Distributed Antenna Systems — There are two different types of DAS systems. One is passive and one is active.
The passive system is typically an open air repeater using coaxial cable only. The passive system uses one or more donor antennas that will communicate with the closest cell towers or base station. The donor antennas connect directly to a repeater or series of repeaters and then the signal is sent from the repeater to a server antenna or series of server antennas. These systems are generally used for smaller coverage area footprints below 80,000 square feet. Examples of where we install these systems are small and large homes, small offices or home offices (SOHO), boats and even cars. They can be either single carrier or multiple carrier systems. These systems are much more cost effective, quick to deploy and easy to install. All of these systems are carrier and FCC approved.*
The active system is different from passive because it uses a fiber optic cable distribution system as well as a different signal source such as a base transceiver station (BTS) or small cell application. These systems are much more complex and require expert RF engineering. Using this system requires a fiber head end that will convert the radio frequency (RF) to light which then sends the light to a remote or series of remotes that then covert the light back to radio frequency (RF) and then distributes to a series of server antennas. These systems are used in large coverage areas above 80,000 square feet such as stadiums, high rise buildings, hospitals, casinos, hotels, etc. These systems can be designed for single carrier use or neutral host, meaning a shared system with one or more carriers.
Public Safety DAS
A Public Safety DAS can work with either a passive or active DAS. Public safety works very similar to a cellular DAS in that it transmits (Tx) and receives (Rx) a signal from a donor site or BTS. The determining factor for which to use either a passive or active system is also determined by the area of coverage or square feet of the facility or venue. It can and often is determined by the governing entity. Learn more about Public Safety DAS here.
Please see the diagram below for more information on how a passive or active DAS works: