Learning notes about optical fiber Access Network

The optical fiber access network is still quite common. So I studied the learning notes about the optical fiber access network and shared them here. I hope they will be useful to you. FTTH), as the name suggests, means that the optical fiber access network directly enters the residence or office space of each user. The Backbone Optical Fiber Transmission Network of China Telecom has already entered the 10G era and is advancing towards 40g. The access network has always been a bottleneck, although ADSL Based on telephone lines and broadband wireless solutions represented by 3G have greatly increased access bandwidth, from the perspective of application potential, only the optical fiber access network can truly achieve dozens or even hundreds of megabytes of access bandwidth, to meet users' needs for video, voice, high-speed Internet access and other high-bandwidth applications.

The development of fiber-optic access networks has experienced twists and turns. in the 1990s S, countries such as Japan and Germany launched the fiber-optic access network home strategy. However, due to technical uncertainties, coupled with cost factors, more importantly, there is a lack of practical application markets, so these plans are put on hold. The rise of Internet and interactive video communication and the decline in the price of optical fiber and optical devices have laid a solid foundation for the development of optical fiber access networks from both the market and technology aspects. However, for most operators, one-step improvement is an risky action. They all adopt the "light-in-copper retreat" strategy and continuously push optical fiber to end users according to market demands. Currently, according to the location of optical network units, optical fiber access networks can be divided into FTTH optical fiber to the household), FTTB optical fiber to the building), FTTP optical fiber to the station) and FTTC optical fiber to the roadside, FTTx.

From a technical point of view, there are also many types of fiber-optic architecture, including two types: one is a point-to-point topology, from the Central Bureau to each user using a fiber; the other is a passive optical network (PON) using point-to-point multi-point topology. The point-to-point solution can greatly reduce the number of optical transceiver and the amount of optical fiber, and reduce the Rack Space required by the Central Bureau, it has the cost advantage and has become the mainstream.

There are two main types of equipment used for optical fiber access networks: local equipment deployed in the IDC of telecom operators, called optical line Terminals (OLT) and equipment close to the user end, it is called an optical network unit (ONU ). According to the current development, fiber-optic households also involve multiple industries and categories, such as indoor optical fiber, engineering and applications, which have strategic significance for the entire telecom industry and even the information industry.

Currently, in the field of optical fiber access network, the hot topic in the industry is the two technical solutions of Passive Optical Networks: GPON and EPON. Simply put, the former has stronger multi-business support capabilities and higher transmission efficiency. It is suitable for deployment of high-end commercial customers and residential customers in the era of full business operation, but the cost is relatively higher. EPON mainly targets data transmission. Its core advantage lies in its relatively low cost. Currently, both technologies are commercially available in different application environments. It is worth noting that both EPON and GPON are moving towards the 10G era. In the short term, 10GEPON has an advantage over 10GGPON, which is mainly a cost issue. In addition, many operators believe that the bandwidth will be sufficient in the next few years. Therefore, the era of two PON combinations should also be around for a while. In fact, in the process of network construction and networking, the construction modes of GPON and EPON are not much different, but they are just the technical choices of operators. Currently, the service provision capability of GPON is basically the same as that of EPON, and there is no service access that GPON can do but EPON cannot do. In the future, in the 10G era, the two technologies may be integrated, that is, the same hardware platform supports both 10GEPON and 10 GGPON. Equipment manufacturers have begun to remove the differences between the two technologies.

In general, without the emergence of other epoch-making technologies, fiber-optic entry is the ultimate goal of broadband access for telecom networks in the next few years or even decades. It will drive the development of a series of related industries, it has formed a market scale of hundreds of billions or even trillions of Yuan. Therefore, fiber-optic entry is one of the core technologies driving the sustainable development of the telecom industry and an important tool for the telecom industry to promote social informatization.