Research on FTTP Network product application Technology of EPON access

Absrtact: Epon technology has a great advantage in broadband access, it is not only low-cost equipment, operation and maintenance of simple, its development more operators to solve the "last kilometer" provides a very low-cost broadband access solutions, Epon technology is in an unprecedented way to transport communications services, Optical communications The entire industry is staring at Epon as the representative of the FTTP technology and market development, can carry three network integration business FTTP network for telecommunications operators to provide a stronger competitive edge.

1, epon development status

Optical fiber is the most effective medium for transmitting data, video and voice services, and can provide unlimited bandwidth. However, each user and the end of the point to achieve point-to-point fiber connection, at both ends of the optical fiber installation of active power equipment, in the end of all optical fiber connection management, its cost is huge, unbearable. Epon overcomes the disadvantage of point-to-point, instead of using point-to-point topology, it does not require electronic devices such as regenerator, amplifiers and lasers to reduce the number of lasers used by the end station. Point-to-Point optical fiber technology is suitable for metropolitan area network and long-distance application, Epon is suitable for the special requirements of access network. Epon is simpler, more efficient and less expensive than other access network technologies. Epon extends the fiber to the last kilometer to achieve high efficiency, high scalability, low maintenance costs, end-to-end optical network.

At present, the access network is still the bottleneck between the large capacity LAN and backbone network, and there is a great difference between the existing solution and the user's demand of access network. At the user side of the local network has generally been able to support the 10M and 100M speed, the metropolitan area Network has been able to support gigabit and gigabit speed, but between the user side and the metropolitan area Network data transmission is mostly less than 1M or even only dozens of k rate. To highlight the priority and importance of access, the IEEE 802.3 Working group renamed the previously known "Last 1 mile" network segment "1th Mile" (the first Mile) and established EFM in November 2000 (Ethernet ILE) Research group, began in July 2001 to develop the IEEE 802.3ah EFM Standard, September 2003 completion of the EFM standard-setting. The Mile Alliance (first mile Ethernet Federation) is a Ethernet industry organization that supports 802.3AH based EFM standardization. EFMA's members include terminal manufacturers, systems integration and communications operators, including Alloptic, Inc., Analog Devices, Hatteras Networks, Infineon Technologies, Passave Technologies, Spirent Communications, Texas instruments, and world Wide packets.

In Epon is now the leading international has salira,alloptic and other emerging companies, there are some established companies such as Nokia Broadband,quantum Bridge, domestic research and development in epon more leading green will company, Huazhong Science and technology, Wuhan Beacon and so on. Among them, the company's multi-service EPON (Ms_epon) system is the most characteristic, its system supports the 1.25G bandwidth of the top and bottom line, supports the automatic joining of ONU, supports TDM service, provides dynamic/static bandwidth allocation, elastic protection switching, and other functions.

In recent years, major telecoms operators have announced strategies for large-scale deployment of FTTP networks. Another major maker of Epon technology, Fujitsu, has also grabbed the market's first piece of cake with the Great Wall Broadband partnership. In the second quarter of 2003, China Netcom announced the first use of epon equipment in Beijing and Changsha to open L2tpvpn business, as well as VoIP, VOD and other services, is the first Chinese operator FTTP contract, the significance of unusual, The domestic main epon equipment supplier Salira Shenglia announced to obtain the China Netcom FTTP equipment order. In 2004, ADC, Corning, Tyco,fons,pirelli,sumitomo began providing fiber-optic cables and outdoor equipment for Verizon Communications, a high-speed, high-capacity FTTP system, for experimental laying. The domestic green will company has completed a number of business in Xuzhou, Jiangsu epon test Network, coverage has reached 4,000 o ' clock.

2, the structure of Epon

Ethernet Pon's passive devices are located in the optical distribution network, including Single-mode optical fiber cables, passive optical splitter/coupler, connectors and connectors. Optical line terminals and multiple optical network units are located at the terminal of Pon. When the light signal is transmitted through a PON, it is distributed through the beam splitter to several fibers, and the uplink signal is merged into the same fiber by the beam splitter/coupler. The passive optical network uses the fiber point to the multi point tree to connect the user on the branch. Pon can also use a protective ring structure for commercial applications, and a bus structure can be used for campus networks and multiple leased user groups.

Optical Network Unit provides interface between user data, image and telephone network and PON. The basic function of ONU is to receive the optical signal and convert it into the format that the user needs (Ethernet, IP multicast, POTS, T1). Ethernet pon a unique performance is ONU in addition to receiving optical signals and conversion, but also provides a 2nd, 3-layer Exchange function, allowing enterprise business within the ONU to implement routing. The Ethernet pon can also use a 3rd wavelength to transmit the image business.

Since ONU is located in each FTTB and FTTH application, the cost will be shared among multiple users, and the design and cost of ONU is a key factor in the construction of the Epon system. Usually, the cost of ONU is 70% of FTTB, in FTTH, the cost of ONU accounts for nearly 80%.

3, the application characteristics of Epon

3.1. Convenient expansion, low operation and maintenance cost. The building does not need to occupy the room and power supply facilities, support remote equipment Onu/ont automatic ranging and automatic joining, network expansion is convenient, and the local terminal equipment and client equipment for unified network management, for operators can greatly reduce operating maintenance costs.

3.2. The wiring of the fiber in the building is simplified. Long distance, wide bandwidth (20km,1.25g), optical fiber access and transmission, optical fiber onu/ont, very suitable for FTTB and Ftto mode, fiber direct to commercial users. The adjustable, prioritized, and bandwidth-guaranteed services that the EPON system can offer will be very attractive.

3.3. Bandwidth allocation flexibility, service is guaranteed. There is a complete system for allocating bandwidth and ensuring that each user, or even each port, is connected based on the required bandwidth allocation (which is different from the port based rate limit for the normal switch) and that the QoS of each user connection is guaranteed according to the business contract.

3.4. Epon is a technology for the future, it is a multi-service platform, it can provide both IP service and traditional TDM business. QoS is fully guaranteed and complies fully with the standards of the IEEE 802.3ah. This not only enables operators in the same set of transmission platform on the basis of user requirements at any time to open the need for a variety of business, and very easy to the full IP service network transition.