Scalability is the ability to locate more than one access point in the same
area. This will increase the available bandwidth of that area for all users
local to that access point. In the past, this scalability was limited to only
frequency hopping spread spectrum (FHSS) products. DSSS products could not
change channels without some reconfiguration. The current Cisco Aironet
products are frequency agile. This means that they can look for and use the
best channel. There are three separate, 11-Mbps channels available. These
channels are completely non-overlapping and non-interfering. Up to a
theoretical 33 Mbps per cell can be achieved with 802.11b devices. However,
users still only operate at a maximum theoretical value of 11 Mbps, since they
can only connect to one AP at any given time.

In the
case of 802.11a, there are eight non-overlapping channels, each up to a
theoretical bandwidth of 54 Mbps. This means that a maximum of eight discrete
systems can reside in the same area, with no interference. Therefore, the
highest aggregate total data rate for an 802.11a system is a theoretical 432
Mbps, for a given cell area. Remember that any connected user will still only
receive up to 54 Mbps. With more APs, users will have a greater chance of
higher data rates.
