Distributed Antenna Systems for High-Rise Buildings in Columbia

JB Technologies is a certified Nextivity Pro Partner — we design, install, and commission CEL-FI QUATRA active DAS and passive DAS systems for commercial cellular coverage.

DAS Installation Services for High-Rise Buildings in Columbia

Columbia's high-rise stock is anchored by the Capitol Center (also called the AT&T Building) at 349 feet and the BB&T Building at 274 feet, both along Main Street within walking distance of the South Carolina State House. The metro has a tight cluster of 10- to 25-story office buildings concentrated in roughly six Downtown blocks, plus the USC and Palmetto Health hospital campuses to the east. Construction skews 1970s-1990s reinforced concrete with steel additions in the 2000s. JB Technologies designs cellular DAS for this compact but dense high-rise inventory.

Local context — Columbia, SC

The Capitol Center on Main Street at 349 feet has been Columbia's tallest building since 1987 and anchors a compact Downtown cluster of roughly 15 buildings above 150 feet — the BB&T Building, AgFirst Farm Credit Bank, Meridian Building, and Palmetto Building among them. Construction is overwhelmingly 1970s-1990s reinforced concrete with reflective glass curtain wall, yielding predictable 12-15 dB PCS attenuation. The USC and Prisma Health campuses east of Downtown add 10- to 15-story medical and academic buildings where DAS requirements are clinically driven. Donor signal across Richland County is strong on Verizon and AT&T; T-Mobile 600 MHz penetration has improved noticeably since 2022.

Why Choose JB Technologies for DAS in Columbia?

• Certified Nextivity / CEL-FI QUATRA Integrator
• Measurement-Driven RF Site Surveys and iBwave Design
• Multi-Carrier Coordination — Verizon, AT&T, T-Mobile
• FCC Part 90 / Part 22 / Part 24 Signal-Source Compliance
• Commissioning Sweeps and As-Built Documentation

What is DAS?

A Distributed Antenna System (DAS) is an engineered network of indoor antennas that distributes commercial cellular signal throughout a building so that tenants, employees, and visitors get reliable voice and data coverage on Verizon, AT&T, and T-Mobile. DAS solves the in-building coverage problem in two architectures. Passive DAS uses a donor antenna on the roof feeding a bi-directional amplifier and a coax-and-splitter distribution grid — cost-effective for buildings under roughly 150,000 square feet with a usable outdoor donor signal. Active DAS converts RF to digital at a head-end and distributes over fiber to remote units, scaling cleanly to multi-million-square-foot venues and supporting all major carriers through carrier-grade signal sources. When the outdoor donor is strong and the building is mid-sized, a single-carrier CEL-FI QUATRA deployment is often the right answer; when the donor is weak, the building is large, or true multi-carrier parity is needed, an active DAS is the durable choice.

Where DAS makes sense

DAS is owner- and tenant-driven — it is the answer to "why does my phone drop calls inside this building?" rather than a building-code mandate. Typical DAS candidates:

1. Large floor plates — offices, hospitals, and campuses over roughly 50,000 sq ft where a single booster cannot cover the area.
2. Dense concrete or steel construction — hardened cores and rebar-heavy slabs attenuate cellular signal 15–25 dB.
3. Impact-rated or low-E glass — modern energy-efficient and hurricane-impact glazing attenuates PCS and AWS bands 10–18 dB.
4. Multi-carrier requirements — tenants and visitors on Verizon, AT&T, and T-Mobile all need parity coverage.
5. Below-grade and parking levels — basements, parking decks, and tunnels where macro signal does not penetrate.
6. Healthcare facilities — nurse-call workflows, BYOD clinical apps, and patient-experience requirements.
7. Hotels and mixed-use towers — in-room and amenity-floor cellular is a guest-experience expectation.
8. Warehouses and distribution centers — metal-clad envelopes and dock-door geometry that block macro signal.
9. Higher-education buildings — libraries, residence halls, and student centers with dense user counts.
10. Stadiums, arenas, and conference venues — capacity-driven deployments, not just coverage.

Typical system costs.

DAS pricing varies with building size, donor-signal strength, carrier mix, and design topology. Two rough ranges hold across most commercial work:

Installed Cost Ranges

• Passive DAS — $0.75 to $1.50 per square foot for single-carrier or limited multi-carrier deployments with a clean donor signal, typical of mid-sized offices and mid-rise residential.
• Active multi-carrier DAS — $2.50 to $5.00 per square foot, driven by remote-unit count, fiber backbone length, carrier signal-source coordination, and AHJ requirements. Hospitals, stadiums, and campus deployments live in this range.
• RF site survey and design package — typically $1,500 to $5,000 depending on building footprint and the number of carriers in scope.
• Factors that drive cost:
  • Donor signal strength — weak outdoor RSSI may force a tower-mounted amplifier, an off-air bi-directional amp upgrade, or a small-cell signal source.
  • Building materials — concrete, low-E glass, impact glazing, and metal cladding each shift the design.
  • Carrier mix — single-carrier QUATRA units are cheaper than tri-carrier active head-ends, and each added carrier requires its own Letter of Authorization.
  • Retrofit vs new construction — pulling fiber and coax in finished spaces costs materially more than rough-in during the shell stage.

Permitting and Carrier Coordination

• Electrical and low-voltage permits — required in most jurisdictions for head-end power and cable distribution.
• Carrier Letters of Authorization (LOAs) — active DAS using signal sources from Verizon, AT&T, or T-Mobile requires per-carrier LOAs and RF-emissions disclosure under FCC Part 90, Part 22, and Part 24.
• FCC signal-booster registration — consumer-class boosters must be registered with the operating carrier; commercial Part 20.21 systems are coordinated upfront.

Commissioning and Ongoing Support

• Commissioning sweeps — downlink and uplink RSSI measured at design points, exported to the building owner and the AHJ when applicable.
• Annual coverage verification — recommended after major tenant fit-outs, antenna relocations, or carrier band-plan changes.
• Warranty and remote monitoring — QUATRA and most active DAS head-ends ship with cloud monitoring; JBT maintains active alarms through a service agreement.

Key Takeaways

• Plan during shell construction — rough-in for fiber and coax pays back many times over versus a finished-space retrofit.
• Match the topology to the building — passive for smaller buildings with good donor, active for large or multi-carrier requirements.
• Confirm carriers early — the carrier mix dictates equipment selection, LOAs, and design timeline.