What is APON, BPON,
EPON, GPON
PON
is a passive optical network, which refers to the ODN (optical distribution
network) between the OLT (optical line terminal) and the ONU (optical network
unit) without any active equipment and only uses optical fibers and passive
components. PON mainly adopts a point-to-multipoint network structure and is
the main technology to realize FTTB/FTTH.
PON
technology contains a lot of content, and it is constantly updated. The
development of xPON technology from APON, BPON, to later GPON and EPON. These
are technologies with different transmission modes and transmission standards
developed in different periods.
What
is APON?
At
the end of the 1990s, the ITU (International Telecommunication Union) first
proposed APON, which uses Asynchronous Transfer Mode (ATM) for packet
communication. APON utilizes the centralized and statistical multiplexing of
ATM, combined with the sharing effect of passive splitters on fiber and optical
line terminals, so that the cost is 20-40% lower than the traditional PDH/SDH
access system based on circuit switching.
What
is BPON?
With
the rapid development of Ethernet technology, APON is basically no longer used.
At this time, the concept of Broadband Passive Optical Network (BPON) was
proposed. BPON is an enhancement after the APON standard. It was also called
APON at first, and then changed to BPON for differentiation. BPON is based on
the ATM protocol, with uplink and downlink speeds of 155 and 622 Mbps,
respectively, plus dynamic bandwidth allocation, protection and other
functions. It can provide services such as Ethernet access, video transmission,
and high-speed leased lines.
What
is EPON?
Due
to the high cost of BPON deployment, it was subsequently replaced by EPON,
which is more cost-effective and faster. EPON is an Ethernet passive optical
network. EPON is based on Ethernet PON technology, which combines the
advantages of PON technology and Ethernet technology, adopts
point-to-multipoint structure, passive optical fiber transmission, and provides
multiple services on Ethernet. Because EPON deployment is economical and
efficient, it is the most effective communication method to realize "three
networks in one" and "last mile".
What
is GPON?
GPON
is a gigabit passive optical network or called a gigabit passive optical
network. EPON and GPON adopt different standards. It can be said that GPON is a
more advanced point, which can transmit larger bandwidth and can bring more
users than EPON. Although GPON has advantages in high speed and multiple
services compared to EPON, the technology of GPON is more complicated and the
cost is higher than that of EPON. Therefore, at present, EPON and GPON are the
technologies with more PON broadband access applications. Which technology to
choose depends more on the cost of optical fiber access and service
requirements. GPON will be more suitable for customers with high bandwidth,
multiple services, QoS and security requirements, and ATM technology as the
backbone. The future development is higher bandwidth. For example, 10 G EPON/10
G GPON has been developed in EPON/GPON technology, and the bandwidth will be
even higher.
As
the demand for capacity of network providers continues to increase, the
versatility of the access network must also be expanded to meet this growing
demand. The advantage of PON technology is that it can reduce the occupation of
backbone optical fiber resources and save investment; the network structure is
flexible and the expansion capability is strong; the failure rate of passive
optical devices is low, and it is not easily interfered by the external
environment; and the business support capability is strong.