my office experienced 802.11b weirdness (sudden bouts of 0% signal for no
apparent reason) earlier this week. i'm fully expecting more tomorrow. 
According to the notice
"Satellite and other spacecraft operations, power systems, high frequency communications, and navigation systems may experience disruptions over this two-week period."
I think you will find that 802.11b and other terrestrial microwave LOS links don't meet any of those criteria and should be unaffected. Some small increase in the noise level may be detected.
Chris Yarnell wrote:
: "Satellite and other spacecraft operations, power systems, high
: frequency communications, and navigation systems may experience
: disruptions over this two-week period."
:
: I think you will find that 802.11b and other terrestrial microwave LOS
: links don't meet any of those criteria and should be unaffected.
"High frequency communications"?
We *are* talking about multi-GHz frequencies here.
"High frequency communications"?
We *are* talking about multi-GHz frequencies here.
HF is generally taken to mean 30Mhz and lower, at least in radio circles.
Ghz I think is in the SHF range.
-ed
Correct.
Kevin
K2KMB
This will not likely affect point-to-point line-of-site communications above 50Mhz.
It will likely affect non-terrestrial communications and HF communications depending
on ionospheric reflection.
Owen
Owen DeLong wrote:
This will not likely affect point-to-point line-of-site communications above 50Mhz.
It will likely affect non-terrestrial communications and HF communications depending
on ionospheric reflection.Owen
Ummm...
900 mhz and 1800 mhz. And facing East or West. And Satellite, somewhat
above 2.0 ghz.
And a significant number of ISPs are currently employing 802.11 2.4 and
5.0+ ghz equipment for last mile links (Proxim Tsunami) and Motorola
Canopy gear.
There are also warnings regarding parts of the power grid.
However, fair warning. Perhaps Sean Donelan knows more?
NK6S
Well, this is more than you really wanted to know, but....
  ELV Exremely Low dc - 3khz
  VLF Very Low Freq 3khz - 30khz
  LF Low Frequency 30khz - 300Khz
  MF Medium 300Khz - 3Mhz
  HF High 3mhz-30mhz
  VHF Very High 30mhz-300mhz
  UHF Ultra High 300-3Ghz
  SHF Super High 3Ghz - 30 Ghz
  EHF Extremely High 30Ghz - 300Ghz
Different folks put the breaks at slightly different places (the.g. the amatuer radio community puts the hf/vhf break @ 50Mhz and the MF/HF break @ 1.8Khz.
And, as a side note, I can't find the URL, but the US Cong is talking about pulling all the funding for the NASA space weather programs. Would mean less/no warning of this sort of stuff.
We now return you to our regularly scheduled off topic discussions
Komrade
Owen DeLong wrote:
At NASA at least, we referred to everything above 1 GHz as microwave. I have
never heard SHF and EHF used in practice (and I worked at 8 GHz and above for years).
There are two basic dangers here
- the electrical grid acts as a big radio antenna and circuit breakers may trip.
- The maximum frequency at which the ionosphere reflects radio waves (the MUF -
http://www.hfradio.org/muf_basics.html )
will increase. Some things that depend on ionospheric reflection may act weird, there
may be interference at higher frequencies which normally do not reflect, but now do, etc.
- it is also possible that dispersion (frequency depend phase changes) at higher
frequency could cut down on bandwidths of broadband systems.
The reflection frequency is almost never higher than 30 MHz anywhere on the planet, and the effects depend on the inverse frequency squared. I doubt that many of the bits moved by the readers of this list go at radio frequencies as low as 30 MHz. Even the cell phone and other bands starting about 700 Mhz are
unlikely to be affected.
Spacecraft may be effected, but this will be because they are bathed in increased radiation. There also may be some cool low latitude aurora.
Does everyone have their generators ready?
http://www.innerx.net/personal/tsmith/13Mar89.html
On 13 March 1989, the voltage of Quebec's power grid began to fluctuate alarmingly. Seconds later, the lights went out across the entire province. Some 6 million people were without electricity for nine hours. Within two days, NASA had lost track of some of its spacecraft and the northern lights were glowing in the sky south of London. As described in the 3 February 1996 issue of The New Scientist, these events had the same cause - a monumental Solar Storm, the fiercest for 30 years
Wouldn't 2.4 ghz fall in that range or does hf mean hf in the classical
sense of something on the scale of 3 to 49 mhz or so.
: Well, this is more than you really wanted to know, but....
: HF High 3mhz-30mhz
I realize this. However, satellite communications (which were mentioned in
the notice) are certainly not in the HF band. I suppose I then interpreted
the NOAA notice such that "high frequency" was being used as a generic term,
not indicative of the band.
Oh well, back to running a network. <yawn>
Rodney Joffe said:
[snip]
900 mhz and 1800 mhz. And facing East or West. And Satellite,
somewhat above 2.0 ghz.
Hmm.
And a significant number of ISPs are currently employing 802.11 2.4
and 5.0+ ghz equipment for last mile links (Proxim Tsunami) and
Motorola Canopy gear.
The PSD of the modulation (BPSK) that Canopy employs is rather, shall
we say, insane when contrasted with CCK or QAM. I'd be impressed to
find a system that experiences errors or goes off-line completely due
to a CME.
Interestingly, I found a few papers discussing the nature (as well as
proposed detection methods, with examples) of the RF signature of a
CME. The two most easily understood (imho) would be the following:
-http://cdaw.gsfc.nasa.gov/news/cannibalism.pdf
"Long-wavelength radio emission in the decameter-hectometric
(DH) wavelengths (21�280 m or 1�14 MHz in frequency) has
proven to be an important diagnostic for understanding very
energetic coronal mass ejections (CMEs) propagating into the
outer corona and interplanetary (IP) medium (Kaiser et al. 1998;
Gopalswamy et al. 1999; Reiner & Kaiser 1999)."
-http://cdaw.gsfc.nasa.gov/publications/gopal2003.cospar.pdf
Page three of this paper has an excellent time/spectrum graph of
several type II and type III CME (radio) bursts:
Again, these researchers are looking at RF spectrum below 10Mhz. One
could maybe reason (or argue) that the onset of the type III events
(which appear to be initially identified by very broad spectral
content) contain components out to (or above) UHF frequency ranges.
However, after looking over these two papers, I don't see that there's
anything "interesting" above 10mhz, let alone 3 GHz+.
If anyone could offer up evidence that has linked path "fading" or
"desensitization" (of an operator's equipment) to a type II or III
CME, _and_ is operating above 3 GHz, I'm all eyes.
--Tk
It means HF in the traditional sense of the word. The cellphone issue
is due to the use of satellite links to many cells. There is no reason
to believe that line of sight (LOS) communications VHF and above are
likely to be impacted by these events as long as they are not depending
on ionospheric propogation.
HF depends on ionospheric bounce. Satellites depend on the signals
being able to penetrate the ionosphere. Both of these will be
effected. Terrestrial microwave and VHF line of site, 802.11,
2.4GHz cordless phones and the like do not.
Owen
KB6MER
Just to add, it seems that I over extended the hf band the cut off as was
correctly pointed out was 30 mhz I believe.
And if anything since friday the vhf band seems improved, 2 meters has
been quite good.
I'd say that I have not noticed any disruption although I've heard tell of
disruptions in the gps network I haven't experienced them personally.