
11
Graphical view of limits/specifications
The ETSI and ANSI specifications define power limits both in terms of absolute
accuracy and relative accuracy (between power levels or ‘steps’).
The examples given in Figure 8 are for transmitters of a specific type and class.
Absolute limits depend on the type and class of the device under test.
No scale:
representation
only
Power
dBm
+43
+41
+39
+37
+35
Top level
absolute
limit is
±2 dB
Other power levels not shown
• Also ±3 dB from top measured level
• Interval between power, steps 2 dB ± 1.5 dB
Example: E-GSM900, Class 5 BTS with dynamic power control, normal conditions
Note: typical max power for a GSM BTS TRX = 43 dBm
Channels:
B, M, T. Single carrier
At least three slots on
Hopping:
On
Detection:
Measured over useful
part of burst (gated)
Log average
Notes: Absolutes
depend on power class
of BTS. The six or more
‘power settings’ for
radio planning are
neglected here.
Figure 8. Mean transmitted RF carrier power, BTS, limits
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