101. OOF Out of Frame
When the position of the frame alignment byte in the input bit stream is not known, the STM-N signal is considered to be in a lost state.
102. OSC Optical Supervisory Channel
Complete the transmission of network management, business calls and other information. Transmission is carried out using a single wavelength with a wavelength of 1510 nm.
103. O-SNCP Optical Subnetwork Connection Protection
1+1 protection based on the optical channel layer, commonly known as dual-shot selection protection.
104. OSNR Optical Signal to Noise Ratio
Optical signal-to-noise ratio is defined as the ratio of optical signal power to noise power over a light effective bandwidth of 0.1 nm. The power of the optical signal generally takes the peak-to-peak value, and the power of the noise generally takes the power level of the intermediate point of the two-phase approach path. Optical signal-to-noise ratio is a very important parameter and is of great significance to estimation and measurement systems.
105. OTDM Optical Time Division Multiplexing
Refers to time division (de)multiplexing within the optical domain. Multiplexing is typically achieved using planar waveguide delay line arrays (or planar lightwave circuits PLC) or high-speed optical switches; while all-optical time domain demultiplexers are often based on four-wave mixing (FWM) or nonlinear fiber-optic ring mirrors ( NOLM) and so on.
106. OTDR Optical Time Domain Reflectmeter
By analyzing the scattered signal returned by the optical transmission signal in the optical cable, judging the condition of the optical cable is a necessary equipment for maintenance of the optical cable.
107. OTN Optical Transmission Net Optical Transport Network
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. Transparent to the transmission rate, data format and modulation scheme, it can transmit ATM, SDH/Sonet and Gigabit Ethernet services with different bit rates.
108. OMN Optical Transport Network
The management system of the optical transport network is a subnet of the TMN.
109. OTU Optical Transform Unit
The optical signal from the SDH is converted into an optical signal that satisfies the requirements of the wavelength division multiplexing system.
110. OXC Optical Cross Connect
It is the most important network component of the optical network. It mainly completes the cross-connect function of the optical channel and the local uplink and downlink functions in the optical transmission layer, and the redistribution of large bandwidth is formed in the network through the loop by the wavelength (Rerouting wavelength). When the cable is disconnected, the optical transport layer acts as a network restoration.
111. PA Pre Amplifier
Increase the receiving level and increase the receiver sensitivity.
112. PMR Private Mobile Radio
It refers to a professional mobile department, such as the public security, military, water conservancy, railway and other departments that are independently constructed and used only for their own use.
113. PON Passive Optical Network
Passive optical networks mainly use passive optical power splitters (couplers) to send information to users. Since the optical power splitter is used to reduce the power, it is suitable for short-distance use.
114. PAMR Public Access Mobile Radio
It refers to a mobile communication network where multiple professional departments share frequency, shared equipment, shared coverage area, share costs, and centrally manage and maintain. It can be used as a virtual communication platform for professional departments.
115. Payload
It is a bit that is really used for telecommunication services and stores the channel overhead that can be used for channel maintenance management.
116. PCM Pulse Code Modulation
The sampled quantized values of the analog signals are transformed into codes.
117. PDH Plesiochronous Digital Hierarchy
It is mainly designed for voice communication. There is no universal standard digital signal rate and frame structure, and international interconnection is difficult.
118. PJE Pointer Justification Count
Indicates that the I bit or D bit of the pointer is inverted and mixed with an event of increasing or decreasing the value of the pointer.
119. PMD Polarisation Mode Dispersion
Refers to the polarization dispersion in a single-mode fiber. The fundamental mode of the single-mode fiber contains two mutually perpendicular polarization modes. During the propagation of the fiber, the fiber is inevitably affected by external factors such as temperature and pressure. So that the two modes are coupled, and their propagation speeds are not the same, resulting in broadening of the light pulse, and the amount of broadening is also uncertain, which is equivalent to random dispersion. As the transmission rate increases, the effect of the dispersion on the communication system becomes more and more obvious, and it is increasingly impossible to underestimate. There is a literature giving the maximum distance of the system limited by PMD according to the formula: L maximum = 1000 / (PMD. bit rate) 2, where: L unit is (root) km, PMD unit 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 properties and corresponding test methods for such random dispersion.
120. POS Packet Over SDH POS
It is a technical model of the network, and its network is mainly connected by high-capacity high-end routers via high-speed fiber transmission channels.
121. POH Path Overhead
The channel overhead byte for channel maintenance management in the STM-N payload area.
122. PON Passive Optical Network
Passive optical networks mainly use passive optical power splitters (couplers) to send information to users. Since the optical power splitter is used to reduce the power, it is suitable for short-distance use.
123. PRC Primary Resource Clock
A high-precision, high-stability clock that is distributed to the following levels of clocks via a synchronous distribution network.
124. QOS Quality of Service
An ATM performance parameter term describing 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.
125. Raman Effect
When a monochromatic light of a frequency f is incident on a substance, scattered light of a frequency such as f±fR and f±2fR other than the frequency f appears in the scattered light, and this phenomenon is called a Raman effect.
126. REG Regenerator
A regenerative, relaying device on the transmission line for overcoming waveform distortion caused by dispersion of signal damage, such as dispersion, in the optical path. REG can be divided into three types: 1R, 2R, and 3R.
127. RSOH Regenerator Section Overhead
Responsible for managing the regeneration section, accessing the regenerator and terminal equipment.
128. Radio channel
Radio channel. A sufficiently wide frequency band for radio communication.
129. RTS/CTS Request to Send/ Clear to Send
It is equivalent to a handshake protocol and is mainly used to improve the efficiency when transferring large files. IEEE 802.11 provides the following solution: In the parameter configuration, if the RTS/CTS protocol is used, the access point and the subscriber station adapter simultaneously set the transmission upper limit byte number. The RTS/CTS handshake protocol is initiated once the data to be transmitted is greater than this upper limit.
130. 3R Regenration, Reshaping, Retiming
Regeneration ensures that the output power point of each connection is equal enough to reach the next node. Re-shaping eliminates the pulse distortion caused by factors such as excellent dispersion. The 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 subnet.
131. SBS Stimulated Brillouin Scattering
When the signal light power injected into the fiber exceeds a certain value, a strong forward transmission signal light is converted into a backward transmission. SRS is related to the macroscopic elastic properties of the medium.
132. SCP Service Control Point
Terminology used in SS7, in order to provide fast and reliable service, an SCP usually refers to a computer or advanced switch that contains a large database.
133. SD Signal Degrade
Refers to the case where the signal has deteriorated beyond a predetermined limit.
134. SDH Synchronous Digital Hierarchy
It is a standardized digital signal structure level for synchronous information transmission, multiplexing, add-drop and cross-connect, and transmits synchronous signals on transmission media (such as optical fiber, microwave, etc.).
135. SHR Self-healing Hybrid Ring SDH
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 the user does not feel that the network has failed.
136. SDM Space Division Multiplex
Using two optical fibers, the working mode is limited to the 1310 nm area.
137. SDXC Synchronous Digital Cross Connector
DXC for SDH provides further controllable VC transparent connectivity and reconnection between ports.
138. SES Severely Errored Second
When there is no less than 30% of the error block or at least one defect in a certain second, the second is considered to be a serious error block second.
139. SESR Severely Errored Second
The ratio of the number of SESs present at the available time to the total number of seconds for a certain test time.
140. SIF Step Index Fiber
The light propagates in a zigzag shape and propagates in the optical fiber. The pulse signal is distorted and has a bandwidth of only 10 MHz.km, which is usually used for short-distance transmission.
141. SMF Single Mode Fibre
Only one mode of fiber can be propagated at the wavelength considered.
142. SMN SDH Management Network
That is, a subset of TMNs that manage SDH network elements.
143. SMS SDH Management Subnetwork SDH
It consists of a series of separate ECCs and associated intra-site data communication links and forms the organic part of the entire TMN. Multiple SMSs form the SMN.
144. Soliton
In a discrete nonlinear medium, the envelope is pulsed. Under certain conditions, the envelope is not only transmitted without distortion, but also has the same characteristics as particles. Optical soliton communication can be realized by using the singular characteristics of optical soliton.
145. STM Synchronous transfer mode
SDH standardized information structure level, called synchronous transfer module, the most basic module is STM-1, the rate is 155Mb / s.
146. SNC Subnetwork Connection
A connection that spans a subnet is called a subnet connection. It can pass information transparently over the subnet, which can be delimited by subnet boundaries.
147. SNI Service Network 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. The interface is implemented in the fog using twisted pair, coaxial cable, microwave or fiber.
148. SOH Section Overhead
The extra bytes necessary to ensure normal, flexible, and efficient transmission of information in the SDH frame structure.
149. SONET Synchronous Optical Network
SDH’s North American Correspondence, which consists of a set of hierarchical standard digital transmission structures that are suitable for transmission on a variety of adapted payloads on physical media.
150. SPM Self-healing Network
The instantaneous change in signal light intensity causes its own phase modulation. This effect is called self phase modulation.
151. SRS Stimulated Raman Scattering
Stimulated Raman scattering is a broadband effect associated with the interaction between light and the vibrational modes of silicon atoms. Stimulated Raman scattering causes the signal wavelength to be like a Raman pump with a longer wavelength signal path or spontaneously scattered Raman shifted light. In any case, short-wavelength signals are always attenuated by this process, while long-wavelength signals are enhanced.
152. SRP Space Recycle Protocol
SRP is a stand-alone MAC layer protocol used to activate DPT functions in ring configuration. The SRP MAC layer provides basic functions such as addressing, packet discarding, and bandwidth management through the propagation of SRP-f a and ring-up control information.
153. SRS Simulated Raman Scattering
It is an inelastic scattering where the frequency of the light wave is reduced or the energy of the photon is reduced. SRS is related to the optical properties of the medium.
154. SPM Self-phase Modulation
In a coherent optical communication system, the refractive index of the fiber is related to the input optical power, which causes the spectrum of the optical pulse to be greatly broadened.
155. TETRA Trans European Trunked Radio
The TETRA system is a new open digital trunking standard for both PMR and PAMR. It was officially confirmed by ETSI in 1995 and is widely used by many European manufacturers. It mainly works in the 400MHz band. Currently, only Maconi has launched commercial products for the 800MHz system.
156. TCM Trellis Coded Modulation
An advanced coding modulation method that makes full use of the redundancy generated in convolutional coding and the memory effect of Viterbi decoding, so that the encoded signal sequence generated by cascading the encoder and the modulator has the largest Euclidean free distance. And its ideal decoding method should be implemented by Viterbi algorithm.
157. TDM Time Division Multiplexing
It is a technique that uses a staggered arrangement of multiple low-speed analog or digital channels to transmit on a high-speed channel.
158. TM Terminal Multiplexing
The low-speed branch electrical signal and the 155 Mb/s electrical signal are incorporated into the STM-1 frame structure and are electrically/photo-switched to the STM-1 optical line signal, which is reversed.
159. TWF True Wave Fiber
The zero dispersion point is in the short wavelength region 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 “positive region” of the dispersion of the fiber. In this region, the self-phase modulation effect SPM can compress the pulse width, thereby contributing to the reduction of the dispersion pressure.
160. TU Tributary Unit
An information structure that provides an adaptation function between the lower-order channel layer and the higher-order channel layer.
161. TUG Tributary Unit Group
Consists of one or more branch units that occupy a fixed, determined position in the high-order VC payload.
162. VC 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.
163. Wander
Phase changes below 10 Hz are called wandering
164. WDM Wavelength Division Multiplexing
The way in which optical signals of different wavelengths are multiplexed into one fiber for transmission (one TDM electrical signal per wavelength) is collectively referred to as wavelength division multiplexing.
165. WLL Wireless Local Loop
The wireless access method designed for the access network generally uses frequencies of 1.8 GHz, 800 MHz, 450 MHz, and even 150 MHz, depending on the regional spectrum arrangement. It has the advantages of fast installation speed, flexible installation, low construction investment, low maintenance cost and good safety.
166. WRS Wavelength Router Switch
It consists of a wavelength division multiplexer/demultiplexer and an optical switch matrix, which allows the selected optical channel to be directly connected through the optical transmission node or cross-connected with other links, or locally on or off the road.
167. WXC Wavelength Cross Connect
A cross-connect device that can be used with a wavelength converter.
168. XPIC Cross-polarisation Interference counteracter
A commonly used interference compensation technique in SDH digital microwave communication systems. In the case of SDH microwave transmission, in order to improve the spectrum utilization, it is often necessary to adopt the same channel or insert channel type cross-polarization frequency reuse method, so it is necessary to introduce interference compensation technology between cross-polarization waves. Its implementation is usually implemented in the baseband and IF bands.
169. XPM Cross-phase Modulation
A nonlinear optical effect caused by the light field itself when two or more channels use different frequencies while propagating in the fiber.
