3 GHz spectrum from BRM
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Ken Jamrogowicz
Nov 10, 2015, 4:14:09 PM11/10/15
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Today I did an airView spectrum of the 3.4 GHz spectrum and the segment above, using a 3 GHz NanoStation with its integrated antenna. The NanoStation is indoors - in my basement. I was astounded to see how much RF was present there. Its true if you do a band scan (at various bandwidths), you will not see any stations reported. That is because these stations do not decode as 802.11.
The very bottom of the band is quiet. But there are very strong signals that cover the upper half of the "ham-only" segment and moderately strong signals down to 3435. Who are these guys?
The signal at 3510 is associated with Radio-location http://www.ntia.doc.gov/files/ntia/publications/compendium/3500.00-3650.00_01MAR14.pdf
Possibly due to the foggy weather today, they have that system cranked up at Dulles?
But there are carriers at 3460 and 3490 MHz, with broad side-bands, that are clearly inside the ham band. Some Googling shows that "band 22" of 3G networks is from 3410-3490 MHz, but it is not clear to me if it is in the US or elsewhere. The two carriers at 3490 and 3530 are symmetrically-spaced about the big one at 3510, so may be related to it in some way.
Anyway, looking a the picture, you can see that there is only a single 40 MHz channel (or two 20 MHz channels) that can be used from here.
Setting the frequency of the NS3 is a bit tricky. To use the bottom 40 MHz of the band you set the operating frequency as 3410 with Upper Extension channel or 3430 with the Lower Extension channel. Other combinations could have you putting a signal below 3400.
Regards
Ken
Ken Jamrogowicz
Nov 11, 2015, 8:37:24 AM11/11/15
to BOAR-Net
I should clarify that it is not a problem to go below 3.4 GHz as the ham allocation goes down to 3.3. The caution would more aptly be applied to the top of the band since the Ubiquiti units go all the way up to 3.7 GHz and that is WAY out of the Amateur allocation.
Further - using 3rd-party firmware would allow you to operate in the 3.3-3.4 segment, but hardware performance is said to drop off quickly below 3.38.
73
Ken
Ken
KE2N
Chris KB3CS
Nov 11, 2015, 6:07:04 PM11/11/15
to BOAR-Net
On Tuesday, November 10, 2015 at 4:14:09 PM UTC-5, Ken Jamrogowicz wrote:
Today I did an airView spectrum of the 3.4 GHz spectrum and the segment above, using a 3 GHz NanoStation with its integrated antenna. The NanoStation is indoors - in my basement. I was astounded to see how much RF was present there. Its true if you do a band scan (at various bandwidths), you will not see any stations reported. That is because these stations do not decode as 802.11.The very bottom of the band is quiet. But there are very strong signals that cover the upper half of the "ham-only" segment and moderately strong signals down to 3435. Who are these guys?
[...]
1. a geosearch of the FCC license database turns up:
Specified Search
mobile license = on
City = Haymarket
State = Virginia
Zip Code = 20169
Radius = 40 Kilometers
Zip Code like 20169
Frequency Upper Band >= 3400
Frequency Assigned <= 3600
No matches found
2. a review of FCC documents on the topic of proposing a new radio service to be designated "Part 96" indicates the 3500 to 3700 MHz spectrum use is nearly all for seaward-facing radiolocation (presumably a dual-use system for civil and military authorities), leaving the spectrum nearly unoccupied in the interior of the lower 48 States.
3. with reference to the current 47 C.F.R. § 2.106 ("Table of Allocations") ( https://transition.fcc.gov/oet/spectrum/table/fcctable.pdf ), the frequency range of 3550 to 3700 MHz is listed as allocated under FCC Rule Part 96 with the entries "Citizen broadband (96)".
The source of the energy you observed may be an artifact of equipment used or a harmonic emission in the local environment.
Martin
Nov 11, 2015, 6:15:03 PM11/11/15
to boar...@googlegroups.com
There's discussion on the AREDN list about US Navy airborne high power radar use in the band.
73 Martin W6MRR
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Ken Jamrogowicz
Nov 11, 2015, 7:02:47 PM11/11/15
to BOAR-Net
According to various allocation tables, Amateurs are "co-secondary" or "co-primary" with the Radiolocation service (depending on which of the two 100 MHz segments we are talking about).
RADAR is one type of radiolocation device.
If you Google 3510 MHz you will find one very specific radiolocation device that operates there. But there must be others.
Long story short - if you live near an airport you may have this issue, on this band. The signal is still there tonight. If I pickup the nanostation and turn it in the direction of the airport, the signal gets a lot stronger.
I expect the interior of the lower 48 states will also have this - perhaps more likely if there is a military presence, or if it is an air force base.
Anyone ?
Jim Kinter
Nov 12, 2015, 9:14:48 AM11/12/15
to BOAR-Net
A few years ago, the ARRL put out a RFC for this bandplan.
The Broadband-Hamnet (/HSMM-Mesh) group urged all users to write in to encourage them to approve 2 20MHz channels at the top of the band for digital work, AND to allow those 2 channels to be used together as 1 40MHz channel, and that is what they finally approved. This was because the UBNT gear could do a 40MHz channel up there, which I have seen 108MB/s over a couple miles in testing.
Reason for us wanting to be up on that end was to steer clear of any weak signal and sat work (if any...) going on lower in the band.
Just seemed the logical place for us to play.
This was about the same time that we urged the ARRL to help us promote using the band in a use-it-or-lose-it (to cell companies) request, now that we had commercially available gear and didnt need to homebrew up/down converters.
Here in North Austin, I will see a blip every so often just above our 3500 band limit, but other than that usually its about a -105dB noise floor from 3450-3500.
I have had a 2.5 mile link using M3's (stock AirOS) over to KE5RS for about 4 years now, and other than my non-plenum/non-UV CAT5e cabling cracking and needing replaced, it has been solid.
73
K5KTF
The Broadband-Hamnet (/HSMM-Mesh) group urged all users to write in to encourage them to approve 2 20MHz channels at the top of the band for digital work, AND to allow those 2 channels to be used together as 1 40MHz channel, and that is what they finally approved. This was because the UBNT gear could do a 40MHz channel up there, which I have seen 108MB/s over a couple miles in testing.
Reason for us wanting to be up on that end was to steer clear of any weak signal and sat work (if any...) going on lower in the band.
Just seemed the logical place for us to play.
This was about the same time that we urged the ARRL to help us promote using the band in a use-it-or-lose-it (to cell companies) request, now that we had commercially available gear and didnt need to homebrew up/down converters.
Here in North Austin, I will see a blip every so often just above our 3500 band limit, but other than that usually its about a -105dB noise floor from 3450-3500.
I have had a 2.5 mile link using M3's (stock AirOS) over to KE5RS for about 4 years now, and other than my non-plenum/non-UV CAT5e cabling cracking and needing replaced, it has been solid.
73
K5KTF
Ken Jamrogowicz
Nov 13, 2015, 8:16:24 AM11/13/15
to BOAR-Net
Thanks Jim.
Well - as you can see - 40 MHz at the top of the band would be the perfect booby prize for folks in this area.
I found that you and KE5RS are completely on the other side of town from the airport and that your beam headings would both be almost perpendicular to it.
I wonder if you have access to a portable unit (like a Nano Station) and could take it for a drive to somewhere with LOS to Austin-Bergstrom?
Cheers
Ken
KE2N
Jim Kinter
Nov 13, 2015, 8:38:12 AM11/13/15
to BOAR-Net
Hi Ken,
We are about 25 miles NW of the airport, so I would expect to not see much from there in this band.
Yes, I have another NSM3 that I could go down by Bergstom and see. Problem is my personal time domain is very bandwidth limited :-)
(And I try to stay out of Austin traffic unless absolutely necessary lol).
But it would be a good test, and next time I have to drop off/pick up someone at ABIA, Ill try and remember to take it and my laptop with me.
73
Jim
We are about 25 miles NW of the airport, so I would expect to not see much from there in this band.
Yes, I have another NSM3 that I could go down by Bergstom and see. Problem is my personal time domain is very bandwidth limited :-)
(And I try to stay out of Austin traffic unless absolutely necessary lol).
But it would be a good test, and next time I have to drop off/pick up someone at ABIA, Ill try and remember to take it and my laptop with me.
73
Jim
William "Bill" Kisse, W3MSH
Nov 23, 2015, 1:47:46 PM11/23/15
to boar...@googlegroups.com
This intruder can also be seen from the Ashton tower - seems to be located generally SSW from the site.
David, W2LNX, and I have attempted to locate the source of this signal with a mobile setup, and to date have not been successful.
Of further concern is the following post about AT&T's plans for our 3 Ghz. spectrum!
AT&T seeks experimental license for technology in 3.5 GHz region - Article dated November 12, 2015.
Per the article "AT&T's application calls for using 3300 MHz to 3650 MHz. Each radio will use a digitally modulated 10 MHz, 20 MHz or 40 MHz channel in the band."
What is the best way for our Amateur community to respond?
73,
Bill
W3MSH
On Tuesday, November 10, 2015 at 4:14:09 PM UTC-5, Ken Jamrogowicz wrote:
Gene Smar
Nov 23, 2015, 3:05:58 PM11/23/15
to boar...@googlegroups.com
All:
Below is a note I sent to Kay Craigie N3KN, ARRL President; Dan Henderson N1ND and Craig Skolaut K0BOG, of the League's Regulatory and Advocacy Department; and Chris Imlay W3KD, League General Counsel:
**********************
Kay and gents:
I'm sure one or more of you is aware of this filing by AT&T, but I thought I'd pass it along regardless:http://www.fiercewireless.com/tech/story/att-seeks-experimental-license-technology-35-ghz-region/2015-11-18?utm_campaign=+SocialMedia. Apparently AT&T intends to test equipment that could occupy the entirety of the Amateurs' 3.3-3.5 GHz microwave band. I'm assuming the League will vigorously protest this proposed testing and, possibly, future deployment.
Thank you for your consideration.
73/88 de
Gene Smar AD3F
Rockville, MD
**********************
On 11/23/15, William "Bill" Kisse, W3MSH wrote:
As I understand it Amateur Radio does not share 3.3-3.5 Ghz. with any other services.
This intruder can also be seen from the Ashton tower - seems to be located generally SSW from the site.
David, W2LNX, and I have attempted to locate the source of this signal and to date have not been successful.
Of further concern is the following post about AT&T's plans for our 3 Ghz. spectrum!
AT&T seeks experimental license for technology in 3.5 GHz region - Article dated November 12, 2015.
http://www.fiercewireless.com/tech/story/att-seeks-experimental-license-technology-35-ghz-region/2015-11-18?utm_campaign=+SocialMedia
Below is a note I sent to Kay Craigie N3KN, ARRL President; Dan Henderson N1ND and Craig Skolaut K0BOG, of the League's Regulatory and Advocacy Department; and Chris Imlay W3KD, League General Counsel:
**********************
Kay and gents:
I'm sure one or more of you is aware of this filing by AT&T, but I thought I'd pass it along regardless:http://www.fiercewireless.com/tech/story/att-seeks-experimental-license-technology-35-ghz-region/2015-11-18?utm_campaign=+SocialMedia. Apparently AT&T intends to test equipment that could occupy the entirety of the Amateurs' 3.3-3.5 GHz microwave band. I'm assuming the League will vigorously protest this proposed testing and, possibly, future deployment.
Thank you for your consideration.
73/88 de
Gene Smar AD3F
Rockville, MD
**********************
On 11/23/15, William "Bill" Kisse, W3MSH wrote:
As I understand it Amateur Radio does not share 3.3-3.5 Ghz. with any other services.
This intruder can also be seen from the Ashton tower - seems to be located generally SSW from the site.
Of further concern is the following post about AT&T's plans for our 3 Ghz. spectrum!
AT&T seeks experimental license for technology in 3.5 GHz region - Article dated November 12, 2015.
http://www.fiercewireless.com/tech/story/att-seeks-experimental-license-technology-35-ghz-region/2015-11-18?utm_campaign=+SocialMedia
On Tuesday, November 10, 2015 at 4:14:09 PM UTC-5, Ken Jamrogowicz wrote:
Today I did an airView spectrum of the 3.4 GHz spectrum and the segment above, using a 3 GHz NanoStation with its integrated antenna. The NanoStation is indoors - in my basement. I was astounded to see how much RF was present there. Its true if you do a band scan (at various bandwidths), you will not see any stations reported. That is because these stations do not decode as 802.11.
The very bottom of the band is quiet. But there are very strong signals that cover the upper half of the "ham-only" segment and moderately strong signals down to 3435. Who are these guys?
The signal at 3510 is associated with Radio-location http://www.ntia.doc.gov/files/ntia/publications/compendium/3500.00-3650.00_01MAR14.pdf
Possibly due to the foggy weather today, they have that system cranked up at Dulles?
But there are carriers at 3460 and 3490 MHz, with broad side-bands, that are clearly inside the ham band. Some Googling shows that "band 22" of 3G networks is from 3410-3490 MHz, but it is not clear to me if it is in the US or elsewhere. The two carriers at 3490 and 3530 are symmetrically-spaced about the big one at 3510, so may be related to it in some way.
Anyway, looking a the picture, you can see that there is only a single 40 MHz channel (or two 20 MHz channels) that can be used from here.
Setting the frequency of the NS3 is a bit tricky. To use the bottom 40 MHz of the band you set the operating frequency as 3410 with Upper Extension channel or 3430 with the Lower Extension channel. Other combinations could have you putting a signal below 3400.
Regards
Ken
Today I did an airView spectrum of the 3.4 GHz spectrum and the segment above, using a 3 GHz NanoStation with its integrated antenna. The NanoStation is indoors - in my basement. I was astounded to see how much RF was present there. Its true if you do a band scan (at various bandwidths), you will not see any stations reported. That is because these stations do not decode as 802.11.
The very bottom of the band is quiet. But there are very strong signals that cover the upper half of the "ham-only" segment and moderately strong signals down to 3435. Who are these guys?
The signal at 3510 is associated with Radio-location http://www.ntia.doc.gov/files/ntia/publications/compendium/3500.00-3650.00_01MAR14.pdf
Possibly due to the foggy weather today, they have that system cranked up at Dulles?
But there are carriers at 3460 and 3490 MHz, with broad side-bands, that are clearly inside the ham band. Some Googling shows that "band 22" of 3G networks is from 3410-3490 MHz, but it is not clear to me if it is in the US or elsewhere. The two carriers at 3490 and 3530 are symmetrically-spaced about the big one at 3510, so may be related to it in some way.
Anyway, looking a the picture, you can see that there is only a single 40 MHz channel (or two 20 MHz channels) that can be used from here.
Setting the frequency of the NS3 is a bit tricky. To use the bottom 40 MHz of the band you set the operating frequency as 3410 with Upper Extension channel or 3430 with the Lower Extension channel. Other combinations could have you putting a signal below 3400.
Regards
Ken
David Bern
Nov 23, 2015, 3:47:02 PM11/23/15
to BOAR-net
-------- Forwarded Message --------
Please, repost for me. The BOAR list won’t accept message from my address. Thanks!!
| Subject: | Fwd: [BOAR-Net] 3 GHz spectrum from BRM |
|---|---|
| Date: | Mon, 23 Nov 2015 14:44:10 -0500 |
| From: | Arthur Feller, W4ART <afe...@ieee.org> |
| To: | David...@Engineer.com |
Please, repost for me. The BOAR list won’t accept message from my address. Thanks!!
73…..
Begin forwarded message:
From: Arthur Feller <afe...@ieee.org>
Date: 23-November-2015 at 02:39:56 PM EST
Subject: Re: [BOAR-Net] 3 GHz spectrum from BRM
On 23-Nov-2015, at 01:47 PM, William Bill Kisse, W3MSH <willia...@gmail.com> wrote:
As I understand it Amateur Radio does not share 3.3-3.5 Ghz. with any other services.
“Understanding?” From where? How about reading 47 CFR 2.106?
A simple read will reveal that the band 3.3 to 3.5 GHz is allocated to radio location on a primary basis and amateur on a secondary basis. Footnotes provide for limitations to both Government and non-Government radiolocation stations and for protection of radioastronomy stations in certain subbands.
Experimental stations may be assigned to ANY frequency on a secondary basis to all regularly licensed stations. See 47 CFR Part 5. So, IF an experimental station causes harmful interference to or receives harmful interference from an experimental station, THEN the experimental station must cure the problem, which means changing operating parameters or going off the air as ordered by the FCC.
Know thy rules before relying upon understandings.
73…..
A miracle is what seems
impossible, but happens anyway.
"Griffin the Arcanan" in MIB3
http://afeller.us
William Kisse
Nov 23, 2015, 7:33:30 PM11/23/15
to boar...@googlegroups.com
Art.
Many thanks for clarifying this for us.
Understood.
73,
Bill
W3MSH
--
The next generation of communications technology in the Amateur Radio service!
Broadband Over Amateur Radio Networks
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