When crisis situations occur and first responders are on the scene, a Public Safety DAS (distributed antenna system) ensures real-time, mission-critical communications between safety professionals during an emergency response.
First responders coordinate efforts via radio signals broadcast within government-mandated frequency ranges, normally in the VHF, UHF, 700, and 800 MHz bands. However, the preponderance of steel, concrete, and low emissivity (Low-E) glass in modern construction creates many challenges for a reliable signal in many buildings. The density of the materials, coupled with the square footage within the structure makes it difficult for first responder radio signals to penetrate and populate the entirety of the space.
Public Safety DAS combats the structural challenges that create RF interference by leveraging an outdoor donor antenna that receives RF transmissions from first responder radios, and those signals are in turn collected, amplified, and rebroadcast within the building structure via the solution’s distributed network of antennas.
There are generally two types of Public Safety DAS, identified as passive and active solutions. While both solutions utilize the same formula of leveraging a signal originating outside the building, then amplifying it and distributing it inside the building via a network of antennas, the decision to utilize an active or passive Public Safety DAS is largely driven by the size of the structure serviced.
A passive solution utilizes coaxial cable and is an excellent choice for buildings up to 150,000 square feet with light density. An active solution is used for very large buildings and requires a combination of coaxial cabling and fiber, which allows signals to efficiently travel a greater distance.