Hybrid Fibre Coaxial (HFC) cable networks
A HFC network consists of a headend office, distribution centre, fibre nodes, and network interface units. The headend office receives information such as television signals, Internet packets, and streaming media, then delivers them through a fibre ring to distribution centres. The distribution centres then send the signals to distribution nodes, which convert the optical signals to electrical signals and redistributes them on coaxial cables to residents’ homes where network interface units send the appropriate signals to the appropriate devices.
Approximately 2 million homes in Melbourne and Sydney are passed by HFC networks owned by Telstra and Optus. Some parts of these networks are currently being upgraded to higher bit rate, but they are highly asymmetric and their upload capability is severely limited, particularly if all users try to download data at the same time. Under the current NBN plan broadband access over these HFC networks will be decommissioned as the NBN comes on stream.