Tunnel broadcasting and wireless trunking communication broadcasting system - the case of Tiantaishan tunnel

Beijing Hengxing Ketong was released on 2022-7-19

Tiantaishan tunnel is G85 Yinkun Expressway （ Baoji, Shaanxi - Pingkan section ） Expressway is an important part of the road , The tunnel crosses the Qinling Mountains , Single hole length 15.6 km , The total length reaches 31.2KM, On 2021 year 10 month 1 The whole line was completed and officially opened to traffic .

Tiantaishan tunnel is the largest highway tunnel in the world that has been built , Tiantaishan tunnel is the controlling project of Baoping Expressway , Clear width 14 rice , Clear height 5 rice , The design speed is... Per hour 80 km , It is a two-way six lane , The vertical height of the tunnel from the ground is 70 rice , Construction scale 、 The construction difficulty ranks first in the world .

One 、 System Overview

In order to strengthen the evacuation and rescue capacity of Qinling Tiantai Mountain Tunnel , Set up wireless system in Tiantai Mountain Tunnel in Qinling Mountains . Tunnel wireless communication system is a multi system 、 Multi band integrated mobile communication system , For maintenance in the tunnel 、 Rescue 、 It is designed to establish flexible communication between patrol personnel and management personnel in the control room , It can transmit information to the staff in the tunnel through the dispatching base station 、 Notices and orders, etc , It can also broadcast tunnel information to drivers of vehicles passing through the tunnel through FM radio transmitter 、 Notices and orders, etc , At the same time, it can provide the relay transfer function for the communication between the fire mobile phone and its corresponding central station .

Tunnel wireless system includes 400MHz Wireless dispatching communication subsystem 、350MHz Public security fire control wireless signal introduction subsystem and 87-108HMz Of FM FM broadcast signal is introduced into subsystem . The wireless system signal access center and control system are set up in the Tiantai Mountain Tunnel Management Office at the southern foot of the Qinling Mountains , Through optical fiber to tunnel 98 Connect the remote machine of the integrated optical fiber repeater , The signal is amplified by the repeater and sent to the tunnel through the special tunnel antenna FM Wireless FM broadcasting and 400MHz Dispatch signal .

Two 、 Function introduction of each subsystem

1、FM FM broadcasting subsystem

FM FM broadcasting subsystem is when vehicles enter the tunnel , You can hear the same sound outside the tunnel without interruption FM FM radio signal , For car radio listening . The system can realize local （ Baoji City ） Listen to the main radio channels , Usually forward and play CCTV 、 Shaanxi station 、 Baoji Station and other traffic stations FM FM radio programs , In an emergency , But now 1-16 Emergency broadcast content is interrupted by channels （ Consistent with the voice of emergency telephone and broadcasting system ）, And can achieve “ Group carrier ” Full band emergency broadcast , Remote day forcibly inserts emergency information or emergency evacuation voice information in the tunnel , The left and right holes can be inserted separately , They don't influence each other . There is no interference with the signal of another repeater adjacent to the tunnel , There is no coherent area at the entrance and exit of the tunnel , And can be achieved with local FM Synchronous coverage of broadcast signals .

Because the tunnel management office is located at the south foot of the Qinling Mountains , The local people cannot accept FM Radio signals , therefore FM The signal is received and coupled by Baoji urban space , It is transmitted to the tunnel management office through optical cable , Then it is transmitted from the near end machine of the tunnel management office to the far end machine in the tunnel .

2、350MHz Public security fire fighting subsystem （ This function is reserved in this project ）

350MHz The public security fire control subsystem introduces the public security fire control cluster signal outside the tunnel into the tunnel , Meet the communication needs of the public security and fire police in the tunnel . Its purpose is to ensure the smooth progress of public security prevention, traffic police dispatching and fire rescue within the tunnel .

In general, the system provides on-site public security personnel and public security command center in the tunnel 、 Between the traffic police and the dispatching center of the Traffic Management Bureau 、 Wireless communication between traffic police inside and outside the tunnel ; In case of fire and other emergencies , Between the fire commander and the fire command detachment in the tunnel , Wireless communication between fire fighters inside and outside the tunnel .

The wireless dispatching intercom system is for the production operation inside the tunnel 、 Maintenance Management 、 Required for commanding and dispatching , And managers 、 Site maintenance personnel 、 Requirements of other staff , Set up an internal mobile communication system . Its purpose is to facilitate maintenance in the tunnel 、 Rescue 、 Establish flexible communication between patrol personnel and control management personnel .

According to the information on the Internet , Baoji Public Security Bureau used PDT Police trunking communication system , Is to use 2 Group frequency 4 Channel trunking communication system . The public security trunking communication system can receive coupling in the urban space of Baoji , It can also be coupled through directional coupler in Public Security Bureau , It is transmitted to the front-end near end machine of the tunnel management office system through optical cable .

3、400MHz Scheduling cluster subsystem

Based on the needs of tunnel management , Build a set of 400MHz Digital trunking communication system , And introduce the signal into the tunnel , It can realize multi team simultaneous multi group call or emergency unified scheduling , Build a set of technologically advanced 、 Mature wireless digital command and dispatching system . The products selected by the system adopt mature technology and have been widely used in the market , Meet the needs of work development . At the same time, in order to ensure the progressiveness of the system , The system adopts digital exchange technology .

For communication function and signal coverage requirements , It is recommended to build a set of digital trunking communication base stations to cover the whole area . The base station is equipped with 2 Digital trunking channel machine , Realize the transfer of interphone signals , Increase coverage , And provide more service channels , Richer business functions .

The channel machine works in digital mode , Each channel machine can provide two call channels , Single base station 2 Multiple channel machines can be provided at the same time 4 Call channels .4 Channels can be assigned to 4 Call groups using at the same time , Due to the adoption of digital trunking technology , On the phone , The service channel used by the interphone can be dynamically and automatically allocated , Single station 2 Channel machine PDT The digital trunking system can support at least about 6 to 8 Call needs of call groups .

It can be realized in the system 4 Groups talk at the same time , They don't influence each other , For example, road administration 、 Security 、 Electrical maintenance and other types of work talk at the same time .

meanwhile , The walkie talkie can be set with off-line function , Write a direct frequency point for each interphone , Away from the system 、 When the base station goes down unexpectedly or the system does not need to be used , Interphones can still communicate directly .

Two 、 Remote end machine of the third mock examination digital optical fiber repeater in tunnel

The system equipment consists of 400M Cluster direct amplifier 、FM FM radio direct amplifier 、 fire 350MHz Cluster direct amplifier 、 The signal pulls the main unit of the high beam 、 Expansion unit and optical remote unit 、 The antenna 、 Lightning arrester 、 Power divider and monitoring components .

The optical remote unit is set in the emergency telephone hole room , The power divider and antenna are used to cover the whole tunnel ; Outside the cave 、 Directional antenna is used in the equipment room in the tunnel , The management station adopts omni-directional antenna .

Each subsystem is in the process of establishing the tunnel management station , Through the main unit 、 The expansion unit, remote unit and optical fiber cover the tunnel site .

1、 The main function ：

The control center personnel call the wireless interphone personnel in the tunnel and at the tunnel entrance through the dispatching base station .

The wireless interphone personnel in the tunnel and at the tunnel entrance can communicate with each other , Intercom communication can be carried out in groups , They don't influence each other .

The system can broadcast tunnel information to drivers of vehicles passing through the tunnel 、 Notices and orders, etc , And the left and right holes can be inserted respectively .

The fire-fighting mobile phone can realize the communication with the fixed fire-fighting central station and the mobile fire-fighting command vehicle , Fire phones can communicate with each other .

2、 Operation mode ：

400MHz The wireless dispatching intercom system works in two-way different frequency half duplex mode .

87-108MHzFM The FM broadcast communication subsystem works in the mode of one-way same frequency simplex .

350MHz The public security and fire protection systems work in two-way different frequency half duplex mode .

3、 ... and 、 Networking mode ：

use SFP Digital optical fiber networking mode , Support star networking 、 Tree networking 、 Ring networking . Support single fiber remote monitoring , Set the repeater working state parameters , Real time transmission to the near end machine and connection to the monitoring platform , Support local network interface parameter settings , Support remote parameter setting through the near end machine .