What do PON, GPON, XG-PON, 10G-EPON stand for? Which analyzers are compatible with them?

March 14, 2019.


PON stands for "passive optical network" referring to the optical network composed by non-active components in all stages between the origin (local exchange) and the external sides (subscriber or clients). The others acronym (GPON, XG-PON…) corresponds to the standard transmission that travel through this physical network. In which are they different? Can they be analyzed using a PROLITE-67?

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PON architecture: the physical layer

PON (Passive Optical Network) is the network architecture used to FTTH (Fiber To the Home) deployment services. As said above, it is composed of passive elements. The fiber cable itself, multiplexers, connector, network terminals etc.


PON architecture allows bidirectional communication between server and clients, but the latter do not communicate with each other.

From the local exchange, a backbone network of optical fibers starts, dividing as it passes through different multiplexers, creating multiple branches that communicate bidirectionally with the trunk network but not between them.

  • The downstream bandwidth from the local exchange is divided among all users and it is a signal with a constant power signal.
  • The upstream bandwidth from the users up to the local exchange is emitted in burst mode: Time frames set for each user. This is known as TDMA (Time Division Multiple Access).

PROLITE-67 optical analyzers indicate if the signal is being sent in burst mode. This way, we can certificate the upstream channel is operating in TDMA mode.

PROLITE-67 OPTICAL ANALYZER

PON networks transmission standards

Each transmission standard uses its own wavelength range. As they evolve, we try to maintain retro compatibility with previous standards using available zones in the light spectrum. That is to say, using wavelengths that are not in use by the above standards.

Let’s focus on the three main standards, sorted from older to newer:

 GPON
(Gigabit PON)
XG-PON
(10 Gigabit PON)
NG-PON2
(Next-Gen PON2)
Upstream (nm)1260-13601260-12801524-1544
1525-1540
1532-1540
Downstream (nm)1480-15001575-15801596-1603
Video (nm)1530-15651530-1565-
Upload (Gbps)1,22,5 / 1040
Download (Gbps)2,51040
Main transmission standards in fiber optics. More standards have been used and others are under research. This table is just an example of the evolution in its development and the achieved bandwidths.

XG-GPON is also known as 10G-EPON.

Have you noticed? GPON and XG-PON Downstream channels share a certain wavelength range (from 1260 to 1280 nm). This happens because even though GPON reserved that band it did not get to use it; therefore XG-GPON could take benefit from that little unused band region.

Wavelength allocations for GPON, XG-PON / 10G-EPON and NG-PON2
Wavelength allocations for GPON, XG-PON / 10G-EPON and NG-PON2. This is the same data depicted in the table above.

XG-GPON / 10G-EPON / NG-PON2 networks analyzers

The PROLITE-67 optical power meters are applicable to work in GPON and to work in XG-GPON and NG-PON2. This is because the wavelength filter integrated in the PROLITE-67 for PON video band (1550-1560 nm) covers up to 1625 nm. This means in addition to PON video this filter also covers the XG-GPON and NG-PON2 downstream.

PON and XG-EPON / 10G-EPON / NG-PON2 meter model PROLITE-67
PON and XG-EPON / 10G-EPON / NG-PON2 meter model PROLITE-67
PROMAX OPTICAL CERTIFIERS

How is the proper network operation certified?

The proper operation is verified with the optical analyzers and the optical certifiers. The difference is that a certifier is calibrated to guarantee the systems meets the regulation parameters if it is used in conjunction with a laser light source and the standardized attenuation test is executed

PROMAX OPTICAL CERTIFIERS

The PROLITE-67 optical power meter and optical certifier includes further benefits not available in all the equipment in the market.

PROLITE-67 optical meter connected in loop through mode, allowing companies to certify the proper operation of an optical service without interrupting the traffic
PROLITE-67 optical meter connected in loop through mode, allowing companies to certify the proper operation of an optical service without interrupting the traffic.
  • It allows being connected in loop through mode to analyze the service without interrupting the data traffic, in exchange for a minimum loss.
  • It allows identifying whether the upstream is emitted in burst mode or not, when operating in loop through mode.
  • The selective attenuation test is triple-band filtered and can be calibrated independently for each band for each wavelength.
  • It includes a visual fault locator to find breakages in the optical fibers under test.
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PROMAX is a leading manufacturer of test and measurement systems, broadcast and TV signal distribution equipment. Our product lines include measuring instruments for cable TV, satellite TV, broadcast, wireless and fibre optics networks, FTTH and GPON analyzers. DVB-T modulators, IP streamers or IP converters (ASI, DVB-T) are among the company’s latest developments.