Ensuring uninterrupted mobile signal in a tunnel can be tricky, but several solutions address this challenge. The best option for your specific situation will depend on factors like:

Tunnel length and shape: Is it a short, straight tunnel or a long, curved one?

Traffic volume and type: Are you looking for coverage for cars, trains, or both?

Desired features: Do you need voice calls, data connectivity, or both?

Budget and regulatory restrictions: Some solutions might be more expensive or require permits.

Here are some common mobile signal coverage solutions for tunnels:

1. Distributed Antenna System (DAS):

This is the most reliable and scalable solution for long tunnels with high traffic volume.

DAS involves installing a network of small antennas throughout the tunnel, distributing the signal from existing cell towers.

It offers seamless handover between antennas and excellent coverage for both voice and data.

2. Signal Boosters/Repeaters:

These devices amplify the existing signal within the tunnel.

They're cost-effective for shorter tunnels but might not provide uniform coverage or support data connectivity.

Ensure you comply with regulations regarding maximum signal amplification permitted.

3. Fiber Optic Repeaters:

These utilize fiber optic cables to transmit the signal from outside the tunnel to antennas placed strategically within.

Offers high-quality signal and less interference compared to traditional boosters.

However, installation can be more complex and costly.

Below is the actual case we made for our customer:

Take the example of a 5km straight road tunnel.a set of 10W air-coupled fiber opƟ c repeater with 1 pcs 

local unit and 5 .pcs of remote units is adopted.A high-gain outdoor plate antenna is installed at the mouth 

of the tunnel to receive the signal from the base staƟ on and connect it to the fibre opƟ c repeater via a 1 / 2 

coaxial cable. local units are installed in tunnels as close as possible to outdoor recepƟ on antennas, and 

five remote units are installed in tunnels of 0.5km, 1.5km, 2.5km, 3.5km and 4.5km. Five remote units are 

connected to local unit via fibre-opƟ c cable.The radio frequency output port of each remote unit needs to 

be connected to a two-way spliƩ er and then to 2 direcƟ onal antennas ( installed in reverse), each covering 

a distance of 500m.

 The system diagram is as follows:

If you are interested to the solutions, please feel free to contact with us.