Fiber to the desktop

Overview

To understand the concept of "Fiber-to-the-Desk", we first understand -----"FTTX" (Fiber-to-the-x) is fiber access.

FTTX

FTTx technology is mainly used to access network optical fiber, ranging from the central office equipment in the regional telecommunications room to the user terminal equipment. The central office equipment is an optical line terminal (OpticalLineTerminal; OLT), the user end equipment is an optical network unit (OpticalNetworkUnit; ONU) or an optical network terminal (OpticalNetworkTerminal; ONT) and an ODN (optical distribution network) device connecting the two.

According to the distance from the fiber to the user, it can be classified into: Fiber to the switch box----FTTCab(FiberToTheCabinet), Fiber to the roadside---- FTTC(FiberToTheCurb), Fiber to the building----FTTB(FiberToTheBuilding), Fiber to the home----FTTH(FiberToTheHome), Fiber to the desktop-FTTD (FiberToTheDesk) and many other service forms. The American operator Verizon collectively refers to FTTB and FTTH as fiber to the premises (FiberToThePremise; FTTP). The above services may be collectively referred to as FTTx.

FTTC

The installation and use of optical cables from the central office to the roadside within a thousand feet from the home or office. Using FTTC, coaxial cables or other media can transmit signals from the roadside to the home or office. FTTC replaces ordinary old-style telephone services, and can complete the distribution of telephone, cable TV, Internet access, multimedia and other communication services through only one line.

In the FTTC structure, the lead-in part is dedicated to the user, and the existing copper cable facilities can still be used, so the expensive lead-in part (sometimes even the wiring part, depending on the location of the ONU) can be postponed. Optical fiber investment has good economic efficiency. Generally, a potential broadband transmission link very close to the user is laid first. Once there is a need for broadband services, the optical fiber can be quickly led to the user to achieve the strategic goal of optical fiber to home. Similarly, if economical needs, coaxial cables can also be used to provide broadband services to users. Since the degree of optical fiberization is very close to the user, it can fully enjoy a series of advantages brought by optical fiberization, such as saving pipeline space, easy maintenance, long transmission distance, and large bandwidth. Since the FTTC structure is a hybrid optical/copper cable system, the last section is still copper cable, and there are outdoor active equipment that needs to be maintained, which is still not ideal from the viewpoint of maintenance and operation. However, if the initial investment and annual maintenance and operation costs are considered comprehensively, the FTTC structure is still the most realistic and economical in OAN when it provides narrowband services below 2Mbit/s. However, when it is necessary to provide both narrowband and broadband services in the future, this structure is not ideal, and it is not enough for future broadband services. You may have to reduce the number of nodes and users, or use the 1500nm wavelength region to transmit broadband services. Another solution is to simply put the broadband service in a separate optical fiber for transmission, for example, using the HFC structure. At this time, the HFC uploads analog or digital image services, while FTTC is mainly used to transmit narrowband interactive services, which has a certain degree of flexibility and independence, but requires two basically independent infrastructures.

FTTB

It uses digital broadband technology. The optical fiber goes directly to the community, and then through the twisted pair (super five twisted pair or 4 pairs of unshielded twisted pair) to Individual users. FTTB uses dedicated line access, no dial-up is required, and easy to install. The client only needs to install a network card on the computer for 24-hour high-speed Internet access. FTTB provides the highest uplink and downlink rate of 10Mbps (exclusive). It is a broadband access method based on optimized optical fiber network technology. It uses fiber to the building and network cable to the home to achieve user broadband access. We call it FTTB+LAN broadband access network (abbreviated as FTTB).

FTTH

refers to the installation of an optical network unit (ONU) at home users or corporate users, which is the closest to the user except FTTD (Fiber to the Desktop) in the optical access series Optical access network application type. The notable technical feature of FTTH is that it not only provides greater bandwidth, but also enhances the transparency of the network to data formats, rates, wavelengths, and protocols, relaxes requirements on environmental conditions and power supply, and simplifies maintenance and installation. FTTH+Ethernet is better than ADSL (ADSL will establish a maximum theoretical download bandwidth of 8Mbps when dialing again. This bandwidth will never change. But in fact, due to the noise detection mechanism of ADSL, if the line condition is not good, the connection established at the beginning is obviously It is impossible to reach the theoretical value. It may be 5Mbps in the end. This bandwidth will not change.) And ISDN (the popular European telephone network form) transmission speed is much faster.

FTTD

FTTD access technology is a rising network technology, which has been used in foreign countries. However, because of the cost of optical fiber and the factors of optical fiber in technology, construction, environmental protection, and safety, FTTD is only used in some governments and security departments in China. A new transmission medium-"plastic optical fiber" appears. The application of FTTD will become more and more extensive.

The advantages of FTTD optical fiber

Fiber to the desktop FTTD (FiberToTheDesktop) refers to the fact that optical fiber replaces the traditional copper cable transmission medium and extends directly to the user terminal computer, enabling the user terminal to realize the network through optical fiber throughout the process Access. The copper cable system still dominates the work area subsystem due to its low cost, simple installation and construction, convenient maintenance and support for PoE Ethernet technology. However, with the development of optical communication technology, the bottleneck of copper cable system upgrades and the complexity of the application environment, the advantages of optical fiber have become more and more obvious: (1) Optical fiber can support longer distances and higher bandwidth Transmission. The new generation of OM4 multi-mode optical cable provides an effective mode bandwidth of at least 4700MHz·km at 850nm wavelength, an injection mode bandwidth of 3500MHz·km, and an injection mode bandwidth of at least 500MHz·km at a wavelength of 1300nm. Both support 10Gbps serial up to 550m. Transmission, and 40/100Gbps transmission over 150m. Zero Water Peak OS2 single-mode optical cable can even reach 40 kilometers of transmission in 10 Gigabit Ethernet. These are simply impossible for the copper cable system. When the transmission distance of the information point exceeds 100 meters, the choice of copper cable system wiring must increase the area management room, increase the network equipment and wiring materials, which will increase the project engineering cost, and may also increase the link failure point. However, fiber optic systems can easily solve this problem.

(2) Optical fiber is a non-metallic substance, and data is transmitted on light waves, which can avoid external electromagnetic interference EMI and radio frequency interference RFI, such as in some special wiring environments: air-conditioned computer rooms, medical equipment rooms in hospitals , Machinery manufacturing plants, etc.; Moreover, there is no crosstalk between the cores, and the signals will not be leaked to the outside, which plays a good role of confidentiality. For example, in some places where information is required to be kept confidential: public security agencies, military industries, high-tech research and development units, etc. .

(3) The operating environment has a wide temperature range; the communication is not charged, and it can be used in flammable and explosive places, and it is safe to use.

(4) Chemical resistance and long service life.

(5) Different sheath materials and internal structures can cope with harsh office environments.

(6) The copper cable system developed from Cat5 to Cat6A, and the cross frame and shielding layer (even double shielding layer) were added to the structure, and the wire diameter became larger and larger, all of which increased invisibly The cost of raw materials, transportation costs, installation auxiliary materials, installation and construction costs, and testing costs of copper cables. The copper cable system has developed from the four test parameters of Cat5 to more than a dozen later, and there is an additional external crosstalk test parameter, which makes the acceptance test of the Cat6A cabling system more cumbersome and time-consuming. However, since the development of optical fiber to this day, the volume and weight have not undergone any changes, and there are generally only two test parameters: "attenuation" and "length". Moreover, with the development of optical communication technology, the cost of raw materials has a downward trend, and installation and construction have become more and more convenient.

(7) The application of 10GBASE-LRM enables OM1 and OM2 optical cables to reach a transmission distance of 300 meters in 10 Gigabit Ethernet, greatly reducing wiring costs.

…….

For these reasons, the application of fiber to the desktop FTTD has become a future development trend. Some people even regard the Cat6A system as the end of the copper cable era. , The optical cable will be the ultimate choice for the network.

Fiber to the Desktop Network

Fiber to the Desktop Network (FTTDnet) was registered and established in 2013, and the ICP record number is Guangdong ICP No. 13031061.

Following the large-scale construction of fiber to the home (FTTH), fiber is further advanced to the user side, that is, to achieve the final network solution-fiber to the desktop (FTTD). Fiber to the desktop (FTTD) refers to the direct connection of optical fiber, a high-speed data transmission medium, to a computer network card. At this stage, desktops or laptops are rarely equipped with optical fiber network cards when they leave the factory. Therefore, users need to configure appropriate optical fiber network cards by themselves.

Some units that require relatively high bandwidth and security, such as public security agencies, financial units, military units, medical and health industries, and even some large enterprises and institutions, have begun to have a high degree of building fiber-to-the-desktop networks. Demand. This is because compared to cables, optical fibers can provide higher bandwidth, longer transmission distance and longer working life. Especially optical fibers are not like cables. As the transmission rate increases, the risk of electromagnetic leakage is also fast. Rising, this is undoubtedly the most attractive for units that have higher requirements for information security.

In response to the domestic demand for fiber-to-the-desktop (FTTD) network construction, the fiber-to-the-desktop network provides an online information display platform for engineering and technical personnel and purchasing personnel. Fiber-to-the-desktop network provides equipment information and price information for Ethernet fiber-to-the-desktop, including fiber routers, Ethernet fiber switches, fiber network cards, optical modules, and fiber transceivers. Plastic optical fiber is a new type of transmission medium in the 100M fiber-to-desktop market, and it is also a direction for fiber-to-desktop networks.

In addition to the market and price information of fiber-to-the-desktop products, fiber-to-the-desktop network is also a communication platform. I hope that the majority of engineering and technical personnel and all friends who are interested in the realization of fiber to the desktop can actively participate in such discussions and jointly promote the popularization of fiber to the desktop in China.