User's Manual

194 APCD-LM043-4.0
File Notes : Based on TN040
Customer Port MAC Address: 00:90:c8:e0:03:75
Hardware ID: 4B
Airlink MAC Address: 00:90:c8:60:03:75
Serial Number: E00375
Modem Type: EUM
RF level +27 dbm +15 dbm
Lo - 905.0 Mhz -14 20
Med - 915.0 Mhz -22 16
High - 925.0 Mhz -22 16
RSSI level -76 dbm -70 dbm -46 dbm
Lo - 905.0 Mhz 45 51 77
Med - 915.0 Mhz 46 51 78
High - 925.0 Mhz 46 51 78
POT Settings: Wiper1: 131 Wiper2: 152
Console>
An RSSI level that falls outside the range of the calibration, or between the calibration points,
can be converted to a received signal strength (RSS) reading in dBm, using the following
simple rules:
• If the measured RSSI is ‘x’ below the RSSI level at the lower calibration point, then the
received signal strength can be calculated as -76dBm - x. Using the above unit as an
example, if you are measuring an RSSI of 42 at a frequency of 915MHz, then the
received signal strength is -76dBm - (46 - 42) = -80dBm.
• Similarly, if the measured RSSI is ‘y’ above the RSSI level at the higher calibration
point, then the received signal strength can be calculated as -46dBm + y. Using the
above unit as an example, if you are measuring an RSSI of 80 at a frequency of
905MHz, then the received signal strength is -46dBm + (80 - 77) = -43dBm.
• For RSSI measurements that fall between two calibration points, you must interpolate
up (1dBm for every unit step in RSSI value) from the lower of the two calibration
points if the RSSI falls below the midpoint of the two calibration points. Likewise, you
must interpolate down from the higher of the two calibration points if the RSSI falls
above the midpoint.
Using these simple rules, the following RSSI-RSS cross-reference table for the above sample
unit, at 915MHz, can be produced: