01 02 Radio Interference Cases in Satellite Services · 2018-04-13 · 1G 2G 3G 4G 5G 6G...

Radio Interference Cases in Satelli te Services

Radio Interference Cases in terrestr ial services01

02

Radio Interference Cases in terrestrial services01

1.Portable Devices2.Directional Antenna

1.Fixed station2.Monitoring Vehicle3.Portable devices etc.

General Steps

1.Characteristic analysis2.Where the interference may come from

1

Interference analysis

2

DF

3

Finding

1

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.

1Case 1: Interference in CDMA System

With the signal strength and DF results,

we can determine the suspect building.

1Case 1: Interference in CDMA System

Distance Measuring Equipment (DME)

Working Frequency: 962~1213MHz

Security threat to civil aviationInterfere the DME communications

1Case 2: Interference in CIVIL Aviation Application

The signal strength is about -15dBm.

interference source

The interfered DME stationWorking frequency:1107MHz


RF parameters

• Transmitting frequency: L-band

(1.0-1.5GHz), S-band (2.3-2.7GHz),

Ku-band (10.7-12.7GHz).

• Transmitting power: 20~33dBm.

• Bandwidth: 2~8MHz.

Wireless Video Transmitter


What is Wireless VEDIO TRANSMITTERS Used for?

Oil fieldForest fire prevention

Water projectPublic security


Case 3：Harmonic of Broadcast

• Civil aviation air-ground communication

frequency 119MHz is interfered.

• The interference is come from the 10th harmonic

of AM 11.94MHz broadcast.

1

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.

1-2Case 4：Interference in Timing System

1

WLAN interference in Olympic Games

• In the northeast corner of Olympic Sports Center stadium, the networkpacket loss rate for WLAN service is about 60%, the network connectionis interrupted.

• According to spectrum monitoring, The interference signal level is 40dBmore than WLAN signal.

Case 5： Interference in WLAN System1

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

1

– (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;

Case 6: Research on Neon Light Interference1


1GHz~6GHz, Light OFF

20

30

40

50

60

70

80Level [dBµV/m]

1G 2G 3G 4G 5G 6GFrequency [Hz]

峰值测量值平均值测量值参考峰值门限参考平均值门限

20

30

40

50

60

70

80Level [dBµV/m]


峰值测量值平均值测量值

参考峰值门限参考平均值门限

1GHz~6GHz, Light ON

30MHz~1GHz, Light OFF

0

10

20

30

40

Level [dBµV/m]

30M 50M 70M 100M 200M 300M 500M 700M 1GFrequency [Hz]

测量值参考门限值

5

10

15

20

25

30

35

40

Level [dBµV/m]


测量值参考门限值

30MHz~1GHz, Light ON• 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.

• Overall, neon devices will not cause radio interference signal when it works properly.


• 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.

30MHz~1GHz, Light OFF 30MHz~1GHz, Light ON

0

10

20

30

40

50

Level [dBµV/m]


MES mobile_preLIM 40-47 Field Strength QP Limit

10

20

30

40

50

60

Level [dBµV/m]


MES lamp-1_preLIM 40-47 Field Strength QP Limit

1GHz~6GHz, Light OFF 1GHz~6GHz, Light ON

20

30

40

50

60

70

80

Level [dBµV/m]


MES 1212-12_preMES 1212-12_pre2

LIM EN55022_1-6_PK_B Field Strength QP LimitLIM EN55022_1-6_AV_B Field Strength QP Limit

20

30

40

50

60

70

80

Level [dBµV/m]


MES lamp-6_preMES lamp-6_pre2

LIM EN55022_1-6_PK_B Field Strength QP LimitLIM EN55022_1-6_AV_B Field Strength QP Limit

• 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;


Size of the LED Screen: 25m*14mPeak Power:270kW

Case Study :LED Screen Interference

Legal SignalInterference Signal

1

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.

Specific Case 7: Pseudo Base Stations1

In building

In vehicle

Antenna

1Specific 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.


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

Bad social Influence


Recognition the Pseudo Base Station

High frequency of location update

Monitor the location update frequency

Mobile phone connect with the pseudo base station shortly, so it would cause a mass of location update



Monitor the SMS length

No voice call service，but send a lot of SMS in same length

No voice call service，and send a lot of SMS in same length


message length


Monitor the LAC value

LAC(Location Area Code ) value is different from its adjacent BS

Monitoring LAC value


Locating with handheld monitoring equipment

Handheld reciever The hidden handheld direction finder


1Specific Case 8:Monitoring on Cheating

in Examinations

3

2

1

3. Transmit the answers back to whom buy this kind of service in the room.

1. Obtain the questions in the examination room and transmit by radio equipment.

2. Solve the questions outside the room.

Receiver system of voice equipment

Rad io Moni to r ing on Cheat ing in Examina t ion1

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.


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.


in Examinations

How does the management department of radio to

avoid the cheating in examination ?

Rad io Moni to r ing on Cheat ing in Examina t ion

Electronic Dog Metal Detector

Radio Shielding Devices


in Examinations

Radio Interference Cases in Satellite Services 02

2Interference Cases in

Satellite Services

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.

Classification of the interference

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


Satellite Services

1. Geo-location

2. Ground Searching


Satellite Services General Steps

- 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

1. Geo-location



-Portable devices-Monitoring Vehicles

Ground Searching

Monitoring Vehicles

-Portable devices



Innovational Technology to find the transmitter

Principle of Weak Signal detection

Weak signal detection in satellite interference finding


Satellite Services

GSM基站发射塔

调制器发射天线

转发上星

GSM Base Transceiver Station(BTS)(935-960MHz)

(950-1450MHz)

or(950-2150MHz)

Uplink

Transmit

Antenna

Modulator

Earth Station

Case 1:Interference from GSM Signals

- Interference from GSM Signals


Satellite Services

• 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.

-Difficulties in Geo-Location


Satellite Services Case 1:Interference from GSM Signals

Modulation Mode

Modulated Rate

Single

Time Slot

ChannelBW

GMSK 270.833 577us 200kHz

- Characteristics of GSM Signals



Time Slot

• 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.

Signalcharacteristic

analysis

Decode to achieve

CGI

BTS location information

Identify the interference source

Investigation of the Interference



MCC MNC LAC CI

460 1 10113 16252

1.05km

Earth Station

BTS



Case 2: Interference in Satellite TV Receiver(1)


Satellite Services

Case 3: Interference in Satellite TV Receiver(2)


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.


Satellite Services

Case 4: Jammer to downlink signal of Satellite TV

Turn off the transmitter jammer

Notice- High building- From North to South- Monitoring Vehicle - LNA is necessary (filter)


Satellite Services

Interfered INTERFERENCE SOURCE

Terrestrial Services

1.CDMA Repeater

2.DME(distance measuring equipment) Wireless Video Transmitter

3.AIR-TO-GROUDN communication 10TH harmonic of the HF broadcast

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

Satellite Services

1. Transponder GSM System

2. TV Receiver Wireless Bridge

3. TV Receiver Radar Signal

4. TV Receiver jammer

Summary of Interference

01 02 Radio Interference Cases in Satellite Services · 2018-04-13 · 1G 2G 3G 4G 5G 6G...

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Transcript of 01 02 Radio Interference Cases in Satellite Services · 2018-04-13 · 1G 2G 3G 4G 5G 6G...