Speaking up for M2M radio innovation

1/27/2012 8:16 PM EST

Perhaps my real issue with this is the idea that ONE unified standard, all the way up the ISO layers, can cover all M2M needs.

What are we talking about? Turning lights on or off in your home is going to be hugely different from telematics between cars traveling on the freeway, for example. The RF layers might not be necessarily different, but the rest will be.

Does it make sense to try to shoehorn these different jobs into a unified, all-encompassing new standard?

1/28/2012 9:55 AM EST

It makes more sense if this standard body is where all the companies come together and agree to interface to each other. If the standard is defined but noone wants to follow, it will never be successful.

1/30/2012 5:37 PM EST

I'm assuming here that you aren't limiting the discussion to RF links only, yes? The reason for long range is, for example, a scheme whereby Samsung can automatically download updates to your HDTV set, for example. This is a typical M2M application that isn't confined to short range. The RF link very well could be, of course, but in that role, the RF link would be no different from, say, your in-home WiFi to reach the broadband modem in your home.

Which is exactly why I don't get the point of this. M2M is no different from any other communication channel, as far as the lower protocol layers go at the very least.

1/31/2012 4:15 AM EST

There's nothing unique about the TV frequency bands that either 802.11 or 802.16 could not be adapted to. And there's nothing implied in M2M that is necessarily restricted to low power or to low data rates or to 1000s of devices on the head of a pin. I've been doing M2M all my career, including (but not by any means exclusively) M2M over Internet protocols, and I'm not at all sure that the boundaries you place on this M2M and/or IoT are valid?

As of now, 802.11 and 802.16 use 20 MHz channels, which can be aggregated up to 40 MHz and eventually even 100 MHz. This can theoretically be achieved by aggregating multiple TV 6 MHz channels, or the 20 MHz channel width can be reduced in the adaptation of 802.11 or 802.16.

Modulation schemes for such comm links are pretty much all migrating to COFDM these days, where the symbols can range from QPSK to 256-QAM. So you can dial in whatever spectral efficiency vs robustness you want, in the TV bands or L band or whatever. Even LTE fits that description, including the 20, 40, 100 MHz aggregated RF channels and the COFDM modulation.

Or if you prefer, the TV bands can be used with 3G style spread spectrum, at roughly the same spectral efficiency as you can dial into any of the other schemes.

I'd say, *if* you want to share the same RF frequency channel among lots of devices, and you only need low data rate, 802.11 is a good bet. But that's just one use case, as far as I'm concerned.

1/31/2012 4:34 AM EST

Also, I'd note that if the M2M scenarios discussed must involve use of comparatively low frequency TV bands, I'm not sure that very short range or very small devices are a good match.

When dealing with high VHF and low UHF, you are talking about long range propagation potential and about relatively long antenna elements. If you decide to use very compact antennas, then the transmitter power may have to be raised to compensate.

All of which told me that if someone is talking about using the TV bands, they must be considering relatively large areas - at least WiFi type of coverage, and possibly even a lot more than that. Not Bluetooth PAN size areas.