Design Con 2015
Breaking News
Comments
Newest First | Oldest First | Threaded View
Bert22306
User Rank
CEO
re: Neul launches white-space smart metering in Cambridge
Bert22306   4/27/2012 7:33:26 PM
NO RATINGS
Clarification: in principle, Ch 52-69 were taken away from TV, with the digital transition. However in fact, since new users of the 700 MHz band have found that adjacent channel interference with Ch 51 TV is or could be a problem, they have petitioned to have TV move off Ch 51 as well. Search under "TV reverse auction," or pay attention to articles about this, to see what is being done to OTA TV these days.

Bert22306
User Rank
CEO
re: Neul launches white-space smart metering in Cambridge
Bert22306   4/27/2012 7:26:46 PM
NO RATINGS
White space devices are supposed to use two methods to determine if they can use a given frequency channel. One is a database, location-oriented. And the other is signal sensing. So if a licensed user comes on and takes one of the white space channels, the white space devices would have to vacate that channel. Our household happens to use only OTA television for TV, so of course I'm all in favor of it surviving and thriving. And I have also witnessed plenty of new program channels on the air, since June 12, 2009. But the FCC, under the current leadership, thinks that wireless broadband is all there is for the future. And they're insisting on taking away another 1/3+ of the spectrum from OTA TV, after just having taken away Ch 51-69 with the digital transition, and Ch 70-83 previously. If they get their way, all channels above Ch 30 will be taken away from TV. So, not a good prospect for the future of OTA TV. Furthermore, handset manufacturers and cell service providers do not see it in their financial interest to incorporate mobile TV receivers in their handsets, to receive OTA TV, if they can sell their own TV service like Vcast. So even that aspect makes OTA TV's survival somewhat iffy.

Peter Clarke
User Rank
Blogger
re: Neul launches white-space smart metering in Cambridge
Peter Clarke   4/27/2012 8:19:54 AM
NO RATINGS
@Dave You are correct about detecting and not interfering with licensed users of the spectrum. I understand the move change from analog to digital is releasing large amounts of spectrum.

Dave.Dykstra
User Rank
Rookie
re: Neul launches white-space smart metering in Cambridge
Dave.Dykstra   4/27/2012 3:01:37 AM
NO RATINGS
I'm curious as to what happens when a new station comes on air using the previously available "white space". Do the devices somehow sense that and change frequency or is there a receiver and controller in the device that enable it to be switched to another frequency? Also, I'm not sure that OTA television is undergoing a demise since I see more on air stations locally than I used to and with them now transmitting digital, we see excellent pictures over the air.

Bert22306
User Rank
CEO
re: Neul launches white-space smart metering in Cambridge
Bert22306   4/27/2012 12:14:16 AM
NO RATINGS
Oh, I guess my real point was, even in spite of this, I don't think this white space idea will be trouble-free, for the reasons I suggested. On the other hand, it could help to accelerate the demise of free over the air television. If TV web sites carry free TV anyway, perhaps that will become the trend anyway.

Bert22306
User Rank
CEO
re: Neul launches white-space smart metering in Cambridge
Bert22306   4/27/2012 12:10:09 AM
NO RATINGS
Yes, in the US anyway. A big part of this effort to use white spaces is to explain what the white space devices have to do before they can assume the space is free. This is controlled by a location database and by signal detection, down to something like -115 dBm. IEEE 802.22 goes into this. It's available for free now, at the IEEE standards web site. http://standards.ieee.org/about/get/802/802.22.html In fact, 802.22.1 is a separate document devoted to answering your question.

Rchandta1
User Rank
Rookie
re: Neul launches white-space smart metering in Cambridge
Rchandta1   4/26/2012 11:56:28 PM
NO RATINGS
Apparently the TV white is free. What happens when there are lot of users vying for this space? Is there any requirement imposed by the FCC to use particular protocol to resolve contention?

Bert22306
User Rank
CEO
re: Neul launches white-space smart metering in Cambridge
Bert22306   4/26/2012 8:00:33 PM
NO RATINGS
Seems to me that we've been seeing one company after another claiming that they have fully mastered this TV white space use problem, and yet the same laws of physics have always applied. When I read articles or press releases that give the motivation for using white spaces, but offer no details of how the supposedly new scheme is implemented, I remain skeptical. The meter reading task might work well, depending how it is implemented. If the electric meter transmits only for a short time, when queried, the disruption to nearby TV receivers might be very tolerable. The fundamental problems remain. First, there is the inverse square law. The power density created by a close-by, low power transmitter can be much greater than the power density of that distant, high powered TV transmitter. And TV receivers out there have only so much selectivity for adjacent channels or even other combinations, such as N +/- 2 and even further. These selectivity figures can be as low as 30 dB or sometimes less. The FCC knows this, because they have done a survey. So when these factors are not mentioned, but only the (rather obvious) motivation for use of someone else's spectrum, I'm left wondering what the whole truth is.



Top Comments of the Week
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Carlos Bueno

Adventures in Userland
Carlos Bueno
Post a comment
Editor’s Note: Excerpted from Lauren Ipsum: A Story About Computer Science and Other Improbable Things, author Carlos Bueno introduces us to Lauren and her adventures in Userland. ...

Max Maxfield

Tired Old iPad 2 vs. Shiny New iPad Air 2
Max Maxfield
9 comments
I remember when the first iPad came out deep in the mists of time we used to call 2010. Actually, that's only four years ago, but it seems like a lifetime away -- I mean; can you remember ...

Martin Rowe

Make This Engineering Museum a Reality
Martin Rowe
Post a comment
Vincent Valentine is a man on a mission. He wants to make the first house to ever have a telephone into a telephone museum. Without help, it may not happen.

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
16 comments
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
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 ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...