In emergency communication networking, it is necessary to connect network nodes in the on-site wireless network, including several mobile vehicles and several independent teams of personnel. Both vehicles and personnel are equipped with wireless network nodes, and real-time interconnection between vehicles, personnel, and groups is required.

This article takes actual requirements as an example to explain the transmission method and business type of information.

(1) Establish a normal communication link on site without interference;

(2) Establish a normal communication link on site in the event of interference in the frequency band below 3GHz;

(3) On the premise of ensuring smooth wireless communication and secure data transmission, complete the transmission and exchange of required images and voice.

System technical indicators

(1) After the positions of each onboard mesh module and portable mesh module are basically determined, the time from powering up the device to successfully networking the network nodes in the system should not exceed 2 minutes

(2) The real-time transmission bandwidth between each person and vehicle, as well as between vehicles, shall not be less than 6M

(3) When the line of sight is visible, the coverage range of the onboard mesh module shall not be less than 2000 meters, and the coverage range of the portable mesh module shall not be less than 800 meters

(4) After 10 hops, the transmission bandwidth of the portable mesh module should not be less than 6M

(5) After 10 hops of the portable mesh module, the network delay does not exceed 100ms

(6) The portable mesh module should be combined with an independent power supply device (battery), and the mesh module and battery should be a unified and closed structural whole

(7) For different application modes of the system, each mesh module can flexibly adapt without the need for manual analysis and configuration

(8) Our company's supporting WiFi mobile phones can achieve fast switching and complete uninterrupted communication when roaming in the network.

Network topology

Network return method

Emergency communication network is a mobile and self-organizing emergency communication network that utilizes mesh network technology to form between vehicles and between vehicles and personnel. Then, the information from the mesh emergency network is transmitted back to the command center through any vehicle.

The main challenge in emergency communication is how to transmit real-time video, voice, and data information of the fleet. There are currently three main types of methods:

(1)  Fiber optic

Using a wired network method, connect any vehicle to the nearby fiber optic network to transmit the emergency network information back to the command center

(2)  satellite

Install satellite transmission and reception equipment on one of the vehicles

(3)  Wireless return method

This method fully utilizes the characteristics of wireless mesh networks, and sets up fixed base stations every 2-5 kilometers in main high-rise buildings in the urban area to provide wireless connection to vehicles in the urban area. The fixed base stations use wireless mesh protocol communication between each other, and ultimately transmit back to the control center.

As shown in the following figure: After the vehicle enters the scene of the incident, the vehicle responsible for wireless transmission and the nearby fixed base station will be interconnected with the nearby fixed base station, thereby achieving information transmission for the entire team.