Is wireless network speed shared or per user?

It's uncommon for a single PC to get the full speed from a 54 Mbps connection anyway...

If there's data going between PC #1 and PC #2 then it will be able to reach some maximum speed (depending on signal strength etc)

If you then add PC #3 sharing data with PC #4 (or #1 / #2) then there will start to be packet collisions if doing file copy (max speed, as that's all the two PCs will be doing, whereas streaming audio might be slower, as will playing games, etc, because of gaps in the data flow).

If you look at the end of the section on 802.11a (on the Wikipedia link below) you'll see how the length of time increases considerably if the speed of connection is below 54 Mbps, so the odds of collisions increases if the connections speeds are lower (as well as data taking longer to transfer).

I've just helped setting up a (big) house with a music server and 'guess what'... there's not a single item using wireless because wire connections will work reliably at 100 Mbps all the time. Later on, with limited work, the 100 Mbps could be replaced with a 1000 Mbps network, for faster file transfers.

Music server connection goes off to a 10/100 switch. Each of the remote zones can be playing different music tracks and ethernet switches separate the data so the master bedroom never sees packets of data for the bathroom whereas in a wireless situation, all the packets would be cluttering up the same radio channel...

It is absolutely shared. You will absolutely NOT get 54Mbps speeds. At best you will get half that with a single client and excellent signal. Then, add more clients, say 5 clients who are all downloading at the same time, then your throughput will go down to 1/5th of the speed of a single client. Best you can hope for (if all 5 clients are doing the same thing at the same time and all have good signal) is about 5Mbps per user.

Well yes it is shared, but you gotta ask the next question, is everyone on the network using the connection at the exact same time? If you make an internet request and everyone else at the exact instant also made one (cant really happen) then your wireless is down to 10.1. but since usually your will make a request and already have the screen, then next makes a request etc then each will get the "full" use. So yes it is shared but unless you are all doing the exact same thing at the same time it really doesn't hit you.

Now if you all download something at the same time your INTERNET connection (which is also shared) will really load down!. Most internet connections are well below the 10 megs.

54 mps is the "POTENTIAL" download speed. There are currently no ISP's that provide that kind of speed. Most broadband connections are within the 1.0 to 8.0 mps range.

Yes the bandwidth is split up between the computers - but of course it would depend also on what is being downloaded - streaming video would take up more of the bandwidth.

yeah its shared by all ...