Various contracts for the design and supply of road and rail tunnel re-broadcasting systems. These systems provide re-broadcast of both FM and AM radio channels and VHF / UHF radio communication facilities for cellular, police, fire, ambulance and utility services. In each case, a tailored system configurations to meet, with precision, the detailed specifications of each customer’s requirements. These systems may use transmission over leaky coax cable with or without bi-directional or monodirectional line amplifiers, fibre optic transmission, and appropriate transmitting and receiving equipment.

Major road tunnels completed include:
- Melbourne’s CityLink tunnel
- Perth’s Graham Farmer Freeway
- Sydney’s Eastern Distributor
- Sydney’s M5 East
- Sydney’s Cross City
- Major rail tunnels completed include: Sydney CBD underground rail stations & Melbourne CBD underground rail stations