DMR  |  2012-08-23

Hytera DMR Solution Smoothes Communication in Sightseeing Tunnel of Kinmen, Taiwan

Source: The Critical Communications Review | Gert Jan Wolf editor

Kinmen, governed by the Taiwan Government, is the strategic stronghold between Chinese mainland and Taiwan. It is located on west side of Taiwan Strait and at southeast of Fujian province across the sea.

Kinmen, governed by the Taiwan Government, is the strategic stronghold between Chinese mainland and Taiwan. It is located on west side of Taiwan Strait and at southeast of Fujian province across the sea. With the shortest distance away from the mainland, Mashan (in Kinmen) and Jiaoyu (in Fujian China) are only 2,310m apart. For historical reasons, many tunnels and air-raid shelters had been dug. With the alleviation of the relationship between the mainland and Taiwan governments, the tunnels and air-raid shelters have been developed by the Cultural Affairs Bureau of Kinmen County into tourist destination.

In the sightseeing tunnels of Kinmen, communication devices in public network like mobile phones cannot work, not even semi-professional walkie talkies; and the humid environment in the tunnel can easily damage the general communication devices. How to maintain the timely and reliable communications in case of emergency is a significant challenge.

To ensure smooth communication in the tunnels, the Cultural Affairs Bureau of Kinmen decided to upgrade the communication systems of all the tunnels, and they preferred digital communications. One tunnel of 1km was then selected for trial. 26 points were set in the tunnel, and an emergency communication device would be distributed at each point. A dispatching center should be established outside the tunnel to monitor the communications throughout the tunnel. Thus tourists can use the nearest communication device to call the dispatching center under emergency situations. 4 communication devices were needed outside the tunnel for the patrol personnel.


pd78x20with20waterproof20box.jpg
PD78X with the waterproof box

Hytera offered a DMR digital communications solution to the Cultural Affairs Bureau of Kinmen to smooth the tunnel communication, including PD78X portable radio, MD78X mobile radio and SmartDispatch dispatching system.

Due to the humid environment, the previous products used in the tunnel had to be replaced within less than one year due to the humid environment, resulting in excessive expense in cost. Considering this, Hytera PD78X DMR portable radio with IP67 water protection was adopted as communication terminal. A waterproof box in which PD78X would operate was added for better protection and the communication was conducted with the hand-held microphone connecting to PD78X, through out of the waterproof box, significantly saving the cost for the customer.

The communication terminals used should operate in an uninterrupted stand-by state for safety reasons. The conventional batteries, however, cannot comply with the requirement for their limited service time. Hytera and our partner in Taiwan designed specially a battery box to supply the power directly when being connected to DC, thus 100% uninterrupted operation of the radios can be guaranteed. The reliability of emergency communications in the tunnel was maximized.


For effective management, Hytera provided the SmartDispatch DMR dispatching solution, and tailored some special functions for the project. GPS positioning is not demanded in this project as the terminals in the tunnel are installed in fixed positions. Instead, it uses map provided by the customer; the map can be changed as required. All the 26 PD78X radios can communicate with the console via individual call.

To monitor the terminal status, the console should back-check the status of the radios (on/off line) following the sequence from No.1 to 26 via the SmartDispatch system. The amount of data required to be processed is limited as only one or two back-checks are needed per day, so that only one MD78X that acts as a gateway and one console client are required in this situation. In addition, there are 4 PD78X to be used by the patrol guards. Managed by SmartDispatch, they are tailored in consistency with the above 26 radios, yet they only need to communicate with the console. And two communication groups are available for the 4 terminals. smartdispatch20with20md78x.jpg
SmartDispatch system and the MD78X


"We couldn't know clearly about the situation in the tunnel in time when emergency strikes with the previous cable telephone for the humidity in the tunnel would damage the cable lines. Now the digital wireless system used not only improves significantly the mobility, but also displays the correct position on the computer screen immediately, and the ultra-clear voice quality is unmatched by the traditional communications."
“We are very satisfied with and amazed by the products from Hytera, and expect such solution to be promoted and used in the following projects.”

                             —— Official of Cultural Affairs Bureau of Kinmen County

Source: Hytera