Tenants complain about dropped calls. Your building manager orders a $500 booster from Amazon. Three months later the complaints are the same — or the carrier calls about interference. This is one of the most avoidable mistakes in commercial real estate.
Distributed Antenna Systems (DAS) and cellular signal boosters both address in-building coverage problems, but they work differently, cost differently, and suit different buildings. Choosing the wrong one wastes money and can create regulatory headaches.
What a Signal Booster Does
A signal booster takes the existing outdoor cellular signal, amplifies it, and rebroadcasts it inside. Three parts: an outdoor donor antenna, an amplifier, and one or more indoor antennas. Boosters amplify whatever signal they receive — if the outdoor signal is weak, the booster amplifies a weak signal. FCC-certified commercial boosters also require carrier notification, a step most building owners skip, putting them in violation of FCC Part 20 rules.
What DAS Does
A Distributed Antenna System is a network of antennas spread throughout a building, fed from a central signal source — typically a direct connection to the carrier's own network rather than an amplified outdoor signal. Coverage is consistent and doesn't depend on what's happening outside the building.
- Passive DAS: Coaxial cable distributes signal from a BDA or amplifier. Lower cost, works well in mid-size buildings.
- Active DAS: Converts signal to fiber and digital, then reconverts at remote antenna units. The practical solution for high-rises and large campuses.
Side-by-Side Comparison
| Factor | Signal Booster | DAS |
|---|---|---|
| Signal source | Amplified outdoor signal | Direct carrier connection |
| Building size | Up to ~50,000 sq ft | Any size |
| Signal quality ceiling | Limited by outdoor signal | Full carrier-grade quality |
| FCC compliance | Carrier notification required | Carrier-managed |
| Typical cost | $2,000–$50,000 | $100,000–$1M+ |
| Installation time | Days to weeks | Months |
When a Booster Is the Right Call
Boosters work well for buildings under 50,000 square feet where outdoor signal is decent and the problem is isolated — a dead zone in a back wing, a basement conference room, a concrete stairwell. A certified commercial booster from Cel-Fi or Wilson Pro, properly installed with carrier notification, solves that at a fraction of DAS cost.
Consumer boosters lack the output power for large commercial spaces and most aren't FCC Part 20 compliant for commercial use. You'll waste money and risk interference complaints from carriers.
When DAS Is the Right Call
DAS is the answer when the building is too large for a booster, when outdoor signal is too weak to amplify meaningfully, when multiple carriers need full quality, or when the building is a high-rise where signal doesn't penetrate from street-level towers. Class A office towers, hospitals, hotels, airports, and stadiums almost always need DAS.
Carrier buy-in is the key variable. Each carrier (AT&T, Verizon, T-Mobile) needs to connect their network to your system — a process that adds months and requires either a neutral-host DAS operator or direct carrier relationships.
ERCES Is a Separate System
ERCES (Emergency Responder Communications Enhancement System) is not the same as commercial DAS. ERCES serves first responder public safety radios on P25 frequencies. Commercial DAS serves tenant cellular on carrier frequencies. They're separate systems with separate codes and separate permitting — though they can sometimes share antenna infrastructure. If your building needs both, plan for them together at the design phase.
Bottom Line
Small building, isolated dead zone, decent outdoor signal: a commercial booster will do it. Large building, multiple floors, multiple carriers, or weak outdoor signal: you need DAS. Getting this wrong early means either underbuilding (tenants still complain) or overbuilding (paying for infrastructure you didn't need).
Not sure which solution your building needs?
We'll assess your building, test outdoor signal levels, and recommend the right approach — booster, passive DAS, or active DAS. No overselling.