EPON Based On Ethernet Access Technology

EPON is based on long-distance optical fiber transmission network Ethernet access technology. EPON uses multipoint architecture, an optical fiber carrying data signals down the line, after 1: N optical splitter signal into N Road, branch coverage of light multiple access point or access users.

EPON and GEPON term in tradition, there is not a state error. Early EPON equipment industry is based FE bus, bus-based EPON equipment GE launched, in order to distinguish called GEPON, EPON equipment industry at present is essentially based on GE bus. At present basically referred to EPON.

A typical system consists of EPON system is composed of OLT, ONU and ODN. EPON network structure is shown in Figure 1.

EPON Network Structure

OLT in the center machine room, it can be seen as a L2 switch or L3 routing switch. In the downstream direction, OLT to provide for passive optical network (ODN) optical interface; In the upstream direction, OLT will provide GE optical or electrical interface, the future of 10Gbit/s Ethernet technology standards after setting, OLT will also support a similar high-speed interface. In order to provide multi-service access, OLT also supports E1 and OC3 interfaces, to achieve the traditional voice access or circuit relay service.

In terms of EPON network management, OLT is the main control center, the built-in OAMP Agent, can manage the ONU in its terminal equipment, to achieve the five functions of network management. EPON network management can be defined on the OLT through the user bandwidth parameter to control the quality of user services by writing an access control list to implement network security control, by reading the MIB to obtain system status and user status information, but also provide a valid user isolation.

ODN is the optical distribution network, composed of passive optical splitter and fiber composition. The passive optical splitter is connected to the OLT and the ONU passive device, its function is to distribute the downlink data and uplink data centralized. The deployment of passive optical splitter is quite flexible, because it is a passive device, be adapted to almost all environments. Generally passive optical splitter ratio has 1:2, 1:4, 1:8, 1:16, 1:32, 1:64 and so on. General recommended a splitting, splitting up not more than two.

ONU is placed on the customer premises side of the terminal device, EPON ONU in the Ethernet protocol, the realization of the second layer of low-cost Ethernet switching. The use of the Ethernet protocol, the process of the communication protocol conversion is no longer necessary to achieve the ONU transparent transmission of user data. Between the OLT to the ONU, it uses encryption protocol to ensure the security of user data.

FTTH Box

Based on EPON FTTH advantage lie in its strong coverage, as far as covering up to 20 km (1:32 split ratio), starting from the end office, after OND connecting the optical access point. Traditional optical access network, optical fiber extends the range to the network access point cutoff general, to achieve fiber to the home, you need to configure a large number of the access point port access layer switch expensive.

With the passive optical network technologies emerge and mature, especially now that the EPON technology that can provide fiber tip directly to the user's economically viable solution, FTTH becomes efficient access. In FTTx solution based on EPON, the introduction of how to solve the optical cable to the building, community, planning OLT, ODN, indoor user terminal (OUN) optical fiber connection becomes key.

For more information, please contact a Sopto representative by calling 86-755-36946668, or by sending an email to info@sopto.com.