Not sure if this is the place to ask this, but I couldn't find a more appropriate StackExchange site. I heard that the quality of wireless connection follows the law of the lowest common denominator – meaning that if 10 users connect to an AP at 50Mbit and one at 5Mbit, everyone gets stuck with 5.
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Can anyone, with 100% accuracy, say whether this is true or not? I'm asking because we have 8-10 WRT54GLs on DD-WRT powering our company network, and wired speeds through those APs are up in the 50-90Mbit, while wireless can't seem to go above 9Mbit.
Best Answer
While the slow client is transmitting data, due to CSMA-CA, no other client can transmit. A slow client will take significantly longer to transmit its packet of data than a fast client.
Similarly while the AP is talking to a slow client all other wireless devices on that channel will have to wait for their turn. The slower the device the longer that the channel is in use for both transmit and receive packets.
Many APs will have minimum connection speed configurable. This may help speed up fast clients, but older devices and clients will be unable to connect.
This particularly shows up with a bad connection where the combination of a slow connection and, probably more importantly, retries plugs up the capacity sufficiently to effectively block the other channels by consuming most of the capacity of the connection.