5 ms·

Seriously, sunspots? Would love to see more about this. Did you write it up anywhere?

paulgerhardt 10y ago
I mean...there's not much more to the story than that. 2011 was a bit crazy for the Sun [1]. There were two or three x-class flares that jammed transmission for a short period. Multiple customer reports coincided with the February and August events that year. The February flare was caused by sunspot 1158 [2] and the August flare was caused by sunspot 1263 [3]. Deploying those locks across hundreds of locations we saw quite a bit of unusual stuff. Locks would work fine on one side of a building but not the other - the bad side faced the San Francisco bay - deduced it was from all the SF/Oakland Radio traffic. Another location would experience problems during baseball games. (Stadium was next door). Cell tower guys have even crazier stories. One involves my colleague who had a bitcoin mine in his garage. Few dozen graphics cards humming along at ~900MHz knocked out the whole voice uplink for 4 square miles. (He happened to be pretty close to the cell tower and raised the noise floor just enough to make cell phones all but useless.) Working in ISM bands can be brutal, but it will teach you a lot and quickly. [1] http://www.space.com/14060-2011-restless-sun-solar-activity-review.html http://www.space.com/14060-2011-restless-sun-solar-activity-... [2] http://www.space.com/10862-sun-erupts-powerful-solar-flare.html http://www.space.com/10862-sun-erupts-powerful-solar-flare.h... [3] https://www.youtube.com/watch?v=heVeq_anewU https://www.youtube.com/watch?v=heVeq_anewU
CamperBob2 10y ago
The "sunspots" explanation doesn't pass the smell test for several reasons. It's the sort of thing you tell a customer to get them to go away and give the problem a chance to resolve itself. More likely, in that part of the spectrum, they were seeing adverse effects from (probably undisclosed) military R&D activities. Might as well have been sunspots, for all they could've done about it.
- yanowitz 10y ago
  For the less-RF-literate (such as myself), can you please elaborate on the several reasons?
  - brians 10y ago
    Sunspots don't cause appreciable increase in RF background at any frequency at sea level. They cause lots more excitation of the ionosphere, so shortwave radio signals bounce better and further, but nothing up in UHF. But other phenomena correlated with sunspots do cause UHF interference, so while wrong on the details I generally believe the story.
    - CamperBob2 10y ago
      But other phenomena correlated with sunspots do cause UHF interference What would be some examples of such phenomena, bearing in mind that we're talking about very short-range wireless links in a band shared with primary military users? It's not as if conflicts in that band haven't arisen before: http://www.w5yi.org/ama_news_article.php?id=191l http://www.w5yi.org/ama_news_article.php?id=191l Another example: http://www.tdsupplies.com/articles/395_MHz_Military_Radio_Remote_Interference.html http://www.tdsupplies.com/articles/395_MHz_Military_Radio_Re...
      - brians 10y ago
        X-ray flares, which get through the ionosphere and mess with VHF and UHF. The collapse of the magnetosphere on the night side following impact of a coronal mass ejection—which not only make a lot of VHF and UHF noise, they have enough power to just break a device.
        CamperBob2 10y ago
        In 433 MHz line-of-sight comms? On the surface of the Earth? If that ever happens, you have much bigger problems than a malfunctioning garage door.
  - VLM 10y ago

I mean...there's not much more to the story than that. 2011 was a bit crazy for the Sun [1]. There were two or three x-class flares that jammed transmission for a short period. Multiple customer reports coincided with the February and August events that year. The February flare was caused by sunspot 1158 [2] and the August flare was caused by sunspot 1263 [3]. Deploying those locks across hundreds of locations we saw quite a bit of unusual stuff. Locks would work fine on one side of a building but not the other - the bad side faced the San Francisco bay - deduced it was from all the SF/Oakland Radio traffic. Another location would experience problems during baseball games. (Stadium was next door). Cell tower guys have even crazier stories. One involves my colleague who had a bitcoin mine in his garage. Few dozen graphics cards humming along at ~900MHz knocked out the whole voice uplink for 4 square miles. (He happened to be pretty close to the cell tower and raised the noise floor just enough to make cell phones all but useless.) Working in ISM bands can be brutal, but it will teach you a lot and quickly. [1] http://www.space.com/14060-2011-restless-sun-solar-activity-review.html http://www.space.com/14060-2011-restless-sun-solar-activity-... [2] http://www.space.com/10862-sun-erupts-powerful-solar-flare.html http://www.space.com/10862-sun-erupts-powerful-solar-flare.h... [3] https://www.youtube.com/watch?v=heVeq_anewU https://www.youtube.com/watch?v=heVeq_anewU

CamperBob2 10y ago

The "sunspots" explanation doesn't pass the smell test for several reasons. It's the sort of thing you tell a customer to get them to go away and give the problem a chance to resolve itself. More likely, in that part of the spectrum, they were seeing adverse effects from (probably undisclosed) military R&D activities. Might as well have been sunspots, for all they could've done about it.

yanowitz 10y ago
For the less-RF-literate (such as myself), can you please elaborate on the several reasons?
- brians 10y ago
  Sunspots don't cause appreciable increase in RF background at any frequency at sea level. They cause lots more excitation of the ionosphere, so shortwave radio signals bounce better and further, but nothing up in UHF. But other phenomena correlated with sunspots do cause UHF interference, so while wrong on the details I generally believe the story.
  - CamperBob2 10y ago
    But other phenomena correlated with sunspots do cause UHF interference What would be some examples of such phenomena, bearing in mind that we're talking about very short-range wireless links in a band shared with primary military users? It's not as if conflicts in that band haven't arisen before: http://www.w5yi.org/ama_news_article.php?id=191l http://www.w5yi.org/ama_news_article.php?id=191l Another example: http://www.tdsupplies.com/articles/395_MHz_Military_Radio_Remote_Interference.html http://www.tdsupplies.com/articles/395_MHz_Military_Radio_Re...
    - brians 10y ago
      X-ray flares, which get through the ionosphere and mess with VHF and UHF. The collapse of the magnetosphere on the night side following impact of a coronal mass ejection—which not only make a lot of VHF and UHF noise, they have enough power to just break a device.
      - CamperBob2 10y ago
        In 433 MHz line-of-sight comms? On the surface of the Earth? If that ever happens, you have much bigger problems than a malfunctioning garage door.
- VLM 10y ago