing model

Mobile Ad-hoc Network (MANET) is formed dynamically by the independent organisation of the mobile nodes connected through wireless links without using any centralised administration. Energy consumption is the most significant issue in the MANETs, since most of the mobile hosts operate on limited battery resources. Reduction in the energy consumption results in the increase in the lifetime and throughput of the network. The performance of existing techniques was less in terms of energy conservation issues. To overcome these limitations, this paper proposes an energy conservation mechanism integrated with a proactive MANET routing scheme. The routing schema is based on the energy level and the mobility of the nodes. Calculation of energy cost is performed based on the prediction of the energy consumption level of the node, using Energy Conserving Advanced Optimised Link State Routing (ECAO) model. The performance of the proposed ECAO model is compared with the existing Optimised Link State Routing and Advanced Optimised Link State Routing models. From the comparison result, it is clearly observed that the proposed model achieves better performance in terms of number of TC messages, Packet Delivery Ratio, average time, end-to-end delay, and link delay and energy consumption.