I’ve been researching the telecare frequency. It’s something both Doro and Emporia announced support for at Mobile World Congress and at first blush it seems to open up a huge opportunity for using mobile phones for keeping an eye on people so that they can live for longer in their own homes.
The idea is that devices such as fall sensors, smoke alarms, burglar alarms, panic buttons and hearing aids can all communicate with a mobile phone in a standard way. A bit like Bluetooth,
If a person presses the panic button or has a fire their carer can be alerted remotely. There are two frequencies set aside for telecare 169MHz and 869Mhz. The 169MHz frequency includes support for hearing aids the 869MHz one does not.
The problem with 169MHz is that it needs long antennas. The lower the frequency the longer the antenna you need. So a mobile phone which works at between 900MHz and 2100MHz can have a very sort antenna. By contrast submarines which often communicate at incredibly low frequencies might tow an antenna miles long. A little bit of physics: An antenna works best when it’s length is equal to the wavelength of the frequency. That is the distance between peaks or troughs in the signal. You can compromise by having an antenna which is a half or quarter of the wavelength. At 869MHz a quarter wave antenna is a little over three inches. So small enough to fit inside a mobile phone or smoke alarm. At 169Mhz it’s more than 16½ inches. Which would be too awkward to use.
Even 3 inches is too long for a hearing aid, and there isn’t enough spectrum to support voice at the 869MHz frequency.
So the 169MHz option is pointless, but what is the real shame is the way the 869MHz frequency is used. Although the frequency is allocated there are no standards for how it is to be used. While you can pair a Motorola bluetooth headset with a Nokia mobile phone or control JBL Bluetooth speakers with an HTC phone, the equipment which supports Telecare has no standard protocols.
In the mobile phone world there are working groups and special interest groups (SIG) which produce standards. So the Bluetooth SIG defines a wide range of protocols and sets up interoperability testing.
None of this exists in telecare, it’s not even clear if the signals are analogue or digital. The upshot of this is that one manufacturer’s sensors won’t work with another manufacturers phones – be they fixed or mobile.
Talking to a few companies there seems to either be a lack of awareness that it could be any different or a feeling that it’s the best way for them to control the whole system.
It could work out with a defacto standard – Doro is compatible with Bosch. But the whole area falls so far short of what is considered normal in the phone world.
You can learn more about the Doro solution in this video.