Title: What’s the Difference between GPON and EPON?
1Whats the Difference between GPON and EPON?
- GPON provides an efficient means of transmission
for Ethernet and TDM. As for the lowest cost
business, the need for a Layer 2 protocol is
Ethernet. Why not choose EPON? We will discuss
the differences between GPON and EPON in the
following and it is these differences that make
GPON become technology choices to the large
operators deployment.
2A good starting point for discussion of GPON and
EPON on access network is making a brief review
toward their mission statement sponsored by
agencies. Based on the following observations,
IEEE promotes EFM Study Group to realize the
Ethernet as an access technologySupports users
to access to the network topology point to
multipoint fiber transmission point to point
fiber transmission point to point copper
transmission.Offers a range of physical layer
specifications 1000BASE-X Extended
temperature range of optical components
1000BASE-X10km, a single-mode fiber (SM fiber)
PON physical layer, 10km, 1000Mbps,
single-mode fiber, 1 16 Single voice grade
copper for no load on the physical
layer.Distance 2500ft, speed 10Mbps support
user access to the remote network OAM remote
fault indication remote loopback link status
monitoring.
3GPON and EPON
- GPON only standardized to the line OAM. In most
cases the management of ONT and the service
provided by ONT is usually supported by SNMP,
thus generating the problem of management and
interoperability. In addition, as the object
being managed is not in accordance with the needs
of the service provider, so, ONT often lack of
some key OM features such as line testing and
other fault isolation tools. - GPON provided protection or redundancy options
for access network, and high-end business
services often need such service characteristics.
Most importantly, GPON has a comprehensive
support, including interoperability from
different vendors between the OLT and ONT. This
greatly reduces the risk of service providers on
the requirements of mixing and matching ONT and
OLT, and by making new entrants provide a
solution for the existing network rapidly,
thereby reducing the entrance of innovation. - There is no inherent security measures to EPON
no encryption on link layer. Since the ONT can
deceive downlink LAN address and communication,
security is further decreased. These risks can be
bypassed by adding encryption on some EPON
transfer layer, but this will complicate the
network or application, and when the application
must be taken in different ways with the end
position different, it will run a timer as a
unified Ethernet protocol.
4The requirements of the light layer between GPON
and EPON is different, because the downlink rate
of GPON is 2.5Gbps while the line rate of EPON is
only 1.25Gbps. However, as the link of 2.5G is a
pair of continuous link transmitter/receiver, and
is similar with the mass-produced SONET OC-48
(SDH STM-16), so there is no extra cost on it.
As for the Uplink rate terms, GPON and EPON
nearly the same, and for the 1.2Gbps line rate,
the cost of them is the same. EPON may need a
little bit extra costs, since it does not support
power classification, that is to say, the
operating range of the receiver in a burst mode
on EPON will be more than GPON. Although the cost
of GPON and EPON transmitter/receiver is the
same, the GPON will have advantages on the budget
of optical link 3 dB compared with EPON. And the
3dB may extend 10km of the fiber distance, or
support twice number of GPON ONT on the same GPON
OLT, greatly reduced the equipment costs of
CO.According to different line coding and cost,
we get the following benefits of each technology
bandwidth
5Different bandwidth gains will affect the split
ratio allowed by each technology in different
ways, and be subject to different OLT port
number/the average throughput. Now we will set an
example to let you know clearly about the
comparison between EPON and GPON. Assuming the
existence of a FTTH network has 10,000 service
users. Neither speculate the type of service
(Internet access, VOIP, using MPEG-2 or -4
standardized IPTV, as well as SDTV or HDTV), nor
speculate the number of services per household,
we just consider the average throughput of
Ethernet-based services into the home. Due to the
technology cost roughly the same, we can also
assume the equipment cost roughly the same, so we
can make the following
6- From the above, now we can use the result to
calculate the average cost/user of each
technology according to average throughput. - The significant cost advantage of GPON is the
decrease of the required OLT numbers. That is to
say, GPON adoption will be cheaper compared with
EPON solutions, and moreover, it will help
operators to bring other cost savings, such as
space, but the most important is power
consumption and heat dissipation. - As a world leading Huawei networking products
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7Conclusion
- As a world leading Huawei networking products
supplier, Huanetwork wholesales original new
Huawei networking equipments, including Huawei
switches, Huawei routers, Huawei symantec
security products, Huawei IAD, Huawei SFP and
other Huawei networking products. Our customers
include telecom operators, Huawei resellers, ISP
and system integrators. If youd like to see the
benefits of Huawei products for yourself, you can
log into www.huanetwork.com, or you can contact
our sales_at_huanetwork.com to get more information
on Huawei Networks solutions.