EXFO is available for 40G/100G high power light source products

Miranda will be introducing a high density optical fiber converter products

Application of GigOptix in 100G optical transmitter four channel driver sample

Application of GigOptix in 100G optical transmitter four channel driver sample

OE Solutions launched 155M SFP intelligent modules supporting packet network

GigOptix 40G coherent optical network launched a new generation of linear transimpedance amplifier

Sumitomo Electric NAB display Thunderbolt optical fiber cable

Hittite 40G/100G launched a compact optical modulator driver

VI company releases 28Gbps multimode optical fiber TOSA/ROSA

The launch of PacketLight metropolitan area and long distance 100G multiplex transponder / transponder

The launch of OMRON 14 Gbps bidirectional optical module

According to 3M MDU launched with MPO fiber optic pre-terminated scheme

Avago launch cloud computing data center and the application of high density 120Gbps parallel optical solutions

South Korea Optowell introduced plastic BOSA and double channel VCSEL component

AFOP launched the aging and test MPO fiber loop device

Asahi technology released 40G QSFP+ full range of products

Suzhou Xu Chong technology limited, a company focused on 10G/40G/100G products of high-end optical module supplier, was formally announced that the whole series of 40G QSFP+ products have been customers can accept bulk orders. With a variety of emerging business of bandwidth demand of rapid growth, the whole communication network will need light transmission bandwidth from the original 10G upgrade to 40G and 100G. The 40/100G IEEE 802.3ba and QSFP+ 40GBASE-SR4 Ethernet standard, QSFP+ 40GBASE-LR4 technical standards have been officially released, the new 40GBASE-ER4 technical standards to be published, the 40G QSFP+ series of products become follow-up network upgrade mainstream light module solutions provided strong support. Asahi technology current quantities can provide the following 4 different transmission distance application products: 40G QSFP+AOC, P/N: TR-QQxxx-N00, in OM3 multimode fiber can support 3-100m transmission distance 40G QSFP+SR4, P/N: TR-QQ85S-N00, in OM3 multimode fiber can support more than 100m transmission distance 40G QSFP+IR4, P/N: TR-QQ13P-N00, in a single-mode optical fiber can support 2km transmission distance 40G QSFP+LR4, P/N: TR-QQ13L-N00, in a single-mode optical fiber can support 10km transmission distance In addition most far can support 40km transmission 40G QSFP+ER4 products will in 2012 Q4 released. Asahi technology marketing director Osa said: " following 10G SFP+ large-scale deployment and application, 40G QSFP+ is considered to be in the next generation of 40G network deployment in the most advantage of a package. With the 10G SFP+ module, QSFP+ bandwidth is improved by 4 times, but in power, volume and cost etc, have an obvious advantage. This price increase from Xu technology the original optical design packaging platform, is brought about by the high optical coupling efficiency and a good cost-effective products. Based on this innovative optical platform developed by 40G QSFP+ products, allows customers to fully enjoy the QSFP+ product brings various convenient application and effectively control the purchase cost " Asahi technology of QSFP+ AOC, QSFP+SR4, IR4, LR4 and other products have been fully began receiving customer batch order.

Emcore pushed J-Type Medallion type 6000 1550nm CATV transmitter

On July 16, 2012, optical communication and the solar power market with compound semiconductor optical devices and subsystems is the leading provider of -- Emcore announced its 1550nm CATV using fiber optic transmitter for the Japanese market to add J-Type Medallion 6000 models. Emcore's new J Medallion 6000 series of externally modulated transmitter is designed for Japan and other markets need long distance and parallel optical transmission CATV and satellite frequency models ( Satellite-Intermediate Frequency Signals, SAT-IF ) application and design. Emcore J Medallion 6000 support industry leading up to 2.8 GHz operating bandwidth, with from 11 to 17 dBm SBS ( Stimulated Brillouin Scattering adjustable, stimulated Brillouin scattering ) inhibition, extended range adjustable AGC ( Automatic Gain Control, automatic gain control ), as well as the very high specific links required OMI ( Optical Modulation Index, optical modulation index ). At the same time, Emcore also for the entire Medallion 6000 platform introduced the next generation WEB GUI and simple network management protocol ( Simple Network Management Protocol, SNMP ) software service. The new WEB GUI and SNMP interface provides many new advanced function, to meet the needs of the world's most advanced network development and growth in demand. Emcore said their patented high power, narrow linewidth laser technology to ensure that the performance of J-Type Medallion 6000. With Emcore optical fiber amplifier, the transmitter can achieve more than 100 km transmission.

Hisense broadband launched a high performance, low power consumption million million SFP+ and XFP optical module

On July 20, 2012, Qingdao Hisense broadband multimedia technology limited company ( abbreviation: Hisense broadband ) were launched two industry is high performance, low power SFP+ and XFP optical module product, can support multiple rate 2.0Gbps~10Gbps transmission, support the maximum transmission distance 20km. Hisense broadband Hisense Group relies on powerful resource, increasing investment in research and development, to the data network, Ethernet speed and reduce power consumption to make outstanding contribution. Hisense broadband launched a new generation of SFP+ LR optical module product ( Hisense Code: LTF1305 ), supports hot plug and play, dual-fibre bidirectional transmission, digital diagnostic monitoring, support industrial temperature range, temperature range can be extended to the ambient temperature -45℃ ~+85 ℃. The optical module in industrial level power control within 1W, commercial level power for less than 0.8W. The product design of ultra-low power consumption, to equipment manufacturer greatly reduces power consumption, and reduces the system board heat radiation design difficulty. The products meet the SFF-8431, SFF-8432 and 10GBASE-LR/LW agreement requirements, mainly used in 10Gbps Ethernet network and data network. The product high performance, transmission part adopts a low jitter, high performance 1310nm DFB laser components, the whole temperature range optical module diagram template margin above 30%; receiving by means of PIN+TIA, OMA sensitivity index is far superior to the international IEEE802.3ae standard requirements. Transmitting, receiving optical devices are Hisense homemade, products with high performance price ratio. Hisense broadband launched a new generation of XFP optical module product ( Hisense Code: LTX1305 ), supports hot plug and play, dual-fibre bidirectional transmission, digital diagnostic monitoring, support industrial temperature range, and can be extended to the ambient temperature -45℃ ~+85 ℃. Industrial level power control within 1.2W, commercial level power control within 1W. The product design of ultra-low power consumption, but also in the industry are in a leading position. Products to meet 10GBASE-LR/LW and SONET OC-192 / SDH STM-64 agreement requirements, mainly used in the 10G SDH optical transmission network, 10G/8G, Ethernet, fibre channel 10G field. The product high performance, transmission part adopts a low jitter, high performance 1310nm DFB laser components, the whole temperature range optical module diagram template allowance can reach 30%; receiving the PIN+TIA scheme, OMA sensitivity index is far superior to the international IEEE802.3ae standard requirements. Transmitting, receiving optical devices are Hisense homemade, products with high performance price ratio.

The launch of TeliSwitch remote control optical divide ratio of PON-AODF system

On July 24, 2012, Israel optical wiring equipment provider TeliSwitch solutions company introduced patent support PON network dynamic change of optical divide ratio of PON-AODF system. TeliSwitch said, the existing PON operator in PON network planning, limited to the technical conditions, usually choose 32 or 64 fixed optical divide ratio, therefore required in the initial business needs and future business requirements make compromise between. When the PON network penetration is relatively low, the OLT port number is a waste, because even if there is only one customer, OLT will be connected to the splitter. In addition, the high splitting ratio also limits the operators to provide high bandwidth service ability. Their use of newly developed PON-AODF system, can be achieved by remote control PON light splitting ratio and save the operator for more than 50% of the OLT port number. The system maintained in PON system passive properties but also for the system to increase the adaptive ability of optical divide ratio regulation. TeliSwithc said their PON-AODF system for PON carriers to provide on-demand OLT port capacity, thus greatly reduce the system operation cost. AODF:Automated Optical Distribution Frame, automatic optical fiber distribution frame. PON:Passive Optical Network, passive optical fiber network.

Cortina publishing industry minimum eight 10G electronic dispersion compensation physical layer devices

On July 26, 2012, as the global consumer and network to provide innovative connection technology firm Cortina Systems, Inc. ( Cortina ) today announced a eight port 10G electronic dispersion compensation ( EDC ) device CS4342, the device has the smallest size, has a low delay characteristic and support a variety of standard. CS4342 17mm x 17mm packages on the market than the other competing products small 34%, the high density of 10GbE SFP+ and 40G QSFP+ line card to save valuable area of printed circuit board. Delay is the data center and financial applications of key parameters, the device to delay is reduced to less than 1 ns, almost without considering the physical layer device layer facing the entire link delay effects. CS4342 for 10G, 40G, 100G fiber and copper cable to the latest standards and technology are integrated together, provides 10Gbase-LRM, 10G Direct Attach Copper, 10GBase-ZR and DWDM and other standards support, equipment manufacturer can accordingly develops supports all the standard line card. CS4342 has been added to the Cortina industry leading to the two and four ports of electronic dispersion compensation physical layer devices product portfolio, to leading system manufacturers shipments. Cortina Systems, Inc. director Scott Feller said: " the market for bandwidth recently growing demand prompted the data center and enterprise switch the ever-increasing density. Cortina and system developers in close cooperation, developed to support a variety of industry standard high performance device, to a new generation of switches and routers need high port count, low power consumption and high density together. " Focus on optical interconnection market research company LightCounting senior vice president Brad Smith said: " is expected over the next few years, the majority of data center interconnect using 10GbE and 40GbE, high density, small size of 10GbE and 40GbE solutions is to satisfy consumer bandwidth intensive applications exponentially key, these include applications to Facebook upload pictures, upload to YouTube video and high definition video streaming. Is expected in the near future, the video application will be to promote the Internet bandwidth increased, one of the main drivers. In these high density solution, space is very precious, regardless of is the switch panel or printed circuit board are so, so all system devices are faced with increasing the degree of integration and reducing the size of the demand. " CS4342 – eight export of electronic dispersion compensation device The CS4342 physical layer devices support 8 duplex 10G link or 2 duplex 40G link. The transmit and receive paths including the clock and data recovery ( CDR ) circuit. The device has a very wide frequency range, covering 1GbE, 1G FC, 2G FC, 4G FC, 8G FC, SONET ( 9.5 - 11.3G ) and 10GbE. Electronic dispersion compensation function so that the device can be matched with linear SFP+ optical module supports 10Gbase-LRM, Direct Attach Copper, 10GBase-ZR and DWDM SMF application. The device is fully consistent with the 10G SFP+ and 802.3ba 40G and 100G nPPI and nAUI code. Transmission path includes 10Gbase-KR standards in line with the 3 fork of the transmission pre-emphasis function. The transmission pre-emphasis function and receive electronic dispersion compensation function of the combination, so that the device supports 10Gbase-KR, 8G FC and electrical backplane applications. The device is completely independent, without the need for an external processor to control the dispersion compensation of the initial convergence or dynamic adaptation. In addition, the device also contains extensive debugging and I/O function, convenient device monitoring.

Rosenberg introduced the optical fiber LC quick plug connector

Cloud computing virtualization Fabric complex network architecture of the launch, fiber network as the main transmission and network management carrier, for cloud computing data center is more and more high density fiber application environment, Rosenberg company has recently launched a patent technology ( Quick Release ) LC quick plug connector. This rapid plug connectors with IEC61754-20 international standard LC connector. The launch of the LC duplex connector incorporates a patented locking releasing device. Rosenberg German R & D department, Dr. Dr. Gerald Berg explains: " a new generation of Quick Release LC connector can be good at data center high density and the maintenance of balance before, patent lock release technique and optical fiber bending insensitive technology, greatly enhancing the optical fiber system in data center application convenience and reliability. " With the explosive increase of servers in the data center, data center requirements significantly reduce the server and storage equipment and network communications equipment covers an area of, and enhances the calculating density, improve the overall data center utilization and efficiency. Data center optical fiber distribution frame density also has ascend beyond the 1HU 96 core and 288 core high density 4HU. The traditional LC connector in high density optical distribution frame of closely arranged connecting port plug operations more difficult, sometimes need the help of other means of operation, increases the operation difficulty and cost, and easy interference to other optical fiber channel, affect the data transmission, thereby reducing the reliability of data center. In view of this situation, Rosenberg patented LC quick plug connector, accord with human body engineering principle, finger pushing and drawing LC optical fiber connector end of the optical fiber connector plug, you can easily complete the swap operation. Especially out of time, an optical fiber connector plug corresponding to the lock unlocked, a new plug device solves the problems of high density application, at the same time with the bend insensitive optical fiber combination, the availability and reliability of the fuse. As the German brand of Rosenberg company has paid attention to the development of the data center, for 4 consecutive years was rated " best data center cabling supplier" and for 3 consecutive years was named "China's top ten brands of wiring ". Innovation and strict is the company's main values, is dedicated to Chinese users with the most excellent data center cabling solutions as their main goal.

Sumitomo Electric released a new generation TYPE-81C touch screen optical fiber fusion splicer

On August 1, 2012, Sumitomo Electric Group released a message to say, a new generation of core open type TYPE-81C optical fiber fusion splicer to be put on the market. The machine is adhering to the " under any environment speeding fusion " concept developed, with small, light weight, strong features, TYPE-81C to achieve the most rapid welding process. Touch screen operation and through the Internet to achieve the remote technical support to provide users with a great convenience, the operation is more simple, more flexible service. Sumitomo Electric Group's subsidiary in China - for Asian trade ( Shenzhen) Limited company general manager Masuke Katsuya commented: " TYPE-81C is from a 30 optical fiber fusion splicer manufacturing history of Japan Sumitomo Electric Group to develop a new generation of products. It contains many innovative, compared to the current market of welding machine, simplifies the user and the operator's use. Touch screen TYPE-81C operation is simple, durable design and remote technical support have greatly reduced the user maintenance cost. All of these short welding time and improve environmental performance improvement will make this core open type welding machine to enter a new era. " TYPE-81C has started in July 1, 2012 in the Chinese market sales.

Analysis of the ROADM equipment management software based on SNMP

This paper introduced one kind based on the SNMP protocol for ROADM network management agent software design and implementation of the program, the method can simplify the design and implementation of Agent, such that Agent put more resources on equipment management and real-time task coordination operation. This scheme can also be used for other equipment. 1 Introduction In recent years, IP, data, video and other business to carry out a wide range of rapid consumption of the optical fiber bandwidth, already matched wavelength is gradually occupied, business development presents the dynamic characteristics. WDM system in expanding its scale at the same time, bound to a new generation of WDM system ULH+ROADM transformation. ROADM ( reconfigurable optical add-drop multiplexer ) with its convenient configuration, can change the wavelength resource allocation, can meet the dynamic needs of the business, and according to the need for intermediate the upper and lower nodes of the wavelength number and the specific wavelength, can avoid wavelength blocking and constructing end-to-end virtual wavelength path [1]. ROADM is ASON key nodes. In the metropolitan area network construction, selection of ROADM equipment, not only can reduce operating costs, ensure the business flexible development, to ensure that the required bandwidth, provide transparent, efficient transmission and exchange; can realize flexible networking, in favor of ASON flow control; and for a smooth transition to next generation network ready. The realization of ROADM mainly have two kinds of train of thought, broadcast / selection type and demultiplexing / multiplexing / cross. Broadcast / selection type ROADM equipment by tunable filter and wavelength blocking filter component. The demultiplexing / Cross / multiplex ROADM device usually adopts the wave division multiplexer / demultiplexer, coupled with controllable light switch [2]. With the rapid development of hardware chip and processor, ROADM equipment single disk can have more processing. So you can be a specific task processing in single disc, instead of Agent to realize. Following the presentation of a ROADM device design and realization scheme of network management agent. This program on ROADM equipment performance, alarm, configuration and proprietary commands and other special treatment, simplified in the command processing module and the response frame processing modules. This can make Agent design more concise, focusing on equipment management and real-time task coordination operation, so that the ROADM device can real-time response network management needs and timely reporting of network information, in order to better the performance of the work. The 2SNMP protocol Based on SNMP protocol simple network management framework, because of the popularity of Internet and get rapid promotion, becoming one of the important technology of network management. SNMP is in the process of constant development, now has SNMPv1/v2/v3 in three main versions; in addition, remote network monitoring ( RMON ) appear to make SNMP to the distributed management to stride one stride. The network management of SNMP model includes four key components: Management ( Manager ), agent ( Agent ), management information base ( MIB ) and network management protocol ( SNMP ), as shown in figure 1. Manager running SNMP client ( Client ) program and network application software, will be responsible for network management commands to the Agent, extracted from the MIB management information and receive from the Agent abnormal event report. The Agent running SNMP server ( Server ) program and MIB handling procedures, is responsible for receiving network management command and MIB implementation of related operations, reported the incident. MIB: preservation and tissue from the tube being cyber source abstract management information. SNMP:Manager and Agent exchange between management information communication rules, is generally based on the realization of the TCP/IP. 3 design and implementation of software 3.1ROADM equipment network management SNMP protocol based on ROADM equipment network management model as shown in figure 2. Diagram of network management agent ( Agent ) as the ROADM equipment and station between the bridges, is running in the managed devices ( ROADM ) in the software, implementation of management process management operation, direct the operation of the local management information base on [3]. The ROADM device Agent with response management station command, collection ROADM equipment information, configuration of ROADM equipment, ROADM equipment information and command execution results are sent to the management station, send TRAP to the management station, save the configuration information and other functions. ROADM Agent MPC860 was selected as the running equipment software hardware platform, operating system using VxWorks embedded real-time multitask operating system; the MPC860 and equipment of each disc communication through MPC860 SPI port to achieve. It can realize the real-time monitoring of equipment, good management performance. Design and implementation of 3.2MIB According to SNMP agreement [4], all managed objects are arranged in a tree structure, in the leaf position on the object is the actual managed objects, each practical managed objects representing some managed resources, activities or the related information. Tree structure itself defines an object to the set of logically related method. ROADM Agent ROADM equipment equipment management system information ( equipment name, device type, device manufacturers, device address ), the operation status of equipment ( alarm or normal ), slot ( slot type information, slot boards in information ), single disc basic information ( hardware, software version, version of the manufacturer information ), single wheel running ( alarm or normal ), single disc temperature, port basic information and port running state. ROADM MIB as shown in figure 3. 3.3 software design ( module ) In accordance with the ROADM device Agent to realize the function of Agent software, will be divided into the following several modules, each module to achieve a specific function, with each other through the function interface link. ROADM equipment Agent software module diagram as shown in figure 4. 3.4 the module realization The communication module: This module to establish socket connection, frame to network management request. From the received UDP packet analyzing the sources of information ( network IP address ). And the data in the UDP header pointer to command parsing module. Response message package module can call the function modules to send Trap or response information to the network management. In embedded systems, will generally be 161 port as the receiving station to the management station sends a request and response information to the port, and the 162 port is used to send Trap to the management station. Command parsing module: This module receives the UDP packet data blocks are analytic, remove community field validation information, to ensure that the legitimate operation; finally will parse out operation object and operation parameters to be passed to the command processing module, a command processing module on the operation of the equipment. The command processing module: This module to realize the management station to ROADM device sends the read, write command analysis and transmission. The process is illustrated in figure 5. First receives the command parsing module pass over the operation object and operation parameters. Then the operation object is analyzed by OID, to find the corresponding device properties ( Equipment, Slot, Card attribute attribute attribute or the Port property ). According to the hardware layer protocol device attributes and attribute values are converted into hardware can identify the sixteen hexadecimal number, packaged into a data frame, was sent to the slave communication module. In response to the frame processing module: This module processing from the lower communication module to report information and response analysis of frame, corresponding managed object properties ( OID ) and managed object attribute values, delivered to the response message package module, and through the interface function to update the database. In alarm and important information to send Trap to Manager. Response message package module: This module will receive the managed object attributes and attribute values ( OID ) bound together, packaged into the appropriate PDU ( protocol data unit ) package, plus the community name and version number, transfer to the upper communication module. Configuration module: network management by the Set command, such as response frame returns to Set news, notice the configuration module will be the new configuration data stored in the database. The system to power up, the module is read out from the database last configuration data, through the command processing module to configure. The communication module: This module establishes a two message queues, one for the ROADM device to send data, another from a ROADM device receives the response frame. The realization of interactive information transparent transmission, completed by Agent software and ROADM communication between devices. The 4 ending ROADM in local / metropolitan area network application, caused various equipment manufacturers and operators of the eager attention. Especially the foreign operators on ROADM cast with high enthusiasm, have wanted to use ROADM to upgrade its infrastructure network idea, and prepare for the future deployment of ROADM technology.

The optical module application characteristics and test parameter values

1 Introduction Today, Ethernet technology has become an indispensable for LAN, also can not be replaced by technology. With the popularization of network, the network scale expanding, Ethernet access technology rapid development, the network transmission rate increase, and the network interconnection and next generation network technology applications, Ethernet transmission method, transmission capacity, service quality more and more attention, in which the transmission distance, transmission rate is the Ethernet transmission ability important reflect, is from the traditional LAN Ethernet technology to the metropolitan area network technology and wide area network technology key. However, from a technical point of view, the transmission rate is higher, limited transmission distance is short; from the application demand, the more high speed, more may be used for transmission, the transmission distance is long. Also because of this pair of contradiction, and high-speed Ethernet to the larger campus backbone and metropolitan area application of rapid expansion, the Ethernet standard transmission distance constraints often encounter challenges: why is the standard distance constraints? In order to meet the actual needs can break through the distance? In this paper, based on the optical media of Gigabit Ethernet standards as reference, emphatically from the media access control method, transmission loss, chromatic dispersion of the transmission of Ethernet transmission distance limitation and breakthrough approach. 2 Gigabit Ethernet standard distance limit Since the 1998 June IEEE 802.3z Gigabit Ethernet standard ( about 1000 Base-SX, 1000 Base-LX and 1000 Base-CX interface ) formally adopted since, has passed the IEEE 802.3ab ( about 1000 Base-T interface ) Gigabit Ethernet standard and IEEE 802.3ae ( about 10 GBase-SR, 10 GBase-LR, 10 GBase-ER, 10 GBase-SW, 10 GBase-LW, 10 GBase-EW and 10 GBase-LX4 10 G Ethernet interface ). But on the long distance transmission of Gigabit Ethernet, the main concern is with the fiber medium related Gigabit Ethernet standard -- IEEE 802.3z. According to the IEEE 802.3z standard, the different optical fiber bandwidth corresponding to the wavelength, the maximum transmission distance as shown in table 1. Wherein, wavelength of 850 nm corresponding to 1000 Base-SX, 1310 nm 1000 Base-LX wavelength corresponding. Table 1 Gigabit Ethernet optical fiber types, corresponding to different wavelength of maximum transmission distance Optical fiber type wavelength ( nm ) mode bandwidth ( MHz• km ) maximum transmission distance ( m ) 62.5 μm multimode 850160220 62.5 μm multimode 850200275 50 μm multimode 850400500 50 μm multimode 850500550 62.5 μm multimode 1310500550 50 μm multimode 1 310400/500550 10 μ m single mode 1 310N/A5 000 In Table 1, and the transmission distance limit is closely related to an important parameter is the modal bandwidth, is a section of the fiber can be adopted by the maximum modulation frequency pulse modulation frequency and the length of the fiber product, it is the embodiment of optical fiber transmission of information capacity, mainly embodies the dispersion on optical fiber system transmission rate, transmission distance effects. Table 1 the relevant parameters in the given condition analysis:①using LD light source rather than low rate system that uses LED light source;②considered the different types, different levels of fiber, especially the traditional optical fiber, the optical fiber emerging not listed but it will provide a better performance;③single-mode fiber mode dispersion can be ignored no, the corresponding mode bandwidth value high enough; the maximum transmission distance without relay amplifying means, dispersion compensation of time distance. 3 key factors influence the transmission distance Effects of Ethernet transmission distance of many factors, such as noise, crosstalk, which is the key factors are the main media access control method, signal transmission attenuation and signal transmission dispersion. The following are their principle, effect analysis, improvement measures. 3.1 media access control method for transmission distance Ethernet media access control method for CSMA/CD is to restrict the transmission distance is the most basic factor, it appears with the Ethernet technology, and with the transmission rate limiting distance shorter. The basic idea of CSMA/CD is to say after hearing, when interference when looking for a chance to say, namely, for each node on the same network, sharing the same transmission medium, monitoring the same network segment of the state, and may try to send data, but at the same time there can be only one node can send all data, other nodes can receive the transmitted data, if the node transmits the data signals are confounded by other signals, that have been in conflict, using backoff algorithm for collision avoidance. Typical backoff is truncated binary exponential backoff algorithm ( Truncated Binary Exponential Backoff ): ( 1 ) when sending a first data when there is a conflict, and m=2; ( 2) give time for r time slices, each slice of time equal to network end-to-end round-trip propagation delay, R 0~2m random number; ( 3) n times when there is a conflict, m (=min n, 10); ( 4) n the maximum value is set to 16, exceeded discard data instead of retransmission. In 10 Mbps, 100 Mbps Ethernet, the minimum frame length of 64 bytes, time slice to send 512 bits required for the 1 Gbps Ethernet, delay, minimum frame length is 64 bytes, time slice is to send 4096 bits required delay. The minimum frame length constant is to ensure that the Gigabit Ethernet Compatibility, but based on CSMA/CD, to ensure that conflicts can instant, effective detection, the round-trip distance must be small enough so that the short frame, first in the last one before sending back the entire network, according to the signal transmission speed of 200000 km/s calculation, for 10 Mbps, 100 Mbps and Gigabit Ethernet round-trip distance were 10240 m, 1024 m and 102.4 M. Considering the delay caused by the connectors and other equipment, especially rate to send the short frame shorter time, thereby greatly reducing the collision domain diameter, segment length becomes unacceptable tens of meters. A solution to this problem is in the Ethernet frame is increased after a data phase difference extended field, whose length is equal to the time slice can send bits minus the minimum number of bits of the frame. This also resulted in Gigabit Ethernet transmission efficiency reduction, solution is introduced into the frame of the emergency mechanism, i.e. once successfully sent a frame, the station can not need to compete and continue to send other frames, the maximum burst size is limited to 65536 bits. 3.2 signal attenuation on the transmission distance Signal on the transmission medium, the energy will gradually loss, thus determines the signal in the absence of the relay when the maximum transmission distance. When the signal propagating in the fiber, is transmitted to theL average light power and incident when the average optical power exponentially decreasing, namely P ( L ) =P ( 0) 10 -α L/10, attenuation coefficientαunit is the dB/km. For Gigabit Ethernet, in Table 1, the maximum transmission distance is determined according to the corresponding transmission system loss characteristics, including the fiber loss, insert loss, optical path penalty, transmission power, sensitivity, rich degree. In IEEE802.3z, based on the worst conditions considered, given in the maximum transmission distance when the link power budget, see table 2. The implementation of the project, if the relevant parameters are consistent with the data in Table 2, the standard distance within the application is sure to succeed. In practical engineering, there are often beyond the standard distance application requirements, Table 2 the worst conditions of link power budget Parameters of 850 nm, 62.5 μ m850 nm, 50 μM1, 300 nm, 62.5 μM1, 300 nm, 50 μM1, 300 nm, 10 μ m, SMF Link power budget ( dB ) 7.57.57.57.57.57.57.58.0 Link distance ( m ) 2202755005505505505505 000 Channel insertion loss ( dB ) 2.382.603.373.562.352.352.354.75 Link power price ( dB ) 4.274.294.073.573.485.083.963.27 Minimum average transmit power ( dBm ) -9.5-11.5-11.5-11.5-11.0 Receiver sensitivity ( dBm ) -17-19 Extinction ratio ( dB ) 9 Affluence ( dB ) 0.840.600.050.371.670.071.190.16 Of or based on the cost and other factors to consider, need to adopt the standard distance shorter but low cost plan, therefore, it is necessary to analyze table parameters: (1 ) standard numerical determination of the premise: considering a variety of possible situations, such as different manufacturers, different types of connectors, different manufacturers, different types of optical transmission characteristics vary widely, such as the early optical fiber. ( 2) the standard on the transmission distance of extended leave " backdoor ": if consistent with other standard conditions, beyond the range is acceptable. ( 3) the table parameters: ①link power budget and transceiving equipment: link power budget values for the minimum average transmission power and receiver sensitivity difference, therefore, if the actual sending and receiving devices with different parameter values in the table, as long as the difference with the link power budget requirements, should also be able to meet the actual needs. ②channel insertion loss: including the link section of optical fiber connection loss, line loss. ③link power price with the exception of the link loss related, and link dispersion, noise and the sending end of the extinction ratio and so on, its reason is the waveform distortion resulting receiver sensitivity decline. ④link power budget and rich degree: a segment to be successfully implemented, is to meet the requirement of bit error rate signal transmission, the link power budget should be large enough, or the channel insertion loss and link power price should be small enough, in order to make the system power is rich and non insufficient, should meet: Margin = link power budget - channel insertion loss - link power price > 0 ( 4) : data in the table for further analysis: In Table 1 channel insertion loss value should contain at least two of the connector insertion loss and optical fiber line loss. With MT-RJ joint each on the maximum insertion loss value of 0.75 for dB, two for maximum insertion loss value of 1.5 dB, 62.5μ m if the use of multimode optical fiber in the 850 nm band transmission signal, according to the maximum optical attenuation 3.75 dB/km calculation, the maximum distance is 220 m 0.825 dB loss, so a total of 2.325 dB channel insertion loss, still meet the 2.33 dB channel insertion loss budget. For the commonly used SC, ST and FC models of the connector, the insertion loss is much smaller, with a company of Wuhan product as an example, the insertion loss of single mode::≤ 0.3 dB, multimode:≤ 0.1 dB, even MT-RJ connector, its actual insertion loss: single-mode:≤ 0.7 dB, multimode:≤ 0.45 dB; on the other hand, a new multimode fiber attenuation has also been reduced in 850, NM < 3 dB/km, 1300 nm < 1 dB/km. Thus, a single channel insertion loss value, the actual power budget has quite rich. ②table link power budget for 7.5 dB or 8 dB, the actual equipment to provide greater link power budget, it means that the system can provide farther transmission distance. The 3.3 dispersion on Ethernet transmission distance The dispersion of fiber for optical signals of different frequency components and different patterns of components caused by the different transmission speed, it makes the optical fiber bandwidth is narrowed, thus limiting the optical fiber transmission capacity, but also limits the optical signal without electric relay transmission distance. The dispersion of fiber are the main mode of chromatic dispersion, dispersion and polarization mode dispersion, which in the fiber type, the transmission rate of the system, light source, modulation mode of different systems have different effects on. At a high rate, long distance optical fiber transmission system, dispersion of the system has significant effect on. As for the 10 G Ethernet, if the G.652 single-mode optical fiber ( NDSF ), and the EA modulator, only 1550 nm wavelength, light source for chirped single longitudinal mode laser source, at this time, dispersion limited distance is mainly composed of frequency chirp power price and the chromatic dispersion power, its dispersion limited distance of about 34 km; the same environment for the 2.5 Gb/s system, its corresponding dispersion limited distance of about 600 km

Optical module and optical fiber connector application guide

One, the optical transceiver module definition The optical transceiver module is composed of optoelectronic devices, circuits and optical interface components, optoelectronic device includes transmitting and receiving the two part. Transmitting part is: input a certain rate of the signal through the internal drive chip processing after driving a semiconductor laser ( LD ) or a light emitting diode ( LED ) emitted from corresponding rate modulated optical signal, its interior with automatic optical power control circuit, the output power of the optical signal to maintain the stability of. The receiving part is: a certain rate optical signal input module by the light detecting diode is converted to electrical signals. The preamplifier output corresponding rate signal, the output signal is generally PECL level. At the same time in the input optical power is less than a certain value will output a warning signal. In two, the optical transceiver module classification In accordance with the rate: Ethernet 100Base ( 100m ), 1000Base ( GPA), 10GE Application of SDH 155M, 622M, 2.5G, 10G In accordance with the package : 1× 9, SFF, SFP, GBIC, XENPAK, XFP, a variety of packaging. 1 x 9 package -- welding type optical module, the general speed of not more than thousand, use SC interface The SFF package­-- welding small packaged optical module, the general speed of not more than thousand, use LC interface The GBIC package -- hot pluggable Gigabit interface optical module, using SC interface The SFP package -- hot plugging of small package module, the highest rate of up to 4G, using LC interface The XENPAK package -- Application in Gigabit Ethernet, using SC interface XFP -- 10G optical module package, available in Gigabit Ethernet, SONET and other systems, uses the LC interface According to the laser types: LED, VCSEL, FP LD, DFB LD In accordance with the emission wavelength: 850nm, 1310nm, 1550nm etc. According to the using modes: non hot-plug ( 1 ×9, SFF ), hot pluggable ( GBIC, SFP, XENPAK, XFP ) In three, a fiber optic connector classification and main specifications and parameters Optical fiber connector is in a section of the fiber ends are mounted on the connecting head, mainly for the use of light distribution. According to fiber type: single mode optical fiber connector ( usually G.652 fiber optical fiber diameter: 9um, diameter 125um), multimode optical fiber connector According to the optical fiber connector is connected to the head form: FC, SC, ST, LC, MU, MTRJ and so on, the current commonly used with FC, SC, ST, LC, Type FC -- the earliest by Japan NTT development. External reinforcement using metal sleeve, fastening means for turnbuckles. Test equipment selection of the joint more. Type SC -- from the development of Japanese NTT company molded plug coupling connector. Its shell with molding with a mold made of plastic, glass fiber, is rectangular; pin by precision made of ceramic, metal slotted sleeve coupling sleeve structure. The fastening way adopts plug pin type, does not require rotation. Type LC -- company's design. The outer diameter of the sleeve is 1.25mm, are usually used in FC-SC, ST 2.5mm half casing outside diameter. Improved application of density. According to the optical fiber connector head pin end points: PC, SPC, UPC, APC According to the optical fiber connector: diameterΦ 3,φ2,φ0.9 Optic fiber connector mainly optical properties, mechanical properties, interchangeability, environmental performance and life. The most important of which is the insertion loss and return loss of the two indicators. In 1, the optical module transmission rate: fast, Gigabit Ethernet, 10GE etc. In 2, the optical module transmitting optical power and receiver sensitivity: transmitting optical power refers to the transmitting terminal of the light intensity, receiving sensitivity can detect the intensity of light. Both in dBm as a unit, is the effect of the transmission distance is an important parameter. The optical module can transmit distance mainly by loss and dispersion two limited. Loss limit according to the formula: loss restricted distance = ( transmitting optical power - receiving sensitivity ) / optical fiber attenuation to estimate. Optical fiber attenuation and the actual selection of optical fiber. The general current G.652 fiber can achieve 1310nm band 0.5dB/km, 1550nm band 0.3dB/km even better. 50um multimode optical fiber in 850nm band 4dB/km 1310nm band 2dB/km. For fast, gigabit optical module dispersion Limited far outweigh the loss is limited, can not be considered. In 3, 10GE optical module according to 802.3ae standard, the transmission distance and the selection of optical fiber type, Hikarumo Hikaru performance. 4, saturated optical power values of light module receiving end maximum detectable optical power, generally -3dBm. When the received optical power greater than the saturation power time can also lead to error code generation. So the emission light power laser module without attenuation loopback test error phenomenon will appear. In five, the optical module failure reason The optical module failure for transmitting end and receiving end failure analysis failure, the specific reasons, most often a problem focused on the following several aspects: 1 of light pollution and damage Due to the pollution and damage caused by the optical interface of optical link loss becomes larger, resulting in optical link. The reasons are: A. optical module, light exposure in the environment of light pollution, dust entering; B. use of optical fiber connector end face have pollution, light pollution two optical module; C. pigtail optical connector end face used improperly, surface scratch; D. use inferior optical fiber connector;

Analysis on the development and Prospect of optical fiber communication technology

Abstract: analysis of the development of optical communication technology history and current situation of the development, and the development trends of optical fiber communication technology are prospected. One, the development of optical communication technology and present situation Optical fiber communication is the birth and development of an important history of the telecommunications revolution. Fiber made from theory to technology and today's high speed optical fiber communication only several years. From the overseas development process we can see, nineteen sixties metaphase, developed the best optical fiber loss in more than 400 DB 1966, British Standard Institute of telecommunications Kao and Hockham theoretically predicted fiber loss can be reduced to 20 dB / km below, Japan in 1969 developed the first root communications with fiber loss of 100 dB / km, 1970 Corelle ( Corning ) using the " powder " has won the loss is less than 20 dB / km and 4 dB / km of low loss fiber, 1974 Baer Lab ( Bell ) using a modified chemical vapor deposition of a better performance than the Corelle company's fiber products. By 1979, germanium doped silica fiber in the 1.55 kilometers of the loss has been reduced to 0.2 dB / km, it has very close by Rayleigh scattering is decided by the quartz fiber loss limit theory. At present the domestic optical fiber and cable production overcapacity, oversupply. Special optical fiber for fiber such as FTTH still needs to be imported, but the total amount of domestic production of optical fiber and cable, with the international market price of no difference, the cost could not be lower, is already zero profit, in the international market competitiveness is not strong, export volume is very small. Twenty years of light technology two major development, WDM and PON, the two have been relatively mature. Multi service transmission platform for the development of two aspects, one is more effective carrier Ethernet service, data service, on the other hand, is to the development of business. The status of AS0N is the current system only within the device, or is in the network to achieve a number of functions, but some of the core role has not been reached. Two, the tendency and prospects of optical fiber communication technology At present, in the field of optical communication has several hot topic for the development of very high speed transmission system, large capacity WDM system, optical transmission network technology, a new generation of optical fiber and optical access network technology, IPoverOptical. ( a ) to high speed system development The current 10Gbps system has begun mass equipment network, mainly in North America, in Europe, Japan and Australia have also started a large number of applications. However, the 10Gbps system for optical fiber polarization mode dispersion is more sensitive, and has laid the cable does not necessarily can satisfy the opening and use of the 10Gbps system requirement, need the actual testing, certification before installation of the opening. Its practical outlet steering light multiplexing mode. An optical way has many kinds, but at present only the wavelength division multiplexing ( WDM ) mode in the large-scale commercial stage, while the other is still at the stage of experimental study. ( two) to the large capacity WDM system evolution Using electricity time division multiplexing system expansion potential has been tried, however optical fiber 200nm available bandwidth resources only with utilization rate of less than 1%, there are 99% resources are still to be discovered. If a plurality of transmission wavelength of staggered light signals at the same time the level of optical fiber transmission, can greatly increase the fiber transmission capacity, this is the wave division multiplexing ( WDM ) is the basic train of thought. Based on the WDM application huge benefits and in recent years the major breakthrough on the technology and market driven, wavelength division multiplexing system development is very rapid. The current global actual laying WDM system has more than 3000, and the practical system for maximum capacity has reached 320Gbps ( 2× 16 × 10Gbps ), the United States of America lucent company has announced that it will launch 80 wavelengths of WDM system, the total capacity up to 200Gbps ( 80 × 2.5Gbps ) or 400Gbps ( 40 × 10Gbps ). Laboratory of the highest level have reached 2.6Tbps ( 13 × 20Gbps ). Predict before long in the future, the practical capacity of the system can achieve 1Tbps level. ( three) to realize optical networking The utility of WDM technology in spite of the great transmission capacity, but basically is to point to point communication based system, the flexibility and the reliability is not ideal. If in the light path can also achieve similar SDH circuit in the transplanting function and cross connect function words, will add a new layer of power. According to this one main train of thought, optical networking can realize large capacity optical network and the network scalability, reconstruction, transparency, and allows the network nodes and the continuous increase in business volume, interconnecting any system and different system signal. Because the optical networking has potential huge advantage, the United States and Europe and Japan and other developed countries put a lot of manpower, material resources and financial resources for research, particularly the United States Department of Defense Advanced Research Agency ( DARPA ) has funded a series of optical interconnection project. Optical networking have become SDH electric network after another new development climax of optical communication. The construction of a maximum transparent, highly flexible and large capacity of the national backbone optical network, not only for the future of the national information infrastructure ( NJJ ) to lay a solid foundation, but also to our country first Century the information industry and national economic development and national security has the extremely important strategic sense. ( four ) the development of new generation optical fiber The traditional G.652 single-mode optical fiber in the adaptation of the super high speed long distance transmission network development needs have been exposed to the output does not from the heart of the situation, the development of new fiber has become the development of the next generation network infrastructure is an important component of. At present, in order to adapt to the backbone and man 's different development needs, has appeared two kinds of novel optical fiber, i.e. non zero dispersion ( G.655 fiber ) and percutaneous absorption optical fiber ( all wave fiber ). Among them, all wave fiber will be the future development focus, is also a research hotspot now. In the long run, BPON indisputably will be the future of broadband access technology development direction, but from the current technology development, cost and application needs of the actual situation, its distance is widely used in Telecom Access Network this one ultimate goal will have a longer development process. ( five) IPoverSDH and IpoverOptical In the business of lP based data services is the current world information industry development of the main driving force, which can effectively support JP business has become a new technology can have long-term technical life logo. At present, ATM and SDH were able to support lP, respectively called IPoverATM and IPoverSDH both each has its own merits. But from long-term look, when IP business volume increased gradually, need above 2.4 gigabit per second link capacity, it may eventually leaves out middle layer SDH, IP directly in a light path runs, form is very simple and unified IP network structure ( IPoverOptical ). Three kinds of IP transmission technology will be in the development of the telecommunication network in different periods and different parts of the network to play its due role in history. But from the perspective of the future. IPoverOptical will be the most long-term vitality of the technology. Especially with the IP business has gradually become the dominant business network, the JP business ideal transmission technology will become the future network especially the backbone leading transmission technology. ( six ) to solve the network bottleneck by means of optical access network In recent years, the core part of network happened to turn the world upside down changes, whether the exchange, or transmission have been updated for several generations. Soon, this part of the network will become the digital control and master, software, network integration and intelligent, but on the other hand, the existing access is still dominated by twisted-pair copper ( more than 90%), primitive simulation system. The technology has the tremendous contrast, restricting the further development of the entire network. In order to fundamentally solve this problem, we must vigorously develop the optical access network technology. Because the optical access network has the following advantages: ( 1) reduce the maintenance cost and failure rate; ( 2) cooperate with local network structure, reducing node, expand the coverage; ( 3) make full use of optical fiber has brought about a series of benefits; ( 4) building a transparent optical network, meet the multimedia era.

Unified Communications: computer technology with traditional communication technologies

Unified communication means, the computer technology and traditional communication technology one of the new communication mode, both the integration of computer networks and the traditional communication network in a network platform, telephone, fax, data transmission, audio and video conferencing, call center, instant communication and many other application service. In the fusion of communication, the telephone network ( VoIP ) is one of the key. It is also called the "three networks convergence ". Triple play is a generalized, social view, at this stage, it does not mean that the telecommunication network, computer network and cable television network network physical one, but mainly refers to senior business application integration. The performance of technology convergence, network layer can achieve interoperability, to form a seamless coverage, the business layer of mutual penetration and cross, the application layer tends to use a unified IP protocol, in the operation of mutual competition, mutual cooperation, toward the human to provide diversified, multiple media, personalized service of the same target gradually converge, industry regulation and policy also tends gradually to unity. The big three network through technical transformation, to provide voice, data, image and multimedia communications business. This is the so-called triple play. Convergence, in concept from different angles and levels of analysis, can be related to the technology, business integration, industry, terminal and network fusion fusion fusion. At present, more important is the application of level to each other using an unified communication protocol. Optimization of IP optical network is a new generation telecommunication network based, is what we call the convergence of combination. The rapid development of digital technology and the comprehensive use of, make the call, and image signal data are available through the unified coding transmission and exchange, all operations in the network will become a unified "0 " or " 1 " bit stream. The development of optical communication technology, integrated delivery of various business information to provide the necessary bandwidth and transmission of high quality, become the ideal business platform network. The development of software technology makes the big three network and terminal through software changes, the final support for various user desired characteristics, functions and operations. The most important is the unified TCP/IP protocol widely used, will make all kinds of IP based on different online business can realize the intercommunication. The first human has uniform for the three network can receive the communication protocol, from a technical for the convergence of three networks laid the solid foundation. However, if according to the traditional approach to integration will be a long-term and arduous process, how to bypass the traditional networks to achieve fusion purpose, that is to find the revolution of telecommunication system of the road, we must grasp the development trend of the technology, combined with China's actual situation, to choose our own road of development. Our actual situation is data communication compared with the developed country starts late, the traditional data communication business size, compared with the developed countries, the protocol multi-service burden is much smaller, therefore, can be as soon as possible towards IP based system, using IP optimization in optical cable optical network, broadband IP network construction, the acceleration of China's Internet network development, and make the Chinese traditional communication network coexist for a long time, saving expenses and make full use of the existing cyber source.

In order to transport network transition to full service broadband revolution

Broadband bearer all kinds of information application is becoming the business income of the main point of growth. Consumers hope that through mobile phone, computer and television screen whenever and wherever possible to enjoy every kind of integrated broadband services, namely the " full service broadband ". Due to the fierce competition, the bandwidth of the price is the rapid decline. Therefore, in the full service broadband consumer demand is excited at the same time, the operator facing data traffic growth is far greater than the business income growth of the enormous challenges. In the severe market environment, competitive, operators must reasonable planning, construction and operation of networks, including CAPEX ( by reducing network construction costs ) and OPEX ( network operation cost, total cost of ownership ) network, realize the full service broadband health development. Advance of optical transmission network has become one of the important measures of transition part. Full service broadband 3 changes Full service broadband to the operator brings out the 3 dimension change: First of all, the operator must face huge challenges to the network data throughput. Statistical data shows, the second quarter of 2009, the global mobile data bandwidth usage increased by nearly 30%, among them Asian growth at 36%. This also means that the rapidly increasing transmission bandwidth increased room and site operation cost, energy consumption. Therefore, operators must improve the data throughput per dollar, and ensure the lowest construction and operation cost, optimize the network, reduce the total cost of ownership. Secondly, the operator must be able to pass fixed and wireless network seamlessly provides various services. In fact, a full service broadband business users, hope to be able to seamlessly use fixed access or wireless access, from the Internet access to the same content and services. Once again, IP business, will promote the network leading the change of the type of business, from TDM to IP packet based transformation. IP networks can make the operator management cost is reduced, and effectively improve the quality of service and profit, has become a full service broadband operation foundation. Transmission network transformation Reasonable selection of equipment needs hierarchy Massive data, business integration and network IP based on optical transport network, raised new requirement, this expression is in: transmission technique choice and product definition should be able to effectively reduce the construction cost, and can simplify the maintenance management, reduce the OPEX; transport network must be able to adapt to the broadband services refers to the level of growth, to network transmission capacity expansion; transmission network can adapt to all kinds of business efficient bearing demand for bandwidth is provided, and a fast and flexible service scheduling; transmission network can meet a variety of business on the transport properties and QoS requirements, and efficient service protection and recovery. However, it is emphasized, transport network function is to provide for the long-term (based on month or year ) connection, and can provide for network fault service restoration. Operations of the IP and the " IP network ", does not mean that the network will use the traditional IP technology, does not mean that the transmission network by router network will be replaced, but the means that should choose to suit IP business efficient, economic and delivery methods. For the evolution of networks, different operators face the situation varies, depending on whether both wired and wireless network, it is a monopoly operators or new entrants, and policy control and operator organization structure. Relative to the router technology, studies have shown that: using hierarchical lower equipment networking, each down two layer, network TCO will be reduced by more than 30 times. In the particular port capacity, the lower layer device to replace the upper device network, will save CAPEX 3～ 7 times. However, greater savings from OPEX. This is because, first of all, the low layer network equipment, for the same capacity, the equipment used on the lower chip power requirements, the size of the device is substantially reduced, power consumption and air conditioning costs will be substantially reduced; second, the low layer equipment configuration and management of maintenance easier, so the maintenance staff technology level is low lower cost, maintenance, low layer device simplifies the operating means that configuration errors may occur in smaller, more easy to fault location and service recovery; in addition, the operator on the optical network equipment depreciation rate is less than the routing device. These are MSTP and Ethernet is still attractive factor. In certain circumstances, strengthening the routing node transfer function to reduce the optical transmission equipment investment is of great significance. It is mainly applied in the operation of new entrants to the market or small scale network ( enterprise network ), but when the expansion of network scale, equipment number up to hundreds of thousands, network total cost of ownership will benefit greatly from a reasonable level of equipment selection. To manage IP bearing evolution At present, in the transport network of metropolitan area level, operators are widely deployed SDH/MSTP. The advantage of SDH technology in network management, protection, at the same time with the economy. Based on the SDH MSTP will have a packet service capacity. However, SDH/MSTP VC based particle scheduling, limiting its bearing IP business efficiency, therefore, operators have begun to PTN evolution. However, although some operators have expressed to stop the SDH deployment, but considering the network continued evolution requires PTN and the mature market still remain time, MSTP will be in 3 to 5 years continue to be deployed and used. At the same time WDM system a large number of applications, and to enter into various levels of network deployment. Wave division multiplexing ( WDM ) extended fiber optic capacity, and reduce the optical fiber transmission cost, solve the scarcity of resources, by using the optical amplifier, single wave rate to 10G WDM transmission distance can reach 4000 kilometers. Along with the high-speed router port, 40G technology has been widely deployed; 100G is also actively promote, and is expected to in 2011 after beginning to mature. Most of the current deployed WDM system is a point-to-point network, based on reconfigurable optical add-drop multiplexing system ( ROADM ), WDM network can evolve into a mesh network, as the SDH in the original transmission network evolution process. From polycyclic to mesh can obtain 20%～ 30% cost savings, while the network deployment scenarios are also from long distance backbone network to the core, convergence and access network WDM network evolution, widely deployed that can better serve the router network, but can also network with You Bo wins business functions provide direct services, to achieve the simplified network level, saving TCO. IP business direct upload to WDM network will face networking, protection and maintenance management deficiencies. In view of this, a new generation of WDM system through the comprehensive support G.709 function, to achieve IP network and optical network maintenance and management as well as network protection system organic union, OTN will, to achieve IP network and optical network in transport plane uniform. The ASON/GMPLS control plane with reconfigurable ROADM has wavelength scheduling function can further enhance the business recovery ability and service deployment capability and resource management. Through further integration of ROADM and the introduction of OTN/ packet cross will generate new device type -- Based on packet optical transport platform ( POTP ). POTP capacity in hundreds of G to several T to support the fixed broadband and mobile data services in packet transmission, will play an important role in. In short, full service broadband era, in order to optimize the network life cycle cost, enhance the network control and management, network service oriented network flexibility and robustness will be transport network evolution of overall objectives and requirements, thus transmitting network evolution strategy not only focus on the promotion business processing hierarchy and Realization of IP routing, whereas the need from the point of business development and network continuity starting to develop based on network performance and cost ( TCO ) optimal overall development strategy and plan, to achieve the IP oriented economic, efficient, reliable and flexible transmission network.

Small package for optical transceiver or into a new generation of trend

Communication network transmission capacity and expanding rate along with the increase of modern information network of optical fiber communication becomes the main transmission means, now in the optical communication network, such as a wide area network ( WAN ), metropolitan area networks ( MAN ), local area network ( LAN ) needed as one of core of optoelectronic devices and optical transceiver optical transceiver module more and more types, are increasingly high requirements, complexity is developing at an amazing speed. Optical transceiver, the optical transceiver module sharp increases in the diversity, needs to continue to develop related technology that satisfies the application requirements. The optical transceiver development direction may be moving towards miniaturization. The optical transceiver optical transceiver module for optical fiber access network core devices promote the trunk optical transmission system to low cost development, makes the optical network configuration is more complete and reasonable. In order to adapt to the requirements of communication equipment for optical device, optical module is highly integrated small package development. Highly integrated photovoltaic module the user without having to deal with high speed analog signal, shorten the R & D and production cycle, reduce the vitality of types of procurement, reduce production costs, therefore also more and more receives equipment manufacturer's favor. The optical transceiver transceiver module of photoelectric device encapsulated by the larger size of the dual-in-line forms for the development of coaxial package forms; optical interface structure from ST, FC to SC and the smaller LC, MT-RJ type connection form, a corresponding optical transceiver optical transceiver module packaging form from the metal packaging development into the plastic package, consisting of a single interface separation module developed to interface transceiver module. Pin arrangement and encapsulated by a dual-in-line 20 foot, 16 foot separation module to the development of the single row 9 feet ( 1X9 ), two 9 foot ( 2X9 ) and the future of double rows of 10 foot and 20 double foot transceiver module. SFF ( Small Form. Factor ) small packaged optical module adopts the advanced precision optics and integrated circuit technology, dimensions of only ordinary duplex SC ( 1X9 ) type optical fiber transceiver module half, in the same space can be doubled optical port number, can increase the line port density, reduce the system cost per port. Because the SFF small package module adopts a similar MT-RJ interface with the copper network, size and common computer network wire interface, is conducive to the existing copper network device to transition to a higher rate of optical fiber network to meet the rapid growth of network bandwidth requirements. Small package for optical transceiver optical transceiver module to the appearance of small package size advantage, so that the network device interface of the optical fiber number doubled, single port rate Gigabit magnitude, to meet the INTERNET era of network bandwidth demand rapid growth. Can say small package for optical transceiver optical transceiver module technology represents a new generation optical communication device development trend, is the next generation high speed network foundation.

Optical fiber amplifier in optical wireless communication applications

Introduction Wireless optical communication with laser as the information carrier, is a not need any cable channel as a communication method. Compared with the microwave communication, wireless optical communication by use of laser high frequency, strong directivity ( confidentiality ), the available spectrum is wide, without the need to apply frequency license; compare with optical communication, optical wireless communication has the advantages of low cost, simple construction, fast. It combines the advantages of microwave communication and optical fiber communication, has become a new broadband wireless access way, got the wide attention of people. However, severe weather conditions, for wireless optical communication system spread signals generated attenuation effect. The air of the scattering particles, can make the light in space, time and angle to produce different degrees of deviation. Atmospheric particles may also absorb the laser energy, so that the signal power decrease in wireless optical communication system, optical fiber communication system of low loss propagation path has ceased to exist. Atmospheric environment changeful objectivity cannot change, to get better and faster transmission effect, in the atmospheric channel transmits optical signals to put forward higher requirements, in general, the power of the light signal can be obtained better transmission effect. With the development of optical fiber amplifier ( EDFA ) is developing rapidly, stable and reliable power source in various applications to meet the requirements of wireless optical communication. 1 EDFA principle and structure Erbium doped fiber amplifier ( EDFA ) has high gain, low noise, wide frequency band, high output power, low loss and polarization insensitive connection etc., directly on the optical signal is amplified, without the need for conversion into an electrical signal, can ensure the optical signal in the case of stable minimum distortion power amplifier. 1.1 EDFA principle In erbium doped fiber pumped enough strong pump, can be most in the ground state Er3+ ion pumping to the excited state, in the excited states of the Er3+ ion and rapidly without radiation transfer to a metastable state. As a result of Er3+ ions in a metastable state, longer service life, thus easily in a metastable state and the ground state is formed between the particle number inversion. When the signal photons through the erbium doped fiber, and is in a metastable state Er3+ ion interactions occur stimulated radiation effect, produce a large number of their identical photons, then through the erbium-doped optical fiber transmission of signal photons increases rapidly, generating signal amplifying function. Er3+ ion in a metastable state, in addition to the occurrence of stimulated emission and stimulated absorption, but also produce spontaneous radiation ( ASE ), it caused the noise of EDFA. 1.2 EDFA structure A typical EDFA structure mainly comprises an erbium-doped fiber ( EDF ), a pumping light source, coupler, isolator. Erbium doped fiber is the core part of the EDFA. It is quartz optical fiber as matrix, mixing in the core of solid laser material of erbium ions, in a few meters to tens of meters of erbium doped fiber, the interaction of light and matter is amplified, enhancement. The optical isolator is the role of inhibition of light reflection, to ensure that the amplifier stable work, it must be a low insertion loss, polarization independent, isolated over 40 dB of. 1.3 EDFA characteristics and performance index Gain characteristics of said amplifier, which is defined as the ratio of the output power and input power: Type : Pout, Pin denote respectively the amplifier output and the input end of the continuous signal power. Gain coefficient is defined from the pump light source input 1 mW pump power through the fiber amplifier to obtain the gain, the unit is dB / mW: Type: G0 is composed of pump intensity of small signal gain coefficient, as a result of gain saturation phenomenon, with increasing signal power, gain coefficient decreased; Is, Ps respectively for the saturation intensity and saturation power, is to show that the gain of material properties, and the doping coefficient, fluorescence time and transition section for. The gain and the gain coefficient of difference: the gain is mainly directed against the input signal, and the gain coefficient is mainly directed against the input pump character. In addition, gain and pumping conditions ( including the power of pump and pump wavelength), the primary pump wavelength was 980 nm and 1480 nm. Because of all the gain factor is different, and the gain must be in the whole fiber integral is obtained, so the characteristics can be used to by selection of the fiber length is relatively flat gain spectrum. 1.4 EDFA bandwidth The gain bandwidth of signal light obtained certain gain amplification wavelength region. In fact EDFA gain frequency change ratio theory is much more complicated, and also the matrix fiber and its doping related. In the EDFA gain spectrum width has reached hundreds of nanometers and gain spectrum is relatively flat. ED-FA gain spectrum in the range of 1525～1565 nm.

The typical application of HyHPY analysis

Nowadays, network traffic growth of 99% from packet flow, namely the Ethernet packet data, instead of voice traffic. From the development trend of the future can see inside, the near future will be from the mobile phone more 3G data, and video traffic, these data flow will make the SDH now such a network was too busy to attend to all. Therefore, domestic and foreign telecom operators are active deployment optimization IP network, and the need for new technology that can be transformed into existing networks based on OTN metropolitan area network infrastructure. Figure 1 shows, these new equipment including: WDM or ROADM device, frame type OTP and a OTP (µ -OTP ). In the global market of optical transmission equipment, mainly OTP/ROADM model of optical transmission equipment demand expands ceaselessly, is gradually replacing the SDH equipment. ( Figure 2) Figure 2: optical transmission equipment revenue PMC-Sierra HyPHY series is derived from HyPHY 20G and HyPHY 10G were associated together, in order to apply micro OTP, any OTP service, rate and port line card and ROADM single chip multi service converged type wavelength converter ( Muxponder ) and ( Transponder ) transmitting transponder. The only difference between product capacity, data and other features are exactly the same. Original equipment manufacturer based on HyPHY series ROADM, OTP and OTP miniature (µ -OTP ) equipment. Not only can satisfy the technical requirement of telecom operators, but also can significantly reduce the operating and capital expenditure. Figure 3: applicable to any business, rate, port multiple business focusing type wavelength converter ( Muxponder ) Multi service converged type wavelength converter ( Muxponder ), is used in WDM or ROADM equipment, need to reduce power consumption and BOM based on cost, satisfy any service, port Muxponder or MSPP-on-l card needs. While the HyPHY 10G/20G for discrete solution, single chip solution can be BOM cost and power consumption reduced by over 50%, to its paired cards ( Mated Card ) between the protection function can be supported in SONET or OTN flow; also can be directly connected to the adjustable WDM ready to XFP or MSA module; the last packet interface, can be for the L2 business to provide optional support. Figure 4: applicable to general transmission responder ( Transponder ) Universal transmission responder ( Transponder ) is used in WDM or in ROADM equipment, this is the HyPHY second applications, 10G traffic input and output flow can be used in 10G, SDH or OTN network. HyPHY 10G can not only make the Transponder power and BOM cost reduced by over 50%, and in Muxponder applications, pairing between the card protection function can be supported in SONET or OTN flow, and can be directly connected to the adjustable WDM ready to XFP or MSA module. In addition, but also with HyPHY 20G 100% PIN and software compatibility. Figure 5 : application to multiple line card OTP Line card application is the most prevalent, system side is some cross plate, and the line side SFP can support different ports, to support different business, such as Ethernet, fibre channel and so on. HyHPY 20G as a single chip solution, can effectively reduce power consumption and BOM cost, and satisfies the high density of any service, port line card needs. In addition, HyHPY 20G SONET/SDH and ODUk support leading function and ODTUk multiplexing function; has the incomparable flexibility, the flow is mapped to the STS-ns or ODU-ks; also has a OTN system interface which can be connected to the OTN, SONET/SDH and can realize the packet structure. Fig 6 applicable to miniature OTP (µ -OTP ) For HyPHY products, especially HyPHY10G chip, through the optimization of the equipment has become very small, while reducing the power consumption, power micro OTP to miniaturization and lower power direction. HyPHY10G supports the industry characteristics of the most abundant, is applied to the OTN or SDH network is a small OTP platform, and with on-chip SONET/SDH and ODUk communication function and ODTUk multiplexing function. Global telecom operators compete to build IP of optimized OTN network must address access integration problems, OTN can replace SONET/SDH. PMC-Sierra HyPHY series OTN support bearing multiple business integration, packet structure bearing the OTN exchange and meet OTP and ROADM requirements standard line card, a comprehensive solution to access integration problems. PMC-Sierra enables OTN to realize end to end instead of SONET/SDH.

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Set your budget for creating the baby nursery. Break down the expenses among furniture, decor, renovations, bedding and storage containers. Use the prepared budget to decide which pieces to buy for the room.
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Brainstorm themes, colors and general design styles for the nursery. Choose the combination that best fits your personality and the rest of the home, while keeping a child-like feeling to it. Use the chosen concepts to plan all of the nursery elements.
Step 4

Paint the walls of the nursery in a color that complements the selected theme and decorating style. Use a low- or no-volatile organic compounds, or VOC, paint for the healthiest option. Regular paint contains toxins that continue to release into the air long after the paint dries.
Step 5

Measure the nursery as a guide for planning the layout. Draw a floor plan of the room with the dimensions, including windows, doors, closets and other structures in the room. Sketch in each of the pieces of furniture for the nursery.
Step 6
the room with fabric.