Embedded Systems Conference
Breaking News
Newest First | Oldest First | Threaded View
User Rank
Re: Didn't we already discuss this?
LarryM99   8/28/2013 7:38:36 PM
I agree completely regarding the disadvantages of using frequencies that propagate well. It actually makes more sense to me to work within the ISM spectrum with a P2P protocol that is frequency-agile. This is simpler both in terms of certification and in terms of minimizing interference with critical functionality. This is where most of the ad-hoc networking experiments are taking place anyway.

User Rank
Re: Didn't we already discuss this?
Bert22306   8/28/2013 7:30:21 PM
Oh, and there's anbother point that keeps getting overlooked. The power levels required for long range (say in the multiple miles) reliable communications, ESPECIALLY for tiny devices with likely tiny antennas, operating in the TV bands, are not going to be low.

This is all easy enough to calculate. If you expect efficient use of the limited TV white space spectrum, where thousands or millions of devices would coexist in a few 6 MHz slices of spectrum, the power will be nowhere near the low milliwatt region. Even if each device doesn't need a lot of b/s of network capacity.

Best to do the numbers, IMO.

User Rank
Didn't we already discuss this?
Bert22306   8/28/2013 7:18:33 PM
I think we already discussed the fact that *if* IoT is done wirelessly, *then* this would require a hefty amount of "frequency reuse" to scale at all.

And that the long range prowess of TV frequencies, since that is the feature of TV frequencies that is being touted as particularly useful here, is exactly what you DON'T want, if you need a lot of frequency reuse. For good frequency reuse, you need to create small cells, not cells that can be multiple tens of miles in diameter.

My suggestion is, mentioning TV spectrum "white spaces" because, at least in some parts of the country, they are available spectrum is okay. However mentioning the long range is a counter-argument that blows the whole case.

I did some numbers last time around. The way to improve on my *clearly* unimpressive result was to reduce the range of the RF link. So  to be consistent, it makes more sense to talk about short range use of TV white spaces, e.g. as wireless mikes do, and show just how much of an interference problem the low TV frequencies create, in this scenario. And keep the long range capabilities sort of under the table.

rick merritt
User Rank
Weightless aint so light
rick merritt   8/28/2013 4:57:53 PM
You are right David. This will require heavy lifting. How about global regulatory issues? And there are other big powers such as Google pushing for SuperWifi over white spaces.

White spaces are cool and spectrum is indeed scarce, but its not like IoT is hurting for a lack of wirleless options.


NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
Brought to you by

Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Special Video Section
The LTC®4015 is a complete synchronous buck controller/ ...
The LTC®2983 measures a wide variety of temperature sensors ...
The LTC®3886 is a dual PolyPhase DC/DC synchronous ...
The LT®3042 is a high performance low dropout linear ...
Chwan-Jye Foo (C.J Foo), product marketing manager for ...
The LT®3752/LT3752-1 are current mode PWM controllers ...
LED lighting is an important feature in today’s and future ...
Active balancing of series connected battery stacks exists ...
After a four-year absence, Infineon returns to Mobile World ...
A laptop’s 65-watt adapter can be made 6 times smaller and ...
An industry network should have device and data security at ...
The LTC2975 is a four-channel PMBus Power System Manager ...
In this video, a new high speed CMOS output comparator ...
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...