How many antennas does it take to cover a large shopping mall with two-way radio, and what does it cost?

For a large Singapore mall — call it 500,000 to 1,000,000 sq ft over several retail levels plus basement carparks — you are almost always looking at one on-site repeater feeding a distributed antenna system (DAS) of roughly 60 to 200 antennas, not a handful of high-power radios. The antenna count is driven by the number of RF shadow zones and floor plates you must cover, not by the headline floor area alone. As a rough budgetary figure, a professionally designed and commissioned two-way radio DAS for a mall of this size runs on the order of S$3 to S$8 per sq ft, but the only number worth quoting firm comes after a site survey.

Why a mall needs so many antennas

A mall is one of the harder buildings I survey, because it is really several different RF environments stacked together. The retail levels have large open atriums where signal travels well, but they are ringed by back-of-house corridors, service lifts, loading docks, cold rooms, plant rooms and fire-rated staircases that behave like separate sealed boxes. Below them sit multi-level basement carparks, and each reinforced-concrete floor slab costs roughly 15 to 25 dB on UHF (400–470 MHz). Two or three basements down, an outside or rooftop signal is simply gone.

The design target I work to is a usable signal of at least −95 dBm at the portable across 95% of the floor area, with a 10 dB fade margin (15 dB where the coverage supports fire and life-safety operations). You cannot hit that in every back corridor and stairwell from one or two antennas. You hit it by distributing many modest antennas so no user is ever more than one slab and a short horizontal run from the nearest one. The atrium might take a single antenna per 1,500–2,500 sq m; a warren of back-of-house rooms on the same floor might need five.

What actually sets the count

A few concrete drivers decide the antenna number:

• Floor plates and levels: each retail level and each basement is its own coverage layer.

• RF shadow zones: cold rooms, plant rooms, loading bays, fire stairs, lift cars and service risers each typically need a dedicated antenna.

• Construction: post-tensioned RC slabs (15–25 dB each) and metal-clad service areas force closer antenna spacing.

• Coverage grade: pushing from 90% to 95% area coverage, and adding fade margin, adds antennas at the difficult edges.

• The uplink: the 4 W portable getting back to the repeater — not the 40 W downlink — is usually the limiting path, so antennas must be dense enough for the handset, not just the base station.

Stack those and a 500,000 sq ft mall commonly lands around 60–120 antennas; a very large or deep-basement complex can exceed 200. Every antenna is fed from the ELV riser through staged directional couplers (typical taps 6, 10, 13, 15, 20 dB) so each antenna port lands within about ±3 dB of its neighbours.

Roughly what it costs

Cost tracks the antenna count, the cabling runs and the active equipment, so it scales with the same shadow-zone complexity that drives the design. As a budgetary order of magnitude in Singapore, a commissioned two-way radio DAS falls in the region of S$3 to S$8 per sq ft. The spread is wide because a mostly-open mall with short riser runs sits at the bottom, while one with deep basements, heavy back-of-house, fire-rated cabling requirements and a tight commissioning programme sits at the top. Fire-rated coax, two-hour-rated equipment rooms and after-hours working — items that rarely appear in a first quote — are what move a job up the range. I never price firm off a floor area figure; the number comes from a survey, a floor-by-floor antenna plan and a coupler schedule a contractor can build and a consultant can audit. For how the finished system is proven, see our explainer on how in-building two-way radio coverage is measured and passed, and on what a coverage system costs and why.

Related questions

Can one repeater cover a whole mall? Usually yes — one 40 W repeater on one licensed channel pair can feed the entire DAS. You add antennas, not repeaters, to reach the shadow zones. A second repeater is only for traffic capacity or a physically separate block, not for range.

Do the basement carparks need their own antennas? Yes. Each basement slab costs 15–25 dB, so below-grade levels are the worst dead zones in the building and each needs dedicated antennas fed down the riser — the same principle as covering a standalone carpark.

Is the antenna count something a supplier can quote over the phone? No. Anyone quoting a fixed antenna count or price from the floor area alone is guessing. The count comes from a walk-through survey that finds the actual shadow zones and checks the uplink budget.

How Suneast solves this

Suneast designs, installs and commissions in-building two-way radio coverage for shopping malls and large retail complexes in Singapore — one on-site repeater feeding a DAS sized to the building's real shadow zones, with antennas placed for retail floors, back-of-house, loading docks, fire stairs, lift cars and every basement carpark level. We work from the CAD floorplan to a downlink-and-uplink link budget, a per-floor antenna layout and a directional-coupler tap schedule, verify the result with a floor-by-floor grid survey against the −95 dBm threshold, and handle the IMDA station licensing the repeater requires.