Coverage scheme and test report of ad hoc network in the emergency communication range in mountainou

1. Project implementation plan

1.1. Ad hoc network construction

1.1.1. Networking concept and deployment mode

The wireless ad hoc network multimedia broadband transmission system is a mobile broadband multimedia communication system designed with a new concept of "wireless mesh network". The system adopts a centerless and distributed network architecture, supports arbitrary network topology, multi-hop relay, dynamic routing, and strong invulnerability. All nodes can realize real-time interaction of multimedia information such as voice, data, and video in complex application scenarios such as fast movement and occlusion of non-line-of-sight.

The deployment method is as follows:

1.1.2自组网技术特点

1、智能化网络，即动态组网、去中心化、易扩展性等

无中心快速组网：设备开机后，会迅速搜索和发现附近的其他设备，无须预先进行网络规划和配置，自动组建网络。当有其他节点加入到现有当中时，新的设备将通过直连或者跳转的方式与原有的网络融合成一个更大的网络，使整个网络的正常的工作不依赖于任一节点。

可靠的网络传输：频率可以灵活配置，使设备在面对多变、复杂、灵活的环境时，依然能够保证正常的通信工作和数据业务。在实际使用过程中，如果节点遭受意外导致业务中断，网络将会重新选择一条链路继续传输数据，保证业务的正常运行。

易于扩展：新的无线自治网设备可直接接入到原有的网络当中；如果某个节点处在网络覆盖范围之外，还可以使用其他节点作为中继点的方式让该节点接入网络。

2、高带宽，支持高清视频传输

设备具备着高带宽的特性，点对点传输速率更可达50Mbps以上，借助着此项特点，可支持高清视频的传输。

3、安全与加密

无线传输对于网络安全与数据加密有着极高的要求和敏感性，可提供以下几种策略与手段：

网络节点与硬件设备唯一的MAC地址捆绑；

网络标识码来区分局域网内节点合法性；

可以选用AES128或AES256加密技术,使整个网络安全可靠；

除此之外，在数据入网之前，通过第三方设备来提高防护等级。

4、产品功能特色

4.1、硬件平台

基于FPGA+ADC芯片的SDR平台方案（可定制实现软硬件国产化率 100%）

   4.2、通信波形

TDD-COFDM+MIMO，可选A,B,C,D四种软件波形，全双工双向通信

1.1.3本项目的部署策略

固定监控点部分采用自组网室外固定台电台：可适用于室外长期无人值守环境，同时可作为运营商备份通信链路，解决运营商网络受到自然灾害时基站断链变为孤岛等问题。全IP 化设计,支持多网 融合/异构组网,军品级设计,有效抵抗各种严峻环境。

护林车部分采用车载电台：在远处距离前端侦测人员20 公里外的应急通信指挥车上安装一台自组网车载节点设备，自 组网车载电台设备通过无线自组网链路与无人机上的自组网机载节点设备构建无线通信网络。

无人机部分采用机载电台：机载模块小巧轻便，固定在无人机上，作为自组网空中中继节点，为现场周边环境及通信网络 提供强有力的链路支持。同时可为无人机自动巡航提供可靠的通信链路。

临时指挥中心部分采用三屏指挥箱电脑：便于携带、即开即用，可展示多画面，内置指挥调度软件4G 和Wi-Fi 模组等，适合野外临时指挥。

1.1.4固定台建设点位信息

固定台配置

室外固定基站型自组网设备具有防腐蚀、防雨水、防高温等特性,可挂载于基站铁塔等固定物体上，通过一定高度可有效扩大自组网之间通信覆盖范围,解决远距离信号传输等问题。同时具有更强发射功率,可与车载、单兵等节点之间保持高速、可靠的双向信号传输。产品可适用于室外长期无人值守环境,同时可作为运营商备份通信链路,解决运营商网络受到自然灾害时基站断链变为孤岛等问题。全 IP 化设计,支持多网融合/异构组网,军品级设计,有效抵抗各种严峻环境。

（室外基站图）

1.1.5单兵手持台配置

单兵手持台自组网设备外形精致、重量轻便，仅840g，便于手持携带或挂于腰肩、背部。可为公安执法、消防救援、特种作战等紧急任务提供高效数字融合通信网络。产品开机状态可控制在秒级，具备自动建链、自动搜寻等特点。为应急指挥提供语音组呼、视频回传、GIS 定位、人员感知等多媒体交互业务。同时可通过无人机链路扩大单兵手持台通信范围，建立突发事件现场、现场指挥中心双向通信链路。

（单兵手持台图）

1.1.6背负台配置

单兵背负基站型自组网设备机动灵活,可将设备背负于身后,减轻额外重量或作为中继基站固定放置。开机上电即可自动建链组网,无需额外配置工作。每台背负基站 节点无需通过中心节点转发数据信息,所有节点都可同时作为数据信息采集节点、中继转发节 点以及数据信息输出节点。组网方式随环境动态变化,满足多场景应用需求。设备在无遮挡环

境下传输距离可达 30KM 以上,在强遮挡环境中,仍然能保持高数据传输通信。军品级设计,有效应用于各种严峻环境领域。

（背负台图）

1.1.7机载台配置

近年来，伴随着能力上的巨大进步,小型无人载具日益被赋予更复杂的任务，不仅是个体任务，更包括协同任务。任务的复杂化智能化对无人系统的通信链路的能力也提出了更高的要求。机载台在尺寸和重量非常小的情况下，实现了强大的自组网通信能力，为中小型无人载具的集群协同提供强有力的链路支持。

（机载台图）

1.1.8车载台配置

移动车载型自组网设备具备1U 产品结构，可满足用户在车辆行驶过程中“动中通”需求。车辆即使在高速状态下行驶，也能与各节点之间保持可靠、高效的双向数据传输。产品内部集成北斗定位、PTT语音、4G/5G 等模块，可满足用户多种通信需求。产品在无遮挡环境下传输距离可达15KM 以上。产品具备AES128/256 加密技术。适用于移动性覆盖、中继接力多跳传输、远距离覆盖等应用场景。军品级设计，有效抵抗各种严峻环境等领域。

(Vehicle table diagram).

1.1.9. Three-screen command box computer configuration

The portable command box adopts an integrated portable computer design, with three 17.3-inch LED display designs, the middle is the main screen, and the left and right sides are slave screens, which can display multiple screens of the dispatching system, which is suitable for field combat command.

(Three-screen command box computer diagram).

1.2.0 explosion-proof individual image transmission helmet camera configuration

With the support of the image transmission command and control center, 4G network or ad hoc network radio, the command system has the functions of map track playback, danger alarm pop-up, electronic fence, remote intercom, group intercom, group broadcasting, cluster intercom, etc., through the first perspective of individual soldiers, the rear command center can quickly respond to various combat scenarios and dangerous disaster relief scenes.

（防爆单兵图传头盔图）

2.结合保护区需求

2.1无人机图传及远程控制

UAV ad hoc network adopts a small-size private network communication module realized by wireless broadband ad hoc network technology, which is small in size and light in weight, suitable for carrying UAVs, unmanned ships, robots or other professional equipment, and can provide IP transparent transmission channels for upper-layer applications such as video, voice, and data. There is no need to rely on basic communication facilities and manual configuration, and the communication network can be quickly established anytime and anywhere. UAV ad hoc network is used by UAV as a mobile node in the network, and in the field of ad hoc network, the more advanced application is the mesh mesh network. Combined with UAV technology and mesh network, using the advantages of wireless remote transmission, can be applied to a variety of complex environment networking communication requirements, at the same time, each UAV adopts mesh network, can make a plurality of UAV equipment carry out large-area network communication coverage; when there is a long communication distance, UAV A can not communicate directly with the remote ground control station D, can directly add the intermediate node B or C mode, signal forwarding, so as to achieve a longer distance coverage network. The small-size ad hoc network module is a set of communication devices with wireless transceiver devices, and several nodes can form an intelligent, multi-hop, mobile, peer-to-peer decentralized temporary autonomous network communication system, and the nodes adopt dynamic mesh connection, no central node, can more effectively distribute network traffic, and has stronger network robustness. Any end node in the network is equal to each other, and the departure or disappearance of any node will not affect the operation of the entire network. Provides a communication support environment without relying on any communication network infrastructure, enabling rapid network deployment.

2.2 Ad hoc network public network coverage

1. Select a suitable location in the forest area, install an appropriate amount of long-distance Mesh-free base station on the tower, make full use of the advantages of high terrain in mountainous areas, and the MESH base station can be co-located and interconnected with the public network base station. Through multi-hop relay and relay forwarding, the collected forest data and image information can be transmitted back in real time around the clock, and the remote command center can be transmitted back through the 5G/4G public network to facilitate real-time viewing and scientific analysisAt the same time, the Mesh handheld provides a WiFi interface, and the public network signal is transmitted to the handheld terminal through the Mesh link through the Mesh base station and the public network base station, and the WiFi hotspot can be shared by the handheld WiFi end, which is convenient for forest operations and rescuers to contact and communicate with the command center through the public network for the first time through mobile phones or tablets

2. Deploy vehicle-mounted MESH nodes on command vehicles and forest ranger patrol vehicles to quickly enter the forest area, facilitate information collection, patrol monitoring and command and dispatch, and provide wireless network support for forest area safety officers;

3. The safety officer carries the individual soldier MESH node on foot, which can go deep into the forest area to perform front-line tasks, which is not only convenient for real-time voice communication with the surrounding vehicle commanders and other safety officers, but also can transmit the high-definition video images collected in the forest area as timely as possible, and provide comprehensive and clear on-site real-time images to the rear platform.

4. The UAV is equipped with airborne ad hoc network node equipment, which can not only further expand the wireless coverage, reduce the coverage blind area, and improve the quality of video backhaul, but also organically combine the aerial mobile monitoring with the ground fixed monitoring and complement each other's advantages, forming a ground-air "three-dimensional" monitoring network to effectively increase the visual range of the monitoring area.

3. Measured data

In order to verify the feasibility of the scheme, the ad hoc network coverage was tested in Taohe National Nature Reserve.

3.1 Test Scenario

A fixed station is deployed at a certain point of the forest fire monitoring system, and the personnel are equipped with handheld stations to walk in the surrounding non-line-of-sight ravines to test the network coverage of ad hoc network equipment.

3.2 Test Equipment

Due to factors such as the large size of the fixed station and the antenna equipped with the fixed station, no battery power supply, and inconvenient carrying, the test equipment was replaced from the fixed station to the piggyback station, and the 10dBi antenna equipped with the fixed station was replaced with an 8dBi antenna.

The test equipment is SDR-A2-20W (backpack station, using 8dBi antenna), SDR-A1-4W (handheld station, using 3dBi antenna), SDR-A3-4W (airborne station, using 3dBi antenna).

3.3 Test Process

Time: November 18, 2023 - November 19, 2023

Test site: On November 18, the Kabuliang point of Zhanzhan Village, Muer Town, installed the piggyback station as a relay, and the two teams tested from the oatmeal ditch and Boyugou respectively. (Note: Due to factors such as the inconvenience of the fixed station to carry in this test, the SDR-A2-20W backpack station was used as the relay point for this test, and the antenna was changed to an 8dBi gain antenna.) The subsequent 233 are all test relay points. ）

Muer Town occupies the Kabuliang point of Zhan Village

A small team can directly see the relay point in the oatmeal ditch, and walk about 2 kilometers in the non-line-of-sight direction from the line-of-sight condition to test voice and video, and the test was successful. The link topology diagram is as follows: (Note: a team uses SDR-A1-4W handheld station for testing, and the antenna uses a 3dBi gain antenna, and the subsequent 216 is a team of test equipment.) ）

Link at line-of-sight conditions

非视距条件下链路

二小队在博峪沟看不到中继点位，在非视距下测试语音、视频，测试成功。链路拓扑图如下：（注：二小队选用SDR-A2-20W背负站作为车载端测试，天线选用8dBi增益天线，后续232均为二小队测试设备。）

Direct communication link between the two squads

On November 19th, at the Ajiao Xiaogou Mountain Beam Point in Zhalie Village, Muer Town, the first team conducted a test in Ajiao Xiaogou, and the second team entered the mountain at the Sangbugou Protection Station, and tested the big paddock ditch and the main ditch of Mayincang respectively. The whole ditch of the large paddock ditch is well covered, and the ground cannot be connected at the end of the main ditch of the Masin warehouse. The UAV is used to establish normal communication at an altitude of 200 meters, and the UAV realizes video transmission at an altitude of 300 meters. Except for the end of the main ditch of Mayincang, the rest of the sections basically achieve full coverage. (Note: Due to the serious occlusion area, it is impossible to communicate directly with the relay node, so the UAV elevation is used as the air relay node, and the subsequent 224 is the UAV relay node.) ）

After the first team established a connection with the second team at the relay node of Ajiao Elementary School, it walked into the mountainous area and walked about 3 kilometers under non-line-of-sight conditions, and could communicate normally within 3 kilometers. The link diagram is as follows:

A small team walks to test the topology of the link at site 1

一小队步行测试点位2链路拓扑图

一小队测试人员

二小队大围场沟链路拓扑图

二小队马阴仓主沟末段通过无人机中继通信链路拓扑图

二小队大围场沟测试点位

The second team of Ma Yin Cang main ditch end-of-the-road UAV relay

3.4 Test Summary

UAV air relay is used in some heavily shielded areas, basically achieving full network coverage within a radius of 10 kilometers.