China’s broadband has entered a period of rapid developmen

When we walk in residential areas and urban villages, we often see advertisements about various types of broadband. The three major operators are full of their advertisements. They only need 88 yuan for broadband to send mobile phones, and a piece of broadband is free to take home. In fact, there are various conditions to be put into the contract. Deep Pit Dou E’s Injustice”. The quality of broadband is closely related to all aspects of work and life. Often, good broadband brings high efficiency and a good mood, while bad broadband is troublesome, worrying, and sad every day. Today, I will take you to understand how broadband is networked. Broadband is professionally called fiber-to-the-home, and there is another term called resident network. That is, China’s “Broadband China” strategy proposed by the State Council in 2012, which is also one of the national strategies. Since then, China’s broadband has entered a period of rapid development.

1. Introduction to Fiber to the Home

Fiber to the Home (FTTP), also known as Fiber to the Home (FTTH), refers to a broadband telecommunications system. Fiber to the home realizes the function of triple play. Triple play refers to the integration of computer network, radio and television network and telecommunication network to form a fully digital and unified network system that supports all services including data, video and voice. communication services delivered to homes or businesses. At this stage, community owners are increasingly demanding information and communication, especially for high-speed access means, and the application of optical fiber has naturally entered the attention of everyone. Optical fiber not only has large frequency bandwidth and communication capacity, but also can effectively and conveniently realize the infinite superposition of application services, which can better meet the development needs of future broadband integrated services, and fundamentally avoid the waste of resources caused by repeated investment. For the smart community, the optical fiber is directly connected to the owner’s home, and the optical network unit (ONU) is installed in the owner’s home. Household (FTTH) technology has the characteristics of providing ultra-large bandwidth, easy maintenance and installation, and is generally considered by industry insiders and experts to be the main form of broadband access network in the future.

EPON topological structure has bus structure, tree structure, ring structure and star structure. For smart cells with high access rate, a tree-structured network should be used during construction, which is beneficial to reduce access costs. The tree-structured EPON adopts a point-to-multipoint (P2MP) structure of a single-fiber bidirectional optical access network in terms of transmission, and its topology is shown in the figure below.

OLT (Optical Terminal Equipment) is a terminal equipment used to connect optical fiber trunks. Its function is to provide the interface between the access network and the local exchange, and completely separate the exchange function of the exchange from the user access. On the one hand, the signals carrying various services are aggregated at the central office and sent to the access network according to a certain signal format for transmission to end users; on the other hand, signals from end users are sent to various service networks according to service types. middle.

ONU (Optical Network Unit) is a device that gets in touch with the network terminal OLT through the POS passive optical splitter. The function of the device is to terminate the optical fiber from the OLT and place it at the customer premises to provide the access network with the interface of the terminal equipment on the user side. The network end of the ONU is an optical interface, and the user end is an electrical interface, so it has electrical/optical and optical/electrical conversion functions, as well as corresponding monitoring and maintenance functions.

OND (Optical Distribution Network) is a general term for the lines and equipment set between the Optical Line Terminal (OLT) and the Optical Network Unit (ONU) in the optical fiber access network to distribute optical signal power and provide optical power between the OLT and the ONU. The physical channel through which the signal is transmitted.

2. Fiber-to-the-home networking solution for smart communities

The EPON networking mode not only simplifies the wiring and routing in the community, but also reduces the repetitive and complicated wiring construction of each system. At the same time, because the optical fiber can provide a large bandwidth, the access network can better realize cable TV broadcasting, broadband and telephone. access, as shown in the figure below.

The entire FTTH broadband access network consists of three parts: OLT, residential fiber network, and ONU. OLT is a multi-service centralized control unit, which is mainly responsible for bandwidth control, authentication management, fault capture, and converts data and video broadcast signals into optical signals for distribution. The OLT supports the division of virtual private networks (VLANs). The community optical fiber network adopts single-mode optical fiber. The ONU is a multi-service subscriber unit that completes photoelectric signal conversion in the user’s home, providing users with high-speed data, bypass voice and video services. In view of today’s household living equipment, in the functional configuration of ONU, it is best to ensure that each household has 4 network ports (each network port rate is about 100Mbit·s-1), 2 telephone ports and a cable TV port. Each network port, telephone port and TV port can be controlled individually, which is convenient for billing and management.

Using EPON networking, the integrated three networks provide their own services for the residents of the community in a new way, and also build a mature and open access platform for the community, so that the subsystems of the smart community can play their roles in a coordinated and unified manner. .

3. Main materials of fiber optic home system
4. The weak current box adopts the specifications of 400*300*250mm. It needs to be equipped with a network switch, TV interface, voice interface, and one strong current socket; it is installed at a height of 300mm at a height of one meter on the ground and reserved for strong current. , network cable, optical fiber, telephone line, cable TV line SYV75-5 and other line pipes to the weak current box, the line pipe needs to reserve the lead wire to ensure that the pre-buried pipe is normal, and the line pipe mouth is blocked and protected, and the pre-buried pipe should be protected as much as possible Do straight, do not bend too much, it is easy to increase the difficulty of threading later.
5. Sheathed optical cable; only use more than 2 cores of sheathed optical fiber, and the sheathed optical fiber needs to strengthen the core protection, that is, there must be steel wire in the sheathed optical cable, which can protect the sheathed optical fiber and is not easy to be broken. Or break it; try to keep folded when threading the cable, the optical fiber is easy to break, and the integrity of the protective sleeve of the cable should be ensured. Leather cable generally has 1 core, 2 core, 4 core models.
6. The optical fiber distribution box of the floor, the overall number before construction, including the room, is convenient for later labeling, including the numbering of the optical fiber of the indoor leather line, and the summary floor needs to be clear and clear, so as to facilitate the construction and release, and will not cause confusion in the later stage . When installing the optical fiber distribution system, try to install it in an open place, which is convenient for maintenance, and easy to find in an obvious place. Optical fiber distribution box 12 cores, 24 cores, 48 cores, 72 cores; 96 cores, 144 cores, 244 cores; 488 cores.
7. Lay out the main optical cable or vertical optical cable. Before laying the main optical cable, the distribution line needs to be installed, or the location of the distribution box has been determined; In the telecommunications room, the wire trough needs to be close to the wire trough that is aggregated to the telecommunications room. It is necessary to consider the problem that the wire trough is too small due to too many optical cables. The indoor main optical cable should be laid with indoor optical cable, which is convenient for construction and laying; outdoor armored optical cable should be laid in outdoor construction, which is beneficial to protect the safety of the optical cable and is not easy to be damaged. Too long is wasted, too short is scrapped. There are 6 cores, 8 cores, 12 cores, 24 cores, 48 cores, 72 cores, 96 cores, 144 cores, and 288 cores of the optical fiber cable. These are used more and are commonly used.
8. Telecom equipment room decoration, the telecommunications equipment room needs to follow the equipment room decoration standards, do a good job of grounding, lightning protection, waterproof and rodent proof, equipment installation is stable, the identification label should be clear and clear, the layout of the equipment room cabinet should be reasonable, and the fiber jumper and optical cable trough should be separation.
9. For ODF cabinets, the distance between the cabinets should be kept at a good distance, not too small, and the distance should be more than 1000mm; the door panels of the cabinets should be opened at the front and back, which is convenient for maintenance and repair; the installation of the cabinets should be stable, and there should be no looseness; the optical cables in the cabinets should be laid out. Neat and beautiful, the optical fiber needs to enter the optical fiber reel and needs to be protected by a protective tube; the direction of the optical fiber reel in the cabinet is the same, it needs to be neat and beautiful, and the flange port should be well protected from dust; Consistent with the real on-site distribution box, to ensure the correctness of the optical fiber tray drawing, which is conducive to later maintenance; the cabinet needs grounding protection; the cabinet jumpers need to be arranged and straightened, and the redundant jumpers need to be arranged in a neat and beautiful manner. 0DF cabinets are mostly of 576 cores and 720 cores.

To sum up, the optical fiber to the home is very simple. The construction process: drawing familiarity → on-site verification → optimization plan → equipment coding → floor pipe wiring → trunk wiring → distribution box installation → equipment room decoration → ODF cabinet installation → label identification → fusion fiber → Optical fiber test → print completion documents → acceptance → enter the maintenance period → completion settlement → final inspection, the project is over, and everyone is safe.