Cable Forum - View Single Post - General VM/O2's plans to move from RFoG to xPON

gunner45 · 01-06-2020, 17:22

One cost effective way of delivering FTTP service is with the use of a passive optical networks (PON). It's a point to multipoint, uses unpowered optical splitters and consists of optical line terminals (OLTs) and optical network units (ONUs) at customer premises.

Different standard groups created different PON standards:
ITU-T G
- BPON
- GPON
- XG-PON

IEEE 802.3
- EPON
- 10G EPON

SCTE
- RFoG

Although RFoG is a type of PON it's never referred to as PON.

RFoG was designed for cable operators who needed to upgrade their HFC network to full fibre without incurring huge costs, and one of the major cost savings is by keeping exactly the same hubs and STBs in customer premises. Here's some high level diagrams of Virgin Media's systems.

HFC
Hub site --- fibre --- optical node --- RF over coax --- distribution cabinet --- RF over coax --- hub/STB

RFoG
Hub site --- fibre --- virtual hub (OLT) --- RF over fibre --- cabinet --- RF over fibre --- ONU -- RF over coax -- hub/STB

As you can see the conversion to/from RF takes place differently: with HFC it's done by the optical node some distance from customer premises but with RFoG done by the ONU inside the termination box on the customer's exterior wall.

Regardless of whether it's HFC or RFoG the transmission of data is still done in accordance with DOCSIS.

01-06-2020, 17:22	#12
gunner45 cf.member Join Date: Nov 2008 Location: London Services: TV Maxit TV with V6 box + phone, M500, VM Hub 3.0 Posts: 94	Re: VM/O2's plans to move from RFoG to xPON One cost effective way of delivering FTTP service is with the use of a passive optical networks (PON). It's a point to multipoint, uses unpowered optical splitters and consists of optical line terminals (OLTs) and optical network units (ONUs) at customer premises. Different standard groups created different PON standards: ITU-T G - BPON - GPON - XG-PON IEEE 802.3 - EPON - 10G EPON SCTE - RFoG Although RFoG is a type of PON it's never referred to as PON. RFoG was designed for cable operators who needed to upgrade their HFC network to full fibre without incurring huge costs, and one of the major cost savings is by keeping exactly the same hubs and STBs in customer premises. Here's some high level diagrams of Virgin Media's systems. HFC Hub site --- fibre --- optical node --- RF over coax --- distribution cabinet --- RF over coax --- hub/STB RFoG Hub site --- fibre --- virtual hub (OLT) --- RF over fibre --- cabinet --- RF over fibre --- ONU -- RF over coax -- hub/STB As you can see the conversion to/from RF takes place differently: with HFC it's done by the optical node some distance from customer premises but with RFoG done by the ONU inside the termination box on the customer's exterior wall. Regardless of whether it's HFC or RFoG the transmission of data is still done in accordance with DOCSIS.