A Multi-Path QoS Routing Protocol in a Wireless Mobile Ad Hoc Network

A mobile ad hoc network (MANET) is one composed of a set of mobile hosts capable of communicating with each other without the assistance of base stations. This paper considers the QoS (quality-of-service) routing problem in a MANET, which is important for many real-time multimedia applications. We propose an on-demand protocol for searching for a multi-path QoS route from a source host to a destination host in a MANET, where a multi-path is a network with a source and a sink satisfying certain bandwidth requirement. Existing works all try to find a uni-path to the destination. The basic idea is to distribute a number of tickets from the source, which can be further partitioned into subtickets to search for a satisfactory multi-path. Through simulations, we justify that the value of our multi-path protocol is in its flexibility: (i) when the network bandwidth is very limited, it can offer a higher success rate to find a satisfactory QoS route than those protocols which try to find a uni-path, and (ii) when the network bandwidth is sufficient, it can perform almost the same as those protocols which try to find a uni-path (in both routing overhead and success rate).     

GRID: A Fully Location-Aware Routing Protocol for Mobile Ad Hoc Networks

A mobile ad hoc network (MANET) is one consisting of a set of mobile hosts capable of communicating with each other without the assistance of base stations. One prospective direction to assist routing in such an environment is to use location information provided by positioning devices such as global positioning systems (GPS). In this paper, we propose a new routing protocol called GRID, which tries to exploit location information in route discovery, packet relay, and route maintenance. Existing protocols, as compared to ours, are either not location-aware or partially location-aware in that location knowledge is not fully exploited in all these three aspects. One attractive feature of our protocol is its strong route maintenance capability – the intermediate hosts of a route can perform a handoff operation similar to that in cellular systems when it roams away to keep a route alive. This makes routes in the MANET more stable and insensitive to host mobility. Simulation results show that our GRID routing protocol can reduce the probability of route breakage, reduce the number of route discovery packets used, and lengthen routes' lifetime.     

MANET Routing with Provably Low Complexity Through Constant Density Clustering and Route Request Broadcast

As mobile ad hoc networks (MANETs) are emerging as important components in critical and large-scale applications, it is crucial to develop MANET routing mechanisms with provably low complexity. In this paper, we give a tutorial overview of the efficient use of elementary node clustering and route request broadcast mechanisms for low-complexity MANET routing. We explain these mechanisms with illustrative examples and discuss their theoretical performance characteristics. We demonstrate that node clustering with constant density and route request broadcasting with a doubling radius technique over the network of cluster leaders can be employed for MANET routing with theoretically proven low complexity. Moreover, we contrast these efficient elementary clustering and route request broadcast mechanisms with clustering and route information accumulation mechanisms in the widely studied AODV and DSR routing protocols and discuss the implications of these various mechanisms for scalable MANET routing.     

A Two-Tier Heterogeneous Mobile Ad Hoc Network Architecture and Its Load-Balance Routing Problem

The mobile ad hoc network (MANET) has attracted a lot of interest recently. However, most of the existing works have assumed a stand-alone MANET. In this paper, we propose a two-tier, heterogeneous MANET architecture which can support Internet access. The low tier of the network consists of a set of mobile hosts each equipped with a IEEE 802.11 wireless LAN card. In order to connect to the Internet and handle the network partitioning problem, we propose that the high tier is comprised of a subset of the mobile hosts, called gateways, which can access to cellular/infrastructure networks. The high tier is heterogeneous in the sense that the network interfaces in the gateway hosts could be IEEE 802.11 cards, PHS handsets, or GPRS handsets characterized by different bandwidths and latencies. Observing that the gateways could become the bottlenecks of the two-tier network, we propose a set of solutions, namely boundary-moving, host-partitioning, and probabilistic solutions, to solve the load-balance routing issue. Implementation issues/concerns of these schemes are discussed. Simulation results are presented to compare these load-balance routing schemes.     

The Broadcast Storm Problem in a Mobile Ad Hoc Network

Broadcasting is a common operation in a network to resolve many issues. In a mobile ad hoc network (MANET) in particular, due to host mobility, such operations are expected to be executed more frequently (such as finding a route to a particular host, paging a particular host, and sending an alarm signal). Because radio signals are likely to overlap with others in a geographical area, a straightforward broadcasting by flooding is usually very costly and will result in serious redundancy, contention, and collision, to which we call the broadcast storm problem. In this paper, we identify this problem by showing how serious it is through analyses and simulations. We propose several schemes to reduce redundant rebroadcasts and differentiate timing of rebroadcasts to alleviate this problem. Simulation results are presented, which show different levels of improvement over the basic flooding approach.     

An Efficient Multicast Routing Protocol in Wireless Mobile Networks

Providing multicast service to mobile hosts in wireless mobile networking environments is difficult due to frequent changes of mobile host location and group membership. If a conventional multicast routing protocol is used in wireless mobile networks, several problems may be experienced since existing multicast routing protocols assume static hosts when they construct the multicast delivery tree. To overcome the problems, several multicast routing protocols for mobile hosts have been proposed. Although the protocols solve several problems inherent in multicast routing proposals for static hosts, they still have problems such as non-optimal delivery path, datagram duplication, overheads resulting from frequent reconstruction of a multicast tree, etc. In this paper, we summarize these problems of multicast routing protocols and propose an efficient multicast routing protocol based on IEFT mobile IP in wireless mobile networks. The proposed protocol introduces a multicast agent, where a mobile host receives a tunneled multicast datagram from a multicast agent located in a network close to it or directly from the multicast router in the current network. While receiving a tunneled multicast datagram from a remote multicast agent, the local multicast agent may start multicast join process, which makes the multicast delivery route optimal. The proposed protocol reduces data delivery path length and decreases the amount of duplicate copies of multicast datagrams. We examined and compared the performance of the proposed protocol and existing protocols by simulation under various environments and we got an improved performance over the existing proposals.     

Integrated Routing and Storage for Messaging Applications in Mobile Ad Hoc Networks

This paper is motivated by the observation that traditional ad hoc routing protocols are not an adequate solution for messaging applications (e.g., e-mail) in mobile ad hoc networks. Routing in ad hoc mobile networks is challenging mainly because of node mobility – the more rapid the rate of movement, the greater the fraction of bad routes and undelivered messages. For applications that can tolerate delays beyond conventional forwarding delays, we advocate a relay-based approach to be used in conjunction with traditional ad hoc routing protocols. This approach takes advantage of node mobility to disseminate messages to mobile nodes. The result is the Mobile Relay Protocol (MRP), which integrates message routing and storage in the network; the basic idea is that if a route to a destination is unavailable, a node performs a controlled local broadcast (a relay) to its immediate neighbors. In a network with sufficient mobility – precisely the situation when conventional routes are likely to be non-existent or broken – it is quite likely that one of the relay nodes to which the packet has been relayed will encounter a node that has a valid, short (conventional) route to the eventual destination, thereby increasing the likelihood that the message will be successfully delivered. Our simulation results under a variety of node movement models demonstrate that this idea can work well for applications that prefer reliability over latency.     

An On-Demand Routing Protocol with Backtracking for Mobile Ad Hoc Networks

A mobile ad hoc network (MANET) is characterized by multi-hop wireless links and frequent node mobility. Communication between non-neighboring nodes requires a multi-hop routing protocol to establish a route. But, the route often breaks due to mobility. The source must rediscover a new route for delivering the data packets. This wastes the resources that are limited in MANET. In this paper, a new on-demand routing protocol is proposed, named on-demand routing protocol with backtracking (ORB), for multi-hop mobile ad hoc networks. We use the multiple routes and cache data technique to reduce the rediscovery times and overhead. After executing the route discovery phase, we find out a set of nodes, named checkpoint, which has the multiple routes to the destination. When a checkpoint node receives a data packet, it caches this data packet in its buffer within a specific time period. When a node detects a broken route during the data packets delivery or receives an error packet, it will either recover the broken route or reply the error packet to the source. If a node can not forward the data packet to the next node, it replies an error packet to the source. This packet is backtracking to search a checkpoint to redeliver the data packet to the destination along other alternate routes. The main advantage of ORB is to reduce the flooding search times, maybe just delay and cost while a route has broken. The experimental results show that the proposed scheme can increase the performance of delivery but reduce the overhead efficiently comparing with that of AODV based routing protocols. Hua-Wen Tsai received the B.S. degree in Information Management from Chang Jung Christian University, Taiwan, in June 1998 and the M.B.A. degree in Business and Operations Management from Chang Jung Christian University, Taiwan, in June 2001. Since September 2001, he has been working towards the Ph.D. degree and currently is a doctoral candidate in the Department of Computer Science and Information Engineering, National Cheng Kung University, Taiwan. His research interests include wireless communication, ad hoc networks, and sensor networks. Tzung-Shi Chen received the B.S. degree in Computer Science and Information Engineering from Tamkang University, Taiwan, in June 1989 and the Ph.D. degree in Computer Science and Information Engineering from National Central University, Taiwan, in June 1994. He joined the faculty of the Department of Information Management, Chung Jung University, Tainan, Taiwan, as an Associate Professor in June 1996. Since November 2002, he has become a Full Professor at the Department of Information Management, Chung Jung University, Tainan, Taiwan. He was a visiting scholar at the Department of Computer Science, University of Illinois at Urbana-Champaign, USA, from June to September 2001. He was the chairman of the Department of Information Management at Chung Jung University from August 2000 to July 2003. Since August 2004, he has become a Full Professor at the Department of Information and Learning Technology, National University of Tainan, Tainan, Taiwan. Currently, he is the chairman of the Department of Information and Learning Technology, National University of Tainan. He co-received the best paper award of 2001 IEEE ICOIN-15. His current research interests include mobile computing and wireless networks, mobile learning, data mining, and pervasive computing. Dr. Chen is a member of the IEEE Computer Society. Chih-Ping Chu received the B.S. degree in agricultural chemistry from National Chung Hsing University, Taiwan, the M.S. degree in computer science from the University of California, Riverside, and the Ph.D. degree in computer science from Louisiana State University. He is currently a Professor in the Department of Computer Science and Information Engineering of National Cheng Kung University, Taiwan. His current research interests include parallel computing, parallel processing, component-based software development, and internet computing.     

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.     

基于地理定位信息的移动自组网路由协议综述

移动自组网是自组网技术的重要应用领域,其关键技术在于路由协议的设计和选取.分析了移动自组网路由协议的基本设计原则和分类,总结了基于地理定位信息的移动自组网路由协议的发展现状和特点,指明了目前研究的热点方向.最后,对移动自组网的发展方向进行了展望.     

Fault-tolerant routing in adversarial mobile ad hoc networks: an efficient route estimation scheme for non-stationary environments

Designing routing schemes that would successfully operate in the presence of adversarial environments in Mobile Ad Hoc Networks (MANETs) is a challenging issue. In this paper, we discuss fault-tolerant routing schemes operating in a network with malfunctioning nodes. Most existing MANET protocols were postulated considering scenarios where all the mobile nodes in the ad hoc network function properly, and in an idealistic manner. However, adversarial environments are common in MANET environments, and misbehaving nodes certainly degrade the performance of these routing protocols. The need for fault tolerant routing protocols was identified to address routing in adversarial environments in the presence of faulty nodes by exploring redundancy-based strategies in networks. It turns out that since the nodes are mobile, the random variables encountered are non-stationary, implying that estimation methods for stationary variables are inadequate. Consequently, in this paper, we present a new fault-tolerant routing scheme that invokes a stochastic learning-based weak estimation procedure to enhance a route estimation phase, which, in turn, is then incorporated in a route selection phase. We are not aware of any reported method that utilizes non-traditional estimates to achieve the ranking of the possible paths. The scheme, which has been rigorously tested by simulation, has been shown to be superior to the existing algorithms.     

Secure multicast routing protocols in mobile ad‐hoc networks

A mobile ad‐hoc network (MANET) is a collection of autonomous nodes that communicate with each other by forming a multi‐hop radio network. Routing protocols in MANETs define how routes between source and destination nodes are established and maintained. Multicast routing provides a bandwidth‐efficient means for supporting group‐oriented applications. The increasing demand for such applications coupled with the inherent characteristics of MANETs (e.g., lack of infrastructure and node mobility) have made secure multicast routing a crucial yet challenging issue. Recently, several multicast routing protocols (MRP) have been proposed in MANETs. Depending on whether security is built‐in or added, MRP can be classified into two types: secure and security‐enhanced routing protocols, respectively. This paper presents a survey on secure and security‐enhanced MRP along with their security techniques and the types of attacks they can confront. A detailed comparison for the capability of the various routing protocols against some known attacks is also presented and analyzed. Copyright © 2013 John Wiley & Sons, Ltd.     

移动自组网QoS路由协议研究

移动自组网是由一组带有无线收发装置的移动节点组成的一个多跳的临时性的自治系统。随着无线通信中多媒体业务的增加,在移动自组网中提供QoS(Quality of Sevice服务质量)保障具有越来越重要的意义,而QoS路由技术则是其中的核心技术和热点问题。文章指出移动自组网QoS路由的困难,对移动自组网典型QoS路由协议进行了详细的分析与比较,并对几种较新的移动自组网QoS路由协议进行了介绍,末了对移动自组网QoS路由协议的发展进行了展望。     

Location aided probabilistic broadcast algorithm for mobile Ad-hoc network routing

On-demand routing protocols are widely used in mobile Ad-hoc network (MANET). Flooding is an important dissemination scheme in routing discovering of on-demand routing protocol. However, in high-density MANET redundancy flooding packets lead to dramatic deterioration of the performance which calls broadcast storm problem (BSP). A location-aided probabilistic broadcast (LAPB) algorithm for routing in MANET is proposed to reduce the number of routing packets produced by flooding in this paper. In order to reduce the redundancy packets, only nodes in a specific area have the probability, computed by location information and neighbor knowledge, to propagate the routing packets. Simulation results demonstrate that the LAPB algorithm can reduce the packets and discovery delay (DD) in the routing discovery phase.     

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.     

一种不可信环境下的匿名位置辅助路由激励机制

不可信环境下的路由性能问题,是移动自组织网(mobile ad-hoc networks,MANET)匿名路由协议面临的主要问题之一.本文为在不可信环境下通过对自私节点进行高效的协作激励,提高匿名路由协议的性能,提出了一种基于哈希链的匿名位置辅助路由激励机制.该机制利用哈希链在计算上的高效性和安全上的不可逆性,达成了对匿名数据转发节点的即时激励;通过基于支付代价的路由选择机制,优化了现有位置辅助路由机制的路由发现过程.匿名性分析证明,该机制能保证参与路由节点的匿名性.效率评价表明,在数据传输总量较大时,该机制对路由性能的影响很小,且该机制在较小规模的网络中有更好的性能.     

Bypass routing: An on-demand local recovery protocol for ad hoc networks

On-demand routing protocols for ad hoc networks reduce the cost of routing in high mobility environments. However, route discovery in on-demand routing is typically performed via network-wide flooding, which consumes a substantial amount of bandwidth. In this paper, we present bypass routing, a local recovery protocol that aims to reduce the frequency of route request floods triggered by broken routes. Specifically, when a broken link is detected, a node patches the affected route using local information, which is acquired on-demand, and thereby bypasses the broken link. We implemented SLR (Source Routing with Local Recovery) as a prototype of our approach. Simulation studies show that SLR achieves efficient and effective local recovery while maintaining acceptable overhead.     

MERIT: A Scalable Approach for Protocol Assessment

MERIT is a framework that can be used to assess routing protocols in mobile ad hoc networks (manets). It uses the novel concept of a shortest mobile path (SMP) in a mobile graph, a generalization of the shortest path problem for mobile environments. As a measure for routing protocol assessment, we propose the mean ratio of the cost of the route used by a protocol to the cost of the optimal mobile path for the same network history. The cost reflects that the route used in a session can change over time because of network dynamics such as topology changes. The aim is for the ratio to be an abstract, inherent measure of the protocol that is as implementation-independent as possible. The MERIT spectrum, which is the ratio expressed as the function of some parameters of interest, is a characterization of protocol effectiveness. MERIT, for MEan Real vs. Ideal cosT, provides a scalable assessment framework: rather than comparing performance measures of different protocols directly, we compare a protocol to the optimal solution. That is, rather than forcing the comparison to be in the same system, it is done once for each protocol in its own environment. Furthermore, we show that there is an efficient algorithm to solve the underlying SMP problem for important cases, making the approach practically feasible. We also investigate generalizations of and extensions within the MERIT framework. We show that the MERIT framework is rich, with much wider generality and potential applicability than assessing routing protocols.     

Cross‐layer design for topology control and routing in MANETs

A mobile ad hoc network (MANET) is a self‐organized and adaptive wireless network formed by dynamically gathering mobile nodes. Since the topology of the network is constantly changing, the issue of routing packets and energy conservation become challenging tasks. In this paper, we propose a cross‐layer design that jointly considers routing and topology control taking mobility and interference into account for MANETs. We called the proposed protocol as Mobility‐aware Routing and Interference‐aware Topology control (MRIT) protocol. The main objective of the proposed protocol is to increase the network lifetime, reduce energy consumption, and find stable end‐to‐end routes for MANETs. We evaluate the performance of the proposed protocol by comprehensively simulating a set of random MANET environments. The results show that the proposed protocol reduces energy consumption rate, end‐to‐end delay, interference while preserving throughput and network connectivity. Copyright © 2010 John Wiley & Sons, Ltd.     

An efficient MAC protocol for multi‐channel mobile ad hoc networks based on location information

This paper considers the channel assignment problem in a multi‐channel MANET environment. We propose a scheme called GRID, by which a mobile host can easily determine which channel to use based on its current location. In fact, following the GSM style, our GRID spends no communication cost to allocate channels to mobile hosts since channel assignment is purely determined by hosts' physical locations. We show that this can improve the channel reuse ratio. We then propose a multi‐channel MAC protocol, which integrates GRID. Our protocol is characterized by the following features: (i) it follows an ‘on‐demand’ style to access the medium and thus a mobile host will occupy a channel only when necessary, (ii) the number of channels required is independent of the network topology, and (iii) no form of clock synchronization is required. On the other hand, most existing protocols assign channels to a host statically even if it has no intention to transmit [IEEE/ACM Trans. Networks 1995; 3 (4):441–449; 1993; 1 (6): 668–677; IEEE J. Selected Areas Commun. 1999; 17 (8):1345–1352], require a number of channels which is a function of the maximum connectivity [IEEE/ACM Trans. Networks 1995; 3 (4):441–449; 1993; 1 (6): 668–677; Proceedings of IEEE MILCOM'97, November 1997; IEEE J. Selected Areas Commun. 1999; 17 (8):1345–1352], or necessitate a clock synchronization among all hosts in the MANET [IEEE J. Selected Areas Commun. 1999; 17 (8):1345–1352; Proceedings of IEEE INFOCOM'99, October 1999]. Through simulations, we demonstrate the advantages of our protocol. Copyright © 2005 John Wiley & Sons, Ltd.