There are several key elements that must be followed in the FTTH project. The correct implementation of these key elements can greatly reduce the investment of the project, increase the speed of construction, and reserve enough space for upgrading or expansion, effectively extending the sustainable operation and upgrading of the network. The elements to be followed in the FTTH project are as follows:
1. The location of the beam splitter
In passive optical networks, the location of the optical splitter plays a vital role in the implementation of the project. The optical splitter is a passive device and can work normally without a power supply, so there are not too many worries in site selection and installation, just pay attention to the pipeline and user distribution. The installation location of the optical splitter is generally not placed in the computer room, and usually selected in the optical distribution box that is closer to the user and the surrounding users are dense. If the optical splitter is installed in the computer room for centralized optical splitting, the advantages of PON cannot be fully reflected.
The correct installation location of the optical splitter can bring the following advantages:
1) Save the investment in the optical cable from the computer room to the optical fiber distribution box
Reasonable location of the optical splitter can greatly save the investment of the optical cable. Take a 24-core fiber optic cable as an example. If the splitter is installed in the computer room and the 24-core fiber optic cable is only used to connect the computer room and the user distribution box, only 24 users can be opened. But if it is used to connect the optical splitter between the central computer room and the outdoor, it can cover 1536 households according to the split ratio of 1:64. In other words, if the installation is reasonable, a 24 core fiber optic cable can be used instead of a 1536 core fiber optic cable.
2) Save space in the computer room and improve management functions.
Installing the optical splitter outdoors can save the space of the rack in the equipment room.
2. The location of the computer room
In a pure FTTH project, at most one computer room may be required. Because the construction of the computer room involves power acquisition, management, operation, backup power supply, air conditioning, etc., it will greatly increase construction and operating costs. Under normal circumstances, operators will not set up FTTH computer rooms in any community unless the nearby computer room is too far away from the user. At present, operators usually install optical distribution boxes or optical cable joint boxes in communities at most.
3. Centralized light splitting
Operators usually perform centralized light splitting outdoors near users. This is a kind of protection for investment, and the optical splitter can be expanded according to the user’s activation. In other words, you can buy less optical splitters when there are fewer users in the early stage. As the number of users is opened, the number of splitters will be gradually increased. However, it is recommended to consider sufficient expansion space when designing in the early stage.
4. Reduce the types of optical cables
In order to facilitate implementation and management, no more than two types of optical cables (excluding household drop cables) will be used in a well-designed passive optical network. This section of fiber optic cable mainly refers to from the central computer room to the user distribution box. In the project completed by Rosenberg, only two types of optical cables can be used from the central computer room or even to the floor distribution box. Reducing the types of optical cables is conducive to increasing the length of the optical cables that need to be used, and is conducive to manufacturers to provide rapid response capabilities and price competitiveness.
5. Easy to expand
At present, the splitting ratio of EPON or GPON can indeed be 1:64. In other words, one PON of the central office equipment can carry 64 users. And according to the standards of 10G-EPON and 10G-GPON, the splitting ratio will reach 1:128. However, in the current implementation of operators, the split ratio is basically not directly 1:64 in the project, and the commonly used splitter is 1:32. Using a split ratio of 1:64 means that the average bandwidth per user of EPON can only reach 16M.
If users generally need to increase bandwidth, they will be stretched. According to the standard of high-definition digital TV, to realize 1080P-level program transmission on the network, the conservative bandwidth required is 22M. If according to the current full configuration settings, when users generally require the bandwidth to be increased to 20M or 30M, the existing network cannot meet the needs at all. It is necessary to upgrade the active network equipment to a 10G network. The upgrade must cause the existing waste of assets and huge reinvestment. Therefore, under normal circumstances, it is still recommended to consider users using a 1:32 optical splitter, which can effectively extend the service life of the current network and bring better return on investment for customers.
Post time: 2021-02-26