Passive Optical Network

Computer NetworkComputer EngineeringMCA


Passive Optical Network (PON) is a FTTH (Fiber to the Home) technology deployed in both domestic and commercial consumers. It is called a passive network since it does not require a power equipment to amplify or process signals. A PON implements point – to – multipoint architecture, where a single optical line is divided into many optical splitters to serve multiple customers. It is used in the last mile of the network connection between an ISP and a user.


The passive optical network has three parts −

  • Optical Line Terminator (OLT) − This is the end office of the service provider.

  • Optical Distribution Network (ODN) − This contains the fibers and splitters, enabling point – to – multipoint connection.

  • Optical Network Unit (ONU) − This terminates the PON and provides services for interface with the customer.

Data Transmission

Data transmission in a PON is a two way traffic −

  • Upstream data transmission − This transmission is from the customer to the ISP. Here, optical combiners combine customer data is into a single signal, through time division multiplexing (TDM).

  • Downstream data transmission − This transmission is from the ISP to the customer. Optical splitters divide the signals and broadcast them to all the premises. Encryption and authentication measures at the customer end determine who can access the data in the transmitted signal.

Types of PONs

The common kinds of PONs are −

  • GPONs (Gigabit-capable PONs)

  • EPONs (Ethernet PONs)

  • BPONs (Broadband PONs)

  • APON (Asynchronous Transfer Mode PONs)

Updated on 03-Aug-2019 19:59:37