Site Troubleshooting Guide LTE
Site Troubleshooting Guide
LTE
RBS 6000 Series
RBS 6102 RBS 6101 RBS 6201 RBS 6601 RBS 6301 RRU
• MetroPCS primarily uses RBS 6201 inside a weatherized cabinet• MetroPCS primarily uses SIMO• Some sites will use RBS 6601 with RRUs, but not currently available
Weatherized Cabinet• Majority of
MetroPCS sites are outdoors
Cabinet – Back
RBS 6201 HardwareDUL – Digital
Unit LTERU – Radio
Unit
SIMO
Tx/Rx1
Rx2
Cabinet DiagramFans
Radio
C Transmission
CC Power
RUs
DUL
SIU
Cabinet – No Jumpers
Power
DULs
RUs
SIU
Cabinet – Jumpers
Power
DULRUs
Antenna Jumpers
Diplexer Site
Diplexer
Input
Output
LTE
CDMA
Diplexer Detail
InputOutput
Diplexers
Visit Preparation• Printed Materials
– RFDS Sheet with all plumbing diagrams– Notes about site access– Directions– Satellite image– Site Shakedown report
• Equipment– Cabinet key– Dummy load set– Sitemaster– Laptop setup to run TEMS Investigation with UE
Equipment
Cabinet Key
Sitemaster
Laptop with UE
First Steps• Best Practices
– Take photos!– Be prepared– Ensure E-UTRAN support is available– Notify relevant parties based on customer procedures
• Visual Inspection– Make sure nothing immediately looks incorrect– Trace the RU-DUL cables to ensure there are no swaps– Ensure the RU-DUL cables have a good connection– Check small QMA wave guide for damage and ensure connection
Photos• Take a photo of the site label to identify pictures
RU to DUL Jumper check• Ensure the RU-DUL jumpers are correct
DUL
RU-DUL Jumpers
RU
RUL QMA Wave Guide Check• Check small QMA wave guide for damage and
ensure connection
Correct
Bent
RUL QMA Wave Guide Check
Bent Connector Disconnected Connector
Common Issues• Sector Swaps• DL or UL throughput low• Bad or no coverage• Azimuth incorrect
Sector Swaps• Causes
– RU-DUL cables– Jumpers from cabinet to diplexer– Jumpers from diplexer to antenna feeders– Antenna feeders to antennas– CDMA incorrect– Do not trust colors on cables
• Troubleshooting Steps– E-UTRAN lock test– Cable tracing
E-UTRAN Lock Test• Procedure
– Have E-UTRAN lock a single sector– Verify the reference signal transmit light stops
blinking– Repeat for each sector
• Conclusion– Ensures that the DUL is configured correctly– Verifies there is no RU-DUL cable swap
E-UTRAN Lock Test• Blinking
– Transmitting reference signals
• No Light– Locked
Antenna Jumper check• Verify all cables match colors in plumbing diagrams• Non-diplex site
– Trace the antenna jumpers from the RUL to the back of the cabinet
– Trace the antenna jumpers from the cabinet to the antenna feeders
• Diplex site– Trace the antenna jumpers from the RUL to the back of the
cabinet– Trace the antenna jumpers from the cabinet to the diplexer– Trace the antenna jumpers from the diplexer to the antenna
feeders
Antenna Jumper Check
Sector 4
• Verify all cables match colors in plumbing diagrams
Sector 5
Sector 6
Antenna Jumper Check• Trace the antenna jumpers from the RUL to the
back of the cabinet
Jumpers exit cabinet
Jumpers at RUL
View – Cabinet Back
Jumpers exit cabinet
Antenna Jumper Check
Jumpers from cabinet
Antenna feeders
• Trace the antenna jumpers from the cabinet to the antenna feeders
Antenna Jumper Check – Diplex• Trace the antenna jumpers from the cabinet to the diplexer
Jumpers enter
Diplexer
Jumpers from cabinet
Antenna Jumper Check – Diplex• Trace the antenna jumpers from the cabinet to
the diplexer
Jumpers enter
Diplexer
Jumpers from cabinet
DL or UL throughput low• Causes
– Backhaul– Antenna system and jumpers– Hardware problems with RU-DUL
• Troubleshooting Steps– Dummy Load Test– Feeder Sweeps– E-UTRAN support
Dummy Load test• Procedure
– Trace the power connector to the RUL and turn it off– Detach the antenna jumpers from the RUL– Connect the attenuators to the RUL– Connect the dummy antennas to the attenuators– Power on the RUL– Have EUTRAN unlock the target sector and lock all other sectors– Place the UE near the dummy antennas– Upload and download a file and record a TEMS log
• Conclusion– Eliminates or identifies antenna system cause of problem
Dummy Load Test• Trace the power connector to the RUL and turn
it off Power light off
Dummy Load Test• Detach the antenna jumpers from the RUL
Disconnected Jumpers
Dummy Load Test
Adapters
Use high power attenuators
Ensure attenuators are connected to both Tx/Rx2 and Rx2
Attenuators
• Connect the attenuators to the RUL
Dummy Load Test
Attenuators
Dummy antennas
• Connect the dummy antennas to the attenuators
Dummy Load test• Power on the RUL
Power light on
Power Connector
Power Button
Dummy Load Test• Have EUTRAN unlock the target sector and lock
all other sectors
Ensure blinking
Dummy Load Test
Dummy antennas
• Place the UE near the dummy antennas
UE
Dummy Load Test• Upload and download a file and record a TEMS
log
Feeder Sweeps• Tests
– Voltage Standing Wave Ratio– Return Loss– Distance to Fault– Covered in a different guide
• Conclusion– Determines if there are problems in the antenna system
E-UTRAN support• Procedure
– Connect to the cell (dummy load or otherwise)– Download or upload a file– Have E-UTRAN monitor the node
• Conclusion– Determines if there is a configuration problem or a
problem in the backhaul
Bad or No Coverage• Causes
– Antenna System– Jumpers not connected– Hardware problems with RU-DUL (damaged
connectors)• Troubleshooting Steps
– Ensure all connectors are tightly secured– Dummy Load Test– Feeder Sweeps
Incorrect AzimuthTroubleshooting Steps
– Drive Test– Visual inspection of antenna direction
THANK YOU