Sorry, cannot agree with that statement.  Just because a system uses
half-duplex does not mean that the speed is halved.  It will only be
halved if the acknowledgement packets are of the same length as the
transmission packets and this is very rarely the case.  For example, if
you send blocks of 10k and the acknowledgement packet is only 0.1k then
the time spent transmitting will be about 100 times longer than the time
spent receiving (even considering the time spent switching between
transmit and receive and the overhead in synchronizing.

We did a lot of tests on this matter to try and determine some rule of
thumb that we could use.  We had heard that 60% would be a suitable
value to use, but in our tests we never got above 40% i.e 4Mbps for
802.11b but and 20Mbps for 802.11g

The above tests were all carried out in a single room with no other
2.4GHz equipment turned on within miles (tests were done on islands).
We were getting nearly 100% in terms of signal strength and link
quality.  However, there was the possibility of reflections from the
walls of the room causing problems which we had no way of investigating.
Last week-end we miraculously got in excess of 40Mbps in an outdoor
environment using 'g' equipment over a distance of about 100 meters.
This was noted as an 'accidental' sidebar to a bigger test and we have
not yet had a chance to re-check the figures.

Hope my ramblings are of some help and did not sow seeds of confusion.

Oliver Leamy

Ogenek Teoranta, Ballingeary, Macroom County Cork
+353 (26) 47808 ; +353 (86) 8337664


-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Company 2210
Sent: 23 June 2003 21:56
To: [EMAIL PROTECTED]
Subject: Re: [smartBridges] speed

Yep. Wireless is half duplex, so whatever your getting divide by 2 to
get
realistic full duplex throughput.

----- Original Message -----
From: "Roger Howard" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, June 23, 2003 9:49 PM
Subject: [smartBridges] speed


> Is there any way to tell what speed an airBridge is connected at
without
> doing a speed test? If it's connected at 1Mbps am I right in assuming
that
> the actual throughput will be about half that?
>
> Thanks,
> Roger
>
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