In recent years, fiber to
the home (FTTH) has begun to receive the attention of global telecommunications
companies, enabling rapid development of technology. Active Optical Network (AON) and Passive Optical Network (PON) are the two major systems that make
FTTH broadband connections possible. So far, most FTTH deployments in planning
and deployment have used PON to save fiber costs. PON has attracted much
attention recently due to its low cost and high performance.
GPON
GPON stands for Gigabit
Ethernet passive optical network. GPON uses ATM for voice, Ethernet for data,
and proprietary encapsulation for voice. It offers faster Gbps than EPON on
downstream and upstream bandwidths.
EPON
EPON stands for Ethernet
passive optical network. EPON uses Ethernet packets instead of ATM
(Asynchronous Transfer Mode) cells. EPON also uses Internet Protocol (IP) to
carry data, voice, and video data. It generally delivers 1G symmetrical
bandwidth, which makes it a popular choice.
Optical
Line Terminal (OLT)
OLT (Optical Line Terminal) is an endpoint hardware device located in a passive optical network (PON)
central office. It is equivalent to a switch or router in a traditional
communication network and is also a multi-service provision platform. The OLT
includes a central processing unit, a gateway router, a voice gateway upstream
card, and a passive optical network card. The main function of OLT is to
control the information float across the ODN, going both directions, while
being located in a central office. The OLT has two float directions: upstream and
downstream.
8PON EPON OLT
Optical
Network Unit (ONU)
ONU converts optical
signals transmitted via fiber to electrical signals. These electrical signals
are then sent to individual subscribers. In general, there is a distance or
other access network between ONU and end user’s premises. Furthermore, ONU can
send, aggregate and groom different types of data coming from the customer and
send it upstream to the OLT. Grooming is the process that optimizes and
reorganizes the data stream so it would be delivered more efficiently. OLT
supports bandwidth allocation that allows making smooth delivery of data float
to the OLT, which usually arrives in bursts from the customer. ONU could be
connected by various methods and cable types, like twisted-pair copper wire,
coaxial cable, optical fiber or Wi-Fi.
Optical
Network Terminal (ONT)
ONU and ONT is basically
the same device. ONT is an ITU-T term, whereas ONU is an IEEE term. ONT is
located at the customer premise, and ONU is located outside the home. The ONU
usually communicates with an optical network terminal (ONT), which may be a
separate box that connects the PON to TV sets, telephones, computers, or a
wireless router.
Conclusion
There are different types
of OLT, ONU, ONT equipment for GEPON, which are the new generation PON equipments
and mainly applied by telecommunication operators in FTTH project. All these
equipment are provided in BAUDCOM.
Baudcom offers a variety of PON equipments. For more information, please
visit Baudcom.
