Why 312 MHz Kicks Butt for Senior Living Emergency Call Systems

When it comes to resident life safety, why would you take a chance having your wireless emergency call fail due to radio interference or being blocked by common building materials? Activate a Tel-Tron pendant or wireless pull cord and rest assured, your emergency call will get through, and help is on the way.  Unlike many of our competitors who use 2.4 GHz technology, Tel-Tron uses 312 MHz which is absolutely the best technology for penetrating building materials and is essentially free of interference from other transmitters operating at the same frequency.

Recently, I was surfing the web on my laptop at my son’s apartment as dinner was being prepared.  I noticed every time the microwave oven was being used in the kitchen my internet connection stalled.  In case you don’t know, the 2.4 GHz frequency spectrum is littered with intentional and unintentional transmitters – 802.11 Wi-Fi, Bluetooth, Zigbee, microwave ovens, security cameras, cordless phones, baby monitors, etc. I couldn’t help but wonder how in the world some of our competitors could offer emergency call transmitters based on 2.4 GHz with all that potential interference out there. So-called, “Wi-Fi pollution” is an especially well-known problem in high-density areas such as large resident complexes with many Wi-Fi access points (see http://en.wikipedia.org/wiki/Electromagnetic_interference_at_2.4_GHz).

In stark contrast, Tel-Tron wireless emergency call transmitters (pendants, wall-mounted call stations, etc.) operate at 312 MHz; far, far away from all that 2.4 GHz pollution.  Except for just a few garage door openers on the market (which operate very infrequently and are not likely to be near your residents), there is no comparable 312 MHz pollution.

And then there’s the issue of penetration. With all other things being equal, as frequency increases, range decreases.  This is most evident inside buildings, because higher-frequency radio waves are more vulnerable to absorption by building materials (such as drywall and concrete), and because higher frequencies are more directional (less apt to bend around corners).  Take a look at the engineering data graphic below that shows how much better lower frequencies penetrate reinforced concrete.  Sound waves share this transmission characteristic with radio waves: think how easily you can hear your neighbor’s low-frequency bass boom through your walls, but not the higher-frequency instruments or vocals.

Q: “Wait a minute Buddy … don’t some Tel-Tron products also utilize 2.4 GHz wireless technology?”

A: Yes we do, but not for resident emergency calls!  Rather, we embrace 2.4 GHz for our wireless high-speed network backbone whereby we use a fully-supervised “self-healing mesh” to contend with all the Wi-Fi pollution (our mesh approach is described here: https://blog.tel-tron.com/2010/05/15/network-heal-thy-self/.  The critical difference is that our pendants and wireless pull cords upload emergency call alerts to the network backbone using 312 MHz, not 2 GHz; residents are using the best-of-breed technology to make sure their emergency call penetrates though floors and walls and is not trounced by a Wi-Fi surfer or a rogue microwave oven.

Finally, I would be remiss if I didn’t mention that many of our competitors use 900 MHz for their wireless emergency nurse call systems.  That certainly is not as bad as 2.4 GHz.  Still, there are tons of 900 MHz cordless phones, wireless speakers, wireless headsets, etc. out there that clutter that frequency band too.  To attempt to compensate for losses and interference from other devices, they typically opt to transmit at higher power levels. Again, why not use “quiet” 312 MHz which is essentially interference-free and has the best wall/floor penetration, and gives you the greatest peace of mind?

One Response to Why 312 MHz Kicks Butt for Senior Living Emergency Call Systems

  1. Bryan Kelso says:

    Interesting write-up on the ‘signal quality’ of the different frequencies in a living space. Never would have guessed! Now, it is so ‘clear’. This information gets you thinking.

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