Best Practices For Next Generation PON Testing


Gigabit broadband is becoming essential, and commercial services and 5G small base stations have brought some opportunities. In this case, operators have begun to consider adopting the next -generation PON device to upgrade their existing optical fiber infrastructure. This article will explore which operators need to understand which knowledge to ensure that its infrastructure can support this migration.

Among the existing FTTH networks, there is usually a feed line fiber (called F1) from the end (CO). This link is sometimes 30 kilometers long. The optical fiber provides a signal for the optical device, and the latter usually provides a signal for 32 optical fibers, and each optical fiber is connected to a different user family. These optical fibers are called F2 fiber.

Typical PON network technology

Figure 1: Typical PON network technology

Whether it is the next -generation PON, traditional or low -speed FTTH network, the first type of major optical fiber problems found at the scene include dirty or damaged connectors. Pollutoring connectors may cause loss or reflection, so the quality of the connector is crucial. The second type of main problems include the physical problems existing in the fiber itself, such as stress on fiber (such as the tie -fiber straps and the fiber tube Bending and twisting, etc.). To facilitate discussions, we mainly pay attention to the challenges and solutions faced by PON and the next generation of PON.

PON Power Meter Introduction

There are two features from the user's home (Optical Network Terminal, ONT), which makes it more complicated to measure and verify:

  1. In the installation phase, ONT is usually in the Keep-Alive mode and sends a short sudden signal, which means that the transmission of the Upstream direction is not continuous. Therefore, the standard power meter cannot measure the signal power from ONT.
  2. ONT will be transmitted Upstream only when receiving signals from CO (optical Line Terminal, OLT). To measure the signal power in the two directions, ONT must receive sufficient power and send it correctly. Conventional power meters (non -passing) cannot measure signal power from ONT because it no longer receives Downstream signals from OLT, so it will not send signals.

For these reasons, in the early 21st century, the test and measurement industry developed a PON -specific power meter, which can measure the emergency signal (that is, fine -tuning, which can detect the specific emergency signal transmission mode of existing PON technology). Therefore, there will be two connections on the device. Insert PON power timing in the network, most signals will continue to pass, so that the network can still be operating, but some signals will be filtered for power measurement. Because transmission is two -way (from C to the user's continuous mode transmission, and the transmission of emergencies from users to CO), such a PON power meter can measure the correct setting of internal light and filtering while measured at the same time. The signal power of the two directions (see Figure 2).

Figure 2: PON power meter

In the traditional GPON, this is very simple, because there is only one wavelength (1310 nm) from the user, a wavelength (1490 nm) from OLT, and sometimes two (increased 1550 nm wavelength for RF). Therefore, wavelength filtering is not required in the uplink direction, and the downlink direction is rarely required to separate the two wavelengths.

There are many advantages in the next generation of PON, such as the bandwidth and the level of light, but it may also become more complicated because it may increase the wavelength in the direction of upward and downlink (see Figure 3).

Table 1: Comparison of traditional, current, and next -generation PON parameters

Tradition And Current Technology Next Generation
PONRate (Downstream / Upstream) 2 .5G/1 .25G 1 .25G/1 .25G 10G/2 .5G 10G/10G 10G/1 .25G 10G/10G 10G/10G
Upstream Wavelength(nm) 1480- 1500 1480- 1500 1575- 1580 1575- 1580 1575- 1580 1575-1580 1596- 1603
Downstream Wavelength(nm) 1310 ±20 1310±50 or 1310±20 1260-1280 1260-1280 1310 ±50 or 1310±20 1270 ±10 1524-1544(Width) 1524-1540 (narrow)
Spaging Ratio 1:128 1 .25G/1 .25G 1:64 1:128 1:64 1:64 1:256

Tradition, current and next generation PON details

Figure 3: Tradition, current and next generation PON details

The wavelength filtering function provided by the standard Pon Power Meter is very limited. In this case, if the wavelength or signal of the power meter reaches exceeds

In one, whether in the upward direction or the downward direction, this power measures to measure the sum of their power -the user cannot know whether one or the other wavelength runs normally, so it is impossible to determine whether the service is normal. Each technology has its own set of uplink and downlink wavelengths (see Figure 3). However, because a variety of technologies can coexist at the same time, a test tool that needs to distinguish all these wavelengths and technologies now requires tools that can detect multiple emergencies and provide through-through function.

In addition, the next-generation PON technology NG-PON2 has its specific band, which will use bandwidth to send multiple signals closely related to the wavelength (see Figure 4). This is called PON (WDM-PON) that is reused in a very narrow transmission band. This process can greatly increase the wavelength of the downward direction. Similarly, it is necessary to measure each wavelength with a more reasonable cost for operators. Because the FTTH deployment does not require a comprehensive light signal analyzer (OSA), it can be easier to reduce costs.

The next-generation PON technology NG-PON2 uses bandwidth to send multiple signals closely related to the wavelength

Figure 4: The next-generation PON technology NG-PON2 uses bandwidth to send multiple signals closely related to the wavelength

Compared with the existing PON technology, the next -generation PON technology is undoubtedly a useful progress, because they provide higher bandwidth and support more customers. In the activation stage, to ensure the correct test, you need to optimize the Pon power meter optimized for the next generation, such as FCST080108N PON Optical Power Meter, CST080124 PON Optical Power Meter, FCST080125 PON Network Resource Verification Meter to avoid accidental failure and high cost afterwards Obdoic.

FCST080108N FCST080124 PNO Optical Power Meter FCST080125 PON Network Resource Verification Meter

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