charles, ive got some orinoco 'silver' wireless cards (model # PC24E-H-FC) made by lucent if youd be interested in borrowing them or purchasing them. let me know.
-matt -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Charles Steinkuehler Sent: Wednesday, June 04, 2003 9:51 PM To: Steve Wright Cc: [EMAIL PROTECTED] Subject: Re: [leaf-user] Improving wireless link Steve Wright wrote: > Charles, > > On the basis that there is some distance involved ; (an assumption) > > My understanding is that some of the cheaper (dlink in particular) > wireless gear has 'timing issues' when the A/Ps are physically far apart. > > In the extreme, you will have to go to a proprietry fix, viz turbocell, > or replace the A/Ps with something a little more tolerant of distance. > > 802.11 was never intended to travel great distances. Indeed it was part > of the 802.11 specification to actually prevent (ha ha) this from > happening - the reason for the proprietry RF connectors. > > In summary, many standard 802.11 wireless cards will do great distances > without getting flaky, but I have heard that the dlink gear is not of > that category. Other cards such the Orinoco PC-cards combined with > turbocell work very well indeed at distances up to 20km, and provide > true data rates in the order of 9MBit/sec (I am told). I don't like the > idea of proprietry *anything*, and I wish there was an open-source > 'turbocell'. Hmm...I hadn't been aware of the distance issue, but I can see where it could potentially be a problem. I doubt, however, that this is much of a problem in my instance. While it is a point-point link, the distance is about 1/2 a block (maybe 400-500 feet, or about 130m). If anything, I think my main issue is multi-path, other 2.4 GHz transmitters nearby, or some other environmental issue. I'm still trying to get access to a spectrum analyzer to do a proper site survey. > In answer to your question, I do not think there is a device you can put > on the ends of a leaky hose - to make the hose not leak. The "hose will still leak", but packet loss in conventional TCP networking signals network congestion, and triggers exponential backoff. I have bandwidth to spare over the wireless link, and am looking for something that makes the link-layer "TCP aware" (or puts a TCP aware "wrapper" around the link, since I don't have direct access to the wireless firmware), as discussed in literature for improving TCP performance over wireless networks...something like the LL-TCP-Aware or LL-SMART-TCP-Aware link protocols in: http://www.stanford.edu/~amaaron/ee359/ee359_tcpproj.pdf I just don't know if anyone's written anything like this for linux that I can try to use... -- Charles Steinkuehler [EMAIL PROTECTED] ------------------------------------------------------- This SF.net email is sponsored by: Etnus, makers of TotalView, The best thread debugger on the planet. Designed with thread debugging features you've never dreamed of, try TotalView 6 free at www.etnus.com. ------------------------------------------------------------------------ leaf-user mailing list: [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-user SR FAQ: http://leaf-project.org/pub/doc/docmanager/docid_1891.html ------------------------------------------------------- This SF.net email is sponsored by: Etnus, makers of TotalView, The best thread debugger on the planet. Designed with thread debugging features you've never dreamed of, try TotalView 6 free at www.etnus.com. ------------------------------------------------------------------------ leaf-user mailing list: [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-user SR FAQ: http://leaf-project.org/pub/doc/docmanager/docid_1891.html
