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How many walkie-talkies do you need before IMDA requires a licence in Singapore?
IMDA's licence threshold for walkie-talkies in Singapore is a minimum of 2 sets, not a maximum of 5. Here is what actually moves you up a licence tier.
info466216
3 days ago4 min read
How do you measure a building's RF noise floor, and what reading means the site needs filtering rather than more signal?
How to measure a building's RF noise floor in dB, and the reading at which filtering beats adding gain. Test method, thresholds and what it costs in coverage.
info466216
4 days ago5 min read
Do satellite or voting receivers make sense as a cheaper alternative to a full in-building DAS?
Voting receivers only fix the uplink. When satellite receivers beat an in-building DAS, when they fail, and what IMDA licensing adds in Singapore.
info466216
5 days ago5 min read
Does COPIF apply to in-building two-way radio coverage, or only to telco and mobile operator facilities?
COPIF covers telco facilities, not your two-way radio DAS. What a Singapore building owner must do instead — riser rules, licensing and coverage specs.
info466216
6 days ago5 min read
What is the penalty in Singapore for operating an unlicensed in-building repeater or booster, and is the building owner or the operator liable?
What Singapore's penalty is for an unlicensed in-building repeater or booster, and whether the building owner or the operator carries the liability.
info466216
Sep 115 min read
What do Singapore's Radio-communication Regulations actually require of a building owner?
Singapore's Radio-communication Regulations licence radio equipment, not buildings. What building owners are actually obliged to do about coverage.
info466216
Sep 104 min read
What percentage of a building's floor area must have working radio coverage?
90% general and 99% critical floor area radio coverage is a US code figure. Singapore prescribes no percentage — here is what to specify instead.
info466216
Sep 95 min read
Does choosing UHF over VHF actually fix basement and stairwell dead zones?
UHF beats VHF in reinforced concrete by roughly 5-10 dB. A basement carpark costs 30-50 dB. Why band choice alone never fixes dead zones.
info466216
Sep 85 min read
Do two-way radios work inside lift cars, and what does it take to cover them?
A lift car adds 40-60 dB on top of the building path. Why radios cut out inside lifts, and what a shaft antenna or leaky feeder actually fixes.
info466216
Sep 75 min read
Is the "200 radios per repeater" figure realistic, and at what call rate does it break?
The 200 radios per repeater figure assumes about three short calls per user per hour. Here is the traffic maths, and what it drops to on a busy site.
info466216
Sep 74 min read
What is the difference between IMDA's Localised Radio-Communication Station Licence and the Localised Private Network Licence?
IMDA's Localised Radio-Communication Station Licence licences equipment; the Localised Private Network Licence licences a network. Which your site needs.
info466216
Sep 45 min read
Why doesn't a walkie-talkie's advertised 300,000 sq ft coverage rating translate into floors covered in a concrete building?
A walkie-talkie's 300,000 sq ft coverage rating says nothing about floors covered in concrete. Here is the dB arithmetic that does, from an RF engineer.
info466216
Sep 34 min read
Do cellular DAS antenna spacing figures apply to a UHF two-way radio DAS?
Cellular DAS coverage-per-antenna figures underestimate a UHF two-way radio DAS by roughly six times. The frequency maths, and what to design to instead.
info466216
Sep 14 min read
What is the "cliff effect" on digital radios, and why do they cut out suddenly instead of just getting noisy?
The digital cliff effect explained: why DMR radios sound perfect then drop dead, the BER threshold behind it, and the fade margin your DAS needs.
info466216
Aug 314 min read
Will a higher-power repeater or a higher-gain antenna fix our coverage problem?
More transmit power only fixes the downlink. Why higher-gain antennas can hurt a high-rise, how to spot an uplink-limited system, and what IMDA allows.
info466216
Aug 315 min read
What antenna spacing should an in-building DAS use per floor, and is there a rule of thumb?
How far apart should in-building DAS antennas be per floor? Real UHF spacing figures, wall-loss numbers and a rule of thumb before your site survey.
info466216
Aug 285 min read
Is DAQ 3.0 or a -95 dBm Signal Level the Right Acceptance Criterion for In-Building Radio Coverage?
DAQ 3.0 and -95 dBm measure different things. Which acceptance criterion should an in-building radio coverage test use? A Singapore RF engineer explains.
info466216
Aug 264 min read
Should we fit a receiver multicoupler and preamplifier at the repeater, or go straight to a DAS?
A mast-head preamp buys 4-9 dB on the uplink only. A DAS buys 40 dB or more both ways. How to tell which one your building actually needs.
info466216
Aug 244 min read
How many channels, users or how much power triggers a higher IMDA licence tier in Singapore?
What pushes a Singapore two-way radio network into a higher IMDA licence tier: 1 W ERP, fleet size, dedicated frequencies and fixed repeater infrastructure.
info466216
Aug 245 min read
How many radios can one repeater channel support before calls start getting blocked?
How many radios one repeater channel supports depends on Erlang traffic, not headcount. Typical figures, DMR two-slot capacity and when to add a channel.
info466216
Aug 225 min read
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