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portege: Very silly question but if there are 10 users on a 54 Mbps router - does it get split by ten so each user will get 5.4 Mbps ?
It is actually FAR more complicated than either answer suggests.
802.11 traffic is time sliced, rather than bandwidth sliced. If 10 users are connected, they all transmit and recieve at maximum speed, but only one is able to do it at once. This is what creates so many problems with VoWLAN on cheap equipment. You are not getting a nice even 5.4Mbps, if everything is fair, you transmit at 54Mbps for 10% of the time, and 0Mbps for 90% of the time while you wait for the other 9 clients.
The other thing to bear in mind, is that 802.11 bandwidth does NOT equate to IP data throughput. Each individual packet has a small overhead, but the big killer is the ACK's. Every 802.11 packet MUST be acknowledged, so sending one frame of IP data, requires two packets at L2 802.11 - DATA, ACK. 54Mbps aggregate throughput is closer to 25Mbps of IP traffic.
To really kick you in the nuts, if your AP is configured in b/g mode, then everytime a b client is heard by the AP regardless of whether it connects to your AP or not, protection mode is invoked. This turns your 1 packet of IP data into a four frame process. RTS, CTS, DATA, ACK. And in case the burning sensation between your legs wasn't bad enough, all management frames travel at the lowest supported rate (1Mbps). This means that your 54Mbps connection, is actually 14.25Mbps when averaged out with 3 management frames.
And while I'm really killing your fun, 54Mbps is the perfect 802.11 bandwidth. This is based on the modulation types used, which is in turn based on signal strength. The further away from the AP you get, the weaker the signal, this causes the AP to negotiate different modulations, which support lower bandwidth. Your average speed is affected by the speeds of all other clients, since you have to wait while they use the medium. If they want to send 10Kb, and are only connected at 2Mbps, that is 26 x longer you have to wait.
All of this adds up to some very good reasons to use quality wireless equipment, and some good incentives to make sure it is set up and configured properly.
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