What is GPON?

GPON stands for Gigabit Passive Optical Network.

It’s a type of fiber-optic broadband technology used by internet service providers (ISPs) to deliver high-speed internet, TV, and phone services to homes and businesses.

 Here’s how it works

Throughput - It supports very high data speeds (up to 2.5 Gbps downstream and 1.25 Gbps upstream in the standard version).

Passive - It doesn’t need powered equipment between the provider’s central office and the customer’s location. Instead, it uses passive optical splitters to divide one fiber into many, serving multiple users.

Optical Network - The entire connection is based on fiber optics, which transmit data using light instead of electricity, allowing for higher speeds and longer distances than copper cables.

Key components:

• OLT (Optical Line Terminal) - Located at the ISP’s central office, it manages the GPON network.
• ODN (Optical Distribution Network) - The passive fiber and splitters in the field.
• ONT/ONU (Optical Network Terminal/Unit) - Installed at the customer’s home or business, converting the optical signal into Ethernet/Wi-Fi for devices.

In short: GPON is the backbone of many FTTH (Fiber To The Home) deployments, enabling very fast, reliable internet. 

Newer generations of passive optical networks

Feature	GPON	XG-PON	XGS-PON
Standard name	ITU-T G.984	ITU-T G.987	ITU-T G.9807.1
Downstream speed	2.5 Gbps	10 Gbps	10 Gbps
Upstream speed	1.25 Gbps	2.5 Gbps	10 Gbps (symmetric)
Split ratio (users per fiber)	Typically 1:32, up to 1:128	1:128	1:128
Coexistence with GPON	N/A (base tech)	Yes (on same fiber using different wavelengths)	Yes
Use cases	Residential broadband, IPTV, VoIP	Enterprise, high-speed residential, 5G backhaul	Enterprise, symmetrical services, cloud applications
Commercial adoption	Very widespread	Growing	Becoming standard in new deployments