Deep Reinforcement Learning-Based Collaborative Routing Algorithm for Clustered MANETs

Flexible adaptation to differentiated quality of service(QoS)is quite important for future 6G network with a variety of services.Mobile ad hoc networks(MANETs)are able to provide flexible communication services to users through self-configuration and rapid deployment.However,the dynamic wireless environment,the limited resources,and complex QoS requirements have presented great challenges for network routing problems.Motivated by the development of artificial intelligence,a deep reinforcement learning-based collaborative routing(DRLCR)algorithm is proposed.Both routing policy and subchannel allocation are considered jointly,aiming at minimizing the end-to-end(E2E)delay and improving the network capacity.After sufficient training by the cluster head node,the Q-network can be synchronized to each member node to select the next hop based on local observation.Moreover,we improve the performance of training by considering historical observations,which can improve the adaptability of routing policies to dynamic environments.Simulation results show that the proposed DRLCR algorithm outperforms other algorithms in terms of resource utilization and E2E delay by optimizing network load to avoid congestion.In addition,the effectiveness of the routing policy in a dynamic environment is verified.

MANETs面向稳定性的自适应路由开销控制算法

为了在节点频繁移动的MANETs网络环境中发现和建立具有较长维持时间的路由,以增强路由的可用性和数据传输的连续性,面向稳定性的路由算法需要中间节点转发更多的RREQ分组,但这会造成路由开销显著增加。为此,提出了一种面向稳定性的自适应路由开销控制算法。算法使用策略型博弈对RREQ转发过程进行建模,利用该博弈存在的混合策略纳什均衡计算RREQ的转发概率,实现RREQ的概率转发。仿真结果表明,提出的面向稳定性的自适应路由开销控制算法不仅保证了路由的稳定性和分组递交率,而且有效地减少了路由开销和传输延迟。

MANETs网络中的一种分布式同步预约多址接入协议

提出了一种MANETs网络中的多址接入控制协议———分布式同步预约多址接入协议(DSRP),解决了隐藏终端和暴露终端问题,并且为实时业务的QoS要求提供了保障.协议以时分多址为基础,给不同类型的业务分配不同的优先级,采用不同的机制对空闲时隙进行竞争及预约.在已预约的时隙中采用发送数据前的预约确认机制,避免了入侵终端问题.在全连通网络中分析了DSRP协议的吞吐量和分组平均丢弃率,并且对协议进行了仿真,结果表明该协议能够达到传输实时业务的要求,适用于MANETs网络.

方向性天线对MANETs路由协议的性能影响研究

本文研究了方向性天线对DSR路由协议性能的影响。通过仿真证明了,当使用方向天线进行分组发送时,由于网络节点获取拓扑信息的效率降低,导致协议的分组交付率降低和路由开销数量增加。分折了此现象产生原因,并提出了一个改进方法;由DSR协议参与控制分组发送时使用的天线模式,对部分影响协议性能最为严重的分组采用全向发送,其余分组使用方向天线发送。仿真证明了使用该方法后,可以明显改善协议性能。

MANETs接入3G系统的通信体制分析

文中简要介绍了移动自组网的概念及其作为蜂窝系统接入网的应用前景,提出了移动自组网接入3G系统的通信体制,并在可行性上进行了分析比较,还对其关键技术作了初步研究。

MANETs中基于非合作零和博弈的入侵检测模型研究

自私节点的存在使得MANETs网络的入侵检测性能低下。针对该问题提出一种基于非合作零和博弈的入侵检测模型。一方面,通过建立代价函数和提高信誉的方式激励自私节点积极参与合作,从而选择出最优领导节点,提高群内节点的生存时间;另一方面,建立领导节点IDS和入侵者的非合作博弈模型,利用求解贝叶斯纳什均衡的方法对其进行求解,按照求解结果为节点分配负载,实现对节点资源的合理使用,提高模型对入侵的检测率。

MANETs节点移动异质性对病毒传播影响

为了研究MANETs节点移动异质性对病毒传播的影响,对节点移动模型进行刻画,并基于元胞自动机理论建立MANETs病毒传播模型。在维持相同期望值而方差相异的情况下,研究节点移动速度、移动持续时间、停留时间和转动角度异质性对MANETs病毒传播的影响。结果表明,减少网络中节点移动异质性,可以有效抑制MANETs病毒传播。

MANETs在军事通信中的应用

MANETs是目前通信技术领域的焦点之一,它具有极强的适应和生存能力,其应用前景十分广阔。首先介绍了MANETs的概念、结构和特点,阐述了MANETs在军事通信中的重要作用,并提出了一种应用阶段的过渡结构。最后指出了MANETs应用于军事通信中的关键技术和研究方向。

基于可编程移动代理的MANETs分布式入侵检测方法

[目的/意义]随着互联网和大数据的迅猛发展,网络安全问题成为了当下人们关注的热点。为了更好的防御主要的网络安全攻击,提出了一种基于可编程移动代理的MANETs分布式自适应入侵检测系统的方法。[方法]首先,把通用的入侵检测模型结合到入侵检测系统中,考虑到(MANETs)无线自组织网系统的关键功能,然后提出了基于规则和基于行为的入侵检测模型。[结果]方案的提出解决了MANETs中入侵检测系统安装面临的固有挑战。用移动代理的可篡改性去检测任何潜在的试图破坏他们所携带的攻击相关的数据。

Light Weight Cryptographic Address Generation(LW-CGA) Using System State Entropy Gathering for IPv6 Based MANETs

In IPv6 based MANETs, the neighbor discovery enables nodes to self-configure and communicate with neighbor nodes through autoconfiguration. The Stateless address autoconfiguration(SLAAC) has proven to face several security issues. Even though the Secure Neighbor Discovery(SeND) uses Cryptographically Generated Addresses(CGA) to address these issues, it creates other concerns such as need for CA to authenticate hosts, exposure to CPU exhaustion attacks and high computational intensity. These issues are major concern for MANETs as it possesses limited bandwidth and processing power. The paper proposes empirically strong Light Weight Cryptographic Address Generation(LW-CGA) using entropy gathered from system states. Even the system users cannot monitor these system states; hence LW-CGA provides high security with minimal computational complexity and proves to be more suitable for MANETs. The LW-CGA and SeND are implemented and tested to study the performances. The evaluation shows that LW-CGA with good runtime throughput takes minimal address generation latency.

Signcryption-Based Key Management for MANETs Applications in Mobile Commerce

Mobile commerce uses wireless device and wireless link to result in the transfer of values in exchange of information, services or goods. Wireless mobile ad hoc networks （MANETs） will bring a revolution to the business model of mobile commerce if such networks are used as the underlying network technology for mobile commerce. Mobile commerce will remain in a niche market until the security issue is properly addressed. Hence, security is also very important for MANET applications in mobile commerce. Robust key management is one of the most crucial technologies for security of MANETs. In this paper, a new solution for key management is proposed using identity-based （ID-based） signcryption and threshold secret sharing. It enables flexible and efficient key management while respecting the constraints of MANETs. In our solution, each mobile host uses its globally unique identity as its public key. It greatly decreases the computation and storage costs of mobile hosts, as well as communication cost for system key management.

Capacity-Optimized Access Scheduling Control for Heterogeneous MANETs with MIMO Links

Multiple-input and multiple-output (MIMO) technique can significantly improve transmission reliability and bandwidth efficiency in wireless networks. However, many upper layer aspects of MIMO links, especially in mobile networks with heterogeneous antennas and strong interference environments, need further investigation. In this paper, we study its impact on medium access and network capacity. Since MIMO links can enhance physical layer capacity and co-channel interference suppression that affects network access scheduling directly, we develop a capacity-optimized access scheduling control (COASC) scheme for mobile ad hoc networks (MANETs) with MIMO links. We formulate the distributed scheduling taking the key of optimization into design to improve the network capacity and transmission reliability. Simulation results are presented to show the effectiveness of the proposed scheme.

Shannon Entropy in Distributed Scientific Calculations on Mobiles Ad-Hoc Networks (MANETs)

This paper addresses the problem of giving a formal metric to estimate uncertainty at the moment of starting a distributed scientific calculation on clients working over mobile ad-hoc networks (MANETs). Measuring the uncertainty related to the successful completion of a distributed computation on the aforementioned network infrastructure is based on the Dempster-Shafer Theory of Evidence (DST). Shannon Entropy will be the formal mechanism by which the conflict in the scenarios proposed in this paper will be estimated. This paper will begin with a description of the procedure by which connectivity probability is to be obtained and will continue by presenting the mobility model most appropriate for the performed simulations. Finally, simulations will be performed to calculate the Shannon Entropy, after which the corresponding conclusions will be presented.

QoS Bandwidth Estimation Scheme for Delay Sensitive Applications in MANETs

For last few years, MobileAd hoc Networks (MANETs) have attracted a great interest in case of wireless and multimedia technologies. Infrastructure less nature of MANETs makes Quality of Service (QoS) provisioning very challenging and important research aspect. To find a QoS constrained route from source to destination, we should be able to effectively determine the available resources throughout the route. The routing protocol is the most integral part of any type of QoS provisioning. It has to decide which route is able to fulfill the requirement of the desired QoS for specified application. In this paper, modification has been proposed in the existing MANET protocols to get the information about total path bandwidth for delay sensitive applications. It uses modified technique for bandwidth estimation and for route maintenance. The proposed protocol is implemented and simulated using NS-2 simulator. Results of our implementation show that there is much improvement in overheads without any impact on overall end-to-end throughput.

Message Cab (MCab): Partition Restoration in MANETs Using Flexible Helping Hosts

Helping hosts are intensively used in various schemes to restore partitioned Mobile Ad Hoc Networks (MANETs).Most of the existing schemes offers only deterministic deployment and fixed routes for the helping hosts, and are thus not able to deal with fluctuating network traffic, which is a practical condition in many MANET applications. In this paper, we argue that flexible helping hosts (referred to as Message Cabs (MCabs)), with deployment and routes that response to the changes in the traffic demand of the network, may overcome this drawback and reduce the message delay in the networks. To demonstrate the effectiveness of this observation, we propose a new helping host scheme namely the Message Cab (MCab) scheme for partition restoration in MANETs, and validate the performance through simulations.

A Distributed Weighted Cluster Based Routing Protocol for MANETs

Mobile ad-hoc networks (MANETs) are a form of wireless networks which do not require a base station for providing network connectivity. Many MANETs’ characteristics that distinguish MANETs from other wireless networks also make routing a challenging task. Cluster based routing is a MANET routing schemes in which various clusters of mobile nodes are formed with each cluster having its own clusterhead which is responsible for routing among clusters. In this paper we propose and implement a distributed weighted clustering algorithm for MANETs. This approach is based on combined weight metric that takes into account several system parameters like the node degree, transmission range, energy and mobility of the nodes. We have evaluated the performance of the proposed scheme through simulation in various network situations. Simulation results show that improved distributed weighted clustering algorithm (DWCAIMP) outperforms the original distributed weighted clustering algorithm (DWCA).

Performance Issues and Behavioral Analysis of Routing Protocols in MANETs

Mobile ad hoc network (MANET) is an autonomous system of mobile nodes connected by wireless links. Infrastructure-less environment and frequently changing topology due to mobility of nodes makes routing a difficult task. There is no centralized control such as base station and can be set up according to demand wherever required. Effective routing protocol is required for finding the optimum path as per the application requirement. In this paper, analysis has been carried out about various basic routing protocols techniques, issues related to them especially in MANETs routing and performance comparison of different proposed approaches in terms of different network performance parameters.

An ACO Look-Ahead Approach to QOS Enabled FaultTolerant Routing in MANETs

MANET routing is critical and routing decision should be made sooner before the node leaves the network.Fast decisions always compensate network performance.In addition,most MANET routing protocols assume a friendly and cooperative environment,and hence are vulnerable to various attacks.Trust and Reputation would serve as a major solution to these problems.Learning the network characteristics and choosing right routing decisions at right times would be a significant solution.In this work,we have done an extensive survey of fault tolerant protocols and ant colony algorithms applied to routing in MANETs.We propose a QoS constrained fault tolerant ant lookahead routing algorithm which attempts to identify valid route and look-ahead route pairs which might help in choosing the alternate path in case of valid route failure.The results prove that the proposed algorithm takes better routing decisions with 20-30 percent improvement compared with existing ant colony algorithms.

Enhanced Timestamp Discrepancy to Limit Impact of Replay Attacks in MANETs

Mobile Ad hoc NETworks (MANETs), characterized by the free move of mobile nodes are more vulnerable to the trivial Denial-of-Service (DoS) attacks such as replay attacks. A replay attacker performs this attack at anytime and anywhere in the network by interception and retransmission of the valid signed messages. Consequently, the MANET performance is severally degraded by the overhead produced by the redundant valid messages. In this paper, we propose an enhancement of timestamp discrepancy used to validate a signed message and consequently limiting the impact of a replay attack. Our proposed timestamp concept estimates approximately the time where the message is received and validated by the received node. This estimation is based on the existing parameters defined at the 802.11 MAC layer.

P2P Overlay Performance in Large-Scale MANETs

We explored how to deploy P2P overlays in ultimately large-scale Mobile Ad-Hoc Networks (MANETs). We therefore studied the performance of P2P overlays such as Chord, creating a number of flat and hierarchical MANET networks. The hierarchical network consists of clusters, interconnected by a backbone. The subnetworks (cluster or the whole network) ran OLSR as network-layer routing protocol. Each cluster had a gateway, interconnected through a backbone that deployed flooding. As we increased the number of clusters, we kept the number of nodes in the Chord overlay constant. Using simulations in OMNeT++, we evaluated the P2P performance. Our results show that an unmodified P2P network does not perform well even for relatively small network sizes. The performance can be improved through the use of a cross-layered P2P solution, such as OneHopOverlay4MANET. However, such cross-layered approaches require complete information about overlay nodes from the routing layer and are therefore not suitable in hierarchical MANETs. For hierarchical underlays, the performance of the P2P overlay deteriorated as we increased the number of clusters. One of the main reasons is that the backbone quickly became a performance bottleneck.