PON ( Passive Optical Network) refers to the optical distribution network doesn't contain any digital camera and electronic power, optical distribution network (ODN) all by the optical splitter and other passive components, without the need for expensive electronic equipment, is really a type of fiber-optic access network. PON cuts down on the amount of fiber and central office equipment required compared with point-to-point architectures.

A PON consists of an optical line terminal (OLT) at the service provider's central office and a quantity of optical network units (ONUs) near end users. In OLT/ONU between the optical distribution network includes optical fiber and passive optical splitter or Fiber Optic Coupler.

OLT
An OLT, generally an Ethernet switch, router, or multimedia conversion platform, is located in the central office (CO) like a core device from the whole EPON system to provide core data and video-to-telephone network interfaces for EPON and also the company.

ONU
ONUs are utilized to connect the client premise equipment, for example PCs, set-top boxes (STBs), and switches. Generally placed at customer's home, corridors, or roadsides, ONUs are mainly accountable for forwarding uplink data sent by customer premise equipment (from ONU to OLT) and selectively receiving downlink broadcasts forwarded by OLTs (from OLT to ONU).

ODN
An ODN includes optical fibers, a number of passive optical splitters (POSs), and other passive optical components. ODNs provide optical signal transmission paths between OLTs and ONUs. A POS can couple uplink data right into a single bit of fiber and distribute downlink data to respective ONUs.

There are two passive optical network technologies: Ethernet PON (EPON) and gigabit PON (GPON). EPON and GPON are used in different situations, and every offers its very own advantages in subscriber access networks. EPON concentrates on FTTH applications while GPON concentrates on full service support, including both new services and existing traditional services for example ATM and TDM.

EPON is really a Passive Optical Network which carries Ethernet frames encapsulated in 802.3 standards. It is a mixture of the Ethernet technology and also the PON technology in compliance using the IEEE 802.3ah standards issued in June, 2004. A typical EPON system consists of three components: EPON OLT, EPON ONU and EPON ODN. It has many advantages, for example lower operation and maintenance costs, long distances and higher bandwidths.

GPON utilizes point-to-multipoint topology. GPON standard differs from other PON standards for the reason that it achieves higher bandwidth and higher efficiency using larger, variable-length packets. And GPON is generally considered the best candidate for widespread deployments. GPON includes a downstream capacity of 2.488 Gb/s as well as an upstream capacity of 1.244 Gbp/s that's shared among users.

There are also many differences between EPON and GPON. EPON, based on Ethernet technology, is compliant using the IEEE 802.3ah Ethernet in the First Mile standard that's now merged in to the IEEE Standard 802.3-2005. It's a solution for the "first mile" optical access network. GPON, on the other hand, is a vital approach to enable full service access network. Its requirements were set force by the Full Service Access Network (FASN) group, which was later adopted by ITU-T as the G.984.x standards-an addition to ITU-T recommendation, G.983, which details broadband PON (BPON).

Both EPON and GPON are known as international standards. They cover exactly the same network topology methods and FTTx applications, incorporate exactly the same WDM technology, delivering the same wavelength both upstream and downstream together with a third party wavelength. PON technology provides triple-play, Ip address TV (IPTV) and cable television (CATV) video services.

Source from EPON And GPON Of Passive Optical Network

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