IDM is a dual line bus type Ethernet fusion communication system

Keywords: Ethernet fusion communication system, Ethernet communication equipment, Ethernet network, bus Ethernet equipment, Ethernet communication, transmission equipment, remote transmission equipment, transmission equipment, etc

System Description
The IDM is a new type of wired fusion communication system developed by our company, which is easy to operate, maintain, and can be quickly deployed and flexibly networked. The design of IDM in the Ethernet fusion communication system based on multi line bus fully considers the communication requirements in complex environments. By using twisted pair cables, it provides a stable, reliable, and easily scalable communication solution.
The product uses domestically innovative second-line Ethernet interface technology, which can connect up to 15 bus networking devices or intelligent terminals through a single double line. A typical network is shown in Figure 1.

Figure 1 Typical Networking

In the multi line bus fusion communication system shown in the above figure, the terminal or device of the multi line can be directly connected on one of the multi line, the IP terminal can be connected through a network adapter, and various voice terminals or communication terminals can be connected through various gateway devices, forming a set of integrated communication command and scheduling system. Among them:
(1).  The MCC6000 portable command and dispatch machine, MCC600-T intelligent dispatch terminal, and reinforced intelligent dispatch terminal all have built-in double line adaptation modules that can be directly connected through double lines, enabling communication and scheduling functions for other intelligent terminals, audio equipment, and video terminals in the system;
(2).  Using a dual line network adapter to connect network monitoring cameras, MCC500 intelligent dispatch terminals, etc. through an IP Ethernet port;
(3).  Using a dual line voice gateway to connect traditional analog telephones through telephone lines;
(4).  Using a dual line radio gateway to access wireless radio intercom equipment;
(5).  Using a dual line common power gateway to connect to a common power telephone through a telephone line;
(6).  Using a dual line broadcast gateway to connect to the broadcast terminal through an audio interface.
The system can also achieve fiber optic interconnection with the command center and transmission interconnection over longer distances through the long-distance relay equipment pulled by the double line, as shown in Figure 2.

Figure 2 Fiber optic remote networking

Characteristics and advantages of the second system
（1）  Random access, intelligent networking, easy to use, and convenient maintenance
The second-line Ethernet interface utilizes advanced digital signal processing technology, which can perform echo cancellation on the reflected clutter appearing on the double line bus, and can reverse the polarity of the signal with the core wire connected in reverse. This way, users do not need to worry about the distribution of access points on the bus or distinguish between the positive and negative polarities of the bus when using the second-line Ethernet interface. The second-line Ethernet interface also has a complete built-in self-organizing network protocol, and there is no master-slave relationship between bus networking devices. Turning off any bus networking device does not affect the networking communication of other devices. In various application scenarios, devices can be connected immediately in the factory state without the need for users to modify or adjust internal parameters.
In the battlefield environment, weapons, equipment, vehicles, and personnel may be attacked and damaged by enemy fire at any time. The requirements for information equipment in practical combat are that the equipment must have good operability, maintainability, and reconfigurability. Through a series of technological innovations and improvements, the bus networking equipment has achieved the practical design goals of two-wire parallel connection, multi-point interconnection, out of the box use, and instant connectivity. As a reference for comparison, SHDSL can only perform point-to-point communication connections on a single double line remote transmission device. When conducting multi-point networking applications, communication nodes have a master-slave relationship. After the master node moves its position, its corresponding slave nodes must be rewired. The bus mode can enable all user nodes to maneuver and connect to the network along the line.
（2）  Long communication distance, high transmission rate, and strong anti-interference ability
There are two types of bus networking devices to choose from, namely long-distance networking and short distance high-speed transmission.
Among them, the measured communication distance of the long-distance networking type equipment can reach up to 10 kilometers. When using the 706 type double line for point-to-point transmission testing with a length of 10 kilometers, the user measured bandwidth of the bus networking equipment can reach 2Mbps.
Among them, the measured communication distance of the short distance high-speed transmission type equipment is within 2 kilometers. When using the 706 type double line for point-to-point transmission testing with a length of 2 kilometers, the user measured bandwidth of the bus networking equipment can reach 10Mbps.
The bus networking equipment adopts packet data transmission technology, and every time packet data is transmitted, it learns the channel balance coefficient in real time, so it can make timely adjustments and adaptations to strong external interference conditions. SHDSL requires a long period of channel equalization training (with a maximum link building time of more than 120 seconds) when the device is started by the multi line remote transmission equipment. When the link is interrupted due to interference, the channel equalization training process needs to be repeated. In the petroleum logging industry, it is necessary to select shaded core wires in multi-core cables for remote data transmission. At this time, the transmission wires are not twisted pair wires and are easily affected by signal interference from other wires. In relevant control experiments, bus networking equipment showed better anti-interference characteristics than SHDSL transmission equipment.
（3）  Support multiple media services, core services can avoid congestion
The bus networking equipment divides the data transmitted on the bus into three priority levels according to business types, with real-time control business designated as high priority level, real-time voice business designated as medium priority level, and network video and file transmission as well as other IP application business designated as low priority level. Bus networking devices dynamically allocate bus bandwidth resources based on the priority level of data transmission, and limit the transmission bandwidth of each real-time control service to within 20kbps. This ensures the real-time performance of high priority services with small traffic, without being affected by low priority network applications with large traffic demands and multiple types of services.
The system supports the access of various voice, media terminals and devices such as voice, video, network terminals, audio terminals, wireless terminals, etc. It also supports functions such as audio and video instant messaging, video surveillance transmission, audio and video conferencing, and integrated communication scheduling.
（4）  Strong scalability and good interoperability
By using repeaters, multiple multiplexed buses can achieve configuration free relay interconnection, forming a linear and tree like bus interconnection network. After the bus deployment is completed, all networking nodes only need to connect the bus networking devices to the preset bus to immediately connect to the network. The network nodes that have already been connected to the network can autonomously evacuate and transfer to other bus covered locations to re connect to the network. The bus networking equipment automatically completes the configuration changes of network parameters without the need for network management scheduling and manual configuration.
Compared to field fiber optic cables, the double line bus network can be quickly connected at any time without the need for professional splicing tools. The operation is simple and fast, and the system can be expanded and interconnected through fiber optic remote relay equipment.
Three main performance indicators
(1).  The maximum number of nodes in a single bus network is 8;
(2).  Long distance transmission model, with a maximum bus span of 10 kilometers and a maximum bandwidth of 2Mbps for bus users;
(3).  High speed transmission model, with a maximum bandwidth of 10Mbps for bus users within a span of 2 kilometers;
(4).  The maximum delay for real-time voice data on the bus is 100ms;
(5).  The transmission efficiency of bus multi-point access can reach 80%;
(6).  The packet loss probability during bus multi-point access is less than 0.1%;
(7).  The average network connection time for bus networking devices is less than 0.3 seconds.
(8).  The maximum number of interconnected buses is 16.
Four main application scenarios
（1）  Construction site (tunnel, railway)
（2）  Rapid network networking for emergency rescue and disaster management
（3）  System networking for oil and gas fields and mining operations
（4）  Networking of military and defense exercise sites
（5）  Broadband access and networking in temporary alert areas