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Post 29/07/2014

FTTH Network

    PON ( Passive optical network ) is a form of fiber –optic network  access , network type connects Point- Multipoint ( P2M), optical fiber makes foundation creat network architecture. Every customer is connected optical network through passive optical splitter without power supply. Hence,  no active equipment in divided network and bandwidth is shared from feeder to user, allows a single fiber to serve many basic branches, from 16-128.PON consists of Opical  Line Terminal ( OLT) in the center of the provider  and Optical Network Units ( ONUs) near last user.
    PON technology reduces the mount of conductor wire and devices in central office more than point-point architecture.
   Forward path is broadcased to all basic branches . Forward path signal transmits to households . Return path signal combines with multiple access protocol , time dividing mulitiple assess ( TDMA). OLT will control ONUs to use time slots for transferring Return path data.

   The advantage of PON is  that  using Splitter without supply power, low price and it can be placed anywhere, no dependent on environmental conditions, without supply power for devices between central lab and the side of  user. In addition, this advantage helps operators reduce maintenance cost and operation. PON architecture allows to reduce the cost of fiber optic cable and devices in CO because it allows many users (usually 32 users) who share same optical fiber.
   PON passive optical network
ITU-T G.983
·         APON (ATM Passive Optical Network): This is the first PON network standard , mainly used for business applications and based on ATM
·         BPON (Broadband PON): is a standard based on APON. It further supports WDM technology, bandwith for uplink is rougher and higher. It also provides the standard management interface OMCI between OLT and ONU/ONT to allow many providers to operate together .
·         ITU-T G.984
·         GPON (Gigabit PON): is the upgrading of BPON standard. It supports higher speed , enhances sercurity and diversity in the selection of 2 layer protocols: ATMGEM,Ethernet.
EPON and GPON is a popular version of  passive optical network ( PON) . The short way network of fiber optic cable is used for internet access , voice over internet protocol ( VoIP), and digital TV transmission in urban areas. Other applications include backhaul connection to basestation cell, Wifi hotspot , distribution antenna systems ( DAS) . The main difference between them lies in the protocol which used for downstream and upstream communication.
Passive Optical Network
       A PON is an Optical network which only uses optical fiber and passive components such as Slitter and  combiners without active ingredients as amplifiers, repeaters, or formative chains . Sothat its cost will be cheaper than those who used significantly active ingredients  . The main disadvantage is that limited distance is shorter to ensure by signal power .  While an active optical network ( AON)can include a range of about 100km ( 62 miles) . A PON often limits a cable up to 20 km ( 12 miles) .PONs is also known as fiber optic network ( FTTH) to home
         FTTx types is used to refer to the distance of fiber . In FTTH, x is for families . You can also see it called as FTTP or optical cable . Other variants are FTTB for optical cable to build . Three versions define system which has optical cable run all ways from providers to customers. Other forms, optical cable does not run all ways to customers. Instead, it is operated with temporary button  in the city block . It is called as FTTN fiber to the node. Other variants are FTTC, or sidewalk cable. Here fiber optic cable does not run ways to home. FTTC and FTTN can be used twisted-pair copper telephone cable ( UTP ) to expand  customer service with low cost. For example : a fast ADSL line gives data to  customer’s deveces .
      The arrangement of typical PON is a point to multi-point ( P2MP) network that an optical line terminal ( OLT) at TV or Internet distribution service provider from 16 to 128 customers on each fiber ( see figure) . Optical slitters is passive fiber-optic device dividing an optical signal into multiple equal optical signals but lower than source signal, distributes signals to users. Optical network unit ( ONU) at the end of PON is at customer’s home.ONU often communicates with an optical network terminal ( ONT), maybe a separate box  that connects PON with TV , phone, computer or a wireless router. OUN/ONT can be used in a device.
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