Electronic Circuit Terminology (1)

LANE LAN Emulation LAN Emulation

When ATM exchange is exchanged with Ethernet, it needs an emulation process for ATM cells.

LMDS Local Multipoint Distribution Service Local Multipoint Distribution Service

A very popular broadband wireless access system that utilizes spread spectrum and polarization techniques. The base station covers approximately 2-10 KM and can provide up to 4.8G of bandwidth. Suitable for wireless access with user-intensive areas.

LOF Loss of Frame Frame Loss

When the frame out -of- synchronization state lasts for 3ms , the SDH device should enter the frame-losing state; and when the STM-N signal is continuously in the fixed-frame state for at least 1ms , the SDH device should exit the frame-losing state.

LOS Loss of Signal Loss of Optical Signal

MI Modulation Instability modulation instability

Modulation Instability A continuous-wave ( CW ) signal or a pulse that momentarily breaks them into a modulated shape. A quasi-monochromatic signal spontaneously produces two symmetrical frequency sidebands. This phenomenon may be observed in areas above the zero dispersion wavelength.

MLCM Multi-Level Coded Modulation Multilevel Code Modulation

A complex coding and modulation method can be regarded as a deletion-type trellis-encoding 64QAM method. Its design idea is the same as that of TCM, that is, the redundancy generated by the error correction code is introduced between those most error-prone symbols to make maximum use of coding redundancy.

MMF Multi Mode Fiber multimode fiber

Two or more modes of fiber can be propagated at the wavelengths considered.

MMDS Multichannel Multipoint Distribution Service Multi-channel Multipoint Distribution Service
Often referred to as wireless cable, wireless systems are commonly used to transmit image services.

MVDS Multipoint Video Distribution Service multipoint video distribution business

UK development of a wireless local loop technology, running 40.5G to 42.5G frequency, and LMDS is very similar, but mainly used in video on demand service.

Ary MQAM Quadrature Amplitude Modulation Quadrature Amplitude Modulation

Multi-ary quadrature amplitude modulation is a carrier control method widely used in medium- and large-capacity digital microwave communication systems. This method has a very high spectrum efficiency. When the modulation system number is high, the distribution of signal vector sets is also reasonable, and it is also more convenient to implement. Currently, 64QAM and 128QAM, which are widely used in large-capacity digital microwave communication systems such as SDH digital microwave and LMDS , belong to this type of modulation.

MSOH Multiplex Section Overhead multiplex section overhead

Responsible for managing the multiplex section and can only be accessed at the terminal equipment.

MSP Multiplexer Section Protection MSP

A protection method of SDH optical fiber communication, the amount of protected traffic is based on the multiplex section, and whether or not the handover is determined by the quality of the multiplex section signal between each node. When the multiplex section fails, the service signal of the multiplex section between the entire nodes turns to the protection section.

MZ Mach-Zehnder Mach-Zehnder modulator The modulator divides the input light into two equal signals and enters the two optical branches of the modulator, respectively. The material used for these two optical branches is an electro-optical material whose refractive index varies with the size of the externally applied electrical signal. Since the refractive index change of the optical branch will lead to the change of the signal phase, when the outputs of the two branch signal modulators are combined again, the synthesized optical signal will be an interference signal with a change in the magnitude and intensity, which is equivalent to the electrical signal. The change is converted into a change in the optical signal, achieving modulation of the light intensity.

NA Numerical Aperture Numerical Aperture

Indicates the ability of the optical fiber to receive and transmit light. The greater the NA , the stronger the optical fiber's ability to receive light and the higher the coupling efficiency from the light source to the optical fiber.

NC Network Connection Network Connection

A network connection consists of a cascade of subnetwork connections and / or link connections and can be seen as an abstract representation of this complex entity. It can transparently communicate end-to-end information on the layer network, delimited by the terminal connection point ( TCP ).

NEL Network Element Layer element layer

The most basic management is responsible for the management of configuration, failure, and performance of a single network element.

NML Network Management Layer Network Management

Manage, monitor, and control areas under its jurisdiction to coordinate different manufacturers' network elements.

NE Network Element Network Unit

Constitute the basic unit of the network.

NZDSF Non Zero Dispersion Shifted Fiber NZDSF

The single-mode fiber that satisfies the requirements of ITU-TG 655 is a dispersion-shifted fiber, but the dispersion is not zero at 1550 nm (corresponding to a dispersion value of 0.1-6.0 ps / nm.km in the wavelength range of 1530-1565 nm according to ITU-TG 655 ). To balance four-wave mixing and other nonlinear effects. Commercial fiber optics such as AT&T TrueWave fiber, Corning SMF-LS fiber (its zero-dispersion wavelength is typically 1567.5 nm , zero dispersion is typically 0.07 ps / nm2.km ), and Corning 's LEAF fiber. China's " big reality " optical fiber and so on.

NNI Network Node Interface network node interface

It can be a simple node with only multiplexing functions, or it can be a complex node with the functions of transmission, multiplexing, cross connection, and switching.

OADM Optical Add Drop Multiplexe Optical Multiplexer

Its function is to select the optical signal from the transmission device to the local optical signal, and at the same time to add the optical signal sent by the local user to another node user without affecting the transmission of other wavelength channels. That is to say, the OADM is implemented in the optical domain. The function of the electrical add-drop multiplexer in the traditional SDH equipment in the time domain.

OA&M Operations, Administration and Maintenance Operations, Management and Maintenance

A set of network management functions for network performance monitoring, failure detection, and system fault diagnosis and protection.

OFA Optical Fiber Amplifier Fiber Amplifier

Refers to a new type of all-optical amplifier that is used in optical fiber communication lines to achieve signal amplification. According to its location and role in the optical fiber line, it is generally divided into relay amplification, preamplification and power amplification three. ODN Optical Distribution Network Optical distribution network, composed of passive optical components

OAN Optical Access Network Optical Access Network

Optical transmission-based access network technology

OBD Optical Branching Device Optical Splitter

Passive optical power splitter (coupler) that distributes the power of the downstream signal and couples the upstream signal

OLT Optical Line Terminal optical line terminal

It provides the interface between the local exchange network side, and is connected to one or more of ODN / ODT, to communicate with the user side ONU.

ONU Optical Network Unit Optical Network Unit

Providing a user interface linked to the optical access network side, and is connected to an ODN / ODT.

OFS Out of Frame Second Frame Out of sync

It has one or more OOF events occurring second called OFS.

OM Optical Multiplex optical multiplexer

Multiple wavelengths are multiplexed into one fiber for transmission.

OMSP Optical Multiplex Section Protect Optical Multiplex Section Protection

This technology only performs 1+1 protection on the optical path without protecting the terminal equipment. A 1×2 optical splitter or optical switch is used at the originating end and the receiving end respectively, and the optical signal of the combining road is separated at the transmitting end, and the optical signal is selected at the receiving end. Optical multiplex section protection is practical only if it is implemented in two separate optical cables.

OOF Out of Frame LOF

When the position of the frame alignment byte in the input bitstream is not known correctly, the STM-N signal is assumed to be in a faded state.

OSC Optical Supervisory Channel Monitoring Channel

Complete the network management, business telephone and other information transmission functions. Use a separate wavelength for transmission at a wavelength of 1510 nm .

O-SNCP Optical Subnetwork Connection Protection Photonic Network Connection Protection

Based on the 1+1 protection of the optical channel layer, which is commonly known as double-selection protection.

OSNR Optical Signal to Noise Ratio OSNR

The optical signal to noise ratio is defined as the ratio of the optical signal power to the noise power within an optical effective bandwidth of 0.1 nm . The power of the optical signal generally takes a peak-to-peak value, and the power of the noise generally takes the power level of the middle point of the two adjacent paths. The optical signal to noise ratio is a very important parameter and is of great significance to the estimation and measurement system.

OTDM Optical Time Division Multiplexing OTDM

Refers to time division (solution) multiplexing within the optical domain. Multiplexing is usually accomplished using planar waveguide delay line arrays (or planar lightwave circuits PLC ) or high-speed optical switches; all-optical time domain demultiplexers are often based on four-wave mixing (FWM) or nonlinear fiber optic loop mirrors ( NOLM ) etc.

OTDR Optical Time Domain Reflectmeter Optical Time Domain Reflector

By analyzing light scattering signal transmission cable in the return signal, the determination condition cable, fiber optic cable is necessary to maintain the equipment.

OTN Optical Transmission Net OTN

The optical transport network is based on DWDM technology and uses OADM , OXC and other network elements to connect point-to-point wavelength division multiplexing equipment. It is transparent to the transmission code rate, data format and modulation method, and can transmit ATM , SDH / Sonet and Gigabit Ethernet services with different code rates.

OMN Optical Transport Network Optical Transport Network Management Network

The management system of the optical transport network is a subnetwork of TMN .

OTU Optical Transform Unit light conversion unit

The optical signal from SDH is converted to an optical signal that meets the requirements of a wavelength division multiplexing system.

OXC Optical Cross Connect OXC

It is the most important network element of the optical network. It mainly completes the cross-connect function of the optical channel and the local add/drop function at the optical transport layer. It forms a large bandwidth redistribution through the rerouting wavelength in the network. When the cable is disconnected, the network is restored from the light transmitting layer (Restoration) effect.

PA Pre Amplifier Optical Preamplifier

Improve reception level and improve receiver sensitivity.

PMR Private Mobile Radio Private Cluster Mobile Communication Network

Refers to a specialized department, such as the public security, military, water conservancy, railway and other departments independently built, only for their own use of cluster mobile communications systems.

PON Passive Optical Network Passive Optical Network

Passive optical networks use passive optical power splitters (couplers) to send information to users. Due to the use of an optical power splitter, the power is reduced, so it is more suitable for short-distance use.

PAMR Public Access Mobile Radio Shared Scheduling Cluster Mobile Communication Network

It refers to a mobile communication network where multiple professional departments share frequencies, share equipment, share coverage areas, share costs, and manage and maintain them in a centralized manner. It can be used as a virtual communication platform for various professional departments.

Payload Payload

It is a bit that is really used in telecommunication services and stores the channel overhead that can be used for channel maintenance management.

PCM Pulse Code Modulation PCM

The sampled quantized value of the analog signal is converted into code.

PDH Plesiochronous Digital Hierarchy quasi-synchronous digital system

It is mainly designed for voice communication . There is no universally unified standard digital signal rate and frame structure, and international interconnection and intercommunication are difficult.

PJE Pointer Justification Count pointer adjustment event

Indicates that the I- bit or D- bit of the pointer is inverted and mixed with the value of the pointer value increases or decreases.

PMD Polarisation Mode Dispersion Polarization Mode Dispersion

Refers to the polarization dispersion in single-mode fiber, which is caused by the fact that the fundamental mode in an actual single-mode fiber contains two polarization modes that are perpendicular to each other. During propagation along the fiber, the fiber is inevitably affected by external factors such as changes in temperature and pressure or disturbances. The coupling between the two modes occurs, and their propagation speeds are also different. As a result, light pulses are broadened, and the amount of broadening is also uncertain, which is equivalent to random dispersion. With the increase of the transmission rate, the influence of the dispersion on the communication system becomes more and more obvious, and it cannot be underestimated. The literature gives the maximum distance of the system limited by PMD according to the formula: L max = 1000 / ( PMD. bit rate) 2 , where: L is (root) km , PMD is PS / KM , and bit rate The unit is Gb / s . Some international standards organizations, such as IEC , TIA, and ITU, consider the development of statistical characteristics and corresponding test methods for such random dispersion.

POS Packet Over SDH POS is a network technology model . Its network is mainly composed of high-capacity high-end routers connected through high-speed optical fiber transmission channels.

POH Path Overhead Channel Overhead

Path overhead bytes for channel maintenance management in the STM-N payload area.

PON Passive Optical Network Passive Optical Network

Passive optical networks use passive optical power splitters (couplers) to send information to users. Due to the use of an optical power splitter, the power is reduced, so it is more suitable for short-distance use.

PRC Primary Resource Clock Reference Master Clock

A high-precision, high-stability clock that is distributed to the lower levels of the clock via a synchronous distribution network.

QOS Quality of Service Service Quality

The ATM performance parameter term describing the transmission quality over a given virtual connection. These parameters include: CTD , CDV , CER , CLR , CMR and SECBR , ALL service classes , Qos Classes , traffic contract , traffic control .

Raman Effect Raman Effect

Pointing to the monochromatic light with a frequency f in a substance, scattered light with frequencies of f±fR and f±2fR other than the frequency f appears in the scattered light, and this phenomenon is called the Raman effect.

REG Regenerator regenerator

Reproduced on a transmission line, a relay device, an optical path for overcoming the accumulated waveform distortion of signal impairments such as caused by dispersion. REG can be divided into 1R , 2R , 3R three types.

RSOH Regenerator Section Overhead regeneration section overhead

Responsible for managing the regeneration section, access to the regenerator and terminal equipment.

Radio channel Radio channel

Radio channel. A sufficiently wide frequency band for radio communication.

RTS/CTS Request to Send/Clear to Send Request / Allow Send Protocol

Equivalent to a handshake protocol, it is mainly used to improve the efficiency when transferring large files. IEEE802.11 provides the following solution: In the parameter configuration, if using RTS/CTS protocol, the access point and subscriber station adapters simultaneously set the number of transmission upper limit bytes. Once the data to be transmitted is greater than this upper limit, the RTS/CTS handshake protocol is started.

3R Regenration, Reshaping, Retiming Regeneration , Reshaping, and Retiming

Regeneration ensures that the output power level of each connection is sufficient to reach the next node. Reshaping eliminates pulse distortion caused by such factors as dispersion. Retiming eliminates the time-domain distortion of the digital pulse so that the downstream clock recovery circuit can accurately receive the signal. 3R eliminates the distortion that the optical signal accumulates in each sub-network.

Stimulated SBS Stimulated Brillouin Scattering Brillouin Scattering

When the signal optical power injected into the optical fiber exceeds a certain value, a strong forward transmission signal light will be converted into backward transmission. SRS is related to the macroscopic elastic properties of the medium.

SCP Service Control Point Service Control Point

The terminology used for SS7 , to provide fast and reliable service, an SCP usually refers to a computer or advanced switch that contains a large database.

SD Signal Degrade signal degradation

The condition that the signal has deteriorated beyond a predetermined limit.

SDH Synchronous Digital Hierarchy Synchronous Digital Transmission System

It is a set of standardized digital signal structures that can carry out synchronous information transmission, multiplexing, demultiplexing, and cross-connecting, and transmits synchronous signals on transmission media (such as fiber optics, microwaves, etc.).

SHR Self-healing Hybrid Ring SDH self-healing ring

The SDH network can automatically recover the carried services from failures and failures in a very short period of time, without human intervention, so that users do not feel that the network has failed.

SDM Space Division Multiplex Spatial Division Multiplex

Using two fibers, simplex working mode, the working wavelength is limited to 1310nm area.

SDXC Synchronous Digital Cross Connector synchronous digital cross-connect

DXCs for SDH can further provide controlled VC transparent connections and reconnections between ports.

SES Severely Errored Second severely errored second

When a 1 second contains at least 30% of errors or at least one defect, the second is considered to be a severe block error second.

SESR Severely Errored Second severely errored second ratio

For a given test time, the ratio of SES to the total number of seconds that are available at the time available.

SIF Step Index Fiber Mutated Multimode Fiber

Light travels in a zigzag shape and propagates through the fiber . The pulse signal is distorted with a bandwidth of only 10 MHz.km and is usually used for short-distance transmission.

SMF Single Mode Fibre single-mode fiber

Only one mode of fiber can be propagated at the wavelength considered.

SMN SDH Management Network Synchronous Digital System Management Network

That is, a subset of TMNs that manage SDH network elements.

SMS SDH Management Subnetwork SDH Management Subnet

It consists of a series of separate ECCs and related intra-site data communication links and forms an integral part of the entire TMN . Multiple SMS constitute SMN .

Soliton Soliton

In a pulsed envelope in a discrete nonlinear medium, under certain conditions, the envelope not only transmits without distortion, but also has the same characteristics as particles. Using the singular characteristics of optical solitons, optical soliton communication can be achieved.

STM Synchronous transfer mode Synchronous Transport Module

SDH standardized information structure level, called synchronous transmission module, the most basic module is STM-1 , the rate is 155Mb/s .

SNC Subnetwork Connection subnet connection

A connection that spans a subnet is called a subnet connection. It can transparently transmit information on subnets, which can be delimited by subnet boundaries.

SNI Service Network Interface Service Node Interface

It is the interface between the wireless local loop system and the switch. It is a digital interface and should meet the access requirements of the PSTN in terms of functionality. The interface is implemented in fog using twisted pair, coaxial cable, microwave or fiber optics.

SOH Section Overhead section overhead

In the SDH frame structure, necessary additional bytes are transmitted to ensure normal, flexible, and efficient transmission of information. Its main role is for OAM&P .

SONET Synchronous Optical Network Synchronous Optical Network

The North American equivalent of SDH is composed of a set of hierarchical standard digital transmission structures, which are suitable for the transmission of various adaptive payloads on physical media.

SPM Self-healing Network Self- phase modulation

The instantaneous change in signal light intensity causes its own phase modulation. This effect is called self-phase modulation.

SRS Stimulated Raman Scattering Stimulated Raman Scattering

Stimulated Raman scattering is a broadband effect associated with the interaction between light and silicon atom vibration modes. Stimulated Raman scattering makes the signal wavelength behave like a Raman pump of longer wavelength signal channels or spontaneously scattered Raman-shifted light. In any case, the short-wavelength signal is always attenuated by this process while the long-wavelength signal is enhanced.

SRP S pace Recycle Protocol Space Reuse Protocol

The SRP is an independent MAC layer protocol that is used to activate the DPT function in the ring configuration. Through the propagation of SRP-fa and ring control information, the SRP MAC layer provides basic functions such as addressing, packet discarding, and bandwidth management.

SRS Simulated Raman Scattering Stimulated Raman Scattering

It is a kind of inelastic scattering. The frequency of light waves is reduced or the energy of photons is reduced. SRS is related to the optical properties of the media.

SPM Self-phase Modulation self-phase modulation

In a coherent optical communication system, the refractive index of the optical fiber is related to the input optical power, which causes the spectrum of the optical pulse to be greatly broadened.

The TETRA Trans European Trunked Radio TETRA system is a new open digital trunking standard for both PMR and PAMR . It was formally established by ETSI in 1995 and is widely adopted by many European manufacturers. It mainly operates in the 400 MHz frequency band, and the 800 MHz system currently has only Maconi. Launched commercial products.

TCM Trellis Coded Modulation Trellis Coded Modulation

An advanced coding and modulation method that makes full use of the redundancy generated in the convolutional coding and the memory effect of Viterbi decoding so that the coded signal sequence generated after concatenation of the encoder and the modulator has the largest Euclidean distance , And its ideal decoding method should be implemented using the Viterbi algorithm.

TDM Time Division Multiplexing Time Division Multiplexing

It is a technology that uses a staggered arrangement of multiple low-speed analog or digital channels to transmit on a high-speed channel.

TM Terminal Multiplexing Terminal Multiplexer

The low-speed tributary electrical signal and the 155Mb/s electrical signal are incorporated into the STM-1 frame structure, and are electrically / optically replaced with the STM-1 optical line signal. The reverse is exactly the opposite.

TWF True Wave Fiber True Wave Fiber The short wavelength region where the zero dispersion point is below 1530 nm . In the optical amplification region of 1530 to 1565 nm , the dispersion coefficient is 1.3 to 5.8 ps/nm.km . The system operates in the dispersion " positive region " of the fiber. In this region, the self-phase modulation effect SPM can compress the pulse width, which helps to reduce the dispersion pressure.

Tributary unit TU Tributary Unit
Provides the information structure of the adaptation function between the lower-order channel layer and the higher-order channel layer.
TUG Tributary Unit Group

It consists of one or more tributary units occupying a fixed position in the high-order VC payload.

VC Virtual Container virtual container

The information structure used to support the SDH channel layer connection is the information terminal of the SDH channel. The encapsulation rate of the virtual container is synchronized with the SDH network, that is, different VCs are synchronized.

Wander Wandering

Phase change below 10Hz is called wander

WDM WDM Wavelength Division Multiplexing

The method of multiplexing optical signals of different wavelengths into one optical fiber for transmission (each wavelength carries a TDM electrical signal) is collectively referred to as wavelength division multiplexing.

WLL Wireless Local Loop is a wireless access scheme designed for access networks. The frequency is typically 1.8GHz , 800MHz , 450MHz , and even 150MHz , depending on the frequency spectrum of the area. It has fast installation speed, flexible and convenient installation, low construction investment, low maintenance cost and safety.