With the development of society informatization, people have a bigger requirement for information such as VR, HDTV, HD video, 3D games, cloud computing, big data, Internet of things, cloud storage and so on, as new applications keep showing up. There’s no doubt that the data boom will lead to a higher requirement for bandwidth capability of Internet, and usually the access network that is closest to the subscriber becomes a bottleneck, which indicates that upgrading and rebuilding for access network is quite necessary at the moment as the original copper cable accessing (ADSL or Cable Modem) can not meet users’ demand any more.
FTTH (Fiber to the Home) can provide higher bandwidth for users to meet different demands of services of voice, video and data with fiber as transmission medium, which will gradually replace the technology of copper accessing. PON (Passive Optical Network) is recognized as the best FTTH accessing technology in the industry with no any active power devices but all passive devices between local side and user side. Due to its advantages such as high bandwidth, good network stabilization, convenience of management and maintenance and low cost, FTTH becomes the current preferred network accessing solution with consistent approbation from big operators all over the world.
Fiber Beam can provide users with end-to-end product solutions.
Introduction of PON Access Technology and Standard
PON (Passive Optical Network) is one kind network system of P2MP (Point to Multiple Point), which consists of OLT (Optical Link Terminal), ODN (Optical Distribution Network) and ONU (Optical Network Unit), its network structure as shown below:
Figure 1 PON Network Structure
PON network implements that optical signal of upstream and downstream can be transmitted in the same fiber by adopting WDM (Wavelength Division Multiplex) technology with the wavelength of downstream optical signal as 1490nm and the wavelength of upstream optical signal as 1310nm. Data is transmitted by broadcasting for downstream and by TDM (Time Division Multiplex) for upstream, so as to realize the communication of P2MP (Point to Multiple Point).
At present, there are two main PON access network solutions, GPON (Gigabit-Capable PON) and EPON (Ethernet Passive Optical Network). PON standardization organization IEEE, ITU-T/FSAN made researches on EPON and GPON technology and released relative standards respectively.
IEEE stands for Institute of Electrical and Electronic Engineers of America, is also an International institute of electronic technology and information science engineers, one of the biggest professional and technical organizations in the world with nearly 400,000 members. In the area of PON accessing, IEEE accomplished the completion of 802.3ah standard in 2004, and combined with IEEE802.3 (Basic standard of Ethernet) as one standard, which has not been changed so far. IEEE studied functions of physical layer and data link layer of 10G EPON with inheriting most technology features of 1G EPON, then rolled out technology of 10G-PON, which only redefined PHY physical specification and raised transmission rate to (10G/DS 1G/US or 10G/DS/US) without changing the existing EPON MAC layer control protocol, 10G EPON standard 802.3av is released in September 2009.
FSAN (Full Service Access Network) is the most influential organization on the research of optical access technology (B-PON,E-PON,G-PON) in the current field, which is started by carriers like BT/Bellsouth and concentrates on the research of next generation optical access network technology.
Standards of communication industry of EPON and GPON in are mainly drafted out by T access network working group of CCSA. At present, related national standards have been developed, like EPON national standard YD/T 1475-2006 “Technical Requirements for Access Network-Passive Optical Network Based on Ethernet (EPON)”and GPON national standard YD/T1949-2009 “Technical Requirements for Access Network-Gigabit-capable Passive Optical Network (GPON) .“
Telecom aims to strengthen the interoperability, operating and managing capability of PON system based on relative international standards and national standards. Version V3.0 of “Technical Requirements for Telecom EPON Devices,” “Technical Requirements for Telecom GPON Devices,” both are issued by Telecom and have good guiding significance on system interoperability
FTTH Solution and Product
Fiber Beam provides FTTH solution, which is new generation passive fiber network product solution based on PON system network and meets relative national and international standards of GPON and EPON, and also meets the transmission requirement of high speed internet, voice and video services. This solution not only can provide the last kilometer access with fiber for all kinds of network operators, but also can be applied on customer professional network for various industries like broadcast and television access network, video monitoring network, enterprise local area network, and servers in customer private network of different industries such as radio and television, transportation, energy sources, electric power, finance and government.
Network topology as shown in figure 2:
Figure 2 FTTH Solution Based on PON System
Introduction of FTTH solution based on PON system:
OLT of local side (Machine room) is the core of PON system, provides uplink interfaces with high speed for information accessing like voice, data, and PON interfaces for passive optical distribution network. OLT is also the control center of PON system, by which network management system can accomplish operations, management and maintenance of PON system.
ONU of user side provides interface for services like data, internet video and VOIP. By applying Ethernet, GEM protocol and so on, to implement transparent transmission of user data in PON system.
There is ODN network between OLT and ONU, which is passive optical distribution network consisting of optical splitter and optical fiber with the function of distributing and converging optical signals. ODN network forwards downstream data to each ONU terminal and aggregates upstream data into OLT device, based on the actual application environment, it can use one splitter solution or two cascaded splitters solution.
There are types of cassette, compact, module inserted and outdoor of OLT products, the series of cassette and mini type of OLT with 1U height can be installed in 19-inches standard rack, and has characteristics of compactness, convenience, high performance, easy to use and deploy, which meets the requirement of volume and performance in compact machine room.
Mini type OLT is smaller and more convenient, which meets the installment requirement in corridor and device cabinet.
Module inserted OLT can be deployed with different amount of modules according to application requirements, which has high level of integration and flexibility, easy to manage and configurate, is product that meets access demand of medium-size network and large-scale network with high cost-effectiveness.
Outdoor type OLT uses cast aluminum IP65 waterproof shell and is applicable in application scenarios of pole, floorstander and corridor.
These products are mainly for two-way network construction of broadcast television network, the “last kilometer” of fiber access provided by telecom operators, big customer broadband access solution, and also apply to high definition video monitoring system and three-in-one network including network, voice and video of government, public security and network of large enterprises.