Carrier Approval Required For Active DAS, Femtocell, Picocell Systems
If you have no cell signal inside nor any signal outside whatsoever, then Passive Distributed Antenna Systems (Passive DAS) will not help create cell signal. An Active DAS, Femtocell or Picocell system will be required which requires a cabled signal feed directly from respective cellular service carrier(s). Therefore, in-building DAS, outdoor DAS (oDAS), fem-to-cell or pico-cell systems require co-operation and explicit approvals from respective mobile service providers.
If you do have some cell signal inside or outside (-100dB or better), passive DAS signal enhancing systems can help greatly. Advantages of a passive DAS solution are that no carrier approvals are required; it works with all carriers; the price is a lot lower; it features easy deployment - it can be designed and implemented in as little as five days. According to the FCC, if they have classified a signal amplifier system or bidirectional amplifiers (BDA) as a "consumer" booster that can be installed without any coordination and approvals with/from carriers.
Active DAS, Femtocell, Picocell Systems may be pricey but are very useful if no cell signal exists inside nor outside the house or building but a drawback is that they require explicit carrier approval and co-ordination. Secondly, large in-building Active DAS and outdoor Active DAS (oDAS) or Small Cell Systems are comparatively very high in price (usually expensive due to higher installation cost) and require comparatively much longer time to design and install. On other hand, in-building Passive DAS is generally much cheaper in cost (price-wise for equipment and pricewise for installation) plus much quicker to install (up to 5 business days). Furthermore, passive DAS does not require carrier approval for consumer signal booster kits. They are pre-approved and only need online signal booster registration with respective carrier. In addition to these advantages, Passive Distributed Antenna Systems also boost cell phone signals of all cellphone service networks, simultanously.