13.8 Passive Optical Networks
559
Table 13.7 A selection of acronyms for FTTx
Acronym
Meaning
FTTB
Fiber-to-the-building or Fiber-to-the-business
The optical fiber line reaches the boundary of a building
FTTC
Fiber-to-the-curb/kerb or Fiber-to-the-cabinet
The street cabinet is within 100 m of the user premises
FTTH
Fiber-to-the-home
The optical fiber reaches the outside boundary of the living space
FTTN
Fiber-to-the-node or Fiber-to-the-neighborhood
The fiber ends in a street cabinet that can be several km from the user
FTTP
Fiber-to-the-premises
This is a generic term covering both FTTB and FTTH
accommodated without affecting other lower-usage customers. The dedicated
wavelength also provides for a higher level of information security compared to
other PONs where users share wavelengths.
The application of PON technology for providing broadband connectivity in the
access network to homes, multiple-occupancy units, and small businesses commonly
is called fiber-to-the-x (FTTx) [56, 66, 67]. Here x is a letter indicating how close
the fiber endpoint comes to the actual user. Table 13.7 lists the acronyms for various
FTTx concepts. FTTP for fiber-to-the-premises has become the prevailing term that
encompasses the various FTTx concepts. FTTP networks can use any of the various
PON technologies.
13.8.2 Active PON Modules
This section gives a snapshot of the basic functions and compositions of the optoelectronic equipment located in the central office and at or near the endpoint
users.
Optical Line Termination (OLT)
The optical line termination (OLT) equipment is located in a central office and
controls the bidirectional flow of information across the network. An OLT must be
able to support transmission distances of up to 20 km. In the downstream direction the
function of an OLT is to take in voice, data, and video traffic from a long-distance or
a metro network and broadcast it to all the users on the PON. In the reverse direction
(upstream), an OLT accepts and distributes multiple types of voice and data traffic
from the network users.
A typical OLT is designed to control more than one PON. Figure 13.41 gives
an example of an OLT that is capable of serving four independent passive optical
networks. In this case, if there are 32 connections to each PON, then the OLT can
distribute information to 128 users.
559
Table 13.7 A selection of acronyms for FTTx
Acronym
Meaning
FTTB
Fiber-to-the-building or Fiber-to-the-business
The optical fiber line reaches the boundary of a building
FTTC
Fiber-to-the-curb/kerb or Fiber-to-the-cabinet
The street cabinet is within 100 m of the user premises
FTTH
Fiber-to-the-home
The optical fiber reaches the outside boundary of the living space
FTTN
Fiber-to-the-node or Fiber-to-the-neighborhood
The fiber ends in a street cabinet that can be several km from the user
FTTP
Fiber-to-the-premises
This is a generic term covering both FTTB and FTTH
accommodated without affecting other lower-usage customers. The dedicated
wavelength also provides for a higher level of information security compared to
other PONs where users share wavelengths.
The application of PON technology for providing broadband connectivity in the
access network to homes, multiple-occupancy units, and small businesses commonly
is called fiber-to-the-x (FTTx) [56, 66, 67]. Here x is a letter indicating how close
the fiber endpoint comes to the actual user. Table 13.7 lists the acronyms for various
FTTx concepts. FTTP for fiber-to-the-premises has become the prevailing term that
encompasses the various FTTx concepts. FTTP networks can use any of the various
PON technologies.
13.8.2 Active PON Modules
This section gives a snapshot of the basic functions and compositions of the optoelectronic equipment located in the central office and at or near the endpoint
users.
Optical Line Termination (OLT)
The optical line termination (OLT) equipment is located in a central office and
controls the bidirectional flow of information across the network. An OLT must be
able to support transmission distances of up to 20 km. In the downstream direction the
function of an OLT is to take in voice, data, and video traffic from a long-distance or
a metro network and broadcast it to all the users on the PON. In the reverse direction
(upstream), an OLT accepts and distributes multiple types of voice and data traffic
from the network users.
A typical OLT is designed to control more than one PON. Figure 13.41 gives
an example of an OLT that is capable of serving four independent passive optical
networks. In this case, if there are 32 connections to each PON, then the OLT can
distribute information to 128 users.