Cooperative Patent Classification


CPC Definition - Subclass H04K

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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

Jamming means used in radar or analogous systems

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

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

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

Secrecy systems used in scanning, transmission or reproduction of documents

Analogue secrecy systems or analogue subscription systems for television

Informative references

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

Arrangements for protecting computers or computers systems

Ciphering or deciphering apparatus per se

Systems with reduced bandwidth or suppressed carrier

Spread spectrum techniques

Photonic quantum communication

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

Transmission systems characterised by the use of a sub-carrier

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

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

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

Systems with reduced bandwidth or suppressed carrier

Spread spectrum techniques in general

By using a sub-carrier

By multiplexing

Transmission systems for secret digital information, encryption of digital signals

Secret or subscription television systems

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

Counter-measures used in radar

Counter-measures used in lidar

Counter-measures used in sonar

Informative references

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

Secret communication

Vehicle anti-theft relating to remote keyless entry

Vehicle anti-theft alarm transmission

Weapons

Defence devices

Radars and GPS

Counter-measures used in radar or analogous systems

Remote keyless entry

Alarm and surveillance

Acoustics

Aerials

Gain control

Automatic frequency control

Electric pulse generators

Transmission

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

Spread spectrum techniques

Suppression or limitation of noise or interference

Monitoring or testing of receivers for locating or positioning the transmitter

Measuring or estimating channel quality parameters

Flow control or congestion control packet switching networks

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

Handfree telephone for vehicles

Television systems

Wireless communications networks

Wireless security

Cognitive radio

Wireless local area networks (WLAN)

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

Shielding

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