Multicast Routing in Mobile Ad Hoc Networks

We focus on one critical issue in mobile ad hoc networks that is multicast routing. Advantages and limitations of existing routing protocols are illustrated. Optimal routes, stable links, power conservation, loop freedom, and reduced channel overhead are the main features to be addressed in a more efficient mechanism. In this paper, we propose a new on-demand multicast routing protocol, named Source Routing-based Multicast Protocol (SRMP). Our proposition addresses two important issues in solving routing problems: (i) path availability concept, and (ii) higher battery life paths. SRMP applies a source routing mechanism, and constructs a mesh to connect group members. It provides stable paths based on links' availability according to future prediction of links' states, and higher battery life paths. This protocol succeeded to minimize network load via designing optimal routes that guarantee reliable transmission and active adaptability. A performance comparison study with On-demand Multicast Routing Protocol (ODMRP) and Adaptive Demand-driven Multicast Routing (ADMR) protocol is undertaken. Analysis results show the strength of the SRMP nodes' selection criteria and its efficient energy consumption compared to the other two protocols.     

Delay Aware and Load Balanced Multi-Path Routing in Wireless Sensor Networks

In wireless sensor networks, a multi-path routing based data gathering algorithm should consider the number of paths and the way to select these paths. The data transfer through these multiple paths should be performed in a load balanced way. There should be some detection technique for routing failures. In this paper, we propose to design a load balanced delay aware multi-path routing. It contains three phases: the multi-path construction phase, Data aggregation phase and the Data transmission phase. The sink calculates the inter-arrival delay and new data sending rate for all the paths and this information is sent as a feedback to the source such that the paths with minimum delay are chosen and the packets are distributed through these paths according to their new data sending rates. By our simulation results we show that our objectives are achieved through this method and so the multi-path routing has been enhanced.     

Increasing the network performance using multi-path routing mechanism with load balance

Research on multi-path routing protocols to provide improved throughput and route resilience as compared with single-path routing has been explored in details in the context of wired networks. However, multi-path routing mechanisms have not been explored thoroughly in the domain of ad hoc networks. In this paper, we propose a new routing protocol which increases the network throughput. The protocol is a multi-path routing protocol with a load balance policy. The simulations show a significant improvement in terms of connection throughput and end-to-end delay, when compared to single-path routing. The second significant contribution of this paper is a theoretical analysis allowing to compare reactive single-path and multi-path routing with load balance mechanisms in ad hoc networks, in terms of overheads, traffic distribution and connection throughput. The results reveal that multi-path routing (using a load balance policy) provides better performance than reactive single-path routing in terms of congestion and connection throughput, provided that the average route length is smaller than certain upper bounds which are derived and depend on parameters specific to the network. These upper bounds are very crucial because they can be taken into account as constraints in the route discovery mechanism so that the multi-path routing protocol is guaranteed to lead to an increase performance than a simple single-path one. Also, our analysis provide some insight into choosing the right trade-off between increased overheads and better performance. We show in particular that for certain networks, a multi-path routing strategy is not worth considering.     

Load balancing geographic routing strategy for aeronautical ad hoc networks

In aeronautical ad hoc networks, the traditional greedy perimeter stateless routing (GPSR) protocol poses sev-eral issues. For example, it is difficult to adapt to the highly-dynamic network environment, and it is prone to cause con-gestions. In order to address the problems, a TTE (time to enter the communication range of the destination)-based load balancing geographic routing (LBGR) protocol was presented. Taking TTE as the main routing decision metrics, this pro-tocol included the TTE-based packet forwarding scheme, multi-path traffic allocation scheme, and local optimum han-dling scheme. Furthermore, the multi-path traffic allocation scheme employing the queueing theory was modeled, and the mathematical expressions of some metrics were derived, such as the mean queue size, mean number of packets waiting in the queue, and mean waiting time. Finally, the analysis of the OMNeT++ simulations shows LBGR protocol has advan-tages over GPSR and some other protocols in terms of the packet delivery ratio and end-to-end delay, and is more suitable for the highly-dynamic aeronautical environment.     

分布式认知无线电网络多路径路由协议研究综述

为了深入研究分布式认知无线电网络的多路径路由问题,阐述了分布式认知无线电网络基本特征以及多路径路由设计面临的问题与挑战。分布式认知无线电网络多路径路由采用多路径并行传输,可有效降低传输时延、增加网络吞吐量与传输可靠性、实现网络负载均衡。根据路由优化目标不同,从吞吐量、带宽、干扰、时延、负载均衡和路由发现六方面对近年来多路径路由协议的主要研究成果进行了分类,然后逐类对多路径路由协议进行了分析和讨论,最后分别从分布式认知无线电网络基本特征的适应性与多路径路由协议特征两个方面进行了比较,并展望了分布式认知无线电网络多路径路由协议需进一步研究的方向。     

A Priority Based Opportunistic Routing Mechanism for Real-Time Voice Service in Mobile Ad hoc Networks

Traditional routing protocols send traffic along pre-determined paths and have been shown ineffective in coping with unreliable and unpredictable wireless medium which is caused by the multi-path fading. The most difference between the opportunistic routing and the traditional routing mechanism is that the opportunistic routing mechanism can use several lossy broadcast links to support reliable transmission. In this paper, an opportunistic routing mechanism for real-time voice service is proposed. This mechanism is based on the dynamic source routing (DSR) protocol with some modifications, the routing messages of DSR are used to construct the forwarder list, which guides the data packets forwarding process. The forwarder nodes have priorities to restrict the number of duplicated packets. Simultaneous flows can be supported well by our mechanism. Simulations show that our mechanism can effectively decrease the data packets transmission times and the amount of the control messages and reduce the end-to-end delay for real-time voice service, the quality of service can be supported well over the unstable wireless channel.     

An Evaluation of Shared Multicast Trees with Multiple Cores

Native multicast routing protocols have been built and deployed using two basic types of trees: single-source, shortest-path trees and shared, core-based trees. Core-based multicast trees use less routing state compared to shortest-path trees, but generally have higher end-to-end delay and poor fault tolerance. In this paper we consider a new type of shared multicast structure that uses multiple, independent, simultaneously-active cores. Our design provides for low end-to-end delay, improved fault tolerance, and low source discovery delay, while balancing bandwidth cost and routing state. These results indicate that shared trees with multiple active cores are a viable alternative to shortest-path trees.     

Multi-Path Routing Protocol with Unavailable Areas Identification in Wireless Sensor Networks

In wireless sensor networks, some areas often become unavailable due to the exhaustion of nodes’ energy, congestion, or disaster. In this paper, we propose a new micro sensor multi-path routing protocol (MSMRP) to avoid the unavailable areas when constructing the routes. A neighbor node table exchanging mechanism in MSMRP is used to avoid the multiple paths intersect and to build a new route around the unavailable areas. We have implemented the proposed protocol in a network with real sensor nodes and conducted experiments to demonstrate the operation and the capability of the MSMRP. Furthermore, we illustrate the performance of MSMRP comparing to ad hoc on demand multi-path distance vector (AOMDV) routing protocol with NS-2 simulations.     

End-to-End Link Reliable Energy Efficient Multipath Routing for Mobile Ad Hoc Networks

Among the many multipath routing protocols, the AOMDV is widely used in highly dynamic ad hoc networks because of its generic feature. Since the communicating nodes in AOMDV are prone to link failures and route breaks due to the selection of multiple routes between any source and destination pair based on minimal hop count which does not ensure end-to-end reliable data transmission. To overcome such problems, we propose a novel node disjoint multipath routing protocol called End-to-End Link Reliable Energy Efficient Multipath Routing (E2E-LREEMR) protocol by extending AOMDV. The E2E-LREEMR finds multiple link reliable energy efficient paths between any source and destination pair for data transmission using two metrics such as Path-Link Quality Estimator and Path-Node Energy Estimator. We evaluate the performance of E2E-LREEMR protocol using NS 2.34 with varying network flows under random way-point mobility model and compare it with AOMDV routing protocol in terms of Quality of Service metrics. When there is a hike in network flows, the E2E-LREEMR reduces 30.43 % of average end-to-end delay, 29.44 % of routing overhead, 32.65 % of packet loss ratio, 18.79 % of normalized routing overhead and 12.87 % of energy consumption. It also increases rather 10.26 % of packet delivery ratio and 6.96 % of throughput than AOMDV routing protocol.     

Robust multi-path routing for dynamic topology in wireless sensor networks

Wireless sensor networks are being widely researched and are expected to be used in several scenarios. On the leading edge of treads, on-demand, high-reliability, and low-latency routing protocol is desirable for indoor environment applications. This article proposes a routing scheme called robust multi-path routing that establishes and uses multiple node-disjoint routes. Providing multiple routes helps to reduce the route recovery process and control the message overhead. The performance comparison of this protocol with dynamic source routing (DSR) by OPNET simulations shows that this protocol is able to achieve a remarkable improvement in the packet delivery ratio and average end-to-end delay.     

An algebraic theory of dynamic network routing

We develop a non-classic algebraic theory for the purpose of investigating the convergence properties of dynamic routing protocols. The algebraic theory can be regarded as a generalization of shortest-path routing, where the new concept of free cycle generalizes that of a positive-length cycle. A primary result then states that routing protocols always converge, though not necessarily onto optimal paths, in networks where all cycles are free. Monotonicity and isotonicity are two algebraic properties that strengthen convergence results. Monotonicity implies protocol convergence in every network, and isotonicity assures convergence onto optimal paths. A great many applications arise as particular instances of the algebraic theory. In intra-domain routing, we show that routing protocols can be made to converge to shortest and widest paths, for example, but that the composite metric of Internet Gateway Routing Protocol (IGRP) does not lead to optimal paths. The more interesting applications, however, relate to inter-domain routing and its Border Gateway Protocol (BGP), where the algebraic framework provides a mathematical template for the specification, design, and verification of routing policies. We formulate existing guidelines for inter-domain routing in algebraic terms, propose new guidelines contemplating backup relationships between domains, and derive a sufficient condition for signaling correctness of internal-BGP.     

A Shoelace-Based QoS Routing Protocol for Mobile Ad Hoc Networks Using Directional Antenna

In this paper, we propose a new quality-of-service (QoS) routing protocol for mobile ad hoc network (MANET) using directional antennas. The proposed scheme offers a bandwidth-based routing protocol for QoS support in MANET using the concept of multi-path. Our MAC sub-layer adopts the CDMA-over-TDMA channel model. The on-demand QoS routing protocol calculates the end-to-end bandwidth and allocates bandwidth from the source node to the destination node. The paths are combined with multiple cross links, called shoelace, when the network bandwidth is strictly limited. Due to the property of the directional antenna, these cross links can transmit data simultaneously without any data interference. We develop a shoelace-based on-demand QoS routing protocol by identifying shoelaces in a MANET so as to construct a QoS route, which satisfied the bandwidth requirement, more easily. The shoelace-based route from the source to the destination is a route whose sub-path is constructed by shoelace structure. With the identified shoelaces, our shoelace-based scheme offers a higher success rate to construct a QoS route. Finally, simulation results demonstrate that the proposed routing protocol outperform existing QoS routing protocols in terms of success rate, throughput, and average latency.     

Load-balancing in MANET shortest-path routing protocols

Mobile ad hoc networks (MANET) are infrastructure-less networks, dynamically formed by an independent system of mobile nodes that are connected via wireless links. Because routing is performed by nodes with limited resources, load should be efficiently distributed through the network. Otherwise, heavily-loaded nodes may make up a bottleneck that lowers the network performances by congestion and larger delays. Regrettably, load-balancing is a critical deficiency in MANET shortest-path routing protocols, as nodes at the center of the network are much heavily-loaded than the others. Thus, we propose, in this paper, load-balancing mechanisms that push the traffic further from the center of the network. Basically, we provide novel routing metrics that take into account nodes degree of centrality, for both proactive and reactive routing protocols. Simulations show that the proposed mechanisms improve the load distribution and significantly enhance the network performances in terms of average delay and reliability.     

ARMR: Anonymous routing protocol with multiple routes for communications in mobile ad hoc networks

A mobile ad hoc network consists of mobile nodes that communicate in an open wireless medium. Adversaries can launch analysis against the routing information embedded in the routing message and data packets to detect the traffic pattern of the communications, thereby obtaining sensitive information of the system, such as the identity of a critical node. In order to thwart such attacks, anonymous routing protocols are developed. For the purposes of security and robustness, an ideal anonymous routing protocol should hide the identities of the nodes in the route, in particular, those of the source and the destination. Multiple routes should be established to increase the difficulty of traffic analysis and to avoid broken paths due to node mobility. Existing schemes either make the unrealistic and undesired assumption that certain topological information about the network is known to the nodes, or cannot achieve all the properties described in the above. In this paper, we propose an anonymous routing protocol with multiple routes called ARMR, which can satisfy all the required properties. In addition, the protocol has the flexibility of creating fake routes to confuse the adversaries, thus increasing the level of anonymity. In terms of communication efficiency, extensive simulation is carried out. Compared with AODV and MASK, our ARMR protocol gives a higher route request success rate under all situations and the delay of our protocol is comparable to the best of these two protocols.     

QoS routing through alternate paths in wireless ad hoc networks

Quality of service (QoS) routing plays an important role in QoS provisioning for mobile ad hoc networks. This work studies the issue of route selection subject to QoS constraint(s). Our method searches for alternate routes with satisfied QoS requirement(s) to accommodate each communication request when the shortest path connecting the source–destination pair of the request is not qualified. In order to effectively reduce protocol overhead, a directed search mechanism is designed to limit the breadth of the searching scope, which aims at achieving a graceful tradeoff between the success probability in QoS route acquisition and communication overhead. Efficient hop‐by‐hop routing protocols are designed for route selection subject to delay and bandwidth constraint, respectively. Simulation results show that the designed protocols can achieve high performance in acquiring QoS paths and in efficient resource utilization with low control overhead. Copyright © 2004 John Wiley & Sons, Ltd.     

An adaptive‐aware energy and queue improvement of AOMDV

Because the node energy and network resources in the wireless sensor network (WSN) are very finite, it is necessary to distribute data traffic reasonably and achieve network load balancing. Ad hoc on‐demand multipath distance vector (AOMDV) is a widely used routing protocol in WSN, but it has some deficiencies: establishes the route by only using hop counts as the routing criterion without considering other factors such as energy consumption and network load; forwards route request in fixed delay resulting in building the nonoptimal path; and cannot update the path status after built paths. For the deficiency of AOMDV, this paper proposes a multipath routing protocol adaptive energy and queue AOMDV (AEQAOMDV) based on adaptively sensing node residual energy and buffer queue length. When sending a routing request, the forwarding delay of the routing request is adaptively adjusted by both the residual energy and the queue length of the intermediate node; when establishing routes, a fitness is defined as a routing criterion according to the link energy and the queue load, predicting the available duration of the node based on the energy consumption rate and adjusting the weight of the routing criterion by the available duration of the node; after the routes are established, the path information status are updated via periodically broadcasting Hello that carries the path information with the minimum fitness, making the source node update the path information periodically. By using NS‐2, simulations demonstrate that compared with AOMDV, AEQAOMDV has obvious improvements in increasing packet delivery ratio, reducing network routing overhead, reducing route discovery frequency, and decreasing the network delay. And AEQAOMDV is more suitable for WSN.     

Adaptive energy aware cluster-based routing protocol for wireless sensor networks

Wireless sensor networks (WSNs) have grown excessively due to their various applications and low installation cost. In WSN, the main concern is to reduce energy consumption among nodes while maintaining timely and reliable data forwarding. However, most of the existing energy aware routing protocols incur unbalanced energy consumption, which results in inefficient load balancing and compromised network lifetime. Therefore, the main target of this research paper is to present adaptive energy aware cluster-based routing (AECR) protocol for improving energy conservation and data delivery performance. Our proposed AECR protocol differs from other energy efficient routing schemes in some aspects. Firstly, it generates balance sized clusters based on nodes distribution and avoids random clusters formation. Secondly, it optimizes both intra-cluster and inter-cluster routing paths for improving data delivery performance while balancing data traffic on constructed forwarding routes and at the end, in order to reduce the excessive energy consumption and improving load distribution, the role of Cluster Head (CH) is shifted dynamically among nodes by exploit of network conditions. Simulation results demonstrate that AECR protocol outperforms state of the art in terms of various performance metrics.

     

A fast and reliable routing technique for wireless mesh networks

In wireless mesh networks (WMNs), real time communications (e.g., Voice over IP (VoIP) and interactive video communications) may often be interrupted as packets are frequently lost or delayed excessively. This usually happens due to the unreliability of wireless links or buffer overflows along the routing paths. The mesh connectivity within the WMN enables the capability to enhance reliability and reduce delay for such applications by using multiple paths for routing their packets. The vital components in multi‐path routing for achieving this are the pre‐determined formation of paths and the technique that the paths are deployed for packet traversal. Therefore, we propose a novel multi‐path routing protocol by introducing a new multi‐path organization and a traffic assignment technique. The designed technique dubbed as FLASH (Fast and reLiAble meSH routing protocol) discovers one primary path between a pair of source and destination based on a new proposed metric, and thereafter selects mini‐paths, which connect pairs of intermediate nodes along the primary path. The primary path and mini‐paths are concurrently deployed, as multiple copies of packets are routed through. This technique compensates for possible outage at intermediate wireless nodes or their corresponding wireless links along the primary path. Routing along mini‐paths is performed in such a way that redundant copies do not cause an excessive congestion on the network. The effectiveness of the proposed scheme is evaluated analytically and through extensive simulations under various load conditions. The results demonstrate the superiority of the proposed multi‐path organization in terms of reliability and satisfactory achievements of the protocol in enhancing delay and throughput compared to the existing routing protocols, especially for long distances and in congested conditions. Copyright © 2010 John Wiley & Sons, Ltd.     

SMORT: Scalable multipath on-demand routing for mobile ad hoc networks

Increasing popularity and availability of portable wireless devices, which constitute mobile ad hoc networks, calls for scalable ad hoc routing protocols. On-demand routing protocols adapt well with dynamic topologies of ad hoc networks, because of their lower control overhead and quick response to route breaks. But, as the size of the network increases, these protocols cease to perform due to large routing overhead generated while repairing route breaks. We propose a multipath on-demand routing protocol (SMORT), which reduces the routing overhead incurred in recovering from route breaks, by using secondary paths. SMORT computes fail-safe multiple paths, which provide all the intermediate nodes on the primary path with multiple routes (if exists) to destination. Exhaustive simulations using GloMoSim with large networks (2000 nodes) confirm that SMORT is scalable, and performs better even at higher mobility and traffic loads, when compared to the disjoint multipath routing protocol (DMRP) and ad hoc on-demand distance vector (AODV) routing protocol.     

Reliable and energy aware query-driven routing protocol for wireless sensor networks

Wireless sensor networks become very attractive in the research community, due to their applications in diverse fields such as military tracking, civilian applications and medical research, and more generally in systems of systems. Routing is an important issue in wireless sensor networks due to the use of computationally and resource limited sensor nodes. Any routing protocol designed for use in wireless sensor networks should be energy efficient and should increase the network lifetime. In this paper, we propose an efficient and highly reliable query-driven routing protocol for wireless sensor networks. Our protocol provides the best theoretical energy aware routes to reach any node in the network and routes the request and reply packets with a lightweight overhead. We perform an overall evaluation of our protocol through simulations with comparison to other routing protocols. The results demonstrate the efficiency of our protocol in terms of energy consumption, load balancing of routes, and network lifetime.