1. Optical communication SDN enters the 2.0 era and integrates with cloud and big data technologies

SDN is a recognized trend of optical communication development. By introducing the open architecture of control and forwarding separation, the network capacity can be significantly improved, and has begun to be gradually deployed on the current network.However, with the gradual deployment of SDN and the continuous increase of network traffic, the deployment flexibility, data storage, processing capacity, security and network stability of SDN controller applications will be greatly challenged.

In the next 3-5 years, SDN technology will enter the 2.0 era. The open network architecture of SDN will be combined with cloud and big data technology to deploy, control and apply in the cloud. The analysis and prediction of traffic with big data technology will become the main characteristics of SDN2.0.Through the introduction of the above technologies, the security and elastic deployment of SDN solutions can be realized, the high requirements of SDN for data storage and data processing can be guaranteed, and the trend of network traffic can be predicted in a multi-dimensional way, so as to further improve the intelligence and agility of the network and ensure customer experience in a high-traffic environment.

 

2. Silicon photonic technology

Silicon photonic technology uses CMOS microelectronic technology to realize the integrated preparation of photonic devices. This technology combines the characteristics of ultra-large scale logic and ultra-high precision manufacturing of CMOS technology with the advantages of ultra-high speed and ultra-low power consumption of photonic technology.It is a kind of subversive technology that can solve the contradiction between long technology evolution and cost.

Since light and electricity are separated and photonic and electronic technologies follow their own development paths, optical communication systems are now facing bottlenecks in terms of power consumption, cost and integration.

At present, a number of key technologies of silicon photonics have been successively made breakthroughs, and it is expected to start commercial use within three years.

 

3. High-speed access, multidimensional multiplexing and coherence technology

The multiplexing dimension in optical communication technology includes time division, wave division, frequency division, code division and mode division, etc.At present, 40G PON adopts time-division and wave-division two-dimensional multiplexing, which is one of the feasible methods in 100G PON.The industry will explore combinations of these more dimensions to provide greater bandwidth for users.In addition, a coherent receiving mode is adopted at the receiving end, which can carry more than 1000 wavelengths in an optical fiber, 1G/10G for each wavelength, and the passive transmission distance is up to 100km, realizing the t-bit access.To provide users with greater bandwidth, lower time delay access services for the operators to provide efficient and low cost of operation and maintenance of the network.

Internet new application layer is emerging in an endless stream, which needs more bandwidth to support the blowout growth of data demand. Government and enterprise key customers and high-end community users will need to enter the home with exclusive wavelength, and some scenarios will have long distance, high bandwidth and low delay access demand.

40G TWDM-PON will start commercial use in five years. Multidimensional multiplexing and coherence technology are also research hotspots.

 

4. Deep integration of IP and optical network improves super-capacity routing

At present, the communication network adopts multi-layer and multi-domain network to carry business, with a wide variety of equipment. The grouping processing capacity of massive data is exponentially improved. Meanwhile, it puts forward higher and higher requirements for the routing computing capacity of super-capacity, which leads to the shortage of computer room space, high energy consumption and low efficiency.The fusion of IP and optical network is one of the effective ways to solve the problem.

IP and optical network integration can be achieved through unified switching kernel technology, with packet /ODUk/VC centralized switching function, so as to reduce network level, save network investment, reduce maintenance cost, and realize network node intensification.By improving the forwarding ability of single slot line card and adopting multi-box cluster technology, the forwarding ability of single node can be greatly improved.Through multi-core processor, distributed software architecture, modular management and other technologies, can achieve tens of millions of level routing table management.

IP and optical convergence, which covers backbone, convergence and access networks, and super-capacity routers with tens of millions of level routing table entries, provide end-to-end solutions for the entire network, and operators have launched pilot programs.

 

5. Build the next generation optical network based on cdc-f optical cross

At present, with the large-scale deployment of 100G technology and the vigorous development of ultra-100g technology, the transmission capacity of WDM/OTN system is improved rapidly, and the flexible scheduling and efficient processing of optical layer have become an important requirement for optical network nodes.

As to further improve the WSS light module integration, WSS light module was used to construct a CDC - F (Colorless, Directionless, Contentionless, Flex Grid) features of optical crossover network technology application in large network nodes, because have large exchange capacity at the same time, wavelength and flexible business operation, low power consumption, low latency, such as key features, easy to build flexible and efficient optical network.

The cdc-f features of optical crossover technology are increasingly valued by operators around the world. Operators have been the first to deploy the technology, and more pilot and commercial applications are expected to be launched in the near future.

 

 

6.Medium and short distance metropolitan area high-speed transmission direct adjustment and inspection technology

In order to satisfy the requirement of long-distance transmission over thousands of kilometers in backbone network, the current mainstream transmission technology is coherent transmission technology.However, the transmission distance between cities is usually less than 300 kilometers.In this case, how to avoid the use of coherent detection (complex system, high cost), to achieve good transmission and networking effect, is now a hot topic of research.

In order to realize short and medium distance transmission, direct modulation and direct detection are considered as the main technologies at present.Modulation, there are many ways, including: PAM-4 transmission, DMT transmission, SSB transmission, and so on.On the receiving side, less optoelectronic devices are used in an incoherent manner.To simplify the system and reduce costs.

In recent years, a number of direct adjustment and direct inspection technology experiments continue to be carried out, through gradual research and continuous optimization, the next three years will start the pilot.

 

7.Toward to the full optical network, from the chip room, board room to the optical interconnection technology

With the rapid development of big data and cloud technology, large-scale data exchange and processing, from short to on-chip and inter-chip, and long to cabinet and data center, are eager for high-speed, stable and reliable interconnection, and conventional cable connection will not be able to cope with it.

At present, interchip and interplate solutions can effectively achieve optical interconnection using silicon-based optoelectronic integration.Interconnection between machine rooms, frames, frames and disks can replace traditional cables by using photoelectric conversion and optical transmission technology. The main solutions include silicon-based photoelectric integration, high-speed VCSEL and directly adjustable DFB.The silicon-based photoelectric integration scheme has the advantages of CMOS process compatibility, high integration and low cost.

In the next few years, optical interconnection technology will be widely used in chip, chip, board, cabinet and computer room.

 

 

8. Green communication, the eternal theme of optical communication technology

With the increase of information consumption, the bandwidth and energy consumption of optical communication are increasing.Nowadays, how to realize green communication has become one of the main efforts in the industry.

In order to achieve green communication, some new technologies are or will be gradually adopted, such as new energy, high integration chip, high efficiency power module, intelligent fan, liquid refrigeration, intelligent flow aggregation, hardware dormancy, new materials and other technologies.

Through the continuous development and optimization of the above technologies, the energy consumption per bit of optical communication equipment will gradually reduce and become more harmonious with the environment.