• We have had massive problems with our protocol analyzer gear the last days.
    Tuesday - yes, when the sun storm arrived - we witnessed that alot of frames did not show up in the protocol analyzer. Especially larger dataframes where either gone or corrupted. Small frames, like beacons, but also voice data did not suffer that much. Although we knew that frames where being sent (pings, streaming video), they did not show up.

    We have tested with different pieces of hardware to be sure:
    Wireshark with Airpcap NX
    Airmagnet analyzer with Proxim 8494 and C1060
    Ethereal with PRISM Duette

    Testing was performed at different locations the last days, all with the same result.
    Only yesterday evening DSSS showed up properly, and, although it is getting better we still miss frames with OFDM.We also saw an increase in retries, but luckily not so bad as you would have assumed from the sniffer traces.

    I wonder if someone has had the same experience, we can still reproduce it. Just start a ping and check if both ToDS and FromDS show up in the sniffer. We have kept our traces....

  • I am having an issue with missing beacons. Sometimes almost 1 sec between them.

    But honestly, I have never looked at just beacons, and since I am experimenting in this area for the first time, I don't know what to expect.

    My signal level seems good, and my rate is 11 Mbps. Since Beacons don't get ACK'd and therefore are never retried, I can't tell anything from that.

    I had been wondering if the solar storm was causing any of it, but have no way to prove it.

    My car radio has definitely been having problems that I am attributing to that though.

  • Frans

    Which country are you in ? Solar storms could well have been the cause. I have been waiting for several years to see if anyone has experienced problems with Wi-Fi.

    The sun is a broadband radiator of RF energy. It sends out energy over a wide spectrum. Usually, it?s mainly satellite systems that get affected ( communications-wise and also with the actual physical electronics ). The intensity of the sun?s solar flares go in an 11 year cycle, leading to a Solar Maximum Event. The energy ( RF and other frequencies ) which is emitted, can only be predicted up to a point. The sun emits energy in the 2.4 and 5 GHz bands, as well as many others. NASA has been predicting for some time now, that this year could be particularly ?bad?.

    Good video from the SOHO spacecraft

    Satellites in geostationary orbit experience a ?Solar-Transit Event? twice a year. During these periods ( highly predictable ), the orbital planes of the spacecraft and the Sun are in line. Most satellite earth stations utilize parabolic antennas. When you look on a spectrum analyzer, you can actually see the noise floor rise. It usually ( depending upon physical location on the earth etc ) slowly increases in intensity over a few days, peaking, then reducing in intensity. During this time, the effect on communications signals can vary from slight interference, to a total ?jamming? of all signals. Customers are advised well in advance. The only way to overcome this natural phenomenon is to physically build a diversity earth station at another location. Military and Governmental groups sometimes do this, when absolute continuity of service is required. This can also be done for Ku and Ka band systems ( 11/12/14 and 20/30 GHz ) which can suffer heavily from rainfall attenuation. Rain tends to fall in ?cells? ( in other words, from a dark raincloud, there is not a uniform density of rain droplets per cubic meter over the whole cloud volume ). The size and angle of the droplets ( the canting angle ) have a large effect on attenuation and depolarization. Rain droplets start off as spheres, then gradually become pear shaped as they reach terminal velocity. Wind can alter the shape and hence the attenuation etc.

    The larger the antenna, the narrower the beamwidth. The ones I used to work on were 105 feet in diameter ( 32 meters or so ) and many hundreds of tons. Geostationary spacecraft are not perfectly stationary, but move in a figure of eight type of pattern. Tracking beacons ( e.g. 3947.5 MHz ) are used to track the spacecraft and also to act as a carrier of telemetry information from the satellite. You need to put the antenna braking system on and deactivate tracking for the transit time, as otherwise the antenna would literally track the sun.

    TV stations often have to co-ordinate with other station affiliates to the physical east of them in order to keep continuity of service ( as one station to the west gets ?hit? with sun interference, the one to the east is not ).

    Coronal mass ejections can cause physical damage to spacecraft. The semiconductors devices used in satellites ( e.g. Gallium Arsenide FETs etc ) can be damaged by the high energy particles. Semiconductor memories can be altered or destroyed. Sometimes the operators will have the spacecraft physically rotate such that it exposes the minimal amount of surface area to the Sun, or may be turned so that ?hardened panels? are presented to the Sun.

    Just as with transformer theory, changing lines of magnetic flux can induce currents. A solar storm caused a large part of the electric grid in Montreal to be shut down one year:


  • Hi Dave,

    thanks for the information. We are located in the Netherlands. I was giving training in a hospital, when we experienced it the first time. More people with similar equipment experienced it. A partner company also reported it, who were working somewhere else.
    I have been monitoring it since then at different places. Never seen it before in 12 yrs of protocol analysis.

    I reported it to a astronomyclub here and they informed me about the ACE satellite , the observations appear to have the same timeline.

    I have traces available if you want.


  • What bothers me the most is why monitoring equipment appears to suffer more than actual Tx/Rx PHY's.

  • Very interesting Frans. Note the 11 year Solar Max cycle and the 12 years you mentioned. Not all Solar Maximum Events are equal.

    I remember the one from two cycles back. Was working on a facility with an antenna that had a very low look angle. Tropical island. At sunrise and sunset, the received signals from the satellite would vary up and down like a yo-yo. A phenomenon known as Troposheric Scintillation ( quite rarely observed to that degree ). Rapid changes in temperature and humidity as the Sun came up or went down, caused the 4 GHz signals to be severely refracted. There is an even rarer event ( at 4 GHz ) known as Ionospheric Scintillation. Basically charged particles from solar flares cause strong changes in the number of free ions in the Ionosphere ( part of HF radio operation ). Usually doesn?t affect satellite operations, but that one was a biggy. We had very sensitive traffic flowing and I told some of the powers that be of my concerns, as I?d contacted the US Naval Observatory who told me it was going to be really big. They relayed it back to even higher, higher ups who said ?It won?t be a problem?. Next day, signals were all over the place and we lost comms. Used the spectrum analyzer to show that it was coming from Ionospheric Scintillation.


  • I got feeback that the holoween flares in 2003 were much bigger in comparison to the last days, wondering why nothing was reported. My answer would be that .11 explosion took place after that year which makes explains the lack of reporting.
    Testing today still gives alot of problems, if you want I can show you with teamviewer.
    What results other than the sniffs would I need to make this solid ?

  • We have the Cognio and AM XT to work with, does not show enough relevant info. Will ask an old collegue with better R-S.

  • Any traces may help. Do you guys have any form of Spectrum Analysis tool available ( physical unit, Metageek etc ) ?

    The interference patterns can be very complex. If you watched the movies, you can see the flares building up and "stretching" (magnetic lines of force are involved ) like a balloon and then "shooting out". Depending upon where you are physically ( interaction of earth's magnetic field etc ) the amount of interference can vary. The intensity can vary dramatically as well.

    I can tell you that it is extremely rare for Wi-Fi to be affected. However, if the storm is large enough, all sorts of things can be affected.

    How far away from your location are the other guys who saw problems ?

    Do you have any airports or military bases near you that you know of ?

    Are you working at 2.4 or 5 GHz or both ?


  • We have a military base at about 15 miles away. Location between similar results about 80 miles. My job is amongst other things to work on cases resulting from vendor implementations. Therefore I need to check frame exchanges and I can tell you this behavior is not normal.
    Testing is being performed for 5 GHz at channels 36, 40, 44 and 48. Both at 20 and 40 MHz. 2.4 GHz at channel 1/20 MHz all against Cisco 1142/3500 icw WiSM and WLC 4404 with 7.0.220 FW.
    I just saved traces with Airmagnet spectrum Analyzer/Cognio Chipset.
    Just now the ace satellite is showing spectacular increase in activity.

    If you send me a PM with email I will send you the following traces of today (from my lab, 8 MB) which concludes everything I am writing about - I have 200 MB more if needed:
    spectrum analysis

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