Cisco Systems 7920 用户手册

difference in transmitter power and receiver sensitivity that matters because the gain of an antenna is 
reciprocal. To verify the cell coverage edge of –67 dBm while the client is actively sending and receiving 
voice size packets, check the access point’s Station Information and Status page for a dBm value of 
–67 dBm or higher.

 shows the ideal WIPT cell with the recommended cell edge signal strength value of -67 dBm 

at an 11-Mbps data rate and the recommended same-channel separation of 19 dBm at an 11-Mbps data 
rate. The two yellow cells have a cell edge of –67 dBm. The measured overlap of a channel should not 
exceed –86 dBm (from the center of the measured cell to the edge of the neighboring cell of the same 
channel). This is the value of –67 dBm plus the 19 dBm for separation. Keeping the separation at 19 dBm 
between same-channel cells produces a cell with minimal throughput degradation because of media 
contention. This helps maintain up to 7 good-quality WIPT calls in a cell. 

100mW

5mW

135108

A typical deployment showing a 15-20% overlap
from each of the adjoining cells.

Provides almost complete redundancy throughout
the cell

The radius of the
cell should be:
67 dBm

The separation of
same channel cells
should be:
   19 dBm
   7920 RSSI=20

67dB

86dB

135075

Channel

1

Channel

11

Channel

6