The above content is approved and announced by the National Science and Technology Term Review Committee
Introduction to FTTO
Fibertooffice (FTTO) is used Optical fiber transmission is a way to connect the communication bureau and company or office users. The introduction of optical fiber is exclusively used by a single company or office user. The ONU is generally placed in the central computer room of the enterprise or unit to obtain the most superior guarantee measures and to facilitate the connection with user equipment. The equipment or network after the ONU/OND is managed by the user. In addition to meeting group users' voice, wired or wireless broadband Internet access, LAN interconnection, video conferencing, IPTV and other services, it can also provide enterprise PBX access and TDM private line access services, and provide a complete QoS guarantee mechanism. The topological structure of the FTTO access network is shown in the figure:
The multi-service access system and access method under the PON network can also be implemented in the FTTO mode. As shown in the figure, first, place the OLT main equipment in the basement machine room. This equipment has the overall function of the overall situation. In actual work, the main equipment can have a decisive influence on the operation of other equipment, and it must be placed in a safer place. The basement computer room has all the conditions to allow the main equipment to operate in an ideal environment. Secondly, the OLT is connected to the IP metropolitan area network through a GE circuit, and 16 PON ports are configured, and the uplink interface is configured with 2 GE optical ports and 2 GE electrical ports. This installation method is different from the EPON+LAN method, but it can also achieve the previous work effect. Relatively speaking, the scope of FTTO service is not small, and it is different from EPON+LAN. In actual applications, both can achieve the purpose of saving costs and improving benefits. Third, when the staff access the system, they will place an ONU in each office, and each ONU can provide 8FE and 16 channels of voice access. It can be seen that, as one of the important components of the multi-service access system and access method under the PON network, the FTTO method can be further promoted and applied in the future.
Proposals for FTTO promotion
Proposals for vigorously promoting the construction of FTTO and access to the optical cable network network structure model:
Original There are not enough backbone resources in the optical fiber ring network. At present, more backbone fiber core resources have been encountered. Therefore, simply relying on the original optical fiber resources to directly implement the construction of FTTO will face the bottleneck problem of backbone resources.
We will vigorously promote the construction of chain and tree trunk optical cables to provide resource capacity for FTTO's massive transformation.
The FTTO promotion should unify the network structure model to avoid frequent subsequent adjustments. In the overall design, can we also propose two access structures, "access-oriented network" and "public user-oriented", and strive to make the future optical cable access network structure clear, easy to grasp, and conducive to maintenance and management.
The optical splitter (OBD) and OLT in the PON network are two important core convergence points. It is especially worth noting that the access of government and enterprise customers has always been the main part of the fiber core of the optical cable network, even if most of the optical fiber dedicated lines of government and enterprise customers in the future will use PON technology to converge. Because its access bandwidth is basically 10 times that of ordinary household users, its convergence ratio is much smaller than that of home customers. The fiber used by government and enterprise customers is still an important part of the fiber used for access to the optical cable network. In the FTTO mode, the demand for backbone fiber cores has increased sharply. It is necessary to plan the deployment location of OLT equipment based on the coverage radius of the OLT, the condition of the cell room, the size of the cell, and the access of government and enterprise customers to reduce the occupation of the backbone optical cable.
From the perspective of the entire access optical cable network within an end office, the service area of each backbone optical node is separated by natural boundaries such as urban roads into a relatively independent combination of plots. The area containing at least one backbone optical node is called the optical service area. Each optical service area contains relatively independent sub-blocks such as the resident network, school, administrative office, commercial finance, etc., which is regarded as a non-uniform grid in the optical service area.
With the large-scale application of FTTO, fiber-optic cables have been extended to users' indoors instead of copper cables, and the number of fiber-optic cables has increased sharply. As the PON technology is used to implement optical fiber access, it is necessary to make full use of the PON network passive optical splitter (OBD) to converge the end of the optical cable.
Coordinate the current local FTTO installation requirements and the contradiction in terms of time difference and implementation conditions between the construction and transformation of the target network. In the follow-up of meeting the current emergency installation requirements, we should The target network structure is in accordance with the organization, optimized and adjusted in a timely manner, to ensure that the access layer structure is clear, which is conducive to maintenance and management.