Light line terminal

The above content is approved by the National Science and Technology Nouns Approval Committee.


The optical line terminal OLT chassis view is shown in Figure 1.


The function of the optical line terminal is as follows:

1, sending Ethernet data to the ONU (optical network unit);

2, initiates and controls the ranging process, and records ranging information;

3, the bandwidth is allocated to the ONU; that is, the start time and send window size of the ONU send data.

EPON Non-Service Light Network System, is a multi-service providing platform while supporting IP services and traditional TDM services. Place the exit of the metropolitan area network edge or community access network, converge it into the IP network, respectively.

EPON passive light network system network is flexible, and the following radius is 20 kilometers in a number of terminals of the business access point, which constitutes an EPON system network. The system supports a variety of business models, adapting to a variety of working environments, providing users with FTTX series solutions.

OLT is in addition to providing a service aggregation function, or a centralized network management platform. Device-based network element management and service-based security management and configuration management can be implemented on OLT. Not only can you monitor, manage equipment and ports, but also you can do traffic and user status monitoring, but also bandwidth allocation for QoS / SLA requirements for different users.

OLT routing function test method can be fully automated with CDROUTER.

Networking mode

There is a typical networking method of OLT as shown in Figure 2:

OLT, a signal that carries various services in the local part The access network is sent in accordance with a certain signal format to transmit to the end user, and on the other hand, the signal from the end user is sent in various service networks, respectively, according to the service type.

OLT can be divided into three parts

core part: including aggregation distribution, business processing, and ODN adaptation function

Business section: Provide service interface function, including Interface adaptation, interface protection, etc., as well as conversion function of signaling processing and medium transmission system with specific services when needed

public part: including power supply and OAM function

networking Structure

The optical access network is an access network that is light as a transmission medium, an alternative copper wire for accessing each family. The optical access network consists of three parts: Olt (Optical Line Terminal, optical line terminal), and ONU (Optical Network Unit, optical network unit), and ODN (Optical Distribution Network, optical allocation network); where OLT and ONU are optical access The core components of the network. The core part of the optical access network. The schematic diagram of the optical access network is shown in Figure 3:

Optical communication network networking

OLT, is the core component of the optical interface, equivalent to the traditional communication network Switch or router, and a multi-service providing platform. Generally placed at the end, providing fiber optic interfaces for user-oriented passive fiber optic networks. Its main implementation is:

  • Upline upper layer network, completing the upstream access of the Pon (Passive Optical Network, Passive Light Network) network.

  • The User-end device ONU is connected to the ODN network (consisting of fiber and passive spectroscope). Implement the control, management and ranging of the user-end device ONU.

ONU is the user-end device in the optical network, placed in the client, with the OLT, implement the Ethernet Layer 2, and the Three-layer function, provide voice to the user , Data and multimedia services. Its main implementation is:

  • Select the data data transmitted by the OLT.

  • responds to the management command issued by the OLT and makes the corresponding adjustment.

  • caches the user's Ethernet data and transmits in the upstream direction in the transmit window allocated in the OLT.

  • Other user management functions.

In short, OLT is like a commander, directing all ONU small soldiers, providing us with low price and high-speed communication services, through the light We are more closely connected together, technology changes life.

Technical Indicators

Ambient temperature

Technical indicators

Light line terminal

Long-term working environment: -5 ° C ~ + 45 ° C

< P> Short-term working environment: -25 ° C ~ + 55 ° C

Working environment humidity

Long-term working environment: 5% RH ~ 95% RH

short-term work Environment: Work 10% RH ~ 100% RH

Pneumatic environment 70kpa <106kpa

Altitude level 4000m

single box full configuration maximum power consumption: 150W < / p>


power supply mode: DC power supply

operating voltage range - 38.4V ~ -57.6V

chassis configuration

Main control board



service board



chassis configuration diagram


Ethernet business class


Upstream interface board






power supply Interface Board


Universal Interface Board

Cita ​​P>

Single Plate Description

EPBA board support 4 EPON port

single board introduction

support 1000BASE-PX10 / PX20 optical module, support farthest 20KM transmission distance

support maximum split ratio 1:64 A EPON port supports 64 ONU

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