Wireless for when lives depend on it


This month my mother turns 90 years old. She is a very active women who still drives a car, lives independently in her own home, and loves gardening.

By Svein-Egil Nielsen, CTO, Nordic Semiconductor

My mother also carries, as many at her age do, a wireless panic alarm. This is designed to be pushed in the event of an emergency to alert the local emergency services.

The problem is, as a loving son who cares deeply about my mother’s wellbeing, I don’t trust this alarm to work reliably in an emergency.

In theory, the alarm once activated uses a proprietary RF protocol to connect to a wireless hub that then sends an emergency signal down a traditional telephone line.

In practice, this particular panic alarm system suffers from a number of shortcomings and is highly unreliable.

We have had to replace the hub many times. And the provider cannot give any reasonable explanation as to why it doesn’t work reliably. They can’t even give me a maximum operating range – they just don’t know.

As an electronics guy my take on this is simple: it’s just poor design.

And I’m afraid that this scenario is not uncommon across the home panic alarm industry.   

Many other home panic alarms, for example, rely on using a home’s Wi-Fi system which to me is just as scary in terms of reliability. Don’t get me wrong: I think Wi-Fi is great for high speed wireless comms. I just wouldn’t want to rely on it in an emergency. The main reason being that Wi-Fi routers come in many shapes and forms. And the typically free units bundled by most home Internet providers are very low cost. This inevitably impacts on both their performance and reliability.

I use just such a unit at my home here in Norway. Given that it was provided by Norway’s largest Internet provider, you would think that it would work seamlessly. But it does not. Every week I have to restart both my Chromecast and Google smart speaker because both simply lose connection. And all our PCs need to be manually disconnected and reconnected as well to maintain their Wi-Fi link. It is surprising to me because some of these devices sit only a couple of meters from the router itself. 

And as with my mother’s panic alarm hub, I have had multiple routers replaced by my Internet provider, and all suffer from the same problems.

So for safety critical panic alarms, I simply would not be able to trust Wi-Fi to work reliably enough for me to feel safe relying on it. And the same would go for a Wi-Fi based smart door lock too, or in fact any device I would expect and need to work seamlessly all the time. I just wouldn’t trust it.

But how did it end up this way?  I think it is very simple.  When the bean-counters at the Internet providers issue their orders to router manufacturers there is one thing they care about above all else: cost. Multiply a few dollars in cost saving by a few million subscribers and it becomes the center of their attention.

They end up furnishing their subscribers with the lowest cost router they can find that can ‘just about’ do the job.

That’s not to say there aren’t decent, enterprise-grade Wi-Fi routers available. You’ll just have to purchase and install one yourself. And they’re expensive. Which is why 99% of consumers simply stick with the router their Internet provider sent them.

So what is the solution for safety critical home applications?

I think it’s getting rid of anything that could possibly interfere with sending a reliable wireless signal. And to me that means a solution that doesn’t depend on routers or hubs anywhere in the world.

Right now the only choice I would trust would be the latest IoT-targeted versions of cellular wireless technology. Namely: NB-IoT and LTE-M. Both of these take away the unreliable router or hub middleman and instead communicate direct to the local cellular network.

And for my mum’s panic alarm, making it cellular would mean she could also use it when she gardens, visits neighbors, or goes to the store.

As a loving son who cares deeply about my mother’s wellbeing, I don’t trust this alarm to work reliably in an emergency