Hello, everyone!
In today's article, I will briefly explain OLT. Let's get started!
OLT stands for Optical Line Terminal. It is the most important element of any PON system. Each PON system consists of:
OLT (Optical Line Terminal),
ODN (Optical Distribution Network), and
ONU (Optical Network Unit).
The task of OLT is to enable the connection of a large number of ONU devices to the MAN/WAN network via the ODN network. During this process, the OLT converts the signal from electrical to optical and vice versa.
It is located usually in CO (Central Office) or Headend. There are also Blade OLT for outdoor applications or remote OLT solutions. Remote OLT is used to reduce the distance between OLT and ONU, for example in urban areas where we have a large number of users or in rural areas with a small number of users. There are special outdoor cabinets for OLT accommodation and other necessary equipment (power supply, EDFA, patch panels, etc.).
The distance between OLT and ONU devices depends on the PON standard, usually up to 20 km. Typical distances are about 10 km. Max distances for GPON are up to 60 km, for XG(S)-PON up to 100 km.
In the next figure, we can see OLTs– MA56xx.
The main elements of OLT are the following:
Chassis. All other OLT elements are located within the chassis.
Control board. Most OLTs have 2 control boards. One is active, the other is standby boards. These are the most important elements of OLT, through which a link is established with the core network, setting, monitoring, and management.
Service board. They allow you to connect ONU devices. There are different types of these boards, such as GPON, XG-PON, XGS-PON, COMBO PON, FLEX PON, P2P, etc.
Fan module. There is only one in the chassis. Easy disassembly is provided in case of need for replacement.
DC power supply board. OLT uses DC - 48V. Most chassis have 2 power modules.
There are different models and sizes (the number of service boards/slots).
The older series of OLTs are:
MA5600T – large-capacity device
MA5603T – medium-capacity device
MA5608 – small-capacity device
The new series of OLTs are:
MA/EA 5800-X17 – large-capacity device
MA/EA 5800-X15 – large-capacity device
MA/EA 5800-X7 – medium-capacity device
MA/EA 5800-X2 – small-capacity device
MA/EA5801 (Pizza OLT) – small-capacity device
EA5801S (Blade OLT) – small-capacity device
The next figure shows new series of OLTs.
This is the end of this topic. I hope you learned something new!
Thank you!
