The latest technology development direction of optical fiber access

From DSL to optical fiber entry, the speed ranges from dozens of K to dozens of M or even hundreds of M, and the broadband access technology has undergone dramatic changes over the past decade. EPON has been used in Japan and South Korea for many years. GPON is always around the world, and 10 Gbit/s PON and other access technologies that can bring higher bandwidth are ready for use.

As the broadband network is booming, the competition for technology selection has now become the second place. How to Apply xPON technology to real-world networks has become the development and exploration direction of the optical fiber access technology.

Total platform abandon technology competition

Whether it is GPON or EPON is the most controversial focus in the past two years. People have given different answers in the fields of technology, business, and maturity. But can operators find a solution that is suitable for both the existing network foundation and future business development while reducing OPEX? The Huawei SingleFAN solution leads the way for a common platform.

Li heshun, director of the Huawei access network marketing Engineering Department, said, "The SingleFAN solution advocates the construction philosophy of Multi-network integration, large capacity, fewer bureaus, and flat networks, which has been highly recognized by major European operators, by reducing the number of CO bureaus, the construction cost and network maintenance cost can be greatly reduced." Li heshun said, "At the same time, the SingleFAN solution advocates a multi-network multi-use, full-scenario coverage, and enables full service load using the PON network, making it the preferred solution for integrated operators ."

It is understood that the SingleFAN solution has full future-oriented evolution capabilities. The system capacity, software architecture, business development, and other aspects reserve sufficient capabilities to provide services from ATM to IP addresses, from copper wire access to optical fiber access, from PSTN to IMS, from IPv4 to IPv6, and from xPON to ng pon, all-round smooth evolution ensures maximum protection of investment.

The development direction of the EPON/GPON platform led by SingleFAN has also been recognized by domestic operators and has become a basic requirement for bidding.

Solves the problem of ODN Management

In FTTx development, the access layer needs to create a huge optical fiber distribution network, that is, the ODN network. The cost of building the ODN network is high. The maximum investment can be 50%-70% of the total investment, which is the focus of FTTx investment. Meanwhile, ODN is also a difficult point for FTTx management. First of all, it is a simple P2P structure than copper lines. The ODN uses P2MP topology, and there are many connection nodes in the network, resulting in complicated network management. Second, optical fiber is more sensitive than copper wires and is more vulnerable to damage.

Therefore, efficient construction, operation, and maintenance of ODN is crucial. An intelligent and accurate management solution is required to ensure that the ODN network is fully utilized to effectively protect long-term investment. At present, how to scientifically manage the ODN network has become the focus of the major operators and ITU-T and other standard organizations.

So can we solve the two core issues of ODN management without changing the passive characteristics of ODN and achieve automatic management of ODN? Huawei proposed an iODN (Intelligent ODN) solution. In the iODN solution, the ODN product adds the following smart features: Optical Fiber identification management, port status collection, port search indication, and visualization tool PDA.

The iODN solution can automatically input and manage the connection information of the ODN optical fiber, ensuring that the existing system information is accurate and synchronized in a timely manner. At the same time, the visualization software of PDA and intelligent LED indication on iODN equipment can realize automatic optical fiber searching and precise operations, greatly improve the O & M efficiency, and achieve efficient operation and maintenance of the ODN network. In addition, based on the iODN architecture, a variety of value-added applications can be developed based on the existing system to automate the entire process of construction and O & M.

Introduce MPLS to the access layer

With the advancement of FTTx, on the one hand, the traditional leased line service is also faced with the dilemma of the ATM switch return. A large number of leased line services need to be accessed with high quality and quality. If a single access is built to carry this service, it will bring a huge burden to operators. On the other hand, the traditional DSLAM mode service configuration mainly uses VLAN configuration, limited by the number of vlan id tags (4 K), it imposes limitations on the development and planning of new businesses. In addition, because the development of new businesses usually spans the entire network, cross-Department operations are much more complicated, low efficiency in business development and distribution. Therefore, the idea of introducing MPLS technology into the access layer is put forward in the industry.

The value of MPLS in the Wan has been confirmed. It simplifies packet processing and improves packet forwarding efficiency. MPLS-based traffic engineering and fast route protection technologies, improves network QoS. As the structure of the metropolitan area network becomes flat and the OLT is moved up, MPLS is expanding from the Wan to the metro and access networks. At present, the man network is evolving from the TDM/ATM network architecture to the Ethernet network architecture. Ethernet-based man and access networks adopt MPLS technology.

At present, operators such as Deutsche Telekom and France Telecom have demanded that OLT devices support this function in the future. Previously, Huawei presented its OLT support for MPLS at the global MPLS forum for the first time and passed the interoperability test of EANTC, an international authoritative testing agency, it is currently the only OLT solution that passes the test in this field, and has been successfully activated by carriers such as Accor in Germany.

However, some experts also pointed out that MPLS protocols are more complex than traditional L2 access protocols. Therefore, equipment vendors are required to have a full understanding of routing protocols. For example, MPLS itself has a large number of protocols, which do not need to be implemented at the access layer. You only need to select a part. From the perspective of devices, MPLS significantly improves the performance requirements of access devices and the management capability requirements of devices. From the perspective of cost, MPLS at the access layer will increase the cost of equipment. Therefore, the current demand for MPLS at the access layer is mainly concentrated in developed countries that focus more on operational efficiency and help them reduce OPEX. However, in the long term, access layer MPLS is a major direction for future product development.

Optical Copper

With the gradual advancement of optical fiber copper withdrawal, DSL access nodes are gradually moved down, and the market share will decrease year by year. However, Wei leping, director of the Technology Committee of China Telecom group, believes that as a way to achieve the last several hundred meters of user access, DSL has at least 10 years of survival. "DSL will coexist with PON for 10 years as the main way for users to access their homes ."

The 10-year survival space will also guide the DSL technology to make breakthroughs. At present, VDSL2 has been continuously optimized, and the use of SuperMIMO technology and other multi-line bundling Technology of ultra-high bandwidth DSL has made significant technological breakthroughs, can provide higher bandwidth at a short distance, the development direction of such technology is also to better co-exist copper and optical fiber technologies.

At the same time, in the mobile business field, it provides a cost-effective backhaul solution for 3G/LTE deployment, and also introduces technologies such as time synchronization, binding, and Crosstalk processing on copper wires. On April 9, January this year, Huawei announced the launch of the world's first DSL prototype supporting 1588v2 time synchronization. This product can transmit 1588v2 high-precision time synchronization signals through DSL lines, and the prototype testing accuracy reaches the GPS level. This technological breakthrough means that during the deployment of 3G/4G, the operator has a more economical backhaul technology option, which can use copper wire resources widely deployed to quickly get rid of GPS deployment restrictions.

People's demand for higher bandwidth has never stopped, so technological innovation continues. A simpler, smarter, and flat broadband access network has taken shape.