On 14-nov-03, at 23:08, Henk Uijterwaal (RIPE-NCC) wrote:
I strongly encourage people to consider bringing 802.11a cards to
future meetings! (Note: Of course, now that I've said that, the
future
hosts will decide against deploying it)
If we go for 802.11a, I sugggest that we ask a vendor (or two) to come
with a pile of cards that people can borrow for a few $$ more than the
manufactuiring price, and can return after the meeting, or not.
Note that 802.11a isn't an option for everyone due to lack of PCMCIA
ports or driver support.
Also, I don't think the troubles we had are inherent to 802.11b. In
Vienna there were even a few more people, but IIRC not wireless
problems to speak of. I do seem to remember there were huge amounts of
base stations deployed there and they used overlapping channels. (But I
may be wrong.)
I believe we had two problems the past week:
1. Congestion
2. Clients jumping to peer to peer networks
Ignoring obvious solutions to 1. such as more 802.11a and better RF
surveying/design, I think adding some 802.11g to the mix might also
help. If the number of 802.11g capable hosts is large it would make
sense to put them on a separate channel (and possibly SSID) where the
higher bandwidth allows for a larger number of clients on a single
channel and the other channels can be used by 802.11b-only hosts. If
the number of 802.11g hosts is small, then it would probably be a good
idea to have the base stations in mixed mode. The g hosts can still
achieve higher speeds this way (although not as high as in g-only mode)
so they'll leave the channel free for b traffic a larger percentage of
the time. Also, the RTS/CTS mechanism that is used to make the b-only
stuff be quiet while 802.11g is doing its thing could in itself be
helpful.
As for 2., it seems some stuff tries to hang on to the same base
station network when the base station in use disappears while other
implementations simply jump to the strongest network they can find,
even if this is a different SSID (when the SSID isn't explicitly
selected) or a peer to peer network using the same SSID. Obviously it
would help if the clients improved their behavior, but wouldn't it also
make sense for the base stations to simply not disappear? That would
also solve the problem.