空中异构战术网络IP通信架构及协议开销分析

空中异构战术无线网络由多种不同类型的无线数据链网络构成，IP通信技术可有效解决空中平台异构无线网络的互联互通问题。给出了空中异构战术无线网络模型，并根据不同类型的无线数据链网络特点，分析了端到端通信协议栈关系以及不同无线数据链网络间协议转换与适配方式。探讨了网络静态和动态IP地址分配方法以及网络的路由架构与寻址方式，提出了不同无线数据链网络间IP报文传输的打包方式。对传输的开销性能仿真对比分析表明，基于通用成帧协议的打包方式的协议开销性能较优。     

基于LSTM模型的动态转发路由协议

文中将容忍延迟网络(Delay Tolerant Network,DTN)应用于船舶通信,提出了一种基于长短时记忆网络(Long Short-Term Memory,LSTM)模型的动态转发路由协议LSTM-DRA(Dynamic Distribution Routing Algorithm Based on LSTM Model),该协议通过比较相遇船舶的预计行驶轨迹来为消息选择最优的中继节点,并使用多副本的策略实现消息的动态转发。同时,采取了拥塞控制策略,以降低网络拥塞。仿真结果表明,LSTM-DRA在提高送达率和降低路由开销等方面具有较高的性能,可实现可靠、低成本的消息传输。     

MTAODV:一种新的高速公路场景下VANET路由协议

在高速公路场景中,针对车辆间通信特性,在AODV的基础上提出了一种基于应用消息类型的改进路由协议(MTAODV).其核心思想是在路由建立过程中充分考虑VANET中应用消息的类型,从而减小路由请求洪泛范围,降低网络开销.仿真实验结果表明,与AODV协议相比,MTAODV协议能够有效地提高分组递交率,降低了路由开销,改善了分组时延和抖动.     

一种增加时限和延迟的AODV协议改进方法

AODV协议是目前比较成熟的应用于移动自组网(MANET)中的一种反应式路由协议,其缺点主要是协议开销比较大,运动情况下路由优化性能不理想。利用为RREQ消息设置时限和为中间节点根据自身队长设置回复RREP消息延迟的方法,提出了一种改进的AODV协议(AODV-DL),有效地提高了网络的投包率和路由优化性能,降低了网络的协议开销。提出了将路由优化性能作为协议的一项新的评价标准。描述了其实现策略,并给出了NS2下的仿真结果。     

基于节点行为的机会网络路由协议

高移动性、频繁中断、稀疏链接、没有基础设施和有限的资源被认为是机会网络的特点。在这样的网络中路由是最大的挑战,在此提出了一个新的基于节点行为的机会网络路由协议(OPNB),用节点的行为信息预测节点在网络中的移动,为消息路由到目标节点发现和选择更好的下一跳节点。协议还集成了对接收消息的确认,有助于中间节点的缓存管理。通过与epidemic路由协议和Probabilistic路由协议比较,OPNB协议在消息的交付数量、开销比率、平均延迟和缓存时间方面的表现相当不错。     

Ad—Hoc网络中广播技术的可扩展性分析

Ad—Hoc无线网络中，通过1-跳邻点的周期性更新或使用反应式路由协议来发现路由。尽管反应式路由协议减少了路由开销，但传统的泛洪（flooding）方式在路由发现过程期间常传播路由请求（RREQ）消息，时延较大。除了开销问题，通过网络传播础砸Q还在其他方面影响着网络的性能。提出了三种可扩展的RREQ广播技术，即加权式p-坚持方法、时隙式1-坚持方法和时隙式p-坚持方法。当路由接受延迟与传统的flooding方式接近或相当时，这些方法可减少75％的路由开销。     

一种适合于移动Ad Hoc网络的路由协议WPRP

针对无线Ad Hoc网络特点,提出了一种无线路径发现路由协议(Wireless Path Finding Routing Protocol,WPRP)。对WPRP协议进行了简要概述,分别介绍了采用最短路径算法(Short Path Algorithm,SPA)查找最短路径;递归环路检测算法(Recursive Loop Check Algorithm,RLCA)消除路由环路;路由校验实现节点间路由同步;自适应时间调节机制进一步减少网络冲突、降低网络开销等方法以及实现过程。OPNET仿真结果表明,与OLSR协议相比,WPRP具有较小的路由开销和较快的收敛速度,是一种动态路由协议,适用于无线Ad Hoc网络。     

一种无线自组织网络动态路由协议

介绍了一种基于稀疏树的无线自组织网络动态路由协议,该协议采用了稀疏树路径生成算法来减少路由更新的数据量并减少网络链路的冗余,采用增量更新来降低路由协议开销并降低对传输带宽的占用,支持单向信道,采用快速路径查找算法消除网络拓扑动态变化过程中的环路与无穷计数问题。仿真结果显示它具有收敛快,开销小等特性,能够较好地适应窄带无线通信环境的需要。     

Ad hoc网络路由协议的仿真及研究

Adhoc网络是一种由节点任意移动、拓扑结构动态、随机且快速变化的自组网。由于其复杂性和多样性,常规路由无法传输信息。所以自组网路由协议一直是无线网络研究中的热点之一。本文对Adhoc网络目前常用的路由协议在OPNET平台上进行了仿真,通过比较和研究网络吞吐量,延时和路由开销等性能参数分析出各路由协议适应的网络环境。     

一种能量平衡的无线体域网络AODV多播路由发现协议

在动态网络拓扑中,AODV协议通过数据源节点S泛洪广播RREQ消息请求到任意目标节点D的路由,而在无线体域网络中,只有一个sink目标节点,除最短跳数路由上的节点外,其他参与RREQ接收和转发的节点浪费了能量。提出了一种能量平衡的无线体域网络AODV多播路由发现协议,通过在节点广播的hello消息中增加到sink的最小跳数hops、到sink的下一跳节点next和节点本身是否具备转发能力isforward 3 个参数,只选择能到达sink节点的邻居节点参与转发RREQ消息,变广播为多播,有效地降低了路由发现的能量开销,并通过能量平衡延长了WBAN的使用寿命。性能分析与模拟实验表明,该协议在RREQ数量、数据传输率和能量消耗等方面优于相似协议EAAODV。     

An efficient algorithm for backbone construction in cognitive radio networks

Numerous research articles exist for backbone formation in wireless networks; however, they cannot be applied straightforward in cognitive radio network (CRN) due to its peculiar characteristics. Since virtual backbone has many advantages such as reduced routing overhead, dynamic maintenance, and fast convergence speed, we intend to propose a backbone formation protocol in CRN. In this paper, we propose a tree‐based backbone formation protocol along with its maintenance. Our protocol is based on non‐iterative approach, thus leading towards limited message overhead and faster convergence speed. The proposed algorithm first forms the tree by maintaining the parent‐child relationship, and second, the parent nodes are connected together to form the virtual backbone. In the end, we evaluate the performance our protocol through extensive simulations.     

Bayesian inference approach for establishing efficient routes in wireless ad-hoc networks

Mobile ad hoc networks (MANETs) are dynamic wireless networks that have no fixed infrastructures and do not require predefined configurations. In this infrastructure-less paradigm, nodes in addition of being hosts, they also act as relays and forward data packets for other nodes in the network. Due to limited resources in MANETs such as bandwidth and power, the performance of the routing protocol plays a significant role. A routing protocol in MATET should not introduce excessive control messages to the network in order to save network bandwidth and nodes power. In this paper, we propose a probabilistic approach based on Bayesian inference to enable efficient routing in MANETs. Nodes in the proposed approach utilize the broadcast nature of the wireless channel to observe the network topology by overhearing wireless transmissions at neighboring nodes in a distributed manner, and learn from these observations when taking packet forwarding decision on the IP network layer. Our simulation results show that our routing approach reduces the number of control message (routing overhead) by a ratio up to 20 % when the network size is 60 nodes, while maintaining similar average route establishment delay as compared to the ad-hoc on demand routing protocol.     

Integrated Social and QoS Trust-Based Routing in Delay Tolerant Networks

We propose and analyze a class of integrated social and quality of service (QoS) trust-based routing protocols in mobile ad-hoc delay tolerant networks. The underlying idea is to incorporate trust evaluation in the routing protocol, considering not only QoS trust properties but also social trust properties to evaluate other nodes encountered. We prove that our protocol is resilient against bad-mouthing, good-mouthing and whitewashing attacks performed by malicious nodes. By utilizing a stochastic Petri net model describing a delay tolerant network consisting of heterogeneous mobile nodes with vastly different social and networking behaviors, we analyze the performance characteristics of trust-based routing protocols in terms of message delivery ratio, message delay, and message overhead against connectivity-based, epidemic and PROPHET routing protocols. The results indicate that our trust-based routing protocols outperform PROPHET and can approach the ideal performance obtainable by epidemic routing in delivery ratio and message delay, without incurring high message overhead. Further, integrated social and QoS trust-based protocols can effectively trade off message delay for a significant gain in message delivery ratio and message overhead over traditional connectivity-based routing protocols.     

Information Theoretic Analysis of Proactive Routing Overhead in Mobile Ad Hoc Networks

This paper considers basic bounds on the overhead of link-state protocols in mobile ad hoc networks. Hierarchical protocols are known for their good scalability properties, and hence this paper considers a two-level hierarchical protocol. In such protocols, nodes need to keep track of shortest path information, link states and cluster membership. Two types of overheads are considered; the memory needed to store routing-related information, including link-states and cluster membership, and the control messages that need to be exchanged to keep track of the changes in the network. Memory overhead is important practically for dimensioning network nodes, while message routing overhead is important since it reduces the effective capacity of the network to carry user data (vis-a-vis control data). The scalability properties of the message routing overhead are analyzed for different modes of network scaling. Practical implications, such as optimal cluster size, average/fixed memory requirement and routing protocol parameter selections are discussed.     

Unified routing protocol based on passive bandwidth measurement in heterogeneous WMNs

The past few years have witnessed a surge of wireless mesh networks (WMNs)‐based applications and heterogeneous WMNs are taking advantage of multiple radio interfaces to improve network performance. Although many routing protocols have been proposed for heterogeneous WMNs, most of them mainly relied on hierarchical or cluster techniques, which result in high routing overhead and performance degradation due to low utilization of wireless links. This is because only gateway nodes are aware of all the network resources. In contrast, a unified routing protocol (e.g., optimal link state routing (OLSR)), which treats the nodes and links equally, can avoid the performance bottleneck incurred by gateway nodes. However, OLSR has to pay the price for unification, that is, OLSR introduces a great amount of routing overhead for broadcasting routing message on every interface. In this paper, we propose unified routing protocol (URP), which is based on passive bandwidth measurement for heterogeneous WMNs. Firstly, we use the available bandwidth as a metric of the unification and propose a low‐cost passive available bandwidth estimation method to calculate expected transmission time that can capture the dynamics of wireless link more accurately. Secondly, based on the estimated available bandwidth, we propose a multipoint relays selection algorithm to achieve higher transmission ability and to help accelerate the routing message diffusion. Finally, instead of broadcasting routing message on all channels, nodes running URP transmit routing message on a set of selected high bandwidth channels. Results from extensive simulations show that URP helps improve the network throughput and to reduce the routing overhead compared with OLSR and hierarchical routing. Copyright © 2016 John Wiley & Sons, Ltd.     

Fuzzy Logic Based Distance and Energy-Aware Routing Protocol in Delay-Tolerant Mobile Sensor Networks

In challenged networks such as Wireless Sensor Networks, limitations such as nodes mobility, short radio range and sparse network density can prevent communications among nodes. Consequently, it can result in long delays in exchanging messages among nodes. Designing Delay-Tolerant Networks is considered to be an approach for dealing with lengthy breakdown of communication between nodes. Using multi-replica methods seems rational for these networks. However, a majority of these methods inject a large amount of replications of a message in the network so as to enhance message delivery probability which consequently leads to the loss of energy and reduction of network efficiency. Two major issues should be considered to achieve data delivery in such challenging networking environments: a routing strategy for the network and a buffer management policy. This study proposes a new routing protocol called Fuzzy-Logic based Distance and Energy Aware Routing protocol (FLDEAR) in delay tolerant mobile sensor network. A FLDEAR is a distance and energy aware protocol that reduces the number of message replications and uses two fuzzy inference systems in routing and buffer management. The results of conducted simulations indicated that this routing algorithm can be used for enhancing data packet delivery ratios and reducing data transmission overhead than several current Delay-Tolerant Mobile Sensor Networks routing protocols.     

Dynamic Relationship-Zone Routing Protocol for Ad Hoc Networks

A new dynamic relationship-zone routing protocol (DRZRP) for ad hoc networks is proposed. In this protocol, each node in the network establishes a neighboring-zone with a radius of ρ hops, and activates a relationship-zone according to the service request frequency and service hotspot condition. DRZRP establishes proactive routing for neighboring-zone and relationship-zone of the node, and the relationship-zone of the node can be dynamically maintained, including: initialization, relationship-zone activation, and relationship-zone inactivation. The simulation results are compared with LSR, ZRP and ZHLS protocols, and DRZRP greatly reduces the communication overhead of routing control messages and significantly improves the average delay of routing requests. The new protocol matches the service relationship among nodes in the network, and has comprehensive performance advantage in communication overhead and routing request delay, which improves the quality of network service.

     

On the performance of heterogeneous MANETs

Recent decades have witnessed the birth of major applications of wireless communication technology, further supported by the increasing capabilities of portable devices, low cost and ubiquitous presence. Despite radio technology diversity, a great deal of existing research focuses on a single and isolated wireless technology at a time, where homogeneous elements are identified by IP addresses. This work presents a heterogeneous technology routing (HTR) Framework, targeted towards scenarios where the heterogeneity of devices and networking technologies is present. Our contribution is many fold. It consists of a framework, which encompasses a process for bootstrapping networks, a routing protocol capable of dealing with multiple network interfaces, and a tuning with multipath extensions. We evaluate the performance of the bootstrap, routing and multipath mechanisms by way of simulation and an actual testbed implementation. The multipath evaluation simulates HTR networks with WiMAX, 3GPP LTE and Wi-Fi support. Results show that our proposal can effectively improve the data delivery ratio for ad-hoc networks and that it reduces the end-to-end delay without major impact on network energy consumption. As part of HTR tuning, we investigate next the impacts of tuning the HELLO refresh interval timer on route convergence and its subsequent energy consumption reduction during this phase. We also compare our tuned HTR with the widely used optimized link state routing protocol. Results show that varying the HELLO refresh interval can improve the convergence time and reduce the energy consumption without major impact on network behavior. Our proposal also includes a new distributed address allocation algorithm, namely, the dynamic node configuration protocol (DNCP). This paper conducts a comparative analysis between the Prime, Prophet and the DNCP schemes using static and dynamic topologies in terms of network setup time, energy consumption and control message overhead. Results show that the DNCP had a lower battery power consumption and less control message overhead while it slightly suffers with regard to setup.

     

车载Ad hoc网络基于转发能力预测的路由策略

在车载Ad hoc网络中,节点的高速移动导致全网拓扑的频繁变化,以街道为单位的路由策略更加高效。传统的研究中使用街道的静态信息或者瞬时的动态信息选择路由路径。前者忽略了车辆节点的动态分布,后者中,精确的全局动态信息获取困难且开销巨大。文章提出街道转发能力来评估街道的路由特性,并预测其持续时间。基于街道转发能力的预测,本文设计了结合静态长度和动态信息的路由策略。仿真结果表明,本策略可以显著提高路由性能。