一种适合于无线网络的竞争广播算法

广播是无线网络中基本且重要的操作.竞争广播算法是一种基于竞争机制的广播协议算法,适合于移动自组网络.分析和仿真结果表明,与泛洪方案相比,竞争广播算法去除了大量冗余转播,改善了网络的广播性能,提高了网络的吞吐量.另外,竞争广播算法思想还能应用于其他网络协议,如应用于路由协议的路由发现过程,提高路由算法的性能等.     

QoS routing in ad hoc wireless networks

The emergence of nomadic applications have generated much interest in wireless network infrastructures that support real-time communications. We propose a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network. The QoS routing feature is important for a mobile network to interconnect wired networks with QoS support (e.g., ATM, Internet, etc.). The QoS routing protocol can also work in a stand-alone multihop mobile network for real-time applications. This QoS routing protocol contains end-to-end bandwidth calculation and bandwidth allocation. Under such a routing protocol, the source (or the ATM gateway) is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real-time applications. In addition, it enables more efficient call admission control. In the case of ATM interconnection, the bandwidth information can be used to carry out intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit (VC) service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine the system performance in various QoS traffic flows and mobility environments via simulation. Simulation results suggest distinct performance advantages of our protocol that calculates the bandwidth information. It is particularly useful in call admission control. Furthermore, “standby” routing enhances the performance in the mobile environment. Simulation experiments show this improvement     

一种最小误码率约束的动态地理协作路由算法

为了提高无线多跳通信的可靠性,提出一种联合物理层和网络层设计的动态地理协作路由(DGCR)算法,推导计算了单个协作单元协作中继节点的选择区域,在该区域内选择的协作中继节点可以满足误码率要求.最佳中继节点的位置会根据实际协作中继节点的位置和目的节点的位置动态选取.仿真计算表明,该算法相比非协作路由算法和传统地理协作路由算法具有更好的误码率性能,更适用于多径条件下的应用.     

Game theoretic approach in routing protocol for wireless ad hoc networks

This paper introduces a game theoretic method, called forwarding dilemma game (FDG), which controls routing overhead in dense multi-hop wireless ad hoc networks. The players of the game are the wireless nodes with set of strategies {Forward, Not forward}. The game is played whenever an arbitrary node in the network receives a flooding packet. In FDG, every player needs to know the number of players of the game. That is why a neighbor discovery protocol (NDP) is introduced. In order for NDP to function, a field is attached to the flooding packets (routing overhead packets). The mixed strategy Nash equilibrium is used as a solution for the FDG. This provides the probability that the flooding packet would be forwarded by the receiver node. FDG with NDP is implemented in AODV protocol in Network Simulator NS-2 to verify its performance with simulations. FDG with NDP improves performance of the AODV compared to the same network with only AODV protocol in moderate and high node densities. FDG can be applied to any routing protocol that uses flooding in the route discovery phase.     

CRUST: Implementation of clustering and routing functions for mobile ad hoc networks using reactive tuple-spaces

This work builds on the LIME (Linda in mobile environment) tuple space framework to implement a system that offers clustering and routing capabilities for mobile ad hoc network (MANET) environments, and provide an agent-like architecture for running distributed and collaborative applications on mobile devices. This paper describes the components that were added to the LIME system, which were necessary to implement engagement and disengagement of hosts into and out of spaces, and illustrates the developed engagement mechanism and routing protocol with the aid of example scenarios. The paper then discusses the system performance obtained from implementing its functions using the ns-2 network simulation software. The obtained results indicate that the system works reasonably well under different conditions (host transmission range, host mobility, and density of hosts in the network). For instance, the time for a host to join a space is well under one second in sparse spaces and goes up to only two seconds in moderately dense spaces). Moreover, the system offers routing performance that is moderately better than that of ZRP, both in terms of route discovery delay and generated traffic.     

SDR: A Stable Direction-Based Routing for Vehicular Ad Hoc Networks

A stable and reliable routing mechanism for vehicular ad hoc networks (VANETs) is an important step toward the provision of long data transmission applications, such as file sharing and music download. Traditional mobile ad hoc network (MANET) routing protocols are not suitable for VANET because the mobility model and environment of VANET are different from those of traditional MANET. To solve this problem, we proposed a new stable routing algorithm, called stable directional forward routing. The novelty of the proposed routing protocol is its combining direction broadcast and path duration prediction into ad hoc on-demand distance vector routing protocols, which including: (1) Nodes in VANET are grouped based on the position, only nodes in a given direction range participating in the route discovery process to reduce the frequency of flood requests, (2) Route selection is based on the link duration while not the hops or other metrics to increase the path duration, (3) Route discovery is executed before the path expiration in order to decrease the end to end delay. The performance of the new scheme is evaluated through extensive simulations with Qualnet. Simulation results indicate the benefits of the proposed routing strategy in terms of decreasing routing control packet, reducing the number of link-breakage events, improving the packet delivery ratio and decreasing the end-to-end delay.     

A QoS Routing Protocol with Bandwidth Allocation in Multichannel Ad Hoc Networks

Mobile multimedia applications have recently generated much interest in mobile ad hoc networks (MANETs) supporting quality-of-service (QoS) communications. Multiple non-interfering channels are available in 802.11 and 802.15 based wireless networks. Capacity of such channels can be combined to achieve higher QoS performance than for single channel networks. The capacity of MANETs can be substantially increased by equipping each network node with multiple interfaces that can operate on multiple non-overlapping channels. However, new scheduling, channel assignment, and routing protocols are required to utilize the increased bandwidth in multichannel MANETs. In this paper, we propose an on-demand routing protocol M-QoS-AODV in multichannel MANETs that incorporates a distributed channel assignment scheme and routing discovery process to support multimedia communication and to satisfy QoS bandwidth requirement. The proposed channel assignment scheme can efficiently express the channel usage and interference information within a certain range, which reduces interference and enhances channel reuse rate. This cross-layer design approach can significantly improve the performance of multichannel MANETs over existing routing algorithms. Simulation results show that the proposed M-QoS-AODV protocol can effectively increase throughput and reduce delay, as compared to AODV and M-AODV-R protocols.     

New Approaches to Routing in Mobile Ad hoc Networks

Worldwide Interoperability for Microwave Access (Wimax) is power station through which mobile network, commonly known as A Mobile Ad-hoc Network (MANET) is used by the people. A MANET can be described as an infrastructure-less and self-configure network with autonomous nodes. Participated nodes in MANETs move through the network constantly causing frequent topology changes. Designing suitable routing protocols to handle the dynamic topology changes in MANETs can enhance the performance of the network. In this regard, this paper proposes four algorithms for the routing problem in MANETs. First, we propose a new method called Classical Logic-based Routing Algorithm for the routing problem in MANETs. Second is a routing algorithm named Fuzzy Logic-based Routing Algorithm (FLRA). Third, a Reinforcement Learning-based Routing Algorithm is proposed to construct optimal paths in MANETs. Finally, a fuzzy logic-based method is accompanied with reinforcement learning to mitigate existing problems in FLRA. This algorithm is called Reinforcement Learning and Fuzzy Logic-based (RLFLRA) Routing Algorithm. Our proposed approaches can be deployed in dynamic environments and take four important fuzzy variables such as available bandwidth, residual energy, mobility speed, and hop-count into consideration. Simulation results depict that learning process has a great impact on network performance and RLFLRA outperforms other proposed algorithms in terms of throughput, route discovery time, packet delivery ratio, network access delay, and hop-count.

     

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.     

Cooperation of Network and Service Layer in Mobile Ad hoc Networks

In this article, we investigate how a service discovery protocol at the service layer in Mobile Ad Hoc Networks can be improved, by utilizing routing information from the network layer. We consider in this article proactive routing protocols as basis for the underlying routing mechanism, and focus on the optimization of proactive service discovery protocols. First we introduce a general framework, enabling the cooperation of service layer and network layer, and then we propose the optimization scheme. The performance evaluation done by simulation shows that the proposed cooperation scheme can optimize the service discovery protocol, i.e. reduce the communication cost of service discovery, by utilizing routing table and topology information.     

A Cognitive Energy Efficient and Trusted Routing Model for the Security of Wireless Sensor Networks: CEMT

There are many smart applications evolved in the area of the wireless sensor networks. The applications of WSNs are exponentially increasing every year which creates a lot of security challenges that need to be addressed to safeguard the devices in WSN. Due to the dynamic characteristics of these resource constrained devices in WSN, there must be high level security requirements to be considered to create a high secure environments. This paper presents an efficient multi attribute based routing algorithm to provide secure routing of information for WSNs. The work proposed in this paper can decrease the energy and enhances the performance of the network than the currently available routing algorithm such as multi-attribute pheromone ant secure routing algorithm based on reputation value and ant-colony optimization algorithm. The proposed work secures the network environment with the improved detection techniques based on nodes’ higher coincidence rates to find the malicious behavior using trust calculation algorithm. This algorithm uses some QoS parameters such as reliability rate, elapsed time to detect impersonation attacks, and stability rate for trust related attacks, to perform an efficient trust calculation of the nodes in communication. The outcome of the simulation show that the proposed method enhances the performance of the network with the improved detection rate and secure routing service.

     

Ad Hoc 网络中的路由技术

作为下一代网络的重要组成部分,Ad Hoc网是目前的一个重要研究热点。根据Ad Hoc网络的特点,总结了Ad Hoc网中的路由技术。从路由查找和维护的角度分析和归纳了网络中关于单播路由、组播路由和QoS路由等的技术特点,指出了不同协议及算法的设计思路和解决策略,为寻求和设计更为高效的适合自组网特点的新型路由技术奠定基础。     

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.     

Unidirectional link-state advertisement based on power control for MANET

Link states are studied in ad hoc network. The characters of unidirectional links are discussed. Unidirectional link-state advertisement based on power control mechanism (ULAPC) for mobile ad hoc networks (MANET) is designed. ULAPC is able to advertise unidirectional link-state to relational nodes. And it may offer help for process of routing discovery in ad hoc network. Based on ULAPC, the routing method solving the problem of unidirectional link is described in ad hoc network. Simulation results show the performance of ULAPC is better than the traditional routing protocols in many aspects.     

基于PCE的ASON路由技术研究

由因特网工程任务组(IETF)路径计算单元(PCE)工作组定义的基于PCE的多协议标签交换/通用多协议标签交换(MPLS/GMPLS)网络结构能有效解决多层网络中端到端的路径计算问题.文章从自动交换光网络(ASON)路由技术的发展趋势出发,根据有关PCE的RFC文档对PCE的体系结构、发现机制和策略进行了较为系统的说明,重点对PCE在ASON路由中的应用及PCE路径保护和恢复机制进行了阐述,表明PCE技术将成为ASON路由技术的首要选择.     

The Impact of Deployment Pattern and Routing Scheme on the Lifetime in Multi-Sink Wireless Sensor Network

Extensive use of sensor and actuator networks in many real-life applications introduced several new performance metrics at the node and network level. Since wireless sensor nodes have significant battery constraints, therefore, energy efficiency, as well as network lifetime, are among the most significant performance metrics to measure the effectiveness of given network architecture. This work investigates the performance of an event-based data delivery model using a multipath routing scheme for a wireless sensor network with multiple sink nodes. This routing algorithm follows a sink initiated route discovery process with the location information of the source nodes already known to the sink nodes. It also considers communication link costs before making decisions for packet forwarding. Carried out simulation compares the network performance of a wireless sensor network with a single sink, dual sink, and multi sink networking approaches. Based on a series of simulation experiments, the lifetime aware multipath routing approach is found appropriate for increasing the lifetime of sensor nodes significantly when compared to other similar routing schemes. However, energy-efficient packet forwarding is a major concern of this work; other network performance metrics like delay, average packet latency, and packet delivery ratio are also taken into the account.

     

On the interplay of network structure and routing strategies in scale-free networks

In this paper, we examine how the structural characteristics of network topologies affect the network performance, and we examine the interplay between structural characteristics of network topologies and routing strategies. We consider routing strategies subject to practical constraints (router technology) and economic considerations (link costs) at layer 3. We propose two new routing methods suitable for implementation in large networks and examine various routing strategies (local, global, and hybrid) with tunable parameters and explore how they can enhance the network performance. We find that there exists an optimal range of values for the tunable parameters to achieve high network performance which depends on the structural properties of the network topology. We also show that our proposed routing scheme, which requires minimum local information, achieves high network performance.     

QRON: QoS-aware routing in overlay networks

Recently, many overlay applications have emerged in the Internet. Currently, each of these applications requires their proprietary functionality support. A general unified framework may be a desirable alternative to application-specific overlays. We introduce the concept of overlay brokers (OBs). We assume that each autonomous system in the Internet has one or more OBs. These OBs cooperate with each other to form an overlay service network (OSN) and provide overlay service support for overlay applications, such as resource allocation and negotiation, overlay routing, topology discovery, and other functionalities. The scope of our effort is the support of quality-of-service (QoS) in overlay networks. Our primary focus is on the design of QoS-aware routing protocols for overlay networks (QRONs). The goal of QRON is to find a QoS-satisfied overlay path, while trying to balance the overlay traffic among the OBs and the overlay links in the OSN. A subset of OBs, connected by the overlay paths, can form an application specific overlay network for an overlay application. The proposed QRON algorithm adopts a hierarchical methodology that enhances its scalability. We analyze two different types of path selection algorithms. We have simulated the protocols based on the transit-stub topologies produced by GT-ITM. Simulation results show that the proposed algorithms perform well in providing a QoS-aware overlay routing service.     

A reliable energy-efficient pressure-based routing protocol for underwater wireless sensor network

Recently, Underwater Wireless Sensor Networks (UWSNs) has witnessed significant attention from both academia and industries in research and development, due to the growing number of applications for wide range of purposes including commercial, scientific, environmental and military. Some of the major applications include pollution monitoring, tactical surveillance, tsunami warnings and offshore exploration. Efficient communication among sensors in UWSNs is a challenging task due to the harsh environments and peculiar characteristics of UWSNs. Therefore, design of routing protocol for efficient communication among sensors and sink is one of the fundamental research themes in UWSNs. In this context, this paper proposes a location-free Reliable and Energy efficient Pressure-Based Routing (RE-PBR) protocol for UWSNs. RE-PBR considers three parameters including link quality, depth and residual energy for balancing energy consumption and reliable data delivery. Specifically, link quality is estimated using triangle metric method. A light weight information acquisition algorithm is developed for efficient knowledge discovery of the network. Multi-metric data forwarding algorithm is designed based on route cost calculation which utilizes residual energy and link quality. Simulations are carried out in NS-2 with Aqua-Sim package to evaluate the performance of RE-PBR. The performance of the proposed protocol is compared with the stat-of-the-art techniques: DBR and EEDBR. The comprehensive performance evaluation attests the benefit of RE-PBR as compared to the state-of-the-art techniques in terms of network lifetime, energy consumption, end-to-end delay and packet delivery ratio.     

The performance of query control schemes for the zone routingprotocol

We study the performance of route query control mechanisms for the zone routing protocol (ZRP) for ad hoc networks. The ZRP proactively maintains routing information for a local neighborhood (routing zone), while reactively acquiring routes to destinations beyond the routing zone. This hybrid routing approach can be more efficient than traditional routing schemes. However, without proper query control techniques, the ZRP cannot provide the expected reduction in the control traffic. Our proposed query control schemes exploit the structure of the routing zone to provide enhanced detection and prevention of overlapping queries. These techniques can be applied to single- or multiple-channel ad hoc networks to improve both the delay and control traffic performance of ZRP. Our query control mechanisms allow ZRP to provide routes to all accessible network nodes, with less control traffic than purely proactive link state or purely reactive route discovery, and with less delay than conventional flood searching