Real cost to transfer rate with mixed "G" and "B" devices??

Running a wireless network with three PCs, all running 802.11g adapters
(1 USB, 1 PCI and 1 PCMCIA).

Also running wirelessly on this network is a Tivo, running an 801.11b
USB adapter.

Is is true that when there are mixed "b" and "g" devices, data rate
across all devices defaults to the 802.11b rate?

If it is: does this reduction come simply because there is an 802.11b
device present in the network, or does it have to be actually passing
data (Tivos only contact the mothership once a day...)?

On Thu, 02 Dec 2004 12:16:21 -0500, (E-Mail Removed) wrote:

~
~ Running a wireless network with three PCs, all running 802.11g adapters
~ (1 USB, 1 PCI and 1 PCMCIA).
~
~ Also running wirelessly on this network is a Tivo, running an 801.11b
~ USB adapter.
~
~ Is is true that when there are mixed "b" and "g" devices, data rate
~ across all devices defaults to the 802.11b rate?

No, this is not true - however, if there are 11b clients associated
with an 11g access point, this will significantly reduce the throughput
available to the 11g clients - from 22Mbps down to about 8Mbps.
(See: White Paper: Capacity, Coverage, and Deployment Considerations
for IEEE 802.11g, http://www.cisco.com/warp/public/cc/...t/80211_wp.pdf .)

~ If it is: does this reduction come simply because there is an 802.11b
~ device present in the network, or does it have to be actually passing
~ data (Tivos only contact the mothership once a day...)?

This speed reduction for 11g clients will be in effect as long as the 11b
client is present, regardless of whether it is passing data.

Aaron

Aaron Leonard wrote:
>
> On Thu, 02 Dec 2004 12:16:21 -0500, (E-Mail Removed) wrote:
>
> ~
> ~ Running a wireless network with three PCs, all running 802.11g adapters
> ~ (1 USB, 1 PCI and 1 PCMCIA).
> ~
> ~ Also running wirelessly on this network is a Tivo, running an 801.11b
> ~ USB adapter.
> ~
> ~ Is is true that when there are mixed "b" and "g" devices, data rate
> ~ across all devices defaults to the 802.11b rate?
>
> No, this is not true - however, if there are 11b clients associated
> with an 11g access point, this will significantly reduce the throughput
> available to the 11g clients - from 22Mbps down to about 8Mbps.
> (See: White Paper: Capacity, Coverage, and Deployment Considerations
> for IEEE 802.11g, http://www.cisco.com/warp/public/cc/...t/80211_wp.pdf .)
>
> ~ If it is: does this reduction come simply because there is an 802.11b
> ~ device present in the network, or does it have to be actually passing
> ~ data (Tivos only contact the mothership once a day...)?
>
> This speed reduction for 11g clients will be in effect as long as the 11b
> client is present, regardless of whether it is passing data.
>
> Aaron

Thanks. Excellent gouge. Guess when Tivo starts supporing 802.11g, it'll
be time to update the DVR:-)