CPC Definition - Subclass H04J

Last Updated Version: 2018.02
MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L 5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N 7/08; in exchanges H04Q 11/00; stereophonic systems H04S)
Definition statement

This place covers:

Multiplex Communication having circuits or apparatus for combining or dividing signals for the purpose of transmitting the signals simultaneously or sequentially over the same transmission path, and monitoring arrangements therefor.

Relationships with other classification places

Class H04 Electric communication technique covers electrical communication systems with propagation paths employing beams of corpuscular radiation, acoustic waves or electromagnetic waves. Subclass H04J refers to multiplex communication in general. If the multiplex communication is specially adapted for particular applications classification is made in other subclasses of class H04.

References
Limiting references

This place does not cover:

Optical monitoring arrangements, independent of the multiplexing method

H04B10/08

Selecting arrangements for multiplex systems

H04Q 11/00

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:

Use of multiplexing in transmission systems for measured values, control or similar signals

G08C 15/00

Arrangements for transmission of digital information affording multiple use of the transmission path

H04L 5/00

Systems for the simultaneous or sequential transmission of more than one television signal

H04N 7/08

Informative references

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

Optical elements, systems or apparatus

G02B

Addressing or transmission in computers

G06F 12/00, G06F 13/00

Electronic switching or gating

H03K 17/00

Transmission in general

H04B

Relay systems

H04B 7/14

Broadcast communication

H04H

Data switching networks

H04L 12/00

Modulated-carrier systems

H04L 27/00

Telephonic Communication

H04M

Selecting techniques

H04Q

Stereophonic systems

H04S

Wireless communication networks

H04W

Frequency-division multiplex systems (H04J 14/00 takes precedence)
Definition statement

This place covers:

Frequency Division Multiplexing, FDM, by multiplexing two or more data sources. Covers particularly hierarchical multiplexing electrical frequencies in stages of power of 2, e.g. 8kHz, 64Khz.

References
Limiting references

This place does not cover:

FDM in satellite systems

H04B 7/15

FDM in radio system

H04B 7/26

OFDM

H04L 5/00

OFDM synchronization

H04L 27/2601

Informative references

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

Hybrid TDM/FDM

H04J 4/00

SCM

H04J 14/0298

FDM in CATV or HFC networks

H04N 7/00

Glossary of terms

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

FDM

Frequency Division Multiplexing

OFDM

Orthogonal Frequency Division Multiplexing

SCM

Multiplexing of electrical subcarriers on an optical wavelength

CATV

CAble Television Systems

HFC

Hybrid Fiber Coax

TDM

Time Division Multiplex

Frequency-transposition arrangements {(modulation with carrier or side-band suppression H03C 1/52, H03C 1/60; single-band suppression H04B 1/00, H04B 15/00; telegraphic communication H04L 27/02, H04L 25/49; transference of modulation from one carrier to another, e.g. frequency- changing H03D 7/00; demodulation or transference of modulation of modulated electromagnetic waves H03D 9/00)}
Definition statement

This place covers:

Systems for transposing frequency channels carrying information onto frequency carriers Covers also FDM multiplexers, demultiplexers

References
Informative references

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

TDM/FDM conversion of transmultiplexing

H04J 4/005

Special rules of classification

H04J 1/08 takes precedence

using digital techniques
Definition statement

This place covers:

Frequency translators, FDM multiplexers, demultiplexers, operating with digital techniques

References
Limiting references

This place does not cover:

Group modulators /demodulators used for transmultiplexing FDM TDM

H04J 4/005

Informative references

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

Digital Filters

H03H 17/00

Special rules of classification

H04J 1/08 takes precedence

Arrangements for supplying the carrier waves {Arrangements for supplying synchronisation signals (carrier supply H04L 5/10; frequency multiplication H03B 19/00, H03B 21/00; mixing H03D 7/00, H03D 9/00; synchronisation in general H03B)}
References
Limiting references

This place does not cover:

- Channel allocation

H04J 1/12

Arrangements for combining channels {(branching filters H01P 1/213, H03H 7/46)}
References
Limiting references

This place does not cover:

Branching filters

H01P 1/213, H03H 7/46

Informative references

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

Discrete frequency-selective devices, e.g. stubs, waveguides, directional filters

H01P 1/00

Intermediate station arrangements, e.g. for branching, for tapping-off {(repeater circuits H04B 3/36, H04B 3/58; two-way amplifiers H03F 3/62)}
References
Informative references

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

Two way amplifiers

H03F 3/62

Repeater circuits

H04B 3/36

Arrangements for reducing cross-talk between channels {(in line transmission systems H04B 3/32; in cables or lines H04B 3/26 - H04B 3/30)}
Definition statement

This place covers:

Frequency allocation, including by demand or to reduce intermodulation;

References
Informative references

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

In line transmission

H04B 3/32

In baseband systems

H04L 25/085

Time-division multiplex systems (H04J 14/00 takes precedence; relay systems H04B 7/14; selecting techniques H04Q)
Definition statement

This place covers:

Hierarchical frame structures, the structure repeats continuously at a fixed rate. Typically these are standard TDM frame structures at 8kHz rate like PDH, SDH or OTN. Other fixed rates frames should also be classified here and related fields.

  • fixed length Ethernet (H04L 12/40)
  • Digital audio transmission in fixed length formats ( H04H, H04R).

Synchronization of TDM Frames

Packet transmission is classified for some specific applications:

Transmission of synchronous services like voice via packets, e.g. VoIP, is classified in H04J 3/0632, when the source clock is recovered.

Alignment of packets using packet flags should be in H04J 3/0602 for fixed line systems and in H04L 7/04 in wireless, satellite or radio systems.

Ranging of packets in an uplink in systems with a TDM frame defined in the downlink, see H04J 3/0682.

Note 1: Ranging or time alignment of a radio/wireless channel preferably in H04W 56/00. For radio/wireless systems data transmitted via a fixed network, e.g. connections between Mobile Switching Centre (MSC) and Base Station (BS) or between several Access Points (AP), documents referring to specific data of the radio/wireless channel are in H04W 56/00, e.g. alignment for handover.

Allocation of packets within a TDM frame, e.g. Ethernet in OTN payload, see H04J 3/16 or lower.

Allocation of packets in an uplink of a systems with a TDM frame defined above in the downlink, H04J 3/1694.

Note 1 : This group refers to the allocation of the bandwidth.

Note 2 : Allocation in wireless systems, see H04W or H04B 7/00;

Note 3 : Allocation of timeslots in PON, H04Q 11/0001 takes precedence

Synchronization of TDMA or packets in the meaning of time alignment, the minimum entity of detection or correction is a bit. Smaller sub-bit values refer to bit synchronization of H04L 7/00

References
Limiting references

This place does not cover:

Recording

G11B

Frame structures of wireless systems

H04B4/26

Relay systems

H04B 7/14

Frame structures of OFDM

H04L 5/00

Alignment of parallel data transmission

H04L 25/14

Synchronization of digital video, e.g. STC or PCR timestamps

H04N 7/24

Selecting techniques

H04Q

Informative references

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

Simulcast or Single Frequency Networks

H04H 20/00

Packet networks

H04L 12/00

Internet protocol

H04L 29/00

Digital audio for loudspeakers

H04R

Glossary of terms

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

SDH

Synchronous Digital Hierarchy

SONET

Synchronous Optical NETwork

OTN

Optical Transport Network

MulDex

Multiplexer/Demultiplexer

Details (electronic switching or gating H03K 17/00)
References
Limiting references

This place does not cover:

Electronic switching or gating

H03K 17/00

Distributors combined with modulators or demodulators {(pulse distributors in general H03K 5/15; pulse counters H03K 21/00 - H03K 29/06; for telegraphy H04L 5/22, H04L 13/00 - H04L 23/00, H04L 25/45; for telephony H04Q 11/04)}
References
Informative references

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

Pulse counters

H03K 5/15

Pulse distributors in general

H03K 21/00

SerDes not adapted for data communication of telecommunication

H03M 9/00

Glossary of terms

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

SerDes

Serializer / Deserializer

{Distributors with CRT}
Glossary of terms

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

CRT

Cathode Ray tubes

{Distributors with transistors or integrated circuits}
Definition statement

This place covers:

Details of multiplexing or demultiplexing of bits or bytes in arrangements specially adapted for time multiplexing.

Distributors with transistors or integrated circuits

References
Informative references

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

Timing and clocking in MulDex

H04J 3/0685

Higher level of abstraction of hierarchical PDH MulDex

H04J 3/1641

Details of discrete elements, e.g. transistors

H03K 17/00

Special rules of classification

Details of bit and byte multiplexers or demultiplexers per se, e.g. 2:1 pulse multiplexers and tree structures thereof, H03M 9/00 takes precedence.

Synchronising arrangements {(for television systems H04N 5/04; bit-synchronisation H04L 7/00)}
Definition statement

This place covers:

Synchronization of TDM networks and some specific synchronization arrangements in TDMA or packet networks.

Synchronization of TDM networks covers:

Detection of FAW and alignment of frames, H04J 3/0602;

Absorbing of phase or frequency differences by buffers, H04J 3/062;

Distribution of synchronization information and organisation of the synchronization network, H04J 3/0635.

Specific synchronization arrangement of packet or TDMA networks are:

Distribution of synchronization information and organisation of the synchronization network, H04J 3/0635

Source clock recovery over packet or ATM networks, e.g. VoIP, H04J 3/0632.

Relationships with other classification places

Synchronization of wireless network when mobility of radio channel is relevant, H04W 56/00.

References
Limiting references

This place does not cover:

Smaller, sub-bit, values refer to bit synchronization

H04L 7/00

Informative references

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

Synchronization in computer networks, e.g. Time of Day

G06F 1/04

Buffers between clock domains

G06F 5/06; H04L 7/005

Glossary of terms

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

FAW

Frame Alignment Word

{Systems characterised by the synchronising information used}
Definition statement

This place covers:

A FAW is used as synchronising information for a TDM frame.

References
Limiting references

This place does not cover:

Specific FAW

H04J 3/0605

Details of the FAW detector

H04J 3/0608

Detection of packet headers, e.g. HDLC flag

H04L 7/04

Informative references

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

Special synchronization information, e.g. for packet or mobile transmission

H04L 7/041

Glossary of terms

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

FAW

Frame Alignment Word

{Special codes used as synchronising signal}
Definition statement

This place covers:

Design rules of constructing FAW.

variable FAW, e.g. for low rate signalling, depending on the synchronization state.

References
Informative references

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

Signalling in TDM

H04J 3/12

Special rules of classification

FAW of standardized frames, e.g. T1, SONET, SDH or OTN are known per se are not classified here. Their detection is classified in H04J 3/0608.

Glossary of terms

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

FAW

Frame Alignment Word

UW

Unique Word

{Detectors therefor, e.g. correlators, state machines}
Definition statement

This place covers:

Detection of FAW by correlators, state machines, forward or backward protection.

References
Informative references

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

Digital correlators

G06F 17/15

Detectors of UW for packet detection or symbol synchronisation

H04L 7/042

{PN codes (H04J 3/0608 takes precedence)}
Definition statement

This place covers:

PN codes used for synchronisation, if the PN synchronisation signals is varying during transmission, e.g. by a feedback Shift-register. Fixed synchronisation signals, e.g. unique words or FAW signals, are not to be classified in this group. This also applies even if the synchronisation signal can be presented as a state of such a PN-code generator. Only if the generator shifts, then the document is classified here.

References
Informative references

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

PN codes used for synchronization in other transmission systems, e.g. packet or mobile

H04L 7/043

Special rules of classification

H04J 3/0608 takes precedence for detection

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

PN code

Pseudo-Noise or Pseudorandom code

{Synchronisation of signals having the same nominal but fluctuating bit rates, e.g. using buffers (pulse-stuffing H04J 3/07; asynchronous-synchronous conversion H04L 5/24; speed conversion H04L 25/05; speed conversion in computers G06F 5/06)}
Definition statement

This place covers:

Rate differences are compensated in a lossless way, e.g. by an elastic buffer or FIFO

References
Limiting references

This place does not cover:

Pulse stuffing

H04J 3/07

Speed conversion in computers

G06F 5/06

Speed conversion, e.g. 8 kHz to 9,2 kHz

H04L 25/05

Glossary of terms

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

FIFO

First In First Out buffer

{Synchronous multiplexing systems, e.g. synchronous digital hierarchy/synchronous optical network (SDH/SONET), synchronisation with a pointer process}
Definition statement

This place covers:

Compensation of fluctuating rates in SDH/SONET or OTN

References
Informative references

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

PDH/SDH interfaces, e.g. desynchronizers

H04J 3/076

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

OTN

Optical Transport Network

{plesiochronous multiplexing systems, e.g. plesiochronous digital hierarchy [PDH], jitter attenuators}
References
Informative references

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

PDH/SDH interfaces, e.g. desynchronizers

H04J 3/076

Slot or bandwidth allocation in PDH

H04J 3/1623

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

PDH

Plesiochronous Digital Hierarchy

{Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] (queuing arrangements in packet switching elements H04L 49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N 7/56)}
Definition statement

This place covers:

Recovery of source clock of Continuous Bit Rate (CBO) service, e.g. VoIP. The invention is located at the edge of the packet network and the output is a stream of bits, e.g. control of playout rate.

media0.png

References
Limiting references

This place does not cover:

Queuing arrangements in packet switching elements

H04L 49/90

Synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals

H04N 7/56

Informative references

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

Flow control or congestion control

H04L 47/10

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

FIFO

First In First Out buffer or elastic buffer

RTS

Residual Time Stamps signalling a source clock offset compared to the network clock

SRTS

Synchronous Residual time stamps signalling a source clock offset compared to the network clock

SFET

Synchronous Frequency Encoding Technique signalling a source clock offset compared to the network clock

CES

Circuit Emulating Switching

{Clock or time synchronisation among nodes; Internode synchronisation (synchronization for ring networks H04L 12/422; data switching networks with synchronous transmission H04L 12/43)}
Definition statement

This place covers:

Distribution of synchronisation information among nodes, e.g. master/slave signalling or SSM.

TOD synchronization.

References
Informative references

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

Clock synchronization path among nodes of more than two levels

H04J 3/0679

In combination with delay compensation using timestamp to determine RTD

H04J 3/0682

Clock synchronization in Computer Networks, e.g. TOD

G06F 1/14

Synchronisation of Ring Networks

H04L 12/422

Data switching networks with synchronous transmission

H04L 12/43

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

SSM

Synchronization Status Message

RTD

Round Trip Delay

NTP

Network Time Protocol

PTP

Precision Time Protocol

TOD

Time Of Day

{Change of the master or reference, e.g. take-over or failure of the master}
Definition statement

This place covers:

Signalling to prevent or recover from a failure in the synchronization network.

References
Informative references

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

Fail safe arrangements within the node

H04J 3/0688

Monitoring and fail safe arrangements in general

H04J 3/14

Fail safe arrangements for synchronizers in general

H04L 7/0083

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

APS

Automatic Protection Switching

{Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP] (bus network with centralized control in which slots are of a TDMA packet structure H04L 12/4035)}
References
Informative references

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

Bus network with centralized control in which slots are of a TDMA packet structure

H04L 12/403

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

TTP

Time Triggered Protocol

{Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L 43/0864)}
Definition statement

This place covers:

media1.png

References
Limiting references

This place does not cover:

Arrangements for monitoring round trip delays in packet switching networks

H04L 43/0864

Informative references

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

Delay compensation for other types of time multiplexing, e.g. TDM/TDMA in a star configuration

H04J 3/0682

Time supervision arrangements, e.g. real time clock

G06F 1/14

Timer mechanisms used in protocols of packet data networks

H04L 69/28

Glossary of terms

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

NTP

Network Time Protocol

PTP

Precision Time Protocol

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

NTP

Network Time Protocol

PTP

Precision Time Protocol

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

  • "PTP" and "IEEE 1588"
{using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet}
Definition statement

This place covers:

Adding or modification of delay information, e.g. residence time in PTP

References
Informative references

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

Interconnection of networks

H04L 12/46

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

PTP

Precision Time Protocol

{Mutual}
Definition statement

This place covers:

Exchange of synchronization information, e.g. buffer fill.Coupling clocks, e.g. by adding weighted signals of clock or phase errors.

References
Informative references

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

Clock selection in a TDM node

H04J 3/0688

{by determining clock distribution path in a network}
Definition statement

This place covers:

Determination or initialisation of clock distribution path among more than two levels of nodes according to parameters, e.g. priority, path length, number of hops, clock quality, statistics.Avoidance of clock loops or timing islands.

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

HMS

Hierarchical Master Slave

PAMS

Pre-Assigned Master Slave

SSM

Synchronisation Status Message

{by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging}
Definition statement

This place covers:

RTD measurement in TDM or TDMA networks for the purpose of timing adjustment, clock correction or time alignment.

References
Limiting references

This place does not cover:

Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays

H04J 3/067

Synchronization in mobile networks

H04W 56/0055

Informative references

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

RTD measurement and compensation in satellite systems

H04B 7/2125

RTD measurement for network management or monitoring

H04L 43/0852

PON in general

H04Q 11/0001

Glossary of terms

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

PON

Passive Optical Network

CATV

CAble TeleVision

RTD

Round Trip Delay

{Change of the master or reference, e.g. take-over or failure of the master}
References
Informative references

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

Monitoring and fail safe arrangements in general

H04J 3/14

Fail safe arrangements of PLL

H03L 7/00

Fail safe arrangements for synchronizers in general

H04L 7/0083

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

APS

Automatic Protection Switching

{Synchronisation in a TDMA node, e.g. TTP}
Synonyms and Keywords

In patent documents, the following abbreviations are often used:

TTP

Time Triggered Protocol

{Synchronisation in a packet node}
Synonyms and Keywords

In patent documents, the following abbreviations are often used:

PTP

Precision Time Protocol

using pulse stuffing for systems with different or fluctuating information rates {or bit rates}
Definition statement

This place covers:

Variable length stuffing; self marking stuff indications

This subgroup does not refer to stuffing of packet flags as line coding to interrupt a long sequence of identical bit values.

References
Informative references

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

Fill bit or bits in non-TDM formats,

H04L 2007/045

Line coding

H04L 25/49

Packet headers or flags

H04L 29/06

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

WTJ

Waiting Time Jitter

STM

Stuff Threshold Modulation

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

  • "justification" and "stuffing"
{Bit stuffing, e.g. PDH}
References
Informative references

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

PDH buffering

H04J 3/0626

PDH framing formats and slot allocation

H04J 3/1623

{Bit and byte stuffing, e.g. SDH/PDH desynchronisers, bit-leaking}
Definition statement

This place covers:

Stuffing in OTN

References
Informative references

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

Buffer arrangements for synchronization in SDH/SONET or OTN

H04J 3/0623

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

OTN

Optical Transport Network

Intermediate station arrangements, e.g. for branching, for tapping-off
Definition statement

This place covers:

ADM Add Drop Multiplexers

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

ADM

Add Drop Multiplexer

{for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks}
Definition statement

This place covers:

Protection in TDM ring networks

References
Limiting references

This place does not cover:

Protection in TDM networks in general

H04J 3/14

Protection in optical ring networks

H04J 14/0287

Protection in packet ring networks, e.g. RPR

H04L 12/437

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

CW

Clockwise

CCW

Counter Clockwise

UPSR

Unidirectional Protection Switched Ring

BLSR

Bidirectional Line Switched Ring

{One of the channel pulses or the synchronisation pulse is also used for transmitting monitoring or supervisory signals}
Definition statement

This place covers:

Bit stealing for signalling, e.g. winking in PDH T1.

References
Informative references

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

LSB bit dropping for making bandwidth available for user payload

H04J 3/1688

Monitoring arrangements {(for SDH/SONET rings H04J 3/085)}
Definition statement

This place covers:

Protection Switching; Testing of TDM systems.

References
Limiting references

This place does not cover:

Monitoring or Protection Switching of TDM rings

H04J 3/085

Protection switching of SDH/SONET or OTN

H04J 2203/006

Informative references

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

Network management

H04L 41/00

in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted (H04J 3/17, H04J 3/24 take precedence)
Definition statement

This place covers:

Covering variable time slot allocation.

H04J 3/1605 fixed standard frame structures.

H04J 3/1682 statistical multiplexers, allocation changes per frame cycle

H04J 3/1694 distributed multiplexers, e.g. access multiplexer

Relationships with other classification places

For specific applications, e.g. video H04N 7/00; or physical medium, e.g. radio H04B 7/00, see more specialized classes

{Synchronous digital hierarchy [SDH] or SONET (H04J 3/1664 takes precedence for interactions with OTN)}
Definition statement

This place covers:

Refers to systems according to ITU recommendations G.707 - G.709 in the versions of 1990 (SDH/SONET)

Radio, satellite and microwave transmission according to the standards mentioned above.

Covers switches, nodes and Cross-connects and respective internal or proprietary formats

References
Limiting references

This place does not cover:

Interactions with OTN

H04J 3/1664

Informative references

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

SDH/SONET or OTN ring networks

H04J 3/085

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

SPE

Synchronous Payload Envelope

{carrying packets or ATM cells}
Definition statement

This place covers:

SPE carries ATM cells or payload data packets

Relationships with other classification places

H04J 2203/0082 Services, Interaction of SDH with non-ATM protocols

H04J 2203/0083 Support of the IP protocol

H04J 2203/0085 Support of Ethernet

References
Informative references

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

Stuffing, destuffing and desynchronization

H04J 3/076

SDH/SONET or OTN ring networks

H04J 3/085

Packet networks in general

H04L 12/00

Data networks and protocols

H04L 29/00

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

PoS

Packet over SONET

GFP

Generic Framing Procedure

SPE

Synchronous Payload Envelope

{Plesiochronous digital hierarchy [PDH]}
Definition statement

This place covers:

Covers switches, nodes and Cross-connects and respective internal or proprietary formats.

Also covers transport of packets via a plesiochronous network, e.g. "ATM over E1".

{Format building algorithm}
Definition statement

This place covers:

Time slot allocation according to rules, e.g. to evenly distributed slots to various users while minimizing the distance to ideal evenly distributed slot allocation for a single user.

References
Informative references

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

Splitting time slots to smaller entities or concatenating time slots to larger entities

H04J 3/1647

Time slot allocation according the instantaneous needs of the sources to be multiplexed

H04J 3/1682

{Format conversion, e.g. CEPT/US}
Definition statement

This place covers:

Format conversion of PDH frames of different standards, e.g. ETSI and ANSI

{Hierarchical systems}
Definition statement

This place covers:

DS0, DS1, DS3 or European PDH, PCM30/32, E1 to E4 according to ITU recommendation G.703. Covers the hardware structure of programmable TDM multiplexer, e.g. internal construction by bus, as described in ITU recommendation G.797.

References
Informative references

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

Electronic details of multiplexers or demultiplexers, e.g. multiplexing of bits or bytes

H04J 3/047

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

MULDEX

Multiplexer Demultiplexer

{Subrate or multislot multiplexing}
Definition statement

This place covers:

Variable allocation of elementary units like time slots, subslots or fragments. The allocation can be modified by splitting elementary units or by combining elementary units to units of larger bandwidth. The overall frame length remains constant.

{Optical Transport Network [OTN]}
Definition statement

This place covers:

Refers to systems according to ITU recommendation G.707 - G.709 in the versions of 2000.

Covers radio and microwave transmission according to the standards mentioned above.

Covers switches, nodes and Cross-connects and respective internal or proprietary formats.

References
Informative references

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

SDH/SONET or OTN ring networks

H04J 3/085

SDH/SONET as preceding technology to OTN

H04J 3/1611

Optical wavelength networks

H04J 14/02

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

SPE

Synchronous Payload Envelope

{carrying packets or ATM cells; (H04J 3/1664 takes precedence for payloads with different packet types)}
Special rules of classification

H04J 3/1664 takes precedence for payloads with different packet types

{interaction with SDH/SONET, e.g. carrying SDH/SONET frames, interfacing with SDH/SONET (H04J 3/1664 takes precedence)}
Special rules of classification

H04J 3/1664 takes precedence

{Time-division multiplex with pulse-position, pulse-interval, or pulse-width modulation}
References
Informative references

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

Fee space optical transmission with PPM or PWM

H04B 10/11

General PPM or PWM transmission

H04B 14/026

PPM or PWM modulation

H04L 25/4902

{Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers}
Definition statement

This place covers:

Allocation of bandwidth changes instantaneously, e.g. on demand or according to buffer fill.

References
Informative references

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

Distributed multiplexers, e.g. access multiplexers

H04J 3/1694

Packet multiplexing in general

H04J 3/247

Hybrid switching, e.g. moveable boundary between CS and PS

H04L 12/64

Voice over Date multiplexing for a single user

H04M 11/06

Statistical multiplexing for video or multimedia

H04N 7/24

Glossary of terms

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

CS

Circuit Switched service

PS

Packet Switched service

{the demands of the users being taken into account after redundancy removal, e.g. by predictive coding, by variable sampling (reducing bandwidth of signals in general H04B 1/66; in PCM-systems H04B 14/046; removal of redundancy in telegraph communication H03M 7/30)}
References
Limiting references

This place does not cover:

Reducing bandwidth of signals in general

H04B 1/66

Reducing bandwidth of signals in PCM-systems

H04B 14/046

Informative references

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

LSB dropping of bit stealing for transporting signalling

H04J 3/125

Digital Speech Interpolation (DSI)

H04J 3/177

Digital Circuit Multiplication (DCM)

H04J 3/177

{Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers (Passive Optical Networks H04Q 11/0062)}
References
Limiting references

This place does not cover:

Time slot allocation in Passive Optical Networks

H04Q 11/0062

Time slot allocation in wireless networks

H04W 72/04, H04B 7/2643

Informative references

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

Time slot allocation in computer networks via CATV or HFC

H04L 12/2801

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

CATV

CAble TeleVision

HFC

Hybrid Fibre Coax

in which the transmission channel allotted to a first user may be taken away and re-allotted to a second user if the first user becomes inactive, e.g. TASI {(speech analysis or identification G10L)}
References
Limiting references

This place does not cover:

DTX in wireless networks for power saving

H04W 76/28, H04W 52/12

Informative references

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

Distributed multiplexers, e.g. access multiplexers

H04J 3/1694

Speech analysis

G10L

Silence suppression in packet networks

H04L 2012/6494

Glossary of terms

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

DTX

Discontinuous Transmission

Comfort Noise

Introduction of noise signal to have a more comfortable audio signal during speech pauses

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

TASI

Time Assignment Speech Interpolation

DSI

Digital Speech Interpolation

{Digital speech interpolation, i.e. DSI}
References
Limiting references

This place does not cover:

PRMA (Packet Reservation Multiple Access),

H04L 12/00, H04W

{Speech activity or inactivity detectors (echo suppressors H04B 3/20)}
References
Informative references

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

VAD

G10L11/02

Instant speaker's algorithm in telephony systems

H04M 3/569

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

VAD

Voice Activity Detection

using frequency compression and subsequent expansion of the individual signals
References
Informative references

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

Frame conversion

H04J 3/1635

in which the sources have different rates or codes {(simultaneous speech and digital data or video transmission H04M 11/06; see provisional also H04J 3/16)}
Definition statement

This place covers:

Different symbol rates in the slots of the TDM frame.

Relationships with other classification places

Different or variable user rates or source rates are classified under H04J 3/1605 or sub-groups.

in which the allocation is indicated by an address {the different channels being transmitted sequentially} (H04J 3/17 takes precedence; in computers G06F 12/00, G06F 13/00 {code multiplex systems H04J 13/00; selecting techniques H04Q; relay systems H04B 7/14})
Special rules of classification

CDMA and Spread-spectrum communication, H04J 13/00 takes precedence.

{the frames being of variable length}
References
Limiting references

This place does not cover:

Variable length frames or packets to avoid errors

H04L 1/0078

{ATM or packet multiplexing}
Definition statement

This place covers:

Generic packet or ATM multiplexing

References
Informative references

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

Packet multiplexing in general

H04L 12/00

in which the information and the address are simultaneously transmitted
Definition statement

This place covers:

Time frequency encoded transmission. The combination of time and frequency is determined by the receiver address and the transmitted information.

Transmission of address by Pulse Position Modulation (PPM).

Random sampling of analog sources

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

RADA

Random Access Discrete Address

Combined time-division and frequency-division multiplex systems (H04J 13/00 takes precedence {; data transmission H04L 5/26; telemetry G08C 15/00})
References
Limiting references

This place does not cover:

Time and Frequency allocation of OFDM systems

H04L 5/00

Informative references

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

Allocation of time/frequency in radio systems

H04B 7/2615

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

OFDM

Orthogonal Frequency Division Multiplexing

{Transmultiplexing}
Definition statement

This place covers:

Translation of TDM into FDM and vice versa.

References
Informative references

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

Group demodulation

H04J 1/05

Satellite systems

H04B 7/15

Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels
Definition statement

This place covers:

Simultaneous transmission of analog and digital, e.g. by overmodulation

References
Informative references

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

FAW having a special amplitude

H04J 3/0614

Multiple use of the transmission path the signals being represented by different amplitude or polarities, e.g. quadriplex

H04L 5/04

Synchronization signal having a special amplitude

H04L 7/06

Glossary of terms

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

FAW

Frame Alignment Word of a TDM frame

Multiplex systems in which each channel is represented by a different type of modulation of the carrier
References
Limiting references

This place does not cover:

Modification of modulation constellation

H04L 27/3483

Orthogonal multiplex systems, {e.g. using WALSH codes} (H04J 13/00 takes precedence)
Definition statement

This place covers:

Orthogonal multiplex systems at the physical layer, techniques relating to problems arising from the multiplexing of users / base stations. Aspects that are covered include

cell search, i.e. how a mobile phone finds the identity of base stations;

interference handling and cancellation, at the transmitter, the receiver or both, especially

subtractive interference cancellation

intercell interference cancellation at the physical layer.

Examples of orthogonal multiplexing techniques are OFDMA [Orthogonal Frequency Division Multiple Access ], SC-FDMA [ Single Carrier Frequency Division Multiple Access ].

Examples of systems using orthogonal multiplexing are LTE [ Long Term Evolution ], LTE-advanced.

Relationships with other classification places

Code multiplexing techniques, orthogonal or not, are classified in H04J 13/00 if the focus is on the code multiplexing aspects and in H04B 1/69 if the focus is on the implementation of the spread-spectrum technique (e.g. details of how the signals are physically transmitted, received and processed).

References
Limiting references

This place does not cover:

Narrowband interference reduction

H04B 1/1036

Direct sequence spread spectrum

H04B 1/7097

Frequency Hopping

H04B 1/713

Spatial processing techniques

H04B 7/02

Allocation of channels of OFDM systems

H04L 5/00

Details of Linear Filters and Decision Feedback Equalisers

H04L 25/03006

Sequence estimation techniques, including multi user sequence estimation

H04L 25/03178

Correlative coding in synchronous or start-stop systems

H04L 25/497

OFDM modulation techniques

H04L 27/2601

OFDM frequency synchronisation techniques

H04L 27/2655

Power management

H04W 52/00

Local resource allocation of wireless systems

H04W 72/00

Informative references

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

Cell search in CDMA systems

H04B 1/7083

Interference aspects in CDMA systems

H04B 1/7097

Broadcast communication

H04H

Modulated-carrier systems

H04L 27/00

Telephonic Communication

H04M

Discovery of network devices for network data management

H04W 8/005

Processing access restriction or access information

H04W 48/16

Special rules of classification

Additional information is classified with the corresponding CPC codes. Classification of additional information is compulsory.

Code division multiplex systems (for frequency hopping H04B 1/713)
Definition statement

This place covers:

Code division multiplexing techniques which are related to the division of the communication medium according to codes.

Aspects that are covered include types of codes, generation of codes and allocation of codes to channels.

Relationships with other classification places

With regard to spread-spectrum techniques, the borderline between H04J 13/00 and H04B 1/69 should be determined based on whether the features relevant for classification are focused on the code multiplexing aspects or the implementation of the spread-spectrum technique (e.g. details of how the signals are physically transmitted, received and processed).

Documents classified in H04J 13/00 containing aspects of spectral spreading of interest for search, may also be classified in group H04B 1/69.

With regard to systems that use frequency hopping as a means to divide the communication medium, it has been agreed that that frequency hopping is excluded from H04J 13/00 even if it is used within the context of multiple access. Because the concepts dealt with in H04J 13/00 do not have relevance for FH-CDMA even though frequency hopping can be used for CDMA (i.e. FH-CDMA), this subject-matter is exclusively classified in H04B 1/713.

References
Limiting references

This place does not cover:

MC-CDMA

H04J 11/00

Details of the signal processing which are covered by systems that use frequency hopping as a means to divide the communication medium

H04B 1/713

Informative references

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

Implementation of the spread-spectrum technique

H04B 1/69

Special rules of classification

Additional information is classified with the corresponding CPC codes. Classification of additional information is compulsory.

When classifying in this group, any aspect of spread spectrum techniques not specific to frequency hopping, and which is considered to represent information of interest for search, may also be classified in group H04B 1/69.

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

CDMA

Code Division Multiple Access

MC-CDMA

Multi-carrier Code Division Multiple Access

OVSF

Orthogonal variable spreading factor

Optical multiplex systems (optical coupling, mixing or splitting, per se G02B)
References
Limiting references

This place does not cover:

Electrical multiplex systems

H04J 1/00, H04J 3/00, H04J 4/00, H04J 7/00, H04J 9/00, H04J 11/00, H04J 13/00

Optical devices per se

G02B, G02F

Laser, amplifier per se

H01S 3/00, H01S 5/00

Optical switching per se

H04Q 11/0001

Informative references

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

Electrical Time-division multiplex systems

H04J 3/00

Optical coupling devices, e.g. optical fibres, optical gratings

G02B 6/00

Optical integrated multiplexers and demultiplexers devices, e.g. AWG, optical interferometers

G02B 6/12007

Optical coupling with wavelength selective means

G02B 6/293

Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics

G02F 1/00

Demodulating light; Transferring the modulation of modulated light; Frequency-changing of light

G02F 2/00

Optical Transmission

H04B 10/00

{Coherencemultiplexing}
Definition statement

This place covers:

Coherence Multiplex for data transmission

References
Limiting references

This place does not cover:

Sensor systems

G08C 15/00.

Coherent homodyne or heterodyne systems

H04B 10/00.

{Optical Code Multiplex}
Definition statement

This place covers:

Optical code division multiplexing systems

References
Limiting references

This place does not cover:

Electrical code division multiplexing

H04J 13/00

{Orthogonal Optical Code Multiplex}
Definition statement

This place covers:

Orthogonal optical code division multiplexing systems

References
Limiting references

This place does not cover:

Electrical orthogonal multiplexing systems

H04J 11/00

Wavelength-division multiplex systems
Definition statement

This place covers:

Wavelength division multiplex systems, in general, as well as WDM equipment terminal, e.g. WDM sources and WDM receivers.

{Add-and-drop multiplexing}
Definition statement

This place covers:

Optical add and drop multiplexing systems for WDM systems

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

OADM

Optical Add and Drop multiplexing

{Arrangements therefor}
Definition statement

This place covers:

Internal arrangements details of OADM for WDM systems

{Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping}
Definition statement

This place covers:

OADM arrangements that first broadcast the input signals, typically implemented with an optical splitter at the input of the OADM, and then select among the signals before they are output.

{Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping}
Definition statement

This place covers:

OADM arrangements that first selects among the input signals at the input of the OADM and then combines the signals before they are output, typically implemented with an optical combiner at the output of the OADM

{Express channels arrangements}
Definition statement

This place covers:

OADM arrangements that allow express channels to be directly brought from the input of the OADM to the input of the OADM, typically for minimising the insertion losses incurred by those channels.

{Interleaved arrangements}
Definition statement

This place covers:

OADM arrangements that include multiplexing and/or demultiplexing using interleavers, e.g. processing the odd and even WDM channels separately.

{Multi-stage arrangements, e.g. by cascading multiplexers or demultiplexers}
Definition statement

This place covers:

OADM arrangements where multiplexing and/or demultiplexing are implemented by a cascading of multiple stages.

{Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]}
Definition statement

This place covers:

Reconfigurable or tuneable OADM arrangements where the optical channels that are actually added or dropped can be changed during the operation of the OADM.

{using optical switches or wavelength selective switches [WSS]}
Definition statement

This place covers:

OADM arrangements where the reconfiguration is accomplish by using optical switches or wavelength selective switches.

{Groups of channels or wave bands arrangements}
Definition statement

This place covers:

OADM arrangements where the groups of channel or wave bands are processed together.

{Architecture aspects}
Definition statement

This place covers:

Architectures aspects of OADM in WDM systems in terms of how they relate to the WDM networks where they are in.

{Bidirectional architectures}
Definition statement

This place covers:

OADM architectures that are prepared to be used in bidirectional networks, meaning that the ports of the OADM are input and output ports at the same time and consequently the fibres connected at those ports transmit optical WDM signals in both directions.

{Multi-degree architectures, e.g. having a connection degree greater than two}
Definition statement

This place covers:

OADM architectures that have more than one input and/or more than one output (the degree of a node in a network is defined as the number of input plus output ports of such node).

{Modular or upgradable architectures}
Definition statement

This place covers:

OADM architectures constituted by modules that are repeated to increase the capabilities of the node, typically to upgrade the number of channels that can be added or dropped.

{For interconnection of WDM optical networks}
Definition statement

This place covers:

OADM architectures that are used for interconnecting different WDM networks, e.g. interconnected rings.

{Power control, e.g. to keep the total optical power constant}
Definition statement

This place covers:

Power control in a WDM system. Subject covers equalizing power of the different wavelengths, e.g. to keep the total optical power constant or to control the optical power per channel in a WDM system so as to maintain constant a particular performance related characteristic. Also covers control of power transients due to add and drop wavelengths, wavelength switching, e.g. caused by protection switching, or wavelength re-allocation.

{Conversion to or from optical TDM}
Definition statement

This place covers:

Conversion from WDM signals into OTDM or vice versa to facilitate the multiplexing or demultiplexing of optical channels.

{Irregular wavelength spacing, e.g. to accommodate interference to all wavelengths}
Definition statement

This place covers:

WDM irregular allocation plans, typically to overcome non-linear effects or to accommodate optical channels of different bit rate. This group covers also regular schemes in which carriers remain unused, e.g. to avoid interference.

{Fixed carrier allocation, e.g. according to service}
Definition statement

This place covers:

Fixed carrier allocation according to service or for a particular use, e.g. dummy channels to keep the power constant.

{Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation}
Definition statement

This place covers:

Wavelength allocation and assignment for WDM and the application of management to WDM networks. It covers routing, e.g. use of tables for wavelength routing, and wavelength allocation algorithms, dynamic allocation of wavelengths and use of a dedicated wavelength for OAM, e.g. optical service channel, and pilot tones for OAM. It also covers optical channel and optical multiplex identification and labelling, optical signalling in WDM networks and WDM networks restoration (in network restoration, as opposed to network protection, all available resources in the network are considered when looking for a new path to be established).

References
Informative references

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

Monitoring of optical transmission parameters in general

H04B 10/07

{WDM optical network architectures}
Definition statement

This place covers:

WDM optical networks defined by the type of interconnection between WDM nodes

{WDM point-to-point architectures}
Definition statement

This place covers:

WDM systems using a point to point network connection between two WDM nodes.

{WDM bus architectures}
Definition statement

This place covers:

Multiple WDM nodes connected to two adjacent WDM nodes, except for the two nodes constituting the bus head-end, and using a common optical fibre supporting a WDM signal.

{WDM tree architectures}
Definition statement

This place covers:

A common WDM node is connected via multiple fibres to a multiplicity of other WDM nodes. It also covers the case of star networks, where multiple WDM nodes are interconnected to other WDM nodes using multiple optical fibres each supporting a WDM signal, typically using a star coupler.

{WDM ring architectures}
Definition statement

This place covers:

WDM architecture where all WDM nodes are connected to two adjacent nodes using a common optical fibre supporting a WDM signal.

{WDM mesh architectures}
Definition statement

This place covers:

WDM architecture where each WDM node is typically connected to every other node using multiple optical fibres, each supporting a WDM signal.

{WDM hierarchical architectures}
Definition statement

This place covers:

WDM networks where different layers of interconnection between the different WDM nodes. Each layer can be of the same type of network architecture or of different types.

{Protection in WDM systems}
Definition statement

This place covers:

Protection aspects in WDM systems, typically switching from a protected resource to a protection resource when a failure occurs. As opposed to network restoration, network protection considers only resources that have a priori been labelled as protection resources.

{Optical multiplex section protection}
Definition statement

This place covers:

Protection is carried out at the level of the whole WDM multiplex.

{Dedicated protection at the optical multiplex section (1+1)}
Definition statement

This place covers:

A WDM multiplex is duplicated and transmitted simultaneously using two WDM multiplex signals. The selection of which WDM signal to receive is done at the WDM level and at the receiver end, typically without considering any specific signalling from the transmitter end.

{Shared protection at the optical multiplex section (1:1, n:m)}
Definition statement

This place covers:

A WDM multiplex is transmitted using working resources and in case that a failure occurs, then the WDM multiplex is switched to the protection resource, typically shared by different nodes. At the receiver end the WDM signal coming via the protection resource is selected, typically this mechanism involves switching or bridging at both transmitter and receiver ends at the WDM multiplex level any requires some signalling between transmitter and receiver ends. The protection WDM multiplex can be used by low priority traffic until protection takes place.

{Dedicated protection at the optical channel (1+1)}
Definition statement

This place covers:

A WDM channel is duplicated and transmitted simultaneously using two WDM channels. The selection of which WDM channel to receive is done at the channel level and at the receiver end, typically without considering any specific messaging from the transmitter end.

{Shared protection at the optical channel (1:1, n:m)}
Definition statement

This place covers:

WDM channels are transmitted using working resources and in case that a failure occurs, then the WDM channel is switched to the protection resource, typically shared by different WDM channels. At the receiver end the WDM signal coming via the protection resource is selected, typically this mechanism involves switching or bridging at both transmitter and receiver ends at the channel level any requires some signalling between transmitter and receiver ends. The protection channels can be used by low priority traffic until protection takes place.

{Optical equipment protection}
Definition statement

This place covers:

WDM is duplicated to protect the equipment against internal faults.

{with sub-carrier multiplexing [SCM]}
Definition statement

This place covers:

Sub-carrier multiplexing system, e.g. for CATV.

Mode multiplex systems
Definition statement

This place covers:

Systems where the different modes of transmission in the optical fibres are used to multiplex different channels of information.

Polarisation multiplex systems
Definition statement

This place covers:

System where the different states of polarisation of the light are used to multiplex different channels of information.

Time-division multiplex systems
Definition statement

This place covers:

Systems using optical time division multiplexing (OTDM). Time multiplexing of optical pulses.

References
Limiting references

This place does not cover:

Optical synchronisation

H04L 7/0075

{Add and drop multiplexing}
Definition statement

This place covers:

Optical add and drop multiplexing systems for OTDM systems.

{Medium access (H04J 3/16 takes precedence)}
Definition statement

This place covers:

Medium access in OTDM systems.

Special rules of classification

H04J 3/16 takes precedence