The technical development of fiber-optic communications has advanced to a point where it is now well in advance of electrical and radio frequency transmission.
This development has highlighted several advantages, such as increased bandwidth, elimination of any spark hazard and increased security by the avoidance of any electromagnetic tapping procedure. Low maintenance, and being able to pack the ultra-thin fiber-optic cables, are also benefits.
Meeting The Challenge
There are several options to consider when bringing fiber-optics to the end user. These include both active and passive optical networks. Within passive optical networks (PON), there are three primary options – broadband, gigabit and Ethernet.
The gigabit passive optical network (GPON) is the speediest of the three options.
This is How GPON Works
The gigabit passive optical network (GPON) is based on the ITU-T G.984 standard. It replaces the G.983 standard.
A single network is made up from an optical line terminal – the property of the service provider – a splitter and up to 64 optical network units. This network does not have to be located on the end user’s premises, but it does serve a single customer. Its task is to convert the optical signal to electrical or radio frequency signals to produce a connection to the customer’s equipment.
The best network units (ONU) are also referred to as an optical network terminal (ONT).
The ONT is usually located on the customer’s premises, but the ONU can be positioned within 20 kilometres of the end user. Apart from this option, the services delivered by both networks are identical.
All information travels over the short-wavelength infrared band employing wavelength division multiplexing, with the data traveling over a 1490 nm signal at a maximum speed of 2.488 gigabits per second.
The next generation of gigabit passive optical network (GPON) will be known as 10G GPON or XG-PON. It will offer symmetric 10 Gb/signals upload and download speeds.
Most GPON customers are homes and small business enterprises, where technology data, voice and IP video needs are best delivered by gigabit passive optical networks. The system can also be configured with a radio frequency overlay at 1550 nm to provide standard cable videos.
Is GPON the First Choice?
Provided it meets certain conditions, GPON technology is the most cost effective.
The optical network terminal (OLT) is relatively costly, so the number of optical network units (ONU) connected to it should be in the 32 to 64 user range. More than 32 units requires a second terminal port, with a minor cost increase.
The more users of an OLT, the more likely degrading during peak usage.
A passive optical network offers the twin advantages of low maintenace costs and an extended mean time between failures (MTBF), since passive components seldom fail.
A GPON can replace existing copper wire cabling and deliver higher data speeds with more reliability. High density areas require less fiber and allows development of ONU and OLT networks.
In a large office building, for example, it is advisable to install an optical line terminal on the premises, or opt for a more compact optical line terminal, which need not be located in a central office.
The Need for Sense and Sensibilty
Whilst the worldwide move to a gigabit passive optical network is growing, there are competitors in the intelligence technolgy field that make claims for support. Allowing for rapid advancement in services and development of system structures, it is time for service providers to make decisions that are based on practicality and cost efficiency.
Thinking about GPON? Infracomm has a solution for you.