enodeb troubleshooting

1) TD-LTE-eNodeB-LTE/TD-Qualcomm UE Limited service

issue(attach not initiating)

Incident Description (Incident Phenomena)

When UE inserted in laptop it receive signal from other network (vendor) initially then after UE

received our home network signal it will not initiate attach request.

until unplug and plug the UE.

Networking Environment

All vendors Network configuration will be same

MCC

MNC

Center frequency

Problem Cause Analysis

For example vendor1, vendor2 vendor 3, ZTE all are radiating same frequency signal

(EARFCN=38800).

UE initially receives vendor 1 signal after that receives ZTE network signal UE will not attach with our

network.

Even UE will not initiate attach procedure.

Because UE tried to attach with (first received vendor network) vendor 1 that time vendor network

forced UE entered in a Limited service.

So UE will not perform any action only it will receive signals(almost dead state).

Solution

We have two solution for this problem

1.We need change MCC or MNC ID for each vendor means each vendor have distinct PLMN ID.

2. We need to enable roaming facility in all vendor networks

2) TD-LTE UE Attach failure


Customer Complain UE is not able to attach to TD LTE coverage.


Radio Coverage is healthy RSRP, SINR & BLER are normal. eNB is alarm free. Signalling link between eNB to EPC is normal.


From Test UE terminal the signal trace on layer 3 is captured shown below. Laptop & UE is normal.

Solution

1) Test UE is normal & working day before 2) Signal trace shows the Attach failure 3) Attach is between eNB to MME but eNB is normal 4) MME S1 signal link is normal 5) Attach Reject message shows cause value unknown APN 6) Contacted NSN EPC engineers for Debugging in EPC 7) EPC upgraded day before yesterday & configuration has been altered. 8) NSN engineers not completed the APN configuration in MME. 9) NSN engineer done configuration in MME for APN

Summary and Notes

Attach failure due to MME incomplete configuration of APN.

3) TD LTE Low data throughput & frequent disconnection


TD LTE UE terminal is limited to 29 Mbps in single user cell. At peak 29 Mbps UE disconnects


eNb with single user in one Cell after 29 Mbps gets disconnected. Transmission is microwave of

ceragon Hybrid IDU Switch. Microwave IDU has capacity of 180Mbps.

RF environment is very good more than -70dBm.

Problem cause Analysis

UE gets disconnected every time it reaches to 29 Mbps following are the steps:

a) Tested with another Laptop & UE same problem occured. b) RF environment is very good. c) Transmission has been suspected. d) Bandwidth limitation asked to confirm from Microwave team

Solution

Microwave bandwidth configuration verified & found the bandwidth is restricted to only 32 Mbps every Node. Shaper of Microwave for every node not allowing to beyond 29Mbps. Configuration has been changed CIR is made 1Mbps & PIR has been removed from Configuration. Shaper is disabled.

4) TDD-user attach successful but service fail


TDD-user attach successful but service fail


IP relationed is wrong

Solution

User can attach to the EPC successfully after add the missing configuration；singnaling part look

fine；now we begain to ping PDN，ping is not ok；now we can use wireshark tool to catch packets

over S1 and the link between EPC and PDN； We can not get any message from the UE（UE‟ip is

212.27.11.142 when we did the test）,So RAN try to find where are the packets going to,In S1

Interface，they can see packets go up to the EPC，but we still can not see it according to UE‟ip is

212.27.11.142 when we did the test； Later we change to monitor GTP mseeage over S1；now we can

get a lot of messages； IP relationed is wrong；RAN part change some parameters and the the

problem solved；

5) MME status is not available


TA is not the same between eNodeB and MME

Solution

According to the signaling in EPC，nothing come from eNodeB；so we have to check the S1

connection。in S1 Interface，the following parameters need to be checked

1> IP address both in MME and eNodeB 2> SCTP port 3> IP connection（we can ping each other）

4> TA（trace area）

We can get the S1 status from eNodeB，because of MME will be used for server end；MME is not

available from eNodeB after checking 1、2 and 3；TA is not the same between eNodeB and MME after

checking 4；S1 can work fine after we change the TA

6) TD-LTE RRU link break up


RRU is runing normal,but suddenly the link break up,in the OMC we can see the alarm is "the software of the board running abnormal" "the communication link of the board break up".


(1)the software of the board restart abnormaly; (2)the optical fiber cable between the BBU and RRU break

Solution

(1)get the information of the black box from the plat staff; (2)check the optical fiber cable between BBU and RRU; (3)change RRU.

7) TD-LTE RRU Power-On Self-Test Failure alarm


in the OMC we saw the alarm that the RRU Power-On Self-Test Failure


the RRU Power-On Self-Test Failure term can't get through

Solution

the RRU Power-On Self-Test Failure term can't get through (1)loggin the RRU, enter ushell,input showPowerOnCheck,if there is shown Filter Type Check Error! or Filter Type Verify Error!,it means that the Power-On filter bandwidth test failure,or we have to change RRU; (2)If there is Power-On filter bandwidth test failure,and there appear VSWR alarm with this RRU,at this time we have to check the antenna of this site; (3)If there is Power-On filter bandwidth test failure,but there is no VSWR alarm with this RRU,we can input BspCheckFilter to retest the filter,if the Self-Test Failure disappear,it means the antenna doesn't connect well when the RRU is power on; (4)if after retest filter the alarm is still exist,we have to collect the log to send to R&D to analyse.

8) Cell establish fail


Cell establish fail: (1)Check from OMC, cell quit service; (2)Board indicator abnormal; (3)UE can‟t access.


(1)RRU or BPLnot run normally; (2)Wrong with fiber/fiber module; (3)Not configure association parameter.

Solution

(1)Check if RRU or BPL has abnormal alarm; (2)Check if configure SCTP, IP, adjacent NE; (3)Check if connecting ling between RRU and BPL is usable, if interface lose; (4)Check if running version is correct.

9) FTP upload failure


Remote LMT login base station, appear FTP upload failure.


(1)Number 21 port of remote PC be occupied ; (2)BBU appear failure.

Solution

(1)Number 21 port of remote PC be occupied, during LMT login process, BBU need to use database file in LMT attached ftp server. In this case, mitigation method as following: open PC task manager to check if there has boot other ftp server process, name such as „ftpserver‟, if yes, close this process, then restart EOMS. If can‟t find other ftp server process in task manager, can reboot PC; (2)BBU appear failure, can attempt login BBU using ftp command of cmd.

10) Can’t remote login RRU through BBU

Problem cause analysis

1)BBU not configure fiber RF resource relation; (2)Fiber module not inserted in configured optical port; (3)Send and receive fiber inserted reversely.

Solution

(1)Check background if fiber RF resource configured, make sure have configured; (2)Check if fiber module inserted in RF resource configured optical port, make sure fiber module inserted optical port is configured optical port; (3)Check if physical connection is normal, if corresponding optical port light on baseband board flick in a rate of 1MHz, if corresponding light not flash insert two fiber reversely, if constant flash mean RRU is booting.

11) TD- LTE eNodeB IP interfaces Troubleshoot Incident Description (Incident Phenomena) eNB has configured with three interfaces like S1_ControlPlane, S1_UserPlane & OAM_IP S1_CP IP can be able to ping the MME but S1_UP IP cannot able to ping the SGW IP. OAM IP can able to Ping the OMM IP.


eNB is normal no alarm. CC Board Diagnose report also normal. Transmission is also normal


1) If we change the IP of S1_CP to S1_UP then the S1_CP IP also not able to ping. 2) If we delete the S1_CP IP then S1_UP IP able to Ping 3) Gateway of each interface belongs to different /24 Gateway at Core Router 4) Only one default gateway IP can be supported by eNB 5) eNB cannot be able to support Vrf function to support 3 different gateway on one Interface

Solution 1) Check the IP configuration of eNB in OMC 2) Three different interface have three gateway 3) eNB not support the Vrf function & have single default gateway 4) Two differentiate the Interface Static route should be added for next two Interface S1_UP & OAM 5) Add the static route for S1_UP & OAM

Summary and notes

eNB not support Vrf function & two support 3 interface on one physical interface require static route to differentiate the defaulte gateway of each interface as next hop.

12) TD-LTE_OMC-LTE/TD-AIX operating system commonly

used commands

AIX boot into multi-user (NORMAL) and single user (SERVICE) to guide two. Multi-user (NORMAL) guide: the host liquid crystal display panel "OK" case, pressing thefront panel of the white power button; single-user (SERVICE) guide: the first system, the AIX CD into the CDROM, press the host before the white power button panel, the display appears on the screen after the second tone before the horn sounds, press the "5" key. System shutdown command and order: 1. The application and database system in order to stop; 2. Use # shutdown command; # Shutdown System, broadcasting system preparing to shut down the message and shut down after one minute. # Shutdown-r System, broadcasting system preparing to shut down the message and shut down after one minute.When the automatic power-off immediately after. # Shutdown-F Shut down system immediately. # Shutdown-Fr Reboot the system immediately.

lsdev command This command is used to view system device information. # Lsdev-Cc device type

Commonly used equipment types: processor, disk, adapter, tape, memory, tty, etc.Lsdev-Cc processor below shows the display results. b) lspv command This command is used to view information on the system hard disk. # Lspv hard drive name Used to check the hard disk information, the display below shows lspv hdisk0 results. # Lspv-l hard disk name Logical volume information used to view hard disk, the next picture shows the lspv-l hdisk0 display results. # Lspv-p disk name Check the hard disk physical partitions.Below lspv-p hdisk0 display results. c) lscfg command This command is used to view the device configuration information. # Lscfg-vl device name Below lscfg-vl hdisk0 display results. d) lsattr command The command to the device attribute information. # Lsattr-El device name Lsattr-El rmt0 below shows the display results. 3 logical volume operation command a) lsvg This command is used to view system-defined VG (volume group). # Lsvg-o Display the current active VG (volume group).Below lsvg and lsvg-o display the results. # Lsvg VG Name View the VG (volume group), including PP size, number, has been used (allocated) space, free space and other information. # Lsvg-l VG Name View the VG (Volume Group) has defined logical volume. Below lsvg-p datavg and lsvg-l datatvg display results. # Lsvg-o | lsvg-il List all mount the logical volume.Below is the command displays the results. 4 File System Operations Commands a) lslv The command used to list all the attributes of the logical volume. b) smitty crjfs (AIX only) This command is used to create a file system. c) mount This command is used to view the installed file system.Below is the command to display information. # Mount the file system name To install a file system. # Mount-a Used to install all the file systems defined # Unmount the file system name Used to unload a file system.

5 file manipulation commands a) ls This command is used to display the file in the current directory files. # Ls-l Display detailed properties file b) cp The command used to copy files. # Cp filename 1 filename 2 1 copy of the file name to the file name is the file name 2 files. c) mv This command is used to rename the file. # Mv filename1 filename2 The file name to a file name to file name 2 files, you can add the full path to the file from one directory to another. d) rm This command is used to delete files. # Rm filename Delete a file, the file name can use wildcards. # Rm-r filename or directory name Delete a file that contains directory. e) chown Also the owner of the file or directory. chown group name | user name filename or directory name of the owner of a file or directory to a group name | user name # Chmod 755 filename To the owner of a file permissions (owner) read, write, execute; with the group's permission to read, execute; other users can read, execute. 6 network command a) netstat # Netstat-in View the use of the card's ip.The figure below shows the results of netstat-in display. b) ifconfig # Ifconfig name of the NIC ip address Modify the network card ip address. c) smitty tcpip This command is used to modify the network card ip address. 7 HACMP operations command a) smitty clstart The command to start HACMP. b) smitty clstop The command to stop the HACMP. Choose graceful stop HACMP Select the takeover to stop the machine HACMP, native applications from the standby machine to take over Choose forced forced to stop the machine HACMP c) / usr / sbin / cluster / clstat The command to display the HACMP status. Nodes and CLUSTER green for normal, red is down or not up HACMP, yellow in the HACMP unstable, may be a node HACMP is started, switch, stop.

d) check the output of HACMP # Tail-f / tmp / hacmp.o HACMP is started, use this command to view the file show whether the error e) Check the address information # Netstat-i Use this command to check the type of network card binding address is correct, three types: boot, service, standby. f) See logical volume groups and file systems # Lsvg-o Should be activated with the command (varyon) of the VG is activated. # Mount Use this command should mount the file system is normal.

12) ZXSDR B8200 TL200-LTE-eNodeB-LTE/TD-BSS-Telnet

TD-LTE eNB BBU for checking the version and SCTP link

info

Incident description

To check the eNB version and SCTP link, one can login to OMC/EMS client and use the Diagnosis tools but for specific results one can telnet the eNB and use specific commands to check the required items.


From OMM server telnet on CC board by using the EnodeB IP address. Before telneting the EnodeB IP address we need to check the connectivity, so first pin gEnodeB ip address then if it is pinging, proceed with the telnet commend.

Ping “IP address”. (Ex:ping 10.212.246.23)

start----->cmd

telnet "IP address" (ex: 10.212.246.23)

Problem cause analysis

To enter into management we need to execute to “./ushell “ command with password zte

#./ushell

After executing the command, the password is “zte”

Solution

ps-----list all processes in cc board and choose MGR.EXE

pad 691------691 is PID for Manager process

VMP-------it shows the board version of cc card in B8200

showtcb------it shows the SCTP link info

pmsClockShow------it shows the GPS info

Sometimes its required to telnet the BBU and check parameters with the help of commands. So few commands have been provided to checked Version, SCTP Link status and GPS status in this document

13) ZXSDR R8962 L23A-LTE-eNodeB-LTE/TD-Telnet TD-

LTE R8962/8964 to check radiation power and vswr values

Incident description

To check the Radio output power and Antenna VSWR, one can login to OMC/EMS client and

use the Diagnosis tools but for instantaneous results one can telnet the eNB and use specific

commands to check the required items.


From OMM server telnet on CC board by using the EnodeB IP address.

Before telneting the EnodeB IP address we need to check the connectivity, so first ping EnodeB ip address then if it is pinging, proceed with the telnet commend. With route command, all route messages will be shown, choose 200.6.xxx.xxx or 200.7.xxx.xxx telnet 10.210.68.94 route telnet 200.6.0.1


Telnet the RRU with /ushell command and password zte.

telnet 200.6.xxx.xxx /ushell zte ps (ps will show all running processes) pad 42

Solution

Radio Frequency and Bandwidth configured for RRU can be checked by: showrf

Antenna vswr for RRU can be checked by: showvswr

Radio power of RRU can be checked by: showpower

There are few changes in commands used for R8964. telent 8964 by ushell and zte telnet 200.7.xxx.xxx ushell zte ps (ps will show all running processes) pad 718 Radio power for RRU can be checked by:

ShowPwrDetinfo

Radio power for RRU can be checked by: showswrate

Uplink Radio power for RRU can be checked by:

BspGetRssiPwr 3,0,0

Summary

This document will help in checking power and vswr values by telnetting the RRU.

14) LTE TDD Reference Network Coverage Investigation

Report

1 Basic Information Of The Reference Network

1.1 Reference Network Overview

There are 2 sites located in reference network.Here lists the important network information in a LTE TDD reference network:

Table 1 Basic System Information

Item Value

Center Frequency 2575MHz

Bandwidth 10MHz

RS power 15dbm

1.2 Basic Information Of The Sites

At present,ZTE has 2sites in Dusseldorf for KPN LTE TDD reference network.The site information including PCI,antenna azimuth,down tilt and location is shown as below

Table 2 Basic Site Information

Site Name PCI Longitude Latitude Azimuth Mtilt Etilt

container

102 6.78732 51.279475 80 4 2

103 6.78732 51.279475 230 0 2

104 6.78732 51.279475 290 0 2

eplus

279 6.785992 51.285556 70 2 2

280 6.785992 51.285556 180 2 2

281 6.785992 51.285556 220 2 2

1.3 The Site Distribution

The site distribution in Google Earth map is shown in the following figure.

Figure 1 The Site Distribution

2 Test Result of Coverage

Usually,the RSRP,RSRQ and RS-CINR are used to describe the coverage of the LTE TDD radio network.The RSRP indicates the signal strength received by the terminal and the RSRQ and RS-CINR indicates the signal quality.The following content shows the network coverage by RSRP and RSRQ of 2 sites.

2.1 Test Tools and Software

The following tools and software will be used during the testing: GPS Laptop CNT MF820

2.2 Coverage of 2 Sites

The coverage of 2 sites is shown as below.From the drive test data we could find out the current coverage status of network.In these figures below,the server cell RSRP and RSRQ are given.

Figure 2 Server Cell RSRP of LTE TDD

Figure 3 Server Cell RSRQ of LTE TDD

3 Summary

Eplus site has a good coverage,It can cover 700m in the dense buildings and cover 3km in the open

area(airport);container site is lower(only 3m) and blocked by the surrounding buildings; The section 2 of Eplus

site with the section 3 of container can finish handover,there is no problem of handover test.

15) priority level coefficient adjusted case


During the DT test，we found out that the download speed of R4 and R5 services of two cells on

Shiquan Road in Siming district, xiamen city were too slow. The average speed was 30kbps, but other

services of those cells were normal


We tested the same termination under other normal cells, and the speed was normal which showed that it was not problems of the termination or the SIM card. On the other hand, as for the difference between configurations of priority level of different HS services, we checked the stream class, the interactive class, the background class and the session class, and figured out the problems were the same. Then we checked the related KPI from OMCR, and the report showed that both cells had every kind of service, and the established ratio was very good. So the current problem was that the download speed of HSDPA is too slow.

(1) first, we doubted interference was the cause, so we checked the ISCP and RTWP through LMT, and the results showed they were both OK.

(2) Excluding interference cause, we suspect there were some problems in the configurations of such cells.

Solution

We asked the researchers to help, and they found out one parameter was abnormal through signaling analysis. They asked us to check the configurations of IUB port. Finally, we found there was one parameter of these cells differed from that of others. We highlighted that as follow: the right parameter of normal cells is 50, but in the abnormal cells, it is 0.

So we corrected the parameter, and did tests, the speed turned to OK, the download speed of R4 and R5 was normal.

Such problems are typical configuration mistake. Next time, facing such problems, we suggest we do comparison of the parameters first, and try to find out the difference between normal and abnormal cells, so we can locate the problems caused by parameters as soon as possible.

During the process of resolving such problems, we found that the parameter do not work out as its configuration in the RNC, in some cases.

During next DT tests, we also found some cells had the same problem. But when we check the parameter, we did not find any mistake. The priority level adjusted coefficient in the IUB was 50. We doubted the parameter do not work out correctly. So we used the signal tracing tool to check this out. The result is as follow, which indicated that although the parameter is 50, but the actual value is 0.

We reconfigurated the parameter to 50(changed from 50 to 0, then changed 0 to 50), but did not resolve the problem. The signal tracing tool also showed ik=0, and the download speed of R4 and R5 is still 30kbps.

We tried to change the parameter to 100 first, this time, the ik became 100, and the speed returned to normal.

Then we modified the parameter to 50, and the ik became 50, the speed remain normal. The signal is as follow:

Devices & Hardware

enodeb troubleshooting