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OT: 802.11g transmission speeds
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My home PC in the 'office' is conencted to my router using 802.11g,
and reports a good signal and a 54Mbps connection. The router is
connected to my PVR via 100mbps lan.
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It's a switch. AFAIK no-one makes hubs any more. ISTBC of course
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No, it's a router. Geddit?
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Heh heh. I've got a hub next to me from Black Box. It sez so on the
blooody thing. :-)
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So, when I copy a 4GB file from the PVR to my desktop, I would expect
it to have to move (4,000,000,000 * 10) bits [10 bit per byte rule of
thumb for transmission overhead), which at 54mpbs is 795 seconds - 13
minutes.
In fact, it takes 4 to 5 times as long - typically 50 minutes to an
hour.
Anyone got any suggestions as to why?
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Is the router set to 802.11g only or is it in "compatability" mode
where it can do 802.11b too. Apparently that significantly reduces
performance. I'm pretty sure that you get nowhere near 54Mbps in real
world transmission even in perfect conditions.
If I could be arsed to web-search to refresh my failing memory, I'd even
tell you why.
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Dunno, but just for grins I would try it first via a wired 100 Mb/s
connection and use that as my baseline, to take out the overhead of
the systems' disks, I/O channels, etc.
My WAG is that there's considerably more overhead in 802.11 protocol
for a start, 54 Mb/s may be the raw bitrate and not anywhere near
the theoretical throughput. I see from Wiki I am right- even without
any bandwidth sharing (neighbor using the same channel(s)?) the max
actual payload transfer is about 25Mb/s.
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Yep. 54Mbps wireless is nowhere near that speed in a real life network.
With various overheads/half-duplexing and all that caper, I would estimate
you're lucky to see 20Mbps actual throughput in ideal conditions.
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Yes wot he said, huge transmission overhead of marketing bollocks. I use
wireless here in the flat but have a handy cable waiting for any serious
file moving. The laptop which plays music and film off the network drive
is also cable connected.
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