In-building cellular problems are caused by a number of factors: the material of the building, the location of the user, and the location of the closest cell site are three of the typical ones. There are a number of technologies that can be utilized to solve this problem, from expensive Active Distributed Antenna Systems (DAS), so-called small cells or Femto cells that require an Internet connection, or a Passive DAS, also known as a Repeater System.
A DAS is usually installed when a venue has a capacity (too many users) problem. Stadiums, arenas and malls are usual suspects for a DAS. There are a number of OEMS that provide these solutions (SOLiD, Commscope, JMA Wireless e.g.). These systems require extensive engineering up-front to determine the location of the head-end equipment and the location and feasibility of cable paths for connecting the head-end to remote antennas. These designs are usually submitted to the carrier(s) for approval before the system is installed, a process that can take months. Additionally, customers need to determine if the carrier(s) will fund any part of the signal source and they will need to sign a retransmission agreement with each carrier.
Small cells are a relatively new technology and depeding on the carrier go by different names. They essentially replace the sophisticated head-end equipment of a DAS with a “routeresque” appliance that provides a signal source. The downside is that many of these systems are for a single carrier, although there are technical ways to provide a multi-carrier small cell solution. To date, the carriers are typically involved in the process of commissioning and optimizing a small cell solution.
The third and least costly of the options to solve in-building cellular problems are Repeaters. Wilson Electronics and SureCall are the primary OEMs that provide equipment for this maket. These systems are suitable for venues from 25 thousand to 300 thousand square feet that have a coverage problem (no signal indoors) not a capacity problem. They involve the mounting of a so-called Donor Antenna on the exterior ot he building where there is adequate cellular signal and using Bi-Directional amplifiers inside the building to boost the signal and distribute it via coax cable to antennas in areas that don’t have signal.
These Bi-Directional Amplifiers are “Consumer” devices so they have been pre-approved for installation by the FCC and the carriers. They are also wideband, meaning the handle the entire spectrum of frequencies used by all the cellular carriers in the United States. Once installed, the system simply needs to be registered on a carrier(s) website. For most customers, these Repeater systems are the most cost effective and elegant solution. The caveats are that they will not increase cellular capacity and they require adequare outdoor cellular signal. Without adequate outdoor signal, there is nothing the Amplifiers can boost.