What is Gigabit Passive Optical Networking (GPON)?

At-a-Glance

  • Stands for Gigabit Passive Optical Network
  • Technology commonly used in the last mile of residential FTTH connections
  • Uses an optical fibre connection that is shared between several users
  • Individual fibres are connected together using fused fibre devices
  • Every signal arrives at every location on the fibre tree
  • Uses different time slots to separate users’ traffic
  • Provides user typical bandwidths in the 100Mb/s to 1Gb/s range

Gigabit Passive Optical Network technology makes use of time division multiplexing (TDM) that enables several customers to access and share the same fibre. Each customer has their own time slot within the overall signal.

The fibre itself is passively split in between the central office of the ISP in one or two stages, typically with a split factor of between eight and 32 ways. The optical line termination (OLT) transmits an aggregate signal from the ISPs central office.

When the optical signal arrives at each customer’s location, the customer ONU equipment accesses only its intended time slot.

Thus, the aggregate bit rate transmitted from the ISP’s central office is shared among the users on each fibre tree.

What is GPON?

Fibre distances are limited to a few kilometres using power splitting which wastes power for signals that enter fibres that are not for the intended customer connection.

Typically, bit rates delivered to end users are between 100Mb/s and 1Gb/s (depending on the number of time slots allocated, and the user’s service level).

GPON’s TDM multiplexing can easily coexist with wavelength division multiplexing, which means GPON can be present on the same fibre with other service types.

GPON-TDM

Typically bit rates delivered to end users are between 100Mb/s and 1Gb/s (depending on the number of time slots allocated, and the user’s service level).

GPON can coexist on the same fibre at the same time as other service types, due to the possibility of using GPON’s TDM multiplexing at the same time as Wavelength Division Multiplexing.