Electronic Circuit Terminology (1)

ADM Add Drop Multiplexer OADM

Broadband management using time-slot interchange, which allows different VCs between two STM-N signals to be interconnected, and has various G.703- specified interface signals (PDH) without tapping and terminating the entire signal Or any branch in the STM-N signal (SDH) access STM-M (M> N) .

AON Active Optical Network active optical network

The active optical network belongs to the point-to-multipoint optical communication system and consists of an ONU , an optical remote terminal OLT, and an optical fiber transmission line.

APON ATM Passive Optical Network ATM passive optical network

An ideal long-term solution that combines ATM multi-service multi-bit rate support capabilities and passive optical network transparent broadband transmission capabilities represents the latest development direction of broadband access technologies for the 21st century.

ADSL Asymmetric Digital Subscriber Line Asymmetric Digital Subscriber Line

Asymmetric Digital Subscriber Line System ADSL is a digital subscriber line DSL system using discrete multi-tone DMT line codes.

AA Adaptive Antenna Adaptive Antenna

An antenna provides a beam that directly points to a target, such as an antenna of a mobile phone, and can automatically adjust power and other factors along with the target movement, and is also called SMART ANTENNA .

ADPCM Adaptive Differential Pulse Code Modulation adaptive pulse code modulation
An encoding technique that reduces the number of analog sampling bits from 8 bits to 3 to 4 bits to complete the compression of the transmission signal. ITU-T recommends that G.721 defines an algorithm for 32 -bit ADPCM ( 8000 samples per second, 4 bits per sampling), its transmission capacity is doubled compared to conventional PCM coding.

ADFE Automatic Decree Feedback Equalizer Adaptive Decision Feedback Equalizer

An equalizer technique that uses the signal after the decision as the input signal for the backward tap to eliminate the effect of noise on the backward tap signal.

AMI Alternate Mark Inversion signal alternately reversed code

A coding technique commonly used in digital transmission, logic 0 is represented by an empty level, and logic 1 is represented by alternately inverted positive and negative voltages.

AON All Optical Net All Optical Network

That is, the signal path between the network and the end user nodes still maintains the form of light, that is, the end-to-end full optical path, and there is no photoelectric converter in the middle. In this way, the flow of optical signals within the network is free from obstacles of photoelectric conversion, and the information transfer process does not need to face the difficulty that the electronic devices cannot process the information rate.

AOWC All Optical Wave Converter All Optical Wavelength Converter

It refers to a device that directly converts information from one wavelength of light to another without undergoing electrical domain processing.

ASK Amplitude Shift Keying Amplitude Keying

A keying technology, corresponding to a binary modulation signal, carries a signal switching between on and off, also known as ON-OFF keying.

ATPC Automatic Transfer Power Control Automatic Transmission Power Control

The main point of the technology is that the output power of the microwave transmitter changes automatically in the ATPC control range by following the change in the receiving level of the receiving means. Its advantages are that it can reduce the interference to adjacent systems, reduce the attenuation problem, reduce the DC power consumption, improve the residual error characteristics, and increase the output power by 2dB under fading conditions.

AWF All Wave Fiber Full Wave Fiber

Eliminating the water peak fiber of 1383nm, so that the 1350 - 1450nm wavelength band 120 can add a plurality of new wavelengths (interval 100GHZ). For urban access network users is very beneficial.

AU Administrative Unit management unit

Provides the information structure of the adaptation function between higher-order channel layers and multiplex section layers .

AUG Administrative Unit Group snap-in group

It consists of one or more management units that determine the location of a fixed location in the STM-N payload.

APD Avalanche Diode Avalanche Photodiode

High-sensitivity detectors that multiply the photocurrent by the avalanche multiplication effect.

BA Booster(power) Amplifier Optical Power Amplifier

It can compensate for the loss of the optical multiplexer and improve the fiber amplifier power.

BACKGROUND BBER Background Block Error Ratio block error ratio

For a determined test time, the number of BBEs that occur at the time available is compared to the total number of blocks that deducted the unavailable time and all blocks during the SES .

BR Basic Rate Access Basic Rate Access

ITU-T is defined as an interface rate of narrowband ISDN , also called 2B+D , B- channel 64K is a bearer channel, and D- channel 16K is a digital signaling channel.

Bluetooth Bluetooth

(a type of wireless LAN) standard jointly developed by equipment manufacturers with a coverage area of 10M , a working frequency band of 2.4G , and a transmission rate of approximately 1M .

C Band C wave band

That is, the operating wavelength is in the range of 1525 to 1560 nm and the bandwidth is about 35 nm .

Chirp 啁啾

When the single-longitudinal mode laser is operated in direct modulation, the change of the injection current will cause the change of the carrier density, which will change the index of the refractive index of the active region. As a result, the optical path length of the laser cavity changes accordingly. Causes the oscillation wavelength to drift over time. Generally need to use external modulation technology to overcome.

C Container C container

The information structure of traffic signals loaded at various rates is denoted as Cn(11,12,2,3,4), and our country only deals with C-12 , C-3 and C-4 . The basic function of the container is to complete the adaptation, ie the code speed adjustment.

CSMA/CD Carrier Sense Multiple Access with Collision Detection Carrier Sense Multiple Access / Collision Detection Protocol

A multiple access technology applied to wired LANs.

CSMA/CA Carrier Sense Multiple Access with Collision Avoidance Carrier Sense Multiple Access / Avoid Collision Protocol

Since wireless products do not easily detect whether there is a channel conflict, 802.11 defines a new protocol, namely ( CSMA/CA ). On the one hand, carrier sensing - to see if the channel is idle; on the other hand, to avoid collisions - when the channel is not idle, wait for a random time until there is a new idle channel before sending priority, so that the probability of signal collisions Minimized. Not only that, in order to make the system more stable, 802.11 also provides CSMA/CA with acknowledgement frame ACK . In the event of other noise interference, or due to unsuccessful listening, signal collisions may occur, and this kind of ACK working at the MAC layer can provide fast recovery capability at this time.

CNR Carrier to Noise Ratio CNR

The ratio of the carrier level to the noise level before any modulation has occurred. Also for C/N .

CP Cross polarization cross polarization

Two antenna systems use the same frequency but one uses horizontal polarization and the other uses vertical polarization, improving spectral efficiency.

The DCF Dispersion Compensating Fiber dispersion compensating single-mode fiber is a large negative-dispersion fiber . This type of fiber is a new type of fiber designed for the 1310 nm that has been laid. A dispersion compensating fiber is added to the G.652 fiber to perform dispersion compensation so as to ensure that the total dispersion of the entire fiber line is zero.

DFF Dispersion-flattened Fiber Dispersion Flat Fiber

Dispersion from a wide band of 1.3um to 1.55um, can be done is very low, almost zero dispersion fiber.

DR Diversity Receiver diversity reception is a measure to reduce the influence caused by fading by selecting or synthesizing two or more receiver outputs with less correlation (that is, quality degradation at the same time). Specifically, it can be divided into different ways such as spatial diversity, frequency diversity, polarization diversity, and angle diversity.

DPT Dynamic Packet Transport Dynamic Packet Transport Technology

This is a brand-new transmission method that Cisco Company proposes - IP optimizes the optical transmission technology. This technology provides the high efficiency of bandwidth usage, the richness of service categories, and the network's advanced self-healing capabilities.

ODM Optical Division ltiplexer optical demultiplexer

Split multiple wavelengths into each fiber to separate the channels.

DSF Dispersion-Shifted Fiber dispersion shifted fiber

It is called the best single-mode fiber with 1550nm performance. By designing the refractive index profile of the fiber, this fiber shifts the zero dispersion to the 1550nm window, which matches the minimum rate reduction window of the fiber, making it possible to transmit at ultra-high speed and long distance.

Dynamic DTM Dynamic Synchronous Transfer Mode Synchronous Transfer Mode

A new technology based on high-speed circuit switching and dynamic time slot allocation. As the second-tier switching/transport technology, DTM has stronger bandwidth management capabilities and adapts to the continuous expansion of optical fiber bandwidth.

Dense Wavelength Division Multiplexing dense DWDM Wavelength Division Multiplexing

Multiple light waves of the same low-loss window are multiplexed with respect to optical wavelength multiplexed coarse wavelength division multiplexing with different low-loss windows.

DLC Digital loop carrier digital loop carrier

Active optical network for areas where users are dense

DXC Digital cross connect equipment Digital Cross Connector

Devices with one or more quasi-synchronous digital hierarchy ( G.702 ) or the same digital hierarchy (G.707) signal ports that can be controllably connected and reconnected between any port signal rate (and its sub-rates).

EA Electricity Absorb Modulation Electroabsorption Modulator

The loss modulator operates at the wavelength of the absorption region of the modulator material. When the modulator is not biased, the wavelength is at the on state. As the bias voltage on the modulator increases, the absorption coefficient at the original wavelength becomes larger, the modulator becomes off-state, and the on-off state of the modulator is light intensity modulation.

EB Error Block Block Error

The bit error performance for high bit rate channels in an SDH network is " block " , which is the set of consecutive bits transmitted in the channel. When an error occurs in any bit in the block, the block is said to be a block error.

ECC Embedded Control Channel embedded control channel

The embedded control channel that passes network management information, whose physical channel is DCC , adopts the seven-layer protocol stack required by ITU-T G.784 .

EDFA Erbium-doped Fiber Amplifier Erbium-doped fiber amplifiers used in the production of fiber, using a special process, in the fiber core layer doped with a very small concentration of antimony ions to produce the corresponding erbium-doped fiber. The doped ions in the optical fiber are excited by the pump light and then transition to the metastable highly excited state. Under the induction of the signal light, stimulated radiation is generated to form a coherent amplification of the signal light. The EDFA works in the 1550 window. The commercial EDFA has low noise, good gain curve, large amplifier bandwidth, compatibility with wavelength division multiplexing ( WDM ) systems, high pumping efficiency, stable operation performance, mature technology, and is favored in modern long-distance high-speed optical communication systems. At present, " erbium-doped fiber amplifier ( EDFA ) + dense wavelength division multiplexing ( DWDM ) + non-zero dispersion fiber ( NZDF ) + photonic integration ( PIC ) " is becoming the main technical direction of long-distance high-speed optical fiber communication lines in the world.

EDFL Erbium-doped Fiber Laser Ytterbium-doped fiber laser

A kind of fiber laser whose emission light wavelength falls in the 1550nm window is composed of an erbium-doped fiber and an optical pump and other related optical circuit components such as a wavelength selector, a polarization controller, and an input/output coupler, etc., having a low threshold, and Compatibility with fiber optic communication systems and other advantages. In particular, the tunable ring-shaped EDFL has a large tuning range and high output power, and has become the mainstream of tunable lasers. The main types thereof are polished tunable WDM device type, DFB type, fiber birefringence tuning type, and piezoelectric tunable optical fiber FP etalon. Type and so on. EDFL is suitable for large-capacity long-distance optical fiber communications and WDM systems.

ES Errored Second errored second

When a 1 second error having one or more blocks, it is called the second errored second.

ESR Errored Second Ratio errored second ratio

The ratio of the number of ESs that occur in available time to the total number of seconds for a given test time.

FEC Forward Error Correction Forward Error Correction ago

It is a kind of data encoding technology. The error detection during transmission is verified by the receiver. If there is any error, the sender is notified of the error. It allows recoding from low bit error coded data to form a list of error-free data streams.

FWM Four-wave Mixing four-wave mixing

Four-Wave Mixing (FWM), also known as four-phonon mixing , occurs when two or three light waves of different wavelengths interact to cause new light waves called side-mixed products or sidebands to occur at other wavelengths. These lights affect normal communications. This nonlinear optical effect is called four-wave mixing.

FDMA Frequency Division Multiple Access Frequency Division Multiple Access

The total frequency band of the communication system is divided into several equally spaced channels (or channels), and the channels are re-allocated to different users. These channels do not overlap.

FTTB Fiber to the Building Fiber to the Building

ONU is placed in the building

FTTC Fiber to the Curb fiber to the curb

ONU is on the roadside

FTTH Fiber to the Home FTTH

ONU is at home

FA Frequency agility Frequency Agility

Refers to the ability of the launch system to automatically frequency hopping to adapt to the environment based on changes in external conditions.

CSMF Common Single Mode Fiber single mode fiber

The single-mode fiber that satisfies the requirements of ITU-T G652 is often referred to as a non-dispersion-shifted fiber with zero dispersion at 1 . 3um low loss window region, 1310nm operating wavelength (loss is 0. 36dB / km). The vast majority of fiber optic cables already installed in China are such optical fibers. With the successful advancement of fiber optic cable industry and semiconductor laser technology, the operating wavelength of optical fiber lines can be shifted to a lower loss ( 0.22dB / km ) 1550nm fiber window.

DSF Dispersion-Shifted Fiber DSF

The single-mode fiber that meets the requirements of ITU-TG 653 has its zero-dispersion wavelength shifted to a very low loss of 1550 nm . This type of optical fiber has been promoted and used in some countries, especially in Japan, and it has also been adopted on the Beijing-Kowloon-Kinmen Line. AT & T in the United States discovered the severe deficiency of DSF at early stage. In the low-dispersion region near 1550 nm , there are harmful nonlinear effects such as four-wave mixing, which hinders the application of fiber amplifiers in the 1550 nm window. Therefore, it has not been widely used.

GE Gigabit Ethernet Gigabit Ethernet Technology

The Gigabit Ethernet standard was formally launched in October 1997 with a maximum transmission rate of 1Gbps and is backward compatible with Ethernet technology and Fast Ethernet technology.

GIF Graded Index Fiber Gradient Multimode Fiber

The light propagates in a sinusoidal shape with a bandwidth of up to 1-2 GHz.km. It is mostly used in LANs that are not very fast .

GS-EDFA Gain Shifted Erbium-doped Fiber Amplifier Gain Translation Erbium Doped Fiber Amplifier

By controlling the degree of inversion of the population of the erbium-doped fiber, the band of 1570 to 1600 nm is amplified, and it can be combined with an ordinary EDFA to obtain a broadband amplifier having a bandwidth of about 80 nm .

GVD Group Velocity Dispersion GVD

In high-speed and high-capacity optical fiber communication, the shape of the optical pulse envelope changes due to the non-linearity of the optical fiber medium. This change in optical signal reception is called group velocity dispersion, and the group velocity dispersion causes transmission waveforms. Broadening. G.654 cut-off wavelength shift single-mode fiber This kind of fiber design considerations are to reduce the 1550nm rate reduction, the zero dispersion point is at or near 1310nm , and therefore the dispersion at 1550nm is higher and can be greater than 18ps/(nm.km) . The use of a single longitudinal mode laser can eliminate the effects of dispersion. It is mainly used for submarine communication optical fiber communication with a long regeneration section distance.

HPF High Pass Filter highpass filter

A filter that allows radio waves that exceed a certain frequency to pass through with little attenuation, while other radio waves below this frequency band are severely attenuated.

HRDS Hypothetical Reference Digital Section Hypothetical Reference Section

That is, a degree model with a certain length and performance specification can be used as a reference model for index allocation. For the SDH digital segment, there are 420km , 280km and 50km lengths.

IDLC Integrated DLC Integrated Digital Loop Carrier

Broadband active optical networks, ie, Integrated Digital Loop Carrier System (IDLC), use SDH or PDH as the transmission platform, providing PSTN, ISDN, B-ISDN, DDN, LANE, Internet, and digital video services to the centralized subscriber area. Access is also an ideal way for broadband integrated access and has great potential for development

IDEN Integrated Digital Enhanced Networks Digital trunking scheduling private network

The iDEN system was introduced in Los Angeles in the United States in 1994. It is a digital trunking system proposed by Motorola and operates in the 800 MHz frequency range. After approximately three years of promotion, it has been put into commercial applications in North America, South America and 13 Asian countries. Its main feature is that it can be compatible with GSM , suitable for large networks and more suitable for PAMR applications.

IEEE 802.3

CSMA/CD LAN, Ethernet standard.

IEEE 802.11

The wireless LAN technology standard promulgated in 1997 by the wireless LAN standard, the IEEE 802.11 specification defines three physical layer (PHY) choices: Infrared, Direct Sequence Spread Spectrum ( DSSS ), and Frequency Hopping Spread Spectrum ( FHSS ). Since the wireless LAN transmission medium (microwave, infrared) is very different from the wired medium, there are some new technical problems objectively. For this reason, the IEEE 802.11 protocol specifies some crucial technical mechanisms such as the CSMA/CA protocol, RTS/ CTS agreement and so on. August 99, 802.11 standard has been further improved and revised, and also adds two new content 802.11a and 802.11b, which extends the provisions of the standard physical layer and MAC layer.

Jitter jitter

One of the important transmission characteristics of the SDH optical transmission network is defined as the short-term deviation of each effective instant of the digital signal from the theoretically specified time position.
K Band K -band, 10G -12G , for satellite communications.

Ku Band Ku Band, 12G -14G for multi-satellite communication

LA Line Amplifier Optical line amplifier

An optical amplifier that compensates for fiber loss on the trunk line.

LEAF Large Effective Area Fiber large effective area optical fiber

Single-mode, non-zero dispersion-shifted fiber operating in a 1550nm window; Compared with a standard non-zero dispersion-shifted fiber, it has a larger " effective area " and its effective area is increased to 72um2 or more, resulting in a large power tolerance. The use of high output power erbium doped fiber amplifiers, ie EDFA and DWDM technology networks.