Fiber-optic communication(FTTx) has always been regarded as the most promising broadband access method after DSL broadband access. Unlike common twisted pair communication, it has higher operating frequency and larger capacity (can be based on users need to upgrade to exclusive bandwidth of 10-100Mbps), less attenuation, no strong electrical interference, strong anti-electromagnetic pulse capability, good confidentiality and so on.
Fiber Broadband Communications (FTTx) includes a variety of access formats such as common FTTP (Fiber to the Presise, FiberToThePremise), FTTB (Fiber to Building, FiberToTheBuilding), FTTC (Fiber to Roadside, FiberToTheCurb), FTTN (Fiber to the Neighborhood, FiberToTheNeighborhood), FTTZ (Fiber to the Zone, FiberToTheZone), FTTO (Fiber to Office, FiberToTheOffice), FTTH (Fiber to the Home or Fiber to Home, FiberToTheHome).
FTTH is the best choice for fiber to enter the home directly
For many home users, FTTH is the best choice. This form can connect optical fiber and optical network unit (ONU) directly to the home. It is a variety of fiber broadband access except FTTD (fiber to desktop, FiberToTheDesk). The form of fiber access that is closest to the user.With the generalization of the form of fiber broadband access, it should be noted that the current FTTH broadband access does not simply refer to fiber to the home, and has generally referred to various fiber-to-the-home access forms such as FTTO, FTTD, and FTTN.
In addition, the reader should pay attention to the difference between the current “FTTx+LAN (fiber + LAN)” broadband access scheme in understanding the FTTH.FTTx+LAN is a broadband access solution that implements “100Mbps to cell or building, 1-10Mbps to home” using fiber +5 twisted pair mode – switch and central office switch and optical network unit (ONU) Connected, the cell uses Category 5 twisted pair cabling, and the user access rate can reach 1-10Mbps.
Unlike the single-family exclusive bandwidth scheme of FTTH, the bandwidth of FTTx+LAN is shared by multiple users or families. When there are many shared users, the bandwidth or network speed of the FTTx+LAN is difficult to guarantee.
FTTH technical standard
At present, it seems that the bandwidth-exclusive ADSL2+ and FTTH have become the mainstream trend of broadband development in the future.In the technology of FTTH, after APON (ATMPON), there is currently a GPON (GigabitPON) standard developed by ITU/FSAN, and two standards of EPON (EthernetPON) developed by the IEEE802.3ah working group are competing.
GPON technology is a new generation broadband passive optical integrated access standard based on ITU-TG.984.x standard. The available bandwidth is about 1111 Mbit/s. Although the technology is complex, it has high bandwidth, high efficiency, large coverage and users. The advantages of rich interfaces are considered by some European and American operators as ideal technologies for broadband access network services.
EPON solution has good scalability and can realize a variety of fiber-to-the-home methods
EPON (Ethernet Passive Optical Network) is also a new type of fiber access network technology. The effective uplink transmission bandwidth is 1000 Mbit/s. It adopts point-to-multipoint structure and passive optical fiber transmission, and can provide multiple kinds on Ethernet. The business combines the advantages of PON technology and Ethernet technology, featuring low cost, high bandwidth, strong scalability, good compatibility with existing Ethernet, and easy management. It is used in Asia, such as China and Japan. More extensive.
No matter which PON fiber system is composed of OLT (Optical Line Terminal, Optical Line Terminal), POS (Passive Optical Splitter), ONU (Optical Network Unit) and its network management system .These parts are installed by the ISP installer during installation, and the home users themselves generally have no conditions to set up themselves.
FTTH layout
In terms of specific functions, the OLT is placed at the ISP central office and is responsible for the connection, management, and maintenance of the control channel.The maximum transmission distance between the OLT and the ONU can reach 10-20km or more. The OLT has a ranging function to test the logical distance between each ONU and the OLT, and accordingly, the ONU is instructed to adjust its signal transmission delay to make different. The signals transmitted by the ONUs of the distance can be accurately multiplexed together at the OLT.OLT devices generally also have a bandwidth allocation function, which can allocate specific bandwidth by the OLT according to the needs of the ONU. Moreover, the OLT device has a point-to-multipoint hub feature, and an OLT can carry 32 ONUs (and can be subsequently extended), and all ONUs under each OLT share 1G bandwidth through time division multiplexing, that is, each ONU can provide upper and lower The maximum bandwidth is 1 Gbps.
A POS passive fiber splitter, a splitter or splitter, is a passive device that connects the OLT and the ONU. Its function is to distribute the input (downstream) optical signals to multiple output ports, enabling multiple users to One fiber is shared to share the bandwidth; in the upstream direction, multiple ONU optical signals are time-division multiplexed into one fiber.
ONU generally has 1-32 100M ports and can be connected to various network terminals
The ONU is a device used by the UE to access an end user or a corridor switch. The single optical fiber can time-multiplex the data of multiple ONUs to one OLT port through a passive optical splitter.Due to the point-to-multipoint tree topology, the investment of the aggregation device is reduced, and the network level is also clearer.Most ONU devices have certain switch functions. The uplink interface is a PON interface. It is connected to the interface board of the OLT device through a passive optical splitter. The downlink is connected through 1-32 100-Gigabit or Gigabit RJ45 ports. Data devices, such as switches, broadband routers, computers, IP phones, set-top boxes, etc., enable point-to-multipoint deployment.
How to network in the family
In general, FTTH to the ONU equipment of the terminal will provide at least four 100M RJ45 interfaces. For users who have four computers connected by wired network cards, they can meet the needs of multiple computers sharing Internet access in the home. In addition, for FTTH networks using dynamic IP, users can also connect to switches or wireless APs for expansion of wired and wireless networks as needed.
Current broadband routers can perfectly support FTTH access solutions
For FTTH terminals that only provide a 100M RJ45 interface using fixed IP, they can be extended by a broadband router or wireless router.In the setting, just in the WEB setting interface of the router, find the “WAN port” option, select the WAN port connection type as “static IP” mode, and then enter the IP address and subnet provided by the ISP in the following interface. The mask, gateway and DNS address are all right.
In addition, users of purchased broadband routers or wireless routers should use it as a switch or wireless AP in the FTTH network. Pay attention to the following points when setting up:To use the wire router as a switch or wireless AP, insert the twisted pair plug from the ONU device directly into any interface in the router’s LAN port. In the management page of the router, turn off the DHCP server function opened by default.Set the IP address of the router and the ONU device using dynamic IP as the same network segment.
Since fiber access provides unlimited bandwidth, Fiber to the Home (FTTH) is known as the “king” of the broadband era and is the ultimate goal of broadband development. After the fiber is delivered to the home, the user’s Internet speed can be greatly increased again. It takes only a few seconds to download a 500MB DVD movie, which is ten times faster than the current ADSL solution. With the continuous reduction of the cost of FTTH erection, the light to the home is moving from dream to reality.