How to mapping Interference problem on TD-LTE Network

1. IMPROVING THE MOBILE EXPERIENCE WORLDWIDE
R.T.W.P Investigation Region M
Ray Khastur

2. 2
1. Overview
2. Border Site Monitoring
3. Investigation Highest RTWP Site
4. OSS Monitoring
5. Summary
Agenda
Ray Khastur

3. 3
Out-Band Emission
Study Case on Region M
TD-LTE
15M
WiMAX
5M
WiMAX
5M
WiMAX
5M
External
Source-FDD
Local ISP
Spurious Emission from Left Side Band Spurious Emission from WiMAX Spurious Emission from LTE
Ray Khastur

4. 4
Overview : Suspect External Interference from Local ISP
The Local Internet Service Provider in M region is detected
also use Band 2300 to 2400 as their allocation also (illegal).
Because on Indonesia Communication and Information
Minister already allocated Band 2.3 GHz only use for
Broadband Wireless Access operator such as First Media,
Berca, Internux, Indosat M2, Telkom and Jasnita as the
winner of bidding spectrum allocation owner ship in specific
region.
One wireless device that many ISP used is MikroTik wireless
communication that can arrange the frequency randomly
based on time.
So between day time and night time they can shifted their
frequency to be undetected on specific location. The reason
is to manipulated scanning activity from BWA operator and
also the government institution.
Ray Khastur

5. 5
Overview : MikroTik Wireless Communication System 2.3 GHz
http://www.itelite.net/offer.php?n=69&lang=en
http://www.itelite.net/offer.php?n=80&lang=en
Ray Khastur

6. 6
Overview: Existing TDD Configuration
UL = 18 Symbols = 1851.43 usDL = 29 Symbols = 2982.86 us UL = 18 Symbols = 1851.43 us
TTG = 105.715us RTG=60us
WiMAX 16e
29:18
DL
ULDL DwPTS(10 os)
TD- LTE 3:1
SSP : 10:2:2
UpPTS(2 OS)
TUD
DL DL
Interference Interference
Interference WiMAX
to TD-LTE
Interference TD-LTE
to WiMAX
To determine TDD Interference from Intra LTE:
•The power receiving strength for the first UL subframes 0 and 6 is used to differentiate TDD long-distance
interference.
•The power receiving strength for the last UL subframes 0 and 12 is used to differentiate interference
caused by GPS clock loss.
In current condition due to there are two kind of external interference (WiMAX and Local ISP), From above
picture showing All UL Symbol of LTE System will have suffered tdd interference from WiMAX Operator. And
also the MikroTik transmiter will also interferer DL and UL every time due to use FDD Technology.
Ray Khastur

7. 7
Border Site of Monitoring
Ray Khastur

8. Ray Khastur 8
Border Site of Monitoring: Border 1
Border 1 on the North City of M, we can see the direction of Interference is coming from South area.

9. 9
Border Site of Monitoring: Border 2
Border 2 on the Center City of M, we can see the direction of Interference is facing to the marked area and
also there are terrestrial link pattern that connecting west M to the inner city
Ray Khastur

10. 10
Border Site of Monitoring: Border 3
Border 3 on the South City of M, we can see the direction of Interference is going to the Border 2 area.
Ray Khastur

11. 11
Border Site of Monitoring: Border 4
Border 4 on the East City of M, we can see the direction of Interference is going to the Border 2 area.
Ray Khastur

12. 12
Investigation Highest RTWP Site
Ray Khastur

13. 13
Investigation Highest RTWP Site:
RTWP Tracing Site 31131_Prapat 54 M-P-RT_2
Inband Emission 1
Inband Emission 2
Ray Khastur

14. 14
Investigation Highest RTWP Site:
RTWP Tracing Site 31601_Ksatria Barat M-P-RT_3
Inband Emission 1
Inband Emission 2
Ray Khastur

15. 15
Investigation Highest RTWP Site:
RTWP Tracing Site 31043_Gatot Subroto M-P-RT_1
Inband Emission 1
Ray Khastur

16. 16
OSS Monitoring : 31131
UL and DL Throughput can’t reach the peak performance
even there is only few subscriber.
Ray Khastur

17. 17
OSS Monitoring : 31601
UL and DL Throughput can’t reach the peak performance
even there is only few subscriber.

18. 18
• There are two kinds of external source on M Region, from WiMAX Operator (TDD Technology) and also
from Local ISP with Wireless MikroTik (FDD Technology). On current situation our huge interferer is
coming from Local ISP than WiMAX Operator. Strongly recommended to solve Local ISP problem need
to be clear.
• Interference issue will affected with many KPI for achieve the target and also have bad user experience
perspective with B Operator LTE Services. (Attach Detach, RRC, eRAB, Service Drop Rate, Intra Freq
HOSR, Latency {Attach Time Delay and Ping} and and Throughput as well)
• With adjacent Band Frequency with WiMAX operator, proper TDD Ratio configuration need to be set up
properly to prevent any TDD Interference and also TDD Ratio configuration will determine the
Throughput achieved.
Summary