Gigabit Passive Optical Networking (GPON)
- Gigabit Passive Optical Network
- A technology used for last mile residential fibre 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 different user’s traffic (rather like GSM radio)
- Provides user typical bandwidths in the 100Mb/s to 1Gb/s range
The fibre itself is passively split in between the Central Office of the ISP either in 1 or 2 stages typically with a split factor of between 8 and 32 ways. The OLT transmits an aggregate signal from the Central office location.
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.
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 100M/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 ofusing GPON’s TDM mutiplexing at the same time as Wavelength Division Multiplexing.