MESH与LTE混合组网的研究

介绍了MESH以及LTE协议的各自特点与优势。针对当前无线网络容量不足、频谱资源紧缺以及特殊环境的应用需求问题,提出了一种MESH与LTE混合组网的方案,并详细介绍了混合组网方案的系统架构,阐述了混合组网的典型网络拓扑与数据交互流程、混合组网设备的工作原理、LTE与MESH混合组网协议以及动态拓扑路由转发协议等关键技术体制和业务收发流程。最后,分别就军事应用、应急通信以及海洋探测领域的不同应用需求,介绍了该方案的应用前景和相关结论。

Modelling a Learning-Based Dynamic Tree Routing Model for Wireless Mesh Access Networks

Link asymmetry in wireless mesh access networks(WMAN)of Mobile ad-hoc Networks(MANETs)is due mesh routers’transmission range.It is depicted as significant research challenges that pose during the design of network protocol in wireless networks.Based on the extensive review,it is noted that the substantial link percentage is symmetric,i.e.,many links are unidirectional.It is identified that the synchronous acknowledgement reliability is higher than the asynchronous message.Therefore,the process of establishing bidirectional link quality through asynchronous beacons underrates the link reliability of asym-metric links.It paves the way to exploit an investigation on asymmetric links to enhance network functions through link estimation.Here,a novel Learning-based Dynamic Tree routing(LDTR)model is proposed to improve network performance and delay.For the evaluation of delay measures,asymmetric link,interference,probability of transmission failure is evaluated.The proportion of energy consumed is used for monitoring energy conditions based on the total energy capacity.This learning model is a productive way for resolving the routing issues over the network model during uncertainty.The asymmetric path is chosen to achieve exploitation and exploration iteratively.The learning-based Dynamic Tree routing model is utilized to resolve the multi-objective routing problem.Here,the simulation is done with MATLAB 2020a simulation environment and path with energy-efficiency and lesser E2E delay is evaluated and compared with existing approaches like the Dyna-Q-network model(DQN),asymmetric MAC model(AMAC),and cooperative asymmetric MAC model(CAMAC)model.The simulation outcomes demonstrate that the anticipated LDTR model attains superior network performance compared to others.The average energy consump-tion is 250 J,packet energy consumption is 6.5 J,PRR is 50 bits/sec,95%PDR,average delay percentage is 20%.

A Proposal for Mitigating Multiple Black-Hole Attack in Wireless Mesh Networks

The Network Layer in wireless mesh networks is responsible for routing packets making it a prime target for intruders and hackers. Black-hole attack is a type of denial-of-service attack which when carried out can disrupt the services of this layer. This paper takes a look at some important detection and mitigation techniques and presents the drawbacks. After analysis of current mechanisms, the paper proposes RID-AODV, a security solution for multiple black-hole attack in wireless mesh networks. Based on the backbone of AODV, RID-AODV combines the ability of route skipping of IDSAODV and route failure correction using reverse route establishment of RAODV. The enhanced protocol RID-AODV, AODV, IDSAODV, and RAODV are implemented in a simulated environment using ns-2.35 simulator. The networks for each protocol are bombarded with up to ten black-hole nodes starting from zero. The results obtained are then analyzed and compared and a discussion is presented.

A Combined Admission and Priority Control Mechanism for Assuring Communication Quality in VANETs integrated with Wireless Mesh Networks

In this paper, we introduce a new combined priority and admission control mechanism applying in the VCN （Vehicular Communication Network） which is designed with an integration of the Vehicular Ad-hoc Networks （VANETs） based on standard IEEE 802.11 p and IEEE 802.11 s WMNs （Wireless Mesh Networks）. Simulation experiments are intensively investigated to evaluate the novel combined priority and admission control mechanism to assure quality of the I2V （Infrastructure to Vehicle） emergency services occurred during the time video flows are being delivered between content servers and cars. The simulation results show effectiveness of proposed priority and admission control schemes in term of the minimized end-to-end delay as well as the increase of throughput and PDR （Packet Delivery Ratio） of the emergency data flow.

基于4G LTE网络的应急通信指挥救治系统设计

目的:通过构建软硬件相结合的应急通信指挥救治系统,满足应急医疗通信要求。方法:在硬件上,利用4G LTE自组网通信终端,构建4G LTE自组通信网。在软件上,搭建应急医疗网络管理平台,对网络、人员、科室等要素进行管理。结果:各科室、各单位的数据、语音、视频可实时传输交互;外出救援单位可携带终端,将救援信息实时回传至后方医院,使院内专家可对危重患者作出实时抢救决策,并在患者抵达前做好抢救准备。结论:该系统的实现能够保障各类医疗信息系统的联通,提高救治效率。

便携式宽窄融合应急通信设备研究

针对现有应急通信设备传输距离短、系统部署复杂、指挥调度设置在后方等问题,结合当前宽窄融合集群方案以及便携式应急通信设备,笔者提出一种应用于应急救援现场的便携式宽窄融合应急通信指挥系统。系统采用PDT+LTE解决方案,基于SIP的软交换技术实现宽带与窄带集群用户的统一管理、混合呼叫、多媒体集群调度等综合业务。结果表明:系统具有宽窄融合于一体、通信调度于一体、自备电源、便携式、即拉即用、免部署特点,覆盖范围为15~20 km。同时系统还可使用LTE专网基站+背负式Mesh拉远方案,扩大事故救援面积,保障救援通信,实现事故现场与前指、后指的二级分布式调度。

High throughput route selection in multi-rate wireless mesh networks

Most existing Ad-hoc routing protocols use the shortest path algorithm with a hop count metric to select paths. It is appropriate in single-rate wireless networks, but has a tendency to select paths containing long-distance links that have low data rates and reduced reliability in multi-rate networks. This article introduces a high throughput routing algorithm utilizing the multi-rate capability and some mesh characteristics in wireless fidelity （WiFi） mesh networks. It uses the medium access control （MAC） transmission time as the routing metric, which is estimated by the information passed up from the physical layer. When the proposed algorithm is adopted, the Ad-hoc on-demand distance vector （AODV） routing can be improved as high throughput AODV （HT-AODV）. Simulation results show that HT-AODV is capable of establishing a route that has high data-rate, short end-to-end delay and great network throughput.

省干100Gbit/s光传送网目标架构设计

针对在LTE时代,省干光传送网(OTN)如何适应业务发展进行网络建设,结合省级干线光传送网的特点和影响省干光传送网建设的各种因素进行分析,提出多环网、少节点、大容量、高安全的目标网架构,为中西部省份的省干光传送网的建设提出建设性的意见。

多通道滤波器在多频融合便携站中的应用

近年来通信技术在各行业应用中需求不断细化,设备小型化、功能集成化趋势不断加深,不同功能领域设备不断融合。根据长大隧道建设期临时通信和运营期应急通信需求,提出使用LTE基站与Mesh自组网基站融合的方案,便携站基于TD-LTE技术,集LTE核心网、LTE基站、Mesh自组网于一体,可快速构建区域型无线专网覆盖,提供宽带接入、宽带集群和宽带自组网等功能。系统携行方便、部署灵活,可迅速提供通信指挥和数据传输等功能,满足长大隧道内LTE网络全覆盖或多区域快速组网通信的需求。该方案存在不同制式、不同频段通信基站的融合,存在基站上下行通信链路的干扰、基站接收机的带内干扰和底噪声较高、基站容量利用率与接收灵敏度不高等问题,影响设备正常功能实现。经多次测试和研究,便携站通过引入高性能滤波器消除LTE基站与Mesh基站上、下行链路的相互干扰,可同时实现二者功能。