Two Different Systems Share One Name
“DAS” gets applied to two jobs that have almost nothing in common except antennas and coax. Deciding which one you actually need is the whole conversation, because they answer to different people, run on different schedules, and get paid for by different budgets.
Public safety radio coverage
This one exists because the fire code says so, and the local fire marshal enforces it. The question is whether a firefighter’s portable radio works in the stairwell, in the elevator, on a below-grade parking level, in a pump room, and at the fire command center. You do not get to choose the frequencies. You are amplifying an agency’s own radio system, which means written permission from the agency that owns that system before anything is energized, because a badly aligned amplifier degrades coverage well beyond the building it sits in. Nearly every Georgia jurisdiction is testing for this at certificate of occupancy, and it is a poor time to discover it.
Cellular coverage
This one exists because tenants and guests complain. Here the carriers hold the cards. An off-air repeater needs carrier consent. A real distributed system needs a carrier-supplied or neutral-host signal source, and the carriers decide which buildings are worth their equipment. The construction is straightforward; the approval timeline is what determines when the system goes live.
The Georgia Buildings Where This Comes Up
- Metro Atlanta high-rises with below-grade parking and deep core areas that nothing outside can reach
- Hospital lower levels and imaging suites, where the shielding that protects the imaging equipment also blocks everything else
- Hotel and conference space around the Hartsfield-Jackson corridor, where guests arrive expecting coverage
- Metal-clad warehouses and cold storage behind the Port of Savannah, where the building envelope is effectively an RF shield
- Production stages in the metro Atlanta film and television cluster, built to keep sound out and incidentally very good at keeping signal out
- Concrete plank student housing in Athens, and multi-building medical campuses in Augusta
The Survey Decides the Design
Nothing useful can be designed from a floor plan alone. We measure donor signal at the roof, then walk the building floor by floor on a grid and record what is actually there. That produces two numbers that matter: how much usable signal exists to work with, and how far below the required level the weak areas sit. Only then does antenna count, cable route and amplifier sizing mean anything. Guessing at this stage is how buildings end up with a system that passes in the lobby and fails in the stairwell that the inspector will walk.
What the Equipment Has to Survive
A public safety system is life safety equipment and is held to that standard. Head end and batteries live in enclosures rated for the environment they are in, with backup power sized to the code-required duration and supervised so that a fault, a battery failure or an antenna disconnect annunciates at the fire alarm panel rather than sitting silent. The rooftop donor antenna and its feed are the most exposed part of the whole system during a Georgia summer, so the coax is bonded to the building grounding system with surge suppression at the entry point. Then it gets tested annually, on record, for the life of the building.
What You End Up Holding
Survey data before and after, a coverage plot referenced to the required signal level, an as-built showing antenna locations and cable routes, cut sheets and settings for the head end, the approval correspondence from the radio system owner or the carriers, and the acceptance test the authority having jurisdiction signed. That package is what makes the annual test straightforward instead of an investigation.
To start with a survey rather than a proposal, call KSEDCO at (888) 360-0035 or reach the Georgia office at 2700 Cumberland Pkwy SE, Suite 410, Atlanta GA 30339.