USB 1.1;2.0;wifi speeds

What is difference in throughput speed when using a usb adapter on a usb
1.1 usb system vs 2.0 on the same system for the same wifi link? IOW,
what is the difference between the speed obtainable under each?

HymieGoogle <HymieGoogle-(E-Mail Removed)> hath wroth:

>What is difference in throughput speed when using a usb adapter on a usb
>1.1 usb system vs 2.0 on the same system for the same wifi link? IOW,
>what is the difference between the speed obtainable under each?

USB 1.1 is limited to 12Mbit/sec thruput. USB 2.0 high rate limits
out at 480Mbits/sec and will handle any wireless USB speed known.

What gets weird is what happens when you plug a USB 2.0 802.11g
wireless device into a USB 1.1 port. There are three possible
algorithms.

1. Take whatever wireless speed is possible and use TCP/IP flow
control to throttle the connection. You can get a 54Mbit/sec wireless
connection, but with a USB 1.1 port, the thruput will max out at
around 9 to 11 Mbits/sec (there's some overhead).

2. Slow the wireless connection down to where TCP/IP flow control is
not needed. You'll get about a 12 or 18Mbit/sec OFDM (802.11g)
connection, with a maximum thruput of 9 to 11 Mbits/sec.

3. Turn off 802.11g completely and revert to 802.11b only. The USB
device will switch to a maximum speed of 11Mbits/sec with a thruput of
about 5Mbit/sec.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558