Working in radio, we spend a lot of time worrying about two things: coverage and overspill. Getting coverage of a building is the core objective of the DeafWatch™ system and achieving coverage can often be a challenge.

Concrete buildings reinforced with meshed rebar steel and metre thick floor or walls can cause several difficulties.  We’ve even enjoyed covering a military training centre with two-centimetre thick hardened steel on every surface. Our customers do like to set us problems to solve!

We like a challenge here at Wireless Alert, it’s why we’ve designed and built the most powerful fire alarm paging system for Deaf people in the market. With the right output, the right licence and the right antenna, we have cracked all but a handful of buildings with just a single transmitter.

With great power comes great responsibility, however, and we take our responsibilities with signal and overspill very seriously.

To explain, overspill is the consequence of the fact that buildings aren’t a perfect circle with a perfect distribution of dense building materials, interference generating electronic devices and moving people throughout. If only they were.

As a result, ensuring complete radio coverage of a building is very much about putting a square peg in a round hole. Or more accurately it is about trying to cover every part of a complex building while minimising the radio that escapes that building. And most buildings are small but tall, or a semi-circle, or a cluster of different houses right on top of each other.

You can do quite a lot. With our unit we can put it anywhere in the building, adjust the signal to an appropriate output and use complicated antennas to minimise this overspill and focus the signal where you really want it.

The problem is that for every concrete wall the signal must get through, there’s an open window which will let the signal fly. This wouldn’t be such a problem if there weren’t people in the market saying that overspill is a huge problem (it isn’t) and untruthfully saying that only they have the solution (thus defying the laws of physics). This tends to confuse customers. Scooby Doo scare tactics and magical thinking can do that.

To put it simply, having poor signal within a building is the norm. Your phone in your pocket proves that. Providing complete coverage is 90% science and 10% art. And when we say art, we mean the practiced workmanship of knowledge built up over decades on radio behaviour on a specific frequency within and between a variety of complex and varied building constructions.

So if someone starts talking about how they can “minimise the overspill and sculpt the signal to the building” take a pause. So much can be done, but within reason. You cannot break E=MC2, Einstein won’t be happy.

And next time you can hear the fire alarm for the building next door and see the people walking out in the street. Think of our Deaf users, who have a vibrating message saying, “FIRE ALARM GEOGRAPHY BUILDING – EVACUATE TO ZONE 2: LIBRARY SQUARE”.

They are the evacuees leading everyone to the correct evacuation point. And we think that’s better than just a siren.