Interferences Between E-GSM 900 MHz and HSPA 850 MHz along Thailand Border - Puttachad Manmontri - ASPF-5 2015

1. Spectrum Management Bureau, Office of NBTC
สำนักงำนคณะกรรมกำรกิจกำรกระจำยเสียง กิจกำรโทรทัศน์ และกิจกำรโทรคมนำคมแห่งชำติ
The National Broadcasting and Telecommunications Commission
March 2015
INTERFERENCES
BETWEEN E-GSM 900 MHz AND HSPA 850 MHz
ALONG THAILAND BORDER

2. The National Broadcasting and Telecommunications Commission
Thailand current usage in band 800/900 MHz
2
Trunked
Radio
(DL)
Land
mobile
/fixed
Cellular/
CAT
849 894 897.5 915
Cellular/
TOT/AIS
960942.5
Cellular/
TOT/AIS
RFID
920
925
Cellular/
CAT/DTAC
839
Cellular/
CAT
Cellular/
CAT/DTAC
884824 851 869861
HSPA 850 HSPA 850
GSM 900/
HSPA 900
GSM 900/
HSPA 900
824 849 869 894 897.5 915 942.5 960

3. The National Broadcasting and Telecommunications Commission
Situation along common border
3
HSPA 850
E-GSM 900
894
880 915
869
Thailand
Neighboring
countries
Reverse duplex
interference

4. The National Broadcasting and Telecommunications Commission
Mitigation techniques
4
1
• Frequency retune
• Band segmentation
2
• Filtering
3
• Reduction of transmitting power
4
• Antenna downtilt

5. The National Broadcasting and Telecommunications Commission
Mitigation techniques
5
 Frequency Retune/Band segmentation
A B A B
Frequency Retune: for some areas along the border
Band Segmentation: for all areas along the border

6. The National Broadcasting and Telecommunications Commission
Mitigation techniques
6
 Filtering

7. The National Broadcasting and Telecommunications Commission
Mitigation techniques
7
 Reduction of transmitting power
Without band segmentation:
Power < -98 dBm/200 MHz at 3 km from the border
With band segmentation:
Power < -98 dBm/200 MHz at 30 km from the border
Examples

8. The National Broadcasting and Telecommunications Commission
Mitigation techniques
8
 Antenna downtilt
Mechanical Tilt
Electrical Tilt

9. The National Broadcasting and Telecommunications Commission
Conclusion
9
 For short term solution, combination of different mitigation
techniques can be used to reduce reverse duplex
interference.
 For long term solution, spectrum harmonization is
recommended.

10. The National Broadcasting and Telecommunications Commission
Thank you
Spectrum Management Bureau
Office of the National Broadcasting and
Telecommunications Commission (NBTC)
Tel. 0 2271 0151-60 ext. 907, 903, 653, 915
Email: spectrum@nbtc.go.th