A lot of applications are somehow related to, or uses the GNSS signal. First Responders like fire brigades or ambulances must rely on their on-board systems the second they leave the garage. In the Mass Transit systems used all around the world locational information of each unit (busses, trains etc.) is essential. Most of the operational time of these units they do have a clear line of site of the sky, so no problem receiving GNSS signals. But at some specific locations like inside terminals, workshops but also inside tunnels the signal cannot be received. For subway or metro systems the signal is not received for most of the operational time. At these locations the on-board systems get unreliable or even cannot operate at all, GNSS reradiating can help you solve this problem.
At aircraft hangars the same problems occurs, servicing the GNSS-navigation system on board of an aircraft is not possible. Towing the aircraft in and out of the hangar brings a lot of risks, time and costs. A reliable GNSS signal inside the hangar enables service personal to test and service the systems inside the hangar in good working conditions with all equipment available.