User's Manual Part 1

SCP-LPS20x-011-012-01H December 20, 2004
72 ADC Telecommunications, Inc.
CONFIGURING OVERLAPPING WIRELESS CELLS
Overlapping wireless cells are caused when two or more access points are within transmission range of each other.
This may be under your control (when setting up multiple cells to cover a large location) or out of your control (when
your neighbors set up their own wireless networks.). In either case, the problems you face are similar.
PERFORMANCE DEGRADATION AND CHANNEL SEPARATION
When two wireless cells operating on the same frequency overlap, it can cause a reduction in throughput in both
cells. This occurs because a wireless station that is attempting to transmit will defer (delay) its transmission if
another station is currently transmitting. On a network with many clients and a lot of traffic, this can severely affect
performance as stations defer multiple times before the channel becomes available. If a station is forced to delay its
transmission too many times, data may be lost.
Delays and lost transmissions can severely reduce throughput on a network. Use the Wireless option on the Status
menu to view this information on your network.
Figure 17 shows two overlapping wireless cells operating on the same frequency. Since both access points are
within range of each other, the number of deferred transmissions will be large.
Figure 17. Overlapping Wireless Cells on Same Frequency
Overlapping wireless cells can cause transmission delays.
cell 1
cell 2
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