The basic rate is an issue that wireless networking will need to address since it effects more than just beacons, all broadcast and multicast traffic are sent out at a slow rate and take far too much air time. At some point the beacons will have to be sent at a faster rate than 1 or 2 mbps thus breaking 802.11b at some point in the future. When this speed increases beacons will take less air time.

Of course you could always turn down the beacon interval, 10 a second is usually fine from my experience and saves a lot of air time. Many APs let you tun this.`

Cheers,
Cliff

On Dec 20, 2003, at 1:06 PM, Bernard Aboba wrote:

Jonn Martell said:

What confuses me though is when vendors talk about possible QOS problems
with multiple BSSIDs? I simply don't get that.

I think what they are referring to is the effect of increasing the number
of Beacons on a single channel. For example, simulations at the Royal
Institute of Technology in Stockholm appear to indicate that with 5 VAPs,
approximately 20% of the AP's capacity will be used for Beacons; with 10
VAPs, 32% of capacity is used. So there are practical limits to how many
VAPs can be Beacon'd, regardless of how many a vendor might support.


For details, see:
http://www.it.kth.se/~hvelayos/papers/TRITA-IMIT-LCN%20R%2003 -02%20Handover%20in%20IEEE%20802.pdf


Links to these and other papers relating to VAPs are available on the
802.11 security website:

http://www.drizzle.com/~aboba/IEEE/

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