Did you force modulations at all or are you letting it auto negotiate? Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373
On Sun, Jan 29, 2012 at 9:16 PM, Scott Reed <[email protected]> wrote: > This link is over 5 years old. XR5 cards will connect and pass a > significant amount of data at -80 if the CCQ stays up. > I am trying to figure out why a 5 year old link suddenly quits and new > hardware doesn't fix it. > > > On 1/29/2012 3:04 PM, Bryan Fields wrote: > > On 1/28/2012 17:05, Scott Reed wrote: > > RB433AH with XR5 at each end. > Signals running around -69/-71. CCQ is the goofy one. Most of the time > one direction is in the 50% range, but varies quite a bit. The other > direction ranges from 16% to 100%. Generally if I see it getting close > to 100% I know the link is going to drop. It comes right back up, > usually at about 50%. > I have tried 20MHz channels, 10MHz channels, 5MHz channels with about > the same results from all. > I have tried 5.2-5.3 frequencies and 5.7-5.8 frequencies. The higher > frequencies work better, but still not well. > > I'm not that familiar with the ubiquiti products, but from the data sheet > the radio will put out 23 dBm and requires a -74dBm signal to work (the data > sheet does not say what channel size this measurement is from, I'll assume a > 20 MHz channel). > > What strikes me is your normal RSL is is only 3dB more than the min RSL > needed to link at 54 mbit/s. This is well within the normal variance of a > radio path (+-3dB), and could be causing the radios to switch back and forth > between data rates (only after taking some errors). It could be > interference, but even 3dB of on channel interference is enough to raise the > noise floor and lower your S/N radio (keep in mind in a ofdm radio the RSL > numbers given assume a perfect noise free system, for ever dB of noise you > have add a dB to your RSL). > > If you want a 54mbit OTA rate you need a much better signal for it to be > reliable. If you need no less than a -74dBm signal, ensure you have a > -60dBm or better signal (rule of thumb) during steady state operation. This > will give you some head room for changes in the atmosphere (K value) and > other issues that pop up from time to time. If you suspect interference, > try to figure out if it's local or remote and where it's at. If you can use > a HP dish to knock down off path noise, do it. When I was deploying > backhaul radios in unlicensed space, I made HP dish's standard on all my > links. > > Unfortunately this is not cheap to do things properly, but it will let you > sleep easy at night. > -- > Bryan Fields > APAC Imports LLC > Phone: 800-721-6502 > Fax: 727-493-1511 > http://apacimports.com > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > > > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.1901 / Virus Database: 2109/4774 - Release Date: 01/29/12 > > > -- > Scott Reed > Owner > NewWays Networking, LLC > Wireless Networking > Network Design, Installation and Administration > > > > Mikrotik Advanced Certified > > www.nwwnet.net > (765) 855-1060 > (765) 439-4253 > (855) 231-6239 > > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
