Radio Interference Cases in terrestrial services. Radio Interference Cases in Satellite Services

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Lynette Powers
5 years ago
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2 01 Radio Interference Cases in terrestrial services 02 Radio Interference Cases in Satellite Services

3 01 Radio Interference Cases in terrestrial services

4 General Steps Interference analysis 1.Characteristic analysis 2.Where the interference may come from DF 1.Fixed station 2.Monitoring Vehicle 3.Portable devices etc. Finding 1.Portable Devices 2.Directional Antenna

5 Case 1: Interference in CDMA System Brief Introduction EVDO does not work. Uplink signal alarmed from Base station A high level signal at 828.4MHz The position of the transmitter is unknown.

6 Case 1: Interference in CDMA System With the signal strength and DF results, we can determine the suspect building.

7 Case 2: Interference in CIVIL Aviation Application Distance Measuring Equipment (DME) Working Frequency: 962~1213MHz Interfere the DME communications Security threat to civil aviation

8 Case 2: Interference in CIVIL Aviation Application interference source The interfered DME station Working frequency:1107mhz The signal strength is about -15dBm.

9 Case 2: Interference in CIVIL Aviation Application Wireless Video Transmitter RF parameters Transmitting frequency: L-band ( GHz), S-band ( GHz), Ku-band ( GHz). Transmitting power: 20~33dBm. Bandwidth: 2~8MHz.

10 Case 2: Interference in CIVIL Aviation Application What is Wireless VEDIO TRANSMITTERS Used for? Public security Water project Oil field Forest fire prevention

11 Case 3:Harmonic of Broadcast Civil aviation air-ground communication frequency 119MHz is interfered. The interference is come from the 10 th harmonic of AM 11.94MHz broadcast.

12 -2 Case 4:Interference in Timing System Road Cycling timing system interference in the Olympic Games Interference appeal shows Road Cycling timing system which is working at 125kHz is affected by unknown discrete signal.

for WLAN service is about 60%, the network connection is interrupted.

13 Case 5: Interference in WLAN System WLAN interference in Olympic Games In the northeast corner of Olympic Sports Center stadium, the network packet loss rate for WLAN service is about 60%, the network connection is interrupted. According to spectrum monitoring, The interference signal level is 40dB more than WLAN signal.

14 常见的霓虹灯 Case 6: Research on Neon Light Interference

15 Case 6: Research on Neon Light Interference (1) Neon self-generated interference Manufacturing process defects, defective, aging; (2) Interference generated by the installation process (3) Interference generated by the transformer Transformer overloading, housing ungrounded, etc.; (4) Interference generated by the control circuit Spark flashes caused by the controller (5) Other reasons Power line coupling, leakage caused by high voltage discharge, etc.; Rain, snow, lightning and other inclement weather;

16 Case 6: Research on Neon Light Interference Neon Works Properly: In 30MHz~1GHz bands, neon leaks a small amount of electromagnetic, radiated power is less than the reference level. In 1GHz~6GHz bands, neon leaks a small amount of electromagnetic, radiated power is less than the reference level. Level [dbµv/m] MHz~1GHz, Light OFF 0 30M 50M 70M 100M 200M Frequency [Hz] 300M 500M 700M 1G 测量值参考门限值 1GHz~6GHz, Light OFF Level [dbµv/m] MHz~1GHz, Light ON 5 30M 50M 70M 100M 200M Frequency [Hz] 300M 500M 700M 1G 测量值参考门限值 1GHz~6GHz, Light ON Overall, neon devices will not cause radio interference signal when it works properly. Level [dbµv/m] G 2G Frequency [Hz] 3G 4G 5G 6G 峰值测量值平均值测量值参考峰值门限参考平均值门限 Level [dbµv/m] G 2G Frequency [Hz] 3G 4G 5G 6G 峰值测量值平均值测量值参考峰值门限参考平均值门限

17 Case 6: Research on Neon Light Interference Neon Works abnormal(electrode virtual connection and arcing): In 30MHz~1GHz bands, neon leaks a wide spectrum electromagnetic energy, and the radiation energy is relatively high. In 1GHz~6GHz bands, the electromagnetic leakage mainly concentrated in 1GHz~2GHz. In general, when electrode is unstable, the electromagnetic interference spreads from 30MHz to 2GHz MHz~1GHz, Light OFF Level [dbµv/m] 50 30M 50M 70M 100M 200M 300M 500M 700M 1G Frequency [Hz] MES mobile_pre LIM Level [dbµv/m] Field Strength QP Limit 1GHz~6GHz, Light OFF 1G 2G 3G 4G 5G 6G Frequency [Hz] MES _pre MES _pre2 LIM EN55022_1-6_PK_B LIM EN55022_1-6_AV_B Field Strength QP Limit Field Strength QP Limit Level [dbµv/m] MHz~1GHz, Light ON 30M 50M 70M 100M 200M 300M 500M 700M 1G Frequency [Hz] MES lamp-1_pre LIM Level [dbµv/m] Field Strength QP Limit 1GHz~6GHz, Light ON 1G 2G 3G 4G 5G 6G Frequency [Hz] MES lamp-6_pre MES lamp-6_pre2 LIM EN55022_1-6_PK_B LIM EN55022_1-6_AV_B Field Strength QP Limit Field Strength QP Limit

18 Case 6: Research on Neon Light Interference Typical case of neon interference: Aviation interference Continuous noise blocks the air-ground communication; Affects aircraft movements; Noise affects the ground command tower; Cable television network interference TV screen appears black lines; Some channel appear snowflake-shaped interference; Cluster communication interference Affects cluster radio communication; GSM interference Affects call quality;

19 Case Study : LED Screen Interference Size of the LED Screen: 25m*14m Peak Power:270kW Legal Signal Interference Signal

20 Specific Case 7: Pseudo Base Stations Illigal radio station pretending to be a base station Send spam message to GSM users in fake phone number. Collect the SIM cards information from the users around. The pseudo base station is composed of transmitter, transmit antenna and control software.

21 Specific Case 7: Pseudo Base Stations In building Antenna In vehicle

22 Specific Case 7: Pseudo Base Stations Giant profits Sending spam messages by using pseudo base station will make great profits. Bypass the supervision Bypass the supervision of telecom administrator and operators.

23 Specific Case 7: Pseudo Base Stations Bad social Influence Illegally occupying frequency resource Deteriorating the EM environment by high-power transmission Interfering normal telecom provider s business Phone users out of service Pseudo Base station

24 Specific Case 7: Pseudo Base Stations Recognition the Pseudo Base Station Mobile phone connect with the pseudo base station shortly, so it would cause a mass of location update Monitor the location update frequency High frequency of location update

25 Specific Case 7: Pseudo Base Stations Recognition the Pseudo Base Station No voice call service, but send a lot of SMS in same length Monitor the SMS length No voice call service, and send a lot of SMS in same length message length

26 Specific Case 7: Pseudo Base Stations Recognition the Pseudo Base Station LAC(Location Area Code ) value is different from its adjacent BS Monitor the LAC value Monitoring LAC value

27 Specific Case 7: Pseudo Base Stations Locating with handheld monitoring equipment Handheld reciever The hidden handheld direction finder

28 Specific Case 8:Monitoring on Cheating in Examinations 1 1. Obtain the questions in the examination room and transmit by radio equipment Solve the questions outside the room. 3. Transmit the answers back to whom buy this kind of service in the room.

29 Radio Monitoring on 1 Cheating in Examination Specific Case 8:Monitoring on Cheating Receiver system of voice in Examinations equipment

30 Specific Case 8:Monitoring on Cheating in Examinations Use GPRS network to automatic log on the server and control the transmitter. Reduce the risk of field operation. Two options of power supply: 220V AC/ 12V DC The look is just like an eraser.

31 Specific Case 8:Monitoring on Cheating in Examinations Center frequency 242.1MHz, Band width 12.5kHz,Power 100W,Modulation type 2FSK. Transmit 120 Chinese characters with a interval of 6 seconds.

32 How does the management Radio Monitoring on 1 Cheating in Examination Specific Case 8:Monitoring on Cheating department of radio to avoid the cheating in examination? in Examinations Electronic Dog Metal Detector Radio Shielding Devices

33 02 Radio Interference Cases in Satellite Services

34 2 Interference Cases in Satellite Services Classification of the interference Two types of radio frequency interferences; i.e. unintentional and intentional A. Unintentional interference is primarily caused by: faulty operation equipment failure poor system design bad installation interference from adjacent satellites interference caused by terrestrial services etc.

35 2 Interference Cases in Satellite Services Classification of the interference Two types of radio frequency interferences; i.e. unintentional and intentional B. Intentional interference - illegal occupation by unauthorized users - Jammer to Satellite TV receiver Few cases are destructive Cut-off the satellite communication Inter-cut of TV programs Result in bad influence in society

36 02 Interference Cases in Satellite Services General Steps 1. Geo-location 2. Ground Searching

37 2 Interference Cases in Satellite Services General Steps 1. Geo-location - Receive the downlink signal from the satellite transponder and measure the TDOA/FDOA parameters to estimate the location of uplink source. - Normally the Geo-location accuracy would be less than 10km. Geo-location

38 2 Interference Cases in Satellite Services General Steps -Portable devices -Monitoring Vehicles Ground Searching Monitoring Vehicles -Portable devices

39 2 Interference Cases in Satellite Services Innovational Technology to find the transmitter Principle of Weak Signal detection Weak signal detection in satellite interference finding

40 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals - Interference from GSM Signals GSM Base Transceiver Station(BTS) GSM 基站发射塔 ( MHz) Earth Station Uplink 转发上星 Modulator 调制器 ( MHz) or( mhz) 发射天线 Transmit Antenna

41 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals -Difficulties in Geo-Location GSM Signals are TDMA signals, Geo-location system has poor performance to locate the TDMA signals. The frequency of service signal from the earth station is unknown, can not being used to locate the earth station.

42 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals - Characteristics of GSM Signals Modulation Mode Modulated Rate Single Time Slot Channel BW GMSK us 200kHz Time Slot

43 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals MCC:Mobile Country Code, figure out in which country the cell is located MNC:Mobile Network Code, figure out which network operator it belongs to LAC: Location Area Code, figure out which location area it belongs to CI: Cell Identity, Figure out the exact one cell Achieve the CGI information, especially its geographical location.

44 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals Investigation of the Interference Signal characteristic analysis Decode to achieve CGI BTS location information Identify the interference source

45 2 Interference Cases in Satellite Services Case 1:Interference from GSM Signals MCC MNC LAC CI BTS 1.05km Earth Station

46 2 Interference Cases in Satellite Services Case 2: Interference in Satellite TV Receiver(1)

47 2 Interference Cases in Satellite Services Case 3: Interference in Satellite TV Receiver(2)

48 2 Interference Cases in Satellite Services Case 4: Jammer to downlink signal of Satellite TV Traits - The whole C & Ku band interfered. - Thousands of families can t watch TV normally. - Not only TV, but also others satellite system were interfered.

High building - From North to South - Monitoring

49 2 Interference Cases in Satellite Services Case 4: Jammer to downlink signal of Satellite TV Notice - High building - From North to South - Monitoring Vehicle - LNA is necessary (filter) Turn off the transmitter jammer

50 Summary of Interference Interfered 1.CDMA 2.DME(distance measuring equipment) 3.AIR-TO-GROUDN communication INTERFERENCE SOURCE Repeater Wireless Video Transmitter 10 TH harmonic of the HF broadcast Terrestrial Services 4. Road Cycling timing system Leakage of a broken signal cable 5. WLAN service Microwave Oven 6. Cluster Communication LED Screen 7. GSM system Pseudo Based station 8. Cheating equipment Cheating Radio Device 1. Transponder GSM System Satellite Services 2. TV Receiver Wireless Bridge 3. TV Receiver Radar Signal 4. TV Receiver jammer

Interference Direction Analysis. Communication Signals

Interference Direction Analysis. Communication Signals 1 PLC Power Line Communications I/Q Analyzer-Magnitude: The display here captures the entire signal in the time domain over a bandwidth of almost 27 MHz, making precise triggering easier. I/Q Analyzer-HiRes