speed vs capacity...wireless.

[Goosemaster]

Simple question.


When adding more clients to an AP/router, do the clients share the 11Mb/s or, do they get 11Mb/s EACH?

If so, what is the average capacity of the AP?

 

[Goosemaster]

From what I have been reading, it seems that the readio can only service one client at a time, so all users do indeed get the 11Mbps, but have to wait for other users data to flow...like token ring.

Is this correct?

 

[ScottMac]

All of the access points behave as a hub. The bandwidth is shared.

You may not be fully understanding the concept of "shared" though. Every client on every hub, switch, AP, or other Ethernet port will always have full-rate access (10 meg, 100 meg, Gig, or whatever ... 1- 11meg in the case of an 802.11b system). The "shared" portion is relative to time. If another client is talking, the client has to wait for the transmit channel (be it a wire or radio wave) to be clear.

So when an Ethernet client gets the opportunity, it will talk at whatever its connection speed is .. not a fraction of it. The variable is when it will get the opportunity. With full duplex Ethernet to a switch, there is no wait at transmit-time; the entrance port is always clear to receive. If the exit port of the switch is busy, the frame is stored (buffered) until the frame can be passed/transmitted out of the switch.

Applying that to an access point, if the AP receives a frame and another frame is being handled by the radio (either coming in or going out), the frame is held until the radio is clear to transmit. The AP can only transmit or receive; it can't do both at the same time. The effect is half-duplex, like a hub (technically a "buffered hub," I guess).

APs can support multiple clients at multiple speeds, so closer clients can have a higher rate while more distant clients or those with less-than-perfect signal quality get lower connection rates.

FWIW

Scott

 

[gunrunnerjohn]

The key point is, a really good 802.11b connection will yield 6-7 megabits of actual network throughput after overhead is accounted for. If you have 5 clients all connected and attempting to utilize the bandwidth, they'll be lucky to have 1 megabit of throughput, since the bandwidth is indeed shared. This will fall off significantly if some of the clients are running at slower speeds due to poor signal conditions, since they'll be consuming more of time for less bandwidth.

 

[JackMDS]

If this issue is really important spread few APs around.

You will get better coverage and more Bandwidth to share.