Overall Design and technical application of man optical cable lines

Maybe many people do not have a special understanding of the man optical cable line. Next we will introduce in detail the overall design and technical application of the man optical cable line. How to build a Metro optical fiber network? First, it should be based on the network structure of the man. Second, according to the construction idea of the man, the topology of the network should be flexible and capable of upgrading. Based on the practice of man construction in recent years, the author puts forward several design ideas of man optical cable network.

1. Core layer optical cable line

The core layer optical cable lines are the core nodes that connect to man, such as telephone exchange bureaus, exchange bureaus, destination bureaus, mobile exchange bureaus, and core/egress routers. The number of core nodes is usually not large, but its position and function are important. It not only requires a large amount of transmission bandwidth, but also requires a large number of business types and high network survivability. Generally, it is a big Telephone Exchange Office and an integrated service equipment installation building. It is usually located in a convenient transportation or an economic and political center in a region. At the same time, there will be wiring cables and many major accounts need to consider on the routes of the man optical cable connecting the core node. Therefore, the optical fiber cables connected to core nodes are generally trunk cables. Generally, the number of fiber cores of the optical fiber cables is relatively large, with hundreds of cores and hundreds or even thousands of cores.

When considering the optical cable network structure of the core layer, we must consider the development of services and the evolution of the network structure according to the business status of the core node of the Metropolitan Area Network. For example, to reduce initial construction costs, the current core layer optical cable layout can be dominated by the ring network structure and virtual grid network configuration method (that is, each node has a direct optical fiber, the typical optical fiber cable network structure and core (taking 148 cores as an example ). In the future, we will continue to improve our services based on actual conditions, and gradually implement grid-based man optical cable lines on physical routes.

The Optical Fiber Ring Network Structure of the virtual lattice network with fiber configuration method has the flexibility of rapid evolution to the lattice network, and is very suitable for quickly establishing a similar ASON Test network. However, it is only a virtual lattice network with poor survivability. If the optical cable is interrupted, multiple edges of the mesh network may be interrupted at the same time. Therefore, a mesh optical network on a physical route should be built under the conditions of conditions permit. The number of cores of the trunk cable should generally meet the needs of users for not less than five years. The total number of outgoing cores can be estimated based on the total urban demand, and then based on the user distribution, distribute each outgoing trunk cable to each bureau.

2. Convergence layer optical cable line

The Convergence layer of man usually has a large number of nodes and is an important business point. It is mainly used to connect the terminal board of the switch, the base station controller, the convergence router, and the leased line user. The convergence capacity is large, in addition, there are many business types, which require effective business aggregation and scheduling, reducing the bandwidth pressure on the core layer, and solving the rationality of bandwidth resource applications. Therefore, the ring network structure is recommended for the optical fiber line of the Convergence layer man, supplemented by the chain network. The biggest benefit of the optical fiber ring network structure is that the reliability of the optical fiber lines in Man is greatly improved, such as line faults in section B and section C, fiber interruptions, it can resume communication from B to C through A, E, and D. However, the premise is that there are redundant optical fibers, but the disadvantage is that the cost is high.

The number of cores of the optical fiber cable at the convergence layer depends on the number of cores required for the active device networking at the convergence layer, that is, the number of cores required for the establishment of the MSTP business platform and data access device networking. Generally, MSTP devices on the aggregation layer must have no more than six open points, and some operators must have no more than eight open points. Generally, an aggregation transmission system is formed based on each of the five opening points. Each aggregation transmission system occupies 4 cores in two directions, and each data access device belongs to two target bureaus (offices) based on each opening point ), each opening point occupies 4 cores.

3. access layer optical cable lines

A Metropolitan Area Network (man) optical cable is an optical fiber line that connects to numerous terminal nodes (such as mobile base stations, remote module bureaus of switches, Data Service nodes, major customers, and important customers) from collection points, various application users or systems are required, and the coverage area is generally not too large. Generally, the star/tree structure is used. For users who need to connect some leased line users, important users, and have high reliability requirements, the ring structure can be used. There are three fiber configuration methods.

Direct Fiber Distribution Method with tree decline

The direct distribution method of tree decline is similar to the direct distribution method of the original audio cable, that is, the user's wiring man cable line is directly derived from the trunk cable, the number of cores of the optical fiber cable gradually decreases from the local terminal to the remote node (remote fiber splitter box. The direct distribution method of tree decline is suitable for areas with relatively small changes and stable user needs.

The directly configured fiber method in tree decline has very poor compatibility, and requires a large number of fiber cores for the trunk cable. The fiber resources are not shared, and the utilization rate of the fiber is low. If the node user forecast is slightly different, some nodes may have insufficient fiber cores and some nodes may have excessive fiber cores. In addition, the direct fiber configuration method with tree decline has poor survivability. In case of a fault in the trunk cable, it will affect a downstream user.