Fast development of optical communication testing technology

In recent years, the main development trends of optical communication technology include capacity improvement, further intelligence, optical transmission of Carrier-class Ethernet, and fiber-to-the-Home. Along with the development of these technologies, optical communication testing technology has also developed rapidly.

The development of the optical communication industry depends on the drive of the market and the development of technology. In recent years, the main development trends of optical communication technology include capacity improvement, further intelligence, optical transmission of Carrier-class Ethernet, and fiber-to-households. The technical standards involved include DWDM, ASON, GPON, and EPON. Along with the development of these technologies, optical communication testing technology is also developing rapidly.

Large Capacity Testing boosts new instruments

With the development of technology and business, the WDM Technology is expanding from the long-distance transmission field to the man field. The WDM system applicable to the man field is called the Metro WDM System. Low cost is the most important feature of Metro WDM Systems. Because the transmission distance of the Metropolitan Area Network is generally no more than 100 kilometers, the external modulation and optical amplifier that must be used by the long-distance network can be omitted. The addition and expansion of wavelength numbers are no longer limited by the band of the optical amplifier, it allows the use of light sources, wave generators, filters and other components with a wide wavelength interval, low wavelength accuracy and stability requirements, which greatly reduces the cost of components, especially passive devices, thus, the cost of the entire system is reduced.

As the WDM Technology continues to advance, major manufacturers of testing instruments have also launched innovative instruments for WDM testing.

Optellent company launched a small 10 Gbit/s Code tester OptoBERT series, the model is OPB-X110. The product has a reference clock, signal format generator, Clock Recovery Circuit, and Error Code Analyzer in a very compact structure, providing a flexible and convenient operation interface, the 10 Gbit/s optical port and electrical port can meet the R & D, production, and testing needs for devices, modules, and subsystems, and can be used in field engineering installation and Fault Locating environments.

However, due to the popularity of new Internet applications represented by P2P, IP traffic continues to increase rapidly. Currently, 10 Gbit/s-based long-distance WDM Networks are insufficient, some sections 80 × 10 Gbit/s have been used up, so the application of the 40 Gbit/s-based WDM system comes to the agenda. Its main advantages include high spectrum efficiency, low transmission cost, low OAM cost, low complexity, and a small number of spare parts, which can effectively reduce the number of IP links, improve node Structure scalability, and improve the core network efficiency and functions.

In addition to market factors, the main factors that affect the application of 40 Gbit/s are technology, price, and polarization mode dispersion (PMD) of optical cable lines ). Technically, the 40g system has made great technological progress after so many years of continuous improvement. A large number of active and passive devices are available, reducing costs quickly. The power flat, non-linearity, color dispersion, and polarization mode dispersion performance of various devices are significantly improved, so that the power redundancy requirements of the system design can be moderately relaxed. In particular, DQPSK/DP-QPSK modulation technology, Electronic Dispersion Compensation and super out-of-band FEC coding and a series of new technology breakthroughs and maturity, for long-distance application cost-effective improvement provides a solid foundation

In terms of the polarization mode dispersion characteristics of optical fiber cables, recent research results by China Telecom show that the polarization mode dispersion performance of most optical fiber cables laid in the east of Beijing-Guangzhou line can basically meet the requirements of 40 Gbit/s transmission, therefore, the polarization mode dispersion of optical cables is no longer a major obstacle to application.

Therefore, the testing instrument market of 40 Gbit/s transmission equipment is active. EXFO introduces an integrated IQS-600 certification system for testing devices and systems up to 40 Gbit/s. The system is a highly modular testing platform that combines both R & D and manufacturing. It integrates various testing instruments in the optical transmission and data communication fields on the PC Control Platform and supports automatic testing, automation software and various extension protocol commands can be run without external computers. It can also remotely monitor the test process, support RAID performance, and implement real-time data mirroring.

Coincidentally, Huawei recently purchased Alibaba's MP1595A40Gbit/sSDH/SONET analyzer for the world's first 40 Gbit/s Submarine Cable System transmission. Huawei uses MP1595A to verify the performance of the 40 Gbit/s transmission system.

At the same time, DigitalLightwave has made breakthroughs in the 40 Gbit/s Testing Instrument Market. DigitalLightwave won orders of $1.08 million from major U.S. carriers to provide the operator with the next-generation NIC software and hardware platform. The NIC platform has two types: handheld and rack-mounted. It supports up to 40 Gbit/s of SONET/SDH, up to 43 Gbit/s of OTN, level-1 Ethernet, next-generation network (VCAT, LCAS, test the technical standards such as the optical fiber channel. In addition, the NIC test platform can be upgraded by users flexibly selecting modules as needed.

1. Optical fiber link field test and Fault Location
2. Research on Optical Fiber parameter test methods