Views: 260 Author: Krystal Publish Time: 2022-05-25 Origin: Site
FTTH (Fiber To The Home) is The ultimate form of access network development. Optical fiber access network is divided into FTTH, FTTB(optical fiber to the building), FTTP(optical fiber to the station) and FTTC(optical fiber to the roadside) based on the location of optical network units, collectively referred to as FTTx. FTTx is divided into fiber to home (FTTH), fiber to building (FTTB) and fiber to roadside (FTTC) in terms of the location of optical network unit (ONU). For residential or building, there are two main ways to connect users with optical fiber: one is to directly connect each home or building with optical fiber; The other is passive optical network (PON) technology, which uses splitters to branch optical signals, with a single fibre providing fibre-to-home service for multiple users.
PON is an all-optical network with tree-like structure, which can use sparse wavelength division multiplexing (CWDM) technology to solve the bidirectional transmission problem. The system is composed of local device OLT(optical line terminal) and client device ONU/ONT(optical network unit/optical network terminal) and ODN(optical distribution network), so called passive , means that ODN is composed of passive optical devices such as passive optical splitter and optical fiber, excluding any active devices. PON technology adopts point-to-multipoint topology structure, and transmits data downstream and upstream through TDM and TDMA respectively.
PON technology can be subdivided into several, different data link layer technology and physical layer PON technology combined to form different PON technology, such as ATM+PON formed APON,Ethernet+PON formed EPON,ATM/GEM+PON formed GPON, this is the biggest difference between various PON technology Advantages of THE PON technology include protection against lightning and radiation interference of passive optical devices, flexible network structure, easy expansion of shared feeder segments, cost saving, service transparency, multi-service support, and easy management and maintenance At present, among a variety of PON-based technologies,EPON has gradually become the most popular FTTH technology due to its advantages in terms of product maturity and price. In particular, GEPON based on gigabit port has become the most suitable FTTH technology at the current stage because it increases the access rate of single optical fiber from 100Mbps to 1000Mbps on the basis of the original EPON Market demand for optical fiber access technology
Fiber to the home (FTTH) is to connect the fiber optic broadband directly to the home. How much bandwidth does the fiber to the home have? From the point of view of the access layer, there are several technologies: EPON, GPON, 10GPON, 40G TWDM PON(the cost is too high to mass production and only a small number of overseas deployment).
1. The maximum downstream bandwidth of EPON is 1 GB (1250M). The maximum downstream bandwidth of EPON is shared with 32 households at most. //2017-09-12 Supplementary: There are many EPON in China with 64 ODN splitters, which can share bandwidth for up to 64 users. The average minimum bandwidth per household is about 20M;
2. The maximum downstream bandwidth of GPON is 2G(2500M). The maximum downstream bandwidth of GPON is shared with 64 households at most. 3. 10GPON is the downstream bandwidth of a maximum of 10 GB (10,000 M). A maximum of 64 households can share 10GPON. In the future, there may be 25G/50G/100GPON, with the same number of shared users but an increase in downstream bandwidth.
Fiber to the Building (FTTB) refers to the access of fiber and bandwidth to the machine room (MxU equipment) in the building, and then pull copper wire from the machine room to the home. The total bandwidth of the optical fiber is divided into EPON/GPON/10GPON, but is usually shared among more households. For example, if THE GPON is shared among 500 users, the minimum bandwidth of each household is 5Mbps (2500M/500=5Mbps). It is usually suitable for high density and wide coverage with low Requirements for Internet access (for example, campus network).