A mouth or aperture, such as of a tube, pipe, etc.; an opening.
A system of ducts for cables, heating or ventilation.
The movement of containers or packages between a terminal and a transporter's inland facilities, or the scheduled transportation service between locations.
All the electrical and communications cables bundled together and distributed through a building.
Plastic conduit or duct used to conceal and protect electrical wiring.
A two-way radio technique that uses a control channel to automatically assign frequency channels to groups of user radios.