Application of Communication Command Dispatch Switch at Highway and High-Speed Railway Construction Sites

Current Status and Challenges:

With the country's grand "Belt and Road" initiative and the establishment of the "Asian Infrastructure Investment Bank," the construction scale of basic transportation infrastructure such as highways and high-speed railways will be greatly accelerated.

These construction sites are generally temporary facilities, mostly located in remote areas with poor communication conditions. There are many construction points along the route, a large number of construction personnel involved, and a significant amount of coordination required, often operating in various hazardous environments. In tunnels and caves, two-way radios cannot function effectively, necessitating the use of telephones and wired intercom systems. WIFI access points can also be reasonably deployed to enable positioning within the tunnel.

In emergency situations, firefighting, public security, health, and power departments may also be involved, requiring each department to coordinate with others. Frequently switching radio channels is impractical, and some units' radios may not operate on the same frequency range or use the same standard, such as the 350M band, 800M band, or air-to-ground communication bands. Leaders may also need to understand the command site situation via GSM mobile phones or landlines.

The best solution is to establish a wired/wireless dispatch system in each construction area, integrating radio communication, landline telephones, GSM phones, and even broadcasting, displays, video cameras, and GPS location information into a single dispatch system.

Since construction sites are generally remote, operators have limited communication resources in these areas, and communication bandwidth is typically low. When establishing a dispatch system, it is advisable to build a dedicated communication system that comprehensively addresses telephony, intercom, networking, and video solutions. Raytrans' dispatch communication is a system that integrates dispatch, communication access, communication transmission, and video transmission, incorporating both fiber optic and wireless transmission, lowering the user's operation and maintenance threshold and making system integration easier. For example, IDM G3CP and IDM M9000 are dispatch devices with transmission interfaces such as SDH.

Dispatch systems in different areas can be networked with each other, enabling both independent operation and collaborative work.

Requirements:

Field command personnel need to be equipped with multiple wireless trunking radios, especially those operating on different frequency bands and standards. These radios are linked together through a single dispatch switch, enabling monitoring, command, and group merging of each radio group via dispatch console operations.

The same dispatch switch can be configured with a dedicated dispatch console for each department (i.e., the same frequency point). Given the complexity of the site and the fact that operators may not be familiar with computers, it is preferable to configure a Danish-key dispatch console without a computer. Sites with a communication vehicle can be equipped with touchscreen dispatch consoles, audio/video dispatch, etc. Through the dispatch console, users can hear both the voices of users in their own group and the collaboration process of other groups of interest, with flexible and convenient selection and configuration at any time.

GSM/CDMA phone cards or 4G communication cards can also be configured on the dispatch switch to maintain communication with the outside world.

Voice recording equipment can also be installed to record all on-site voice communications.

A comprehensive dispatch system can also bind video signals to achieve voice and data coordination. It can also synchronize with geographic location information, simultaneously displaying the location information of dispatched objects.

Application System:

The following figure shows an example of an on-site dispatch system application.

(1) IDM M9000 Communication CommandDispatch Switch Function Overview:

The IDM M9000 shown in the figure can accommodate 12 access service cards.

If radio interface cards are inserted, each card can connect up to 4 radios (trunking);

If telephone cards are inserted, 8 telephone lines (FXO or FXS) can be supported;

If GSM/CDMA phone cards are inserted, 2 SIM card mobile phone lines can be accessed.

The WG300 processing card features IP telephone gateway functionality, enabling interoperability between analog voice services and IP (compliant with SIP standard VOIP protocol), allowing dispatch and data storage over IP.

The central processing card WG300 also provides TDM-based telephone switching functionality. Voice services on the IDM M9000 can undergo program-controlled telephone switching, with user ports and trunk ports being interchangeable, totaling 120 channels.

The central processing card WG300 supports multi-party voice conferencing, allowing conference rooms to be allocated for trunking radios and IDM MCC keypad dispatch consoles, thereby enabling flexible multi-party communication.

The central processing card WG300 also features E1-based digital signaling extension functionality, supporting conversion of China No. 1, China No. 7, and PRI signaling.

(2) IDM MCCDispatch Console Function Overview:

The IDM MCC is an IP keypad dispatch console without a computer system. It can be connected to the IDM M9000 via an Ethernet switch, offering flexible installation locations. It features a built-in 10W loudspeaker and can be deployed over any IP channel for convenient use.

The IDM MCC is equipped with 5 sets of radio group corresponding keys (the mapping can be configured).

Monitoring function: When monitoring a selected radio group, the corresponding indicator light displays the monitoring status color. If there is audio on that channel's radio trunking, the loudspeaker outputs the audio, and the corresponding channel indicator light flashes simultaneously.

Talk function: If a channel is allowed to talk (configurable), the talk-allowed indicator light for that channel illuminates. Pressing the group broadcast key then broadcasts the microphone audio across all allowed trunking groups.

For more advanced dispatch functions, a dispatch server and touchscreen dispatch console are required.

(3) IDM NTD421 is a chain-network optical terminal that can be directly connected to the IDM M9000 dispatch switch, providing network, telephone, and data access. It is well-suited for use in tunnel construction.

For greater Ethernet bandwidth, the IDM GTD 442 chain-network device can be used.

If traditional telephone services are not required, the IDM POE-M8 chain-network gigabit media converter can be used. This device features POE power supply functionality, facilitating terminal access such as POE-powered WIFI routers and POE-powered network cameras. The IDM POE-M8 has a total power supply capacity of 150W. If POE power supply is not required, the cost of this device can be significantly reduced.