Troubleshooting High/Low/Deaf RSSI on site
Steps to follow while TS: -
Step 1:
- Check with crew if all Jumpers are plugged in properly.
- Once crew confirm all connections are in place, check ask if there is TMA in the line for a specific
carrier, if Yes get the details of TMA model and check how it is plumbed on site. (Externally powered
& controlled by CCU/MCU or internally powered up by the by LTE Radios)
- If the TMA is controlled by internal source, ask crew for SR# of serving Radio and the radio port
where TMA is connected. (ALD port or RF Ports)
- Check if all the Attenuation parameters are scripted as per market Requirements. (especially for
the For Deaf RSSI scenarios)
If there is TMA on site, then make sure the UlAttenuation/ TMA gain values are set to zero while
the loads are below the TMAs in the line and update the UlAttenuation/ TMA gain values once the
loads are moved above the TMAs
Step 2: With Dummy load on Radio ports as shown in above fig. (Test 1) Run RSSI test with full power
on the specific carrier.
- If Fails, Radio is Faulty.
- If it shows passing readings with in ranges, move to next step.
Step 3: With Dummy load at the end of Jumpers before Diplexers as shown in above fig. (Test 2). Run
RSSI test with full power on the specific carrier.
- If Fails, Replace the Jumper. Repeat Step-3 after replacement.
- If it shows passing readings with in ranges, move to next step.
Step 4: With Dummy load on Diplexer ports as shown in above fig. (Test 3). Run RSSI test with full
power on the specific carrier.
- If Fails, Diplexer is Faulty.
- If it shows passing readings with in ranges, move to next step.
Step 5: With Dummy load at the end of Jumpers before Antenna as shown in above fig. (Test 4). Run
RSSI test with full power on the specific carrier.
- If Fails, Replace the Jumper. Repeat Step-5 after replacement.
- If it shows passing readings with in ranges, proceed to normalize the connection and run fresh set
of RSSI readings and if RSSI issue persist then it might be Faulty Antenna.
If there is TMA on site, then make sure the UlAttenuation/ TMA gain values are set to zero while
the loads are below the TMAs in the line and update the UlAttenuation/ TMA gain values once the
loads are moved above the TMAs.
Step 6: With Dummy load on combiner (Pentaplexer) before Hard line starts, as shown in below fig.
Run RSSI test with full power on the specific carrier.
1. With Dummy load on pentaplexer before SBT (Smart Bias-T).
- If Fails, pentaplexer is Faulty.
- If it shows passing readings with in ranges, move to step 2.
2. With Dummy load on SBT before Hard line starts.
- If Fails, check RSSI readings without SBT on that respective line and if RSSI trends in range then
conclude SBT is Faulty. Replace SBT and repeat the step.
- If it shows passing readings with in ranges, move to next step.
Step 7: With Dummy load at Hard line before TMA. Run RSSI test with full power on the specific
carrier.
- If Fails, Hard line is Faulty. Replace Hard line and repeat step 7.
- If it shows passing readings with in ranges, move to next step.
Step 8: With Dummy load on TMA. Run RSSI test with full power on the specific carrier.
- If Fails, TMA is Faulty.
- If it shows passing readings with in ranges, move to step 5.
Faulty Antenna:
- Ask crew to swap the Jumpers with other Antenna if possible and check if RSSI fails again. If RSSI
trends within range, then Antenna is in Good Condition.
- Crew can also perform PIM testing on the antenna ports to check for any issues
External Interference: Perform Min / Max ETilt test to make sure no External Interference causing
RSSI issue on site.
PIM testing: Crew will also perform PIM tests to rule out issues in the RF path and on the antenna
ports.
