CPC Definition - Subclass H04K

Last Updated Version: 2017.08
SECRET COMMUNICATION; JAMMING OF COMMUNICATION
Definition statement

This place covers:

This subclass covers secret line and radiation transmission systems in which the signal is modified at the transmitting station in such a way that the information cannot be intelligibly received without corresponding modification at the receiving station.

The signal can be modified using, for example, frequency scrambling or scrambling by combination with a second signal.

This subclass also covers the jamming of communications and counter-measures against jamming or against surveillance.

Relationships with other classification places

Systems using reduced bandwidth or suppressed carrier techniques, or using sub-carriers or spread spectrum techniques are classified in H04B. In particular, spread spectrum as counter-measure against jamming is classified in H04K 3/00 whereas spread spectrum communication as such is classified in H04B.

Analogue scrambling, jamming or counter-measures to achieve secure communication are classified in H04K whereas encryption of digital signals is classified in H04L.

References
Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Means for anti-jamming used in radar or analogous systems

G01S 7/36

Jamming means used in radar or analogous systems

G01S 7/38

Counter-measures or counter-counter-measures used in lidar or analogous systems

G01S 7/495

Counter-measures or counter-counter-measures used in sonar or analogous systems

G01S 7/537

Arrangements for the secret or secure communication of digital information, encryption of digital signals

H04L 9/00

Secrecy systems used in scanning, transmission or reproduction of documents

H04N 1/44

Analogue secrecy systems or analogue subscription systems for television

H04N 7/16

Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangements for protecting computers or computers systems

G06F 21/00

Ciphering or deciphering apparatus per se

G09C

Systems with reduced bandwidth or suppressed carrier

H04B 1/66, H04B 1/68

Spread spectrum techniques

H04B 1/69

Photonic quantum communication

H04B 10/70

Protection from unauthorised access for optical transmission, e.g. eavesdrop protection

H04B 10/85

Transmission systems characterised by the use of a sub-carrier

H04B 14/08

Arrangements for preventing the taking of data from a data transmission channel without authorisation

H04L 12/22

Selective content distribution, e.g. interactive television, VOD

H04N 21/00

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Secret communication

Secret line and radiation transmission systems, i.e., those in which the signal is modified at the transmitting station in such a way that the information cannot be intelligibly received without corresponding modification at the receiving station.

Jamming of communication

Apparatus, circuits or systems purposefully trying to interfere with the physical transmission and reception of communication.

Frequency scrambling

Transposing or inverting parts of the frequency band or by inverting the whole band

Follower jammer

Jammer adapted to determine and follow the frequency of a jamming target signal that uses frequency hopping techniques

Look-through mode

Operation mode wherein jamming and monitoring of the jamming target alternate

Reactive jammer

Jammer wherein jamming is activated only when a target has been detected

RCIED

Remote Controlled Improvised Explosive Device

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • “confidential”, "sensitive", “undercover”, “private”, “sneaky”
  • “hidden”, "scrambled", "blinded", "obscured", "obfuscated", "masked", "concealed", "covert", "coded"
Secret communication
Definition statement

This place covers:

Secret communication in the analogue domain for speech and non-speech data.

Relationships with other classification places

Secret communication in the analogue domain, or analogue scrambling, jamming or counter-measures are classifed in H01K 1/00 whereas transmission systems for the secret or secure communication of digital information are classified in H04L, with details of encryption in the digital domain most likely classified in H04L 9/00 and H04L 12/00.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Ciphering or deciphering apparatus per se

G09C

Systems with reduced bandwidth or suppressed carrier

H04B 1/66

Spread spectrum techniques in general

H04B 1/69

By using a sub-carrier

H04B 14/08

By multiplexing

H04J

Transmission systems for secret digital information, encryption of digital signals

H04L 9/00, H04L 12/00

Secret or subscription television systems

H04N 7/16, H04N 21/00

Jamming of communication; Counter-measures
Definition statement

This place covers:

"jamming", only when it means purposefully trying to interfere with the physical transmission and reception of communication.

Provided this condition is met, this group covers devices and methods for:

  • jamming of communication, e.g. jamming by intentionally decreasing the signal to noise ratio, deceptive jamming (H04K 3/65), passive jamming (H04K 3/68), destructive jamming (H04K 3/62);
  • countermeasures against jamming (H04K 3/20);
  • countermeasures against undesired self-jamming resulting from jamming (H04K 3/28);
  • countermeasures against surveillance, interception or detection (H04K 3/82);
  • other electronic countermeasures using or against electromagnetic or acoustic waves (H04K 3/00);
  • signal detection techniques used in relation to jamming for interception and monitoring of the jamming target signal (H04K 3/45);
  • signal detection techniques used in relation to anti-jamming for jamming detection (H04K 3/22);
  • signal detection techniques used in relation to anti-surveillance for surveillance detection (H04K 3/822)

In particular, this group covers:

  • jamming for testing or assessing countermeasures (H04K 3/94);
  • jamming used to prevent cellular phone communication (H04K 2203/16), e.g. in a vehicle during motion (H04K 3/415), in particular areas, including prisons, hospitals, planes, petrol stations, theatres (H04K 3/84), and to trigger RCIEDs (H04K 3/92 and H04K 2203/24);
  • jamming used to prevent reception of positioning data using GPS (H04K 3/90);
  • jamming used to prevent wireless communication in ad hoc networks or in sensor networks (H04K 2203/18);
  • jamming used to prevent exchange of data between wirelessly connected devices or device units, on Bluetooth, infrared or near field links;
  • jamming used to prevent unauthorized access to network, service or information (H04K 3/86), including access to a WLAN network (H04K 2203/18) and access to information stored in contactless carriers, including RFID carriers (H04K 2203/20);
  • jamming used to prevent transmission of an alarm against burglary or vehicle theft (H04K 3/88);
  • jamming used to prevent remote control of devices (H04K 3/92);
  • jamming used to prevent surveillance (H04K 3/82), e.g. of speech in meeting rooms (H04K 2203/12), of electromagnetic emissions from a computer screen H04K 2203/14);
  • jamming used to prevent interception or detection of a wirelessly transmitted signal (H04K 3/825).
Relationships with other classification places

Terminology

Jamming should be understood as meaning "intentional disturbance".

Interference should be understood as meaning "unintentional disturbance".

Anti-jamming

Jamming and anti-jamming techniques are covered by H04K 3/00 and lower.

Anti-interference techniques are covered by H04B.

Cancellation of "self-jamming"

  • intentional self-jamming (e.g. self-jamming of receiver to counter interference; self-jamming of transmitter to counter surveillance): H04K;
  • undesired self-jamming caused by transmitting: H04B 1/525;
  • undesired self-jamming caused by transmitting a jamming signal intentionally: H04B 1/525 and H04K 3/28;

If the intentional self-jamming signal is known by the transmitter and the receiver of the jammed signal (and can therefore be regarded as a shared secret): H04K 1/00

Other cases of intentional self-jamming: H04K 3/00

References
Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Counter-measures used in radar or analogous systems

G01S 7/00

Counter-measures used in radar

G01S 7/36, G01S 7/38

Counter-measures used in lidar

G01S 7/495

Counter-measures used in sonar

G01S 7/537

Informative references

Attention is drawn to the following places, which may be of interest for search:

Secret communication

H04K 1/00

Vehicle anti-theft relating to remote keyless entry

B60R 25/00

Vehicle anti-theft alarm transmission

B60R 25/102

Weapons

F41

Defence devices

F41H 11/00

Radars and GPS

G01S

Counter-measures used in radar or analogous systems

G01S 7/00

Remote keyless entry

G07C 9/00

Alarm and surveillance

G08B

Acoustics

G10K

Aerials

H01Q

Gain control

H03G 3/00

Automatic frequency control

H03J 7/00

Electric pulse generators

H03K 3/00

Transmission

H04B

Reducing, in transceivers, leakage of transmitter signal into the receiver

H04B 1/525

Spread spectrum techniques

H04B 1/69 - H04B 1/719

Suppression or limitation of noise or interference

H04B 15/00, H04B 1/10

Monitoring or testing of receivers for locating or positioning the transmitter

H04B 17/27

Measuring or estimating channel quality parameters

H04B 17/309

Flow control or congestion control packet switching networks

H04L 47/135

Network architectures or network communication protocols for network security for supporting lawful interception, monitoring or retaining of communications or communication related information

H04L 63/30

Handfree telephone for vehicles

H04M 1/6075

Television systems

H04N 7/00

Wireless communications networks

H04W

Wireless security

H04W 12/00

Cognitive radio

H04W 16/14, H04W 72/082

Wireless local area networks (WLAN)

H04W 84/12

Self-organizing networks, ad-hoc networks and sensor networks

H04W 84/18

Shielding

H05K 9/00

Special rules of classification

A patent document should be classified in H04K 3/20 when the countered signal disturbance is:

  • intentional (whether offensive or defensive) or
  • used in a military, security or confidentiality context.
Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Jamming of communication

Purposefully trying to interfere with the physical transmission or reception of communication

Self-jamming resulting from jamming

Undesired interference, caused by a jamming device, to the communication of the jamming device itself or of a friendly device, and resulting from intentionally interfering with the communication of adversary devices

Follower jammer

Jammer adapted to determine and follow the frequency of a jamming target signal that uses frequency hopping techniques

Look-through mode

Operation mode wherein jamming and monitoring of the jamming target alternate

Reactive jammer

Jammer wherein jamming is activated only when a target has been detected

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

(F)FH

(Fast) Frequency Hopping

GPS

Global Positioning System

NFC

Near Field Communication

RCIED

Remote Controlled Improvised Explosive Device

RFID

Radio Frequency IDentification

WLAN

Wireless Local Area Network