GPON

I ran into this technology while working, and I wanted to find out what it specifically is. To put it simply, it is one way of implementing optical networking. Below I will provide a very short introduction to this technology.

Gigabyte-capable Passive Optical Networking

Passive optical network consists of a central office node, called an optical line terminal (OLT), one or more user nodes, called optical network units (ONUs) or optical network terminals (ONTs), and the fibers and unpowered (passive) splitters between them. ONUs and ONTs are devices that terminate the optical network and present customer service interfaces to the user. The difference between those two is that ONT is usually connected to a customers own device (eg. wireless access point) within the customers apartment. Whereas ONU is connected to the internal network of a building through which the connection is forwarded to multiple apartments.

Active vs passive optical networking (fetched from wikipedia)

The passive optical splitters allow a single optical fiber to serve multiple customers. However, as you can see from the picture, passive splitter cannot sort data packets individually. All the packets are sent in broadcast manner. That is, every packet is forwarded to every device connected to that splitter. Those devices will then pick only the packets that are actually meant for them and discard the others.

There are multiple advantages for using GPON. For example, it supports 20 km service coverage. Such a long reach allows ISPs to reduce the number of network nodes and save money. Furthermore, with inexpensive passive splitters one fiber connection can be split up to 64 ONTs. Replacing old copper wires can be done in a cost effective way with this technology. Fast connections even up to 1Gbits/s will be available to consumers. GPON standard is technically capable of providing mainstream connection speeds of 2,49 Gbits/s downstream and 1,24 Gbits/s upstream.

All of the GPON connections I have ran into have been Fiber-To-The-Home solutions. The picture below to clarifies the meaning of  FTTH.

Red for optical fiber, yellow for ethernet/VDSL/ADSL (Fetched from Wikipedia)

Sources

http://www.slideshare.net/mansoor_gr8/gpon-fundamentals
https://en.wikipedia.org/wiki/Network_interface_device#ONT
https://en.wikipedia.org/wiki/Passive_optical_network
http://www.accton.com/Newspage.asp?sno=80