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[tiffy]

Can anyone advise on the OR fibre (FTTP) signal wavelength?
I believe it to be 850nm as this is the highest light signal measurement on my very basic and cheap Chinese Optical Power Meter which I bought just for fun and in an effort to increase my FO knowledge base.
The meter can measure 850,980,1300,1310,1490,1550 & 1625nm wavelengths, 980nm and upwards giving a proportionately lower light signal reading above 850nm.

If I remember correctly, the OR sub-contractor who installed my FTTP said he expected a light reading of -20dBm or less to certify his splice integrity, I failed to ask regarding the signal wavelength, not sure he would have known!

The Optical Power Meter used listed here:
Op Pwr Mtr
Gone up in price since my purchase, took approx 3 weeks to arrive from China.

Edit: Typo correction.

[Alex Atkin UK]

Standard GPON?
Upstream (nm)   1260-1360
Downstream (nm)   1480-1500

[licquorice]

Definitely won't be 850nm or 980nm as they will be multimode fibres.

[tiffy]

Thanks to both for replies.
So it's single mode fibre?
Attached, a basic Excel graph of my FTTP meter readings.

[burakkucat]

Looking in my "doings", I have a copy of the GPON port specifications for the Huawei HG8240 ONT. (That is the original Openreach branded 4+2 ONT.)

The "go" (Tx) and "return" (Rx) wavelengths will be similar for all currently deployed Openreach ONTs, regardless of manufacturer.

[burakkucat]

Just found some further information --

For downstream, the operating wavelength range should be 1480 to 1580 nm.
For upstream, the operating wavelength range should be 1260 to 1360 nm.

[tiffy]

@ b*cat:
Great information, many thanks, suitably archieved for future reference.

With my very simplistic outlook I was just considering a single spot wavelength rather than US/DS paths, after all my dabbling on DSL should have known better!
Assuming the 850nm wavelength, highest signal reading was significant was a bit of a "bum steer" on my part.

From my signal graph, the signal readings at 1310 & 1490nm wavelengths are approx. 14.4dBm so certainly within the perceived spec. subject to the accuracy of a 14 quid Chinese Optical Power Meter.
And, of course my FTTP is working faultlessly!

[Black Sheep]

Can anyone advise on the OR fibre (FTTP) signal wavelength?
I believe it to be 850nm as this is the highest light signal measurement on my very basic and cheap Chinese Optical Power Meter which I bought just for fun and in an effort to increase my FO knowledge base.
The meter can measure 850,980,1300,1310,1490,1550 & 1625nm wavelengths, 980nm and upwards giving a proportionately lower light signal reading above 850nm.

If I remember correctly, the OR sub-contractor who installed my FTTP said he expected a light reading of -20dBm or less to certify his splice integrity, I failed to ask regarding the signal wavelength, not sure he would have known!

The Optical Power Meter used listed here:
Op Pwr Mtr
Gone up in price since my purchase, took approx 3 weeks to arrive from China.

Edit: Typo correction.

For commissioning purposes - all splitter nodes and their respective CBT's are tested twice, at both 1310nm & 1550nm ... and if they pass, these results are then stored on various systems.

The figure the sub-contractor mentioned to you, should actually be a reading of less than 25dBm. 

[burakkucat]

And, of course my FTTP is working faultlessly!

Long may it continue to do so. 

[tiffy]

For commissioning purposes - all splitter nodes and their respective CBT's are tested twice, at both 1310nm & 1550nm ... and if they pass, these results are then stored on various systems.

The figure the sub-contractor mentioned to you, should actually be a reading of less than 25dBm.

Many thanks for your much valued input, straight from the horses or is it sheep's mouth 

I'am sure the OR optical signal testing will involve something slightly more sophisticated than my 14 quid Chinese meter 

[dee.jay]

Without a doubt, it will be single mode fibre as that can cover long distances.

Multimode fibre is typically used within Data Centres or networks where the distances are a lot shorter.

I have worked with DC networks for the past 10 years

[tiffy]

@dee.jay:
Thanks for the additional fibre information.

My very limited experience with fibre distribution started back in 1997 when distributed control systems started to utilise fibre to replace the previously used co-axial data highways, believe multi-mode fibre was used, the distances involved were relatively short on off-shore oil & gas platforms, the main big advantages being speed and total noise immunity.

Still a lot to learn about fibre in the telecommunications industry.

[Black Sheep]

I'am sure the OR optical signal testing will involve something slightly more sophisticated than my 14 quid Chinese meter 

No - they use the same meter's, Tiffy 

[craigski]

I'm curious. This meter will measure the power of the light from the OLT at a specific frequency. But I cant see how it measures it the other way?

[licquorice]

With a test cord to plug into the ONT.