Distributed antenna systems (DAS) are a useful technology for allowing greater communication in areas where cellular signal coverage might decline. Building materials such as concrete and steel block out cellular frequencies, which is why distributed antenna system is necessary.
For those who don’t know, there are five main components of distributed antenna systems (DAS). With this in mind, let’s examine each element so you can get a better understanding of how this system works.
The first component of a DAS is a source for the system to obtain a cellular signal. Major companies such as AT&T, Verizon and T-Mobile are service providers that offer signal sources throughout a given area. For a DAS to obtain a signal feed, it needs to seek permission to use the network provided by one of these carriers.
The DAS Tray (also known as the Point-of-Interface or POI Tray) serves as the main connection between the signal sources coming from outside the system and the head-end unit, which you will learn about later. The purpose of a DAS tray is to combine incoming radio frequencies from various sources and deliver them to the head-end unit.
This tray helps attenuate RF signals because these signals often have more power than a head-end unit can handle. For example, without a DAS/POI tray, an Emergency Responder Radio Coverage System might experience power loss or overheat.
The head-end unit is one of the most important pieces of equipment for a DAS system because it serves as the main traffic controller for radio frequencies in a DAS system. This unit takes incoming frequencies from the DAS tray and directs them through the network. In addition, it also filters outgoing signals.
An active DAS will use radio units to transmit frequencies throughout the system. The head-end unit sends a signal to the radio unit, where it will separate them according to their frequency, amplify the signals, and transmit these signals to the antennas.
Finally, a DAS will use fiber optic cables to connect all the components. For an active system, the best choices are thin and lightweight cables so they can fit into tight spaces. These thin cables can connect radio units that are far away from each other without losing the signal.
Overall, DAS is a fascinating technology that helps us communicate and stay safe during emergencies. Now that you know the five main components of distributed antenna systems (DAS), you can have a greater appreciation the next time you see one of these systems out in public.