LTE troubleshooting guide

1. Site Troubleshooting Guide LTE

2. RBS 6000 Series RBS 6101 RBS 6201 RBS 6601 RBS 6301 RRU RBS 6102 • 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

3. Weatherized Cabinet • Majority of MetroPCS sites are outdoors

4. Cabinet – Back

5. RBS 6201 Hardware DUL – Digital Unit LTE RU – Radio Unit SIMO Tx/Rx1 Rx2

6. Cabinet Diagram Fans Radio RUs DUL CC Power SIU C Transmission

7. Cabinet – No Jumpers Power RUs DULs SIU

8. Cabinet – Jumpers Antenna Jumpers Power DUL RUs

9. Diplexer Site Diplexer LTE CDMA Output Input

10. Diplexer Detail Output Input Diplexers

11. 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

12. Equipment Sitemaster Laptop with UE Cabinet Key

13. 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

14. Photos • Take a photo of the site label to identify pictures

15. RU to DUL Jumper check • Ensure the RU-DUL jumpers are correct DUL RU RU-DUL Jumpers

16. RUL QMA Wave Guide Check • Check small QMA wave guide for damage and ensure connection Bent Correct

17. RUL QMA Wave Guide Check Bent Connector Disconnected Connector

18. Common Issues • Sector Swaps • DL or UL throughput low • Bad or no coverage • Azimuth incorrect

19. 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

20. 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

21. E-UTRAN Lock Test • Blinking • Transmitting reference signals • No Light • Locked

22. 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

23. Antenna Jumper Check • Verify all cables match colors in plumbing diagrams Sector 4 Sector 5 Sector 6

24. Antenna Jumper Check • Trace the antenna jumpers from the RUL to the back of the cabinet Jumpers exit cabinet Jumpers at RUL

25. View – Cabinet Back Jumpers exit cabinet

26. Antenna Jumper Check • Trace the antenna jumpers from the cabinet to the antenna feeders Jumpers from cabinet Antenna feeders

27. Antenna Jumper Check – Diplex • Trace the antenna jumpers from the cabinet to the diplexer Jumpers from cabinet Jumpers enter Diplexer

28. Antenna Jumper Check – Diplex • Trace the antenna jumpers from the cabinet to the diplexer Jumpers from cabinet Jumpers enter Diplexer

29. 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

30. 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

31. Dummy Load Test • Trace the power connector to the RUL and turn it off Power light off

32. Dummy Load Test • Detach the antenna jumpers from the RUL Disconnected Jumpers

33. Dummy Load Test • Connect the attenuators to the RUL Use high power attenuators Adapters Attenuators Ensure attenuators are connected to both Tx/Rx2 and Rx2

34. Dummy Load Test • Connect the dummy antennas to the attenuators Attenuators Dummy antennas

35. Dummy Load test • Power on the RUL Power light on Power Button Power Connector

36. Dummy Load Test • Have EUTRAN unlock the target sector and lock all other sectors Ensure blinking

37. Dummy Load Test • Place the UE near the dummy antennas Dummy antennas UE

38. Dummy Load Test • Upload and download a file and record a TEMS log

39. 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

40. 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

41. 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

42. Incorrect Azimuth Troubleshooting Steps • Drive Test • Visual inspection of antenna direction

43. THANK YOU