LTE ENodeB Troubleshooting Training v1.0

© 2006 Clearwire Corporation CONFIDENTIAL & PROPRIETARY, Limited Distribution to Authorized Persons Only

Huawei LTE eNodeB Troubleshooting Overview

• Jeff Fry, Wimax/LTE Systems Integration & Test, Technology Development

LTE eNodeB Troubleshooting Document:

• <Some location on portal>

LTE eNodeB Troubleshooting Overview:• LTE LMT/EMS • Subscriber Troubleshooting• eNodeB Troubleshooting• eNodeB Log Files


Dual-mode Wimax/LTE: Basics

• TD-LTE, Band 41– EARFCN=40590 (freq=2590MHz)– 20 MHz

• LTE deployed as 3 sectors using Reuse-1 (one frequency).• Each configured carrier is a Cell.• LTE initially deployed as S111.


Network Architecture

• MME – Mobile Management Entity controls mobile signaling: network attach/authentication (to HSS), handovers, idle mode

• SGW – Service Gateway provides the user plane data traffic.• HSS – Home Subscriber Server provides subscriber provisioning.• Important interfaces from the eNodeB:

– S1-U : interface to the SGW– S1-MME : interface to the MME– X2 : interface to another eNodeB for mobility


Dual-mode Wimax/LTE: Shared BS

• Wimax and LTE run on the same base station with addition of LTE cards.

• Wimax and LTE share the same radio head (RRU).• Separate backhaul for Wimax & LTE. GigE for LTE and 100MB ETH

for Wimax.

LTE Cards: LBBP, LMPT

LTE Carriers on 2nd fiber

Wimax Carriers on 1st fiber


eNodeB LMT Access

• Local Maintenance Terminal is still web-based HTTP.• Primary use MML for field techs.• Access is local or remote.


EMS for LTE: Main Topology

• eNodeB Topo Object is initially created in a default EASY_DEPLOYMENT subnet alongside Wimax BTS.

• Can be moved to a new LTE subnet.


EMS for LTE: CME

• New CME (CM Express) menu/component for configuration management.• Configuration viewing only via Panorama Browser. View many eNodeB

configurations in bulk.• Configuration changes made in a planned area (workspace).• Parameter comparison and audit functions available.


EMS for LTE: Alarms

• Alarms can be sent by the Wimax BS and eNodeB.• Some alarms are common and will only be sent by the Wimax BS.


Subscriber Troubleshooting

• Subscriber troubleshooting options in LTE are limited.• DSP S1INTERFACE:;• That’s it! No subscriber mac tracing or signal tracing due to architecture.


eNodeB Troubleshooting: Equipment Status

• Maintenance->Device Panel to visually see equipment and status.


eNodeB Troubleshooting: Equipment Status (2)

• DSP BRD:; Shows LTE boards and occupied Wimax slots.

• DSP BRDVER:; Shows board versions.


eNodeB Troubleshooting: Equipment Status (3)

• LST ALMAF:; Shows LTE only alarms.• DSP GPS:; Shows GPS status.

• Resetting:– RST ENODEB:;– RST BRD:;


eNodeB Troubleshooting: Configuration Management

• View LTE configuration via CME Panorama Browser.

• Make configuration changes via MML or a CME workspace.


eNodeB Troubleshooting: Configuration Management (2)

• Configuration backup, restoring, and download via Maintenance->Backup Management->NE Backup


eNodeB Troubleshooting: Configuration Management (3)

• Configuration audits can be performed via CME->Compare Parameters.• Compare with other eNodeBs and templates.


eNodeB Troubleshooting: eNodeB Licensing

• LTE has a new licensing scheme: – Separate license file for each eNodeB.– License file provided by Huawei based on ESN.– License applied during commissioning process.

• License->NE License Management->Standalone License to apply and view licenses.

• DSP LICENSE:; MML command to view actual license data on eNodeB.


eNodeB Troubleshooting: S1 Configuration and Status

• S1-MME and S1-U interfaces to MME and SGW respectively.• X2 interfaces to other eNodeBs for mobility signaling.• SCTP is transport layer for S1 and X2.• SCTP link status:

– LST SCTPLINK:;– DSP SCTPLNK:SCTPNO=0;

• DSP S1INTERFACE:; S1 Interface Status.

• DSP X2INTERFACE:; X2 Interface Status.

• LST S1SIGIP:; S1-MME configuration.• LST S1SERVIP:; S1-U configuration.• LST X2ENODEB:; X2 configuration.


eNodeB Troubleshooting: Cell Configuration and Status

• DSP CELL:; Shows cell status.

• LST CELL:; Shows cell configuration.


eNodeB Troubleshooting: Cell Configuration and Status (2)

• BLK CELL / UBL CELL – activate/deactivate cell – CELL_HIGH_BLOCK - immediately deactivates cell.– CELL_MIDDLE_BLOCK – deactivates after a time period.– CELL_LOW_BLOCK – deactivates when no subs.

• ACT CELL / DEA CELL – activate/deactivate cell is equivalent to CELL_HIGH_BLOCK.


FIN

• Questions?

LTE ENodeB Troubleshooting Training v1.0

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