Introduction of PON Access Technology and Standard
PON (Passive Optical Network) is one kind of 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 3 PON Network Structure
PON network implements that optical signal of upstream and downstream. With the downstream optical signal wavelength as 1490nm and the upstream optical signal wavelength as 1310nm, it can be transmitted in the same fiber by adopting WDM (Wavelength Division Multiplex) technology. Data is transmitted by broadcasting for downstream and TDM (Time Division Multiplex) for upstream to achieve 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, did researches on EPON and GPON technology and released relative standards, respectively.
IEEE stands for the Institute of Electrical and Electronics Engineers of America. It is also an international institute of electronic technology and information science engineers with nearly 400,000 members, one of the biggest professional and technical organizations globally. In PON accessing, IEEE accomplishes 802.3ah standard in 2004 and combines with IEEE802.3 (basic standard of Ethernet) as one standard, which has not been changed so far. IEEE studied functions of the physical layer and data link layer of 10G EPON with inheriting most technical features of 1G EPON. Then rolled out the 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 was released in September 2009.
Figure 4 PON Standards History and Roadmap
FSAN (Full Service Access Network) is the most influential organization in 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 China are mainly drafted out by the 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) “.
China Telecom aims to strengthen interoperability, operate, and manage the PON system’s capability based on relative international standards and national standards. Version V3.0 of “Technical Requirements for China Telecom EPON Devices” “Technical Requirements for China Telecom GPON Devices,” both are issued by China Telecom and have good guiding significance on system interoperability.
FTTH Solution and Product
C-Data provides FTTH solution, a new generation passive fiber network product solution based on the PON system network, meets relative national and international standards of GPON and EPON, and 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 5:
Figure 5 FTTH solution based on PON system
Introduction of FTTH solution based on PON system:
OLT of the local side (Machine room) is the core of the PON system. It provides high-speed uplink interfaces for information access, such as voice, data, and PON interfaces for the passive optical distribution network. OLT is also the control center of the PON system, by which the network management system can accomplish operations, management, and maintenance of the PON system.
ONU of the user side provides an interface for data, internet video, and VOIP. By applying Ethernet, GEM protocol, etc. to implement transparent transmission of user data in the PON system.
ODN network between OLT and ONU, a passive optical distribution network consisting of optical splitter and optical fiber, distributes and converges optical signals. ODN network forwards downstream data to each ONU terminal and aggregates upstream data into the OLT device. Based on the actual application environment, it can use one splitter solution or two cascaded splitters solution.
C-Data manufactures EPON and GPON products that meet various application scenarios, including cassette type, module inserted type, mini type and outdoor type of OLT products, SFU type, HGU type, and CATV type of ONU products, and so on.
There are types of the 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 the 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 amounts of modules according to application requirements, which has a high level of integration and flexibility, easy to manage and configure, a product that meets access demand of medium-size network large-scale network with high cost-effectiveness
Outdoor type OLT uses cast aluminum IP65 waterproof shell and is applicable in the pole, floor stander, and corridor application scenarios.
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.
Related products as follows:
GPON Product: different combinations of two active transmission equipment, including namely-Optical Line Termination (OLT) and Optical Network Unit(ONU).
- GPON OLT: Cassette OLT and rack-mounted OLT (Module inserted)
- GPON ONU: Data type, data + voice type, data + WIFI type, data + voice + WIFI
EPON Product: a device that serves as a provider endpoint of a passive optical network, multiplexing between the conversion devices on the other end of that network (called either optical network terminals or optical network units).
- EPON OLT: Cassette OLT, rack-mounted OLT (Module inserted), outdoor OLT
- EPON ONU: Data type, data + voice type, data + WIFI type, data + voice + WIFI