Access point connectivity is a shared network model. One user connected to an access point downloading a Linux DVD ISO image of, say, 3.5GB from an intranet site (eliminating the variable of "last mile" Internet connectivity) may experience average throughput of (for the sake of argument) 50Mbit/sec. from an 802.11g access point. At this rate, the download will finish in about (3.5GB*8b/B)/0.05Gbit/sec.=) 560 seconds or somewhat over nine minutes.

Add nine more computers downloading the same image, and the task will be completed in slightly over one and a half hours ((3.5GB*10*8b/B)/0.05Gbit/sec.=5,600 seconds). Those same 10 computers connected to a switch at 100Mbit/sec. with an uplink to the server at 1Gbit/sec. would complete downloading the image in 1/20 the time -- or about five minutes. Other variables, such as contention, packet overhead and signal strength are ignored in this example, but it illustrates the magnitude of the bandwidth difference well.

There are inherent limitations to the number of connections to an access point. A good rule of thumb for designing is that each access point can support 20-30 simultaneous users. Applications that don't demand high bandwidth and/or low latency will suffer performance when the number of simultaneous access point users is too great.

How the access points connect to the backbone is important as well. In the previous example, the wireless access point was assumed to have a wired 100Mbit/sec. connection as an uplink. What about in mesh networks? Depending on how the mesh is laid out, an uplink at 54Mbit/sec. may connect to an access point that feeds two others, and the uplink capacity to the backbone network for each of the two edge access points is therefore decreased by 50%. More access points relying on the uplink would mean a further reduction in bandwidth.

If the primary use is for Internet access, the bandwidth limitation typically lies in the ISP connection. In those cases, LAN bandwidth limitations are usually not much of a consideration. If mobility and cost is, wireless may be the way to go, but there is also the security aspect. Wireless network connectivity adds security issues because of the inherent nature of the unrestricted physical medium.