Mike Bilow wrote:
> I would concede that this is theoretically true, and the 21% number comes from
> precisely the Poisson model that I mention. However, it is important to
> recognize that this number only applies in the context of measuring channel
> capacity. In other words, pure ALOHA falls off to 21% throughput
> asymptotically under the specific condition of approaching maximum channel
> loading to capacity. This is exactly why one might choose to trade capacity
> for yield, as I discuss above, and why maximizing yield might be reasonable if
> not carried to extremes. That is, SWR really is important, but it is not a
> measure of absolute effectiveness or we would trade antennas for dummy loads.
Hm. What I was trying to say is that with pure ALOHA the maximum
throughput you can expect is %21 of capacity. Not: "the minimum yield is
21%". Or am I misreading you here? Actually ALOHA falls down to 0% under
high packet generation rates or many stations. the "or" is logical,
non-exclusive here. Of course you can always try to trade response time
for capacity, but at least with ALOHA it won't help. It doesn't really
matter if you suffer from collisions or from having deep output queues
:-)
Gruss,
Matthias
