Intermittent Wireless - Seems to follow a pattern.



  • EDIT - I edited the original subject of 'looks like a wave form' as I guess it doesn't strictly, it does however follow a pattern of signal strength. I've also been a bit briefer with current problem below.

    Current Issue:

    Signal strength seems up and down with a seemingly constant period between the up and downs (in red), view the image in new tab if you wish to see the whole thing - the right appears cut off -

    .

    This is on a completely fresh install with the wireless interface setup up with both WPA and WPA2 with the SSID of 'Wizard'. All other APs in the area work fine as can be seen. Has anyone any ideas what may be causing it? Futher reading below in case it answers any questions.

    Thanks

    ORIGINAL POST ->

    Hi,

    If the subject intrigued you feel free to skip the Wizard_inSSIDer image at the bottom to see what I mean, the one in question is in red. I have searched Google and the forums intensely trying to find out what’s happening here and what I may be doing wrong and found some items which partially match what I am experiencing and haven't solved the issues I hope you guys can help with. I shall reply with the fix once it’s sorted.

    The current situation - I have just restored factory defaults, set the WAN and LAN interface, enabled the wireless interface as an AP, set an SSID and set a WPA/WPA2 PSK. I enabled the DHCP server on the wireless interface on a separate range to the LAN IPs and set a rule to allow traffic between the LAN and Wireless interface (so haven't actually bridged the interfaces) and to the WAN interface from the wireless interface (LAN can already access WAN). Looking at inSSIDer from a laptop 5 feet away the signal strength of the SSID in question 'Wizard' is constantly rising and falling as per the attached image. Curr, Admin, guestest and the multiple AGS SSIDs are separate APs, some multi SSID on single APs - completely separate to this setup.

    So brief background -

    I have an ITX board - CV700A-3R10U - http://www.lex.com.tw/product/pdf/CV700A.pdf (pdf warning) with 1GB RAM, 1 GHz processor running off USB.

    The WNIC is a Mini-PCI card with what I believe is the AR5212 chipset (Atheros AR5212A-00 printed on the chip) which according to http://doc.pfsense.org/index.php/Supported_Wireless_Cards should be supported - the only difference is the one on the list does not have the A on the end, not sure if that is an issue.

    The original problem I had with wireless was the error "ath0: stuck beacon: resetting (bmiss count 4)" and although I could connect to the AP while these messages were being displayed on the console, there was no traffic moving between the client and the AP. What was at that stage different in the setup was I had set up two SSIDs configured (purely just testing) with rules allowing traffic between those interfaces I wanted to talk to each other, which were all working fine when they were.

    I scrapped the whole multiple SSID idea as a first step of trying to diagnose this problem; I was concerned that it might be affecting the performance of the wireless NIC. I restored factory defaults and set up the wireless interface under interfaces as normal (as opposed to the wireless clones I used originally for multiple SSID) as outlined above under current situation which is where I'm at now.
    I have only one aerial connected by a u.FL to SMA pig tail to the wireless NIC. The wireless NIC has two u.FL connectors which I understand to be the primary and secondary aerials and not rx and tx separately and so only having one connected should be ok, though I invite correction! I have tried plugging the same aerial in to both u.FL connectors on the card and it’s exactly the same on either one. I don't think this card 'spreads the load' between the connectors unless someone can suggest otherwise.

    Any questions please ask, luckily work is very quiet today and I shall be able to get back to you very quickly!

    Images that may be of interest are below, including the inSSIDer output. It is worth noting that its unlikely to be an interference issue, I would expect the other APs (including ones we test in this office (IT office)) all the time to do the same which they do not.

    Thanks in advance

    Luke

    Images -

    http://dl.dropbox.com/u/10264940/pfsense_photos/IMG_20111118_114131.jpg
    http://dl.dropbox.com/u/10264940/pfsense_photos/IMG_20111118_114447.jpg
    http://dl.dropbox.com/u/10264940/pfsense_photos/IMG_20111118_114550.jpg
    http://dl.dropbox.com/u/10264940/pfsense_photos/IMG_20111118_114905.jpg
    http://dl.dropbox.com/u/10264940/pfsense_photos/Wizard_inSSIDer.png



  • Just an update. I've disabled all protection, so now an open AP and its the same. I also disabled the DHCP server on that interface, purely part of a process of elimination and its also the same after that. Set the signal strength to 80 just to try another value - same. Tried in both B and G - same, A doesn't work at all but that could be that the laptop and my htc desire don't work on A. Set manually to a free channel (7) - same. Could it be a wireless driver issue? Could it be that the motherboard has a VIA chipset that I've read on one post? Is there a power saving mode/setting that I'm not yet aware of and needs changing? I am unsure what could be triggering this sort of behaviour from the AP. Any help would be greatly appreciated :)



  • For completeness, I have added 'kern.cam.boot_delay=10000' and 'debug.acpi.disabled="thermal"' to /boot/loader.conf do deal with a boot issue and to deal with false thermal errors coming up. I'm am also currently updating the bios which I agree should have been done earlier ! :S



  • On the latest bios now, unfortunately still the same.  ???



  • For single-antenna setups with Atheros cards, you need to disable antenna diversity and select an antenna for receive and transmit, whichever one gives higher signal strength when you measure it.  If you are using the 2.0 version of pfSense, these options are exposed through the wireless configuration page for the interface.



  • Thank you so much for your response, hit the nail right on the head its working a treat now! :D This opens up to a few other questions - Firstly are two antennas better than one and why? I've read http://doc.pfsense.org/index.php/Wireless_Details and the reason suggested for two antennas is to overcome regulatory restrictions by using a higher gain rx antenna. To your knowledge is the load split between both so that one recieves and one transmits at the same time or the one chipset uses either antenna one at a time / in series (excuse any poor terminology, I hope its not unclear what I mean). Also what is diversity? On the link it suggests its used for two antennas but not why - just wish to understand what I'm playing with! If two antennas look the way to go I intend to use two identical antennas and wonder what is the best distance to place them apart - I'm thinking either 18cm apart or 12cm, so out of phase or in phase. I suppose if only one antenna is used it wont matter, as long as theyre not right next to each other. Thanks again, greatly appreciated.



  • I wrote this http://forum.pfsense.org/index.php/topic,43501.0.html for you and others to understand diversity and why it's wanted/needed in some cases. Hope you find it helpfull.



  • Brilliant :) I read it and recognised your handle before realising you replied to this! Very helpful post, thank you.


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