Re: [8023-10GEPON] FW: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
Dear all,
The class of laser is standardized in each country, it is standardized
in JIS(Japanese Industrial Standards) JISC6803 in Japan, and IEC 60825-1
is the base.
In ad hoc on wavelength and co-existence, 1210nm and 1580nm are also
discussed as the candidates. In Table 1 of IEC 60825-1, the output of
the laser limited with Class 1 is as follows,
1210nm 15.6mW(+12dBm)
1310nm 15.6mW(+12dBm)
1420nm 10mW(+10dBm)
1490nm 10mW(+10dBm)
1550nm 10mW(+10dBm)
1580nm 10nm(+10dBm)
Regards,
Takahashi
MITSUBISHI ELECTRIC CORPORATION
----- Original Message -----
From: Pete Anslow
To: STDS-802-3-10GEPON@listserv.ieee.org
Sent: Thursday, November 02, 2006 7:36 AM
Subject: Re: [8023-10GEPON] FW: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
Glen,
You asked ? “Can we somehow translate the 60825 requirements into a maximum limit for launch power at ONU?”
The answer is that to do this properly you have to apply all of the rules found in IEC 60825-1 and 60825-2 and the maximum power you get depends on
wavelength. However, Table D.1 of IEC 60825-2 contains the limits for 11 um mode field diameter single mode fibre for the following wavelengths:
1310 nm 15.6 mW (+12 dBm)
1420 nm 10 mW (+10 dBm)
1550 nm 10 mW (+10 dBm)
“is it reasonable to anticipate that a customer sooner or later will decide to look directly into the ONU connector?”
I think that the answer to that is definitely “Yes”
“Is it reasonable that a customer will try to pry open a shutter door that a connector may have.”
I think that this is much more difficult to answer and may be affected by how difficult it is to do etc.
“Is the ONU’s mode of operation when it shuts down its laser when it sees no incoming signal a reasonable measure to classify higher-power optics as
class 1?”
I think that the correct terminology for equipment that operates at high power levels and automatically shuts down in the event of loss of continuity
of the link is that it is Hazard level 1.
The answer to whether an ONU is Hazard level 1 because of a shutdown mechanism depends on things like the time between the loss of continuity of the
link and the power reduction (I think that this must be < 1 second for unrestricted locations) and the reliability of the shutdown mechanism (e.g.
software based shutdown may not be reliable enough).
This is a complex subject ? see IEC 60825-2 for details.
IEC 60825-2 also contains information specific to PONs. For example clause D.4.6
Regards,
Pete Anslow
Nortel Networks UK Limited, London Rd, Harlow, Essex CM17 9NA, UK
External +44 1279 402540 Fax +44 1279 405670 ESN 742 2540
Email: pja@nortel.com
--------------------------------------------------------------------------------
From: Glen Kramer [mailto:glen.kramer@teknovus.com]
Sent: 01 November 2006 20:51
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] FW: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
> Class 4 lasers are of high power … may have sufficient energy to ignite materials …
That’s what I need! Now we are talking business.
Seriously, our RAP stated that our project won’t “result in any health, safety, security, or environmental guidance that affects or applies to human
health or safety”. For 1G EPON, clause 60 explicitly limits us to class I optics and it explicitly refers to IEC 60825:
60.8.2 Laser safety
1000BASE-PX10 and 1000BASE-PX20 optical transceivers shall conform to Class 1 laser requirements as
defined in IEC 60825-1, under any condition of operation. This includes single fault conditions whether
coupled into a fiber or out of an open bore. Conformance to additional laser safety standards may be
required for operation within specific geographic regions.
I am not very clear how to interpret the Class I rules below:
A class 1 laser is safe for use under all reasonably-anticipated conditions of use; in other words, it is not expected that the maximum permissible
exposure (MPE) can be exceeded. This class may include lasers of a higher class whose beams are confined within a suitable enclosure so that access to
laser radiation is physically prevented.
What are all reasonably-anticipated conditions and what is expected MPE? For example, is it reasonable to anticipate that a customer sooner or later
will decide to look directly into the ONU connector? Is it reasonable that a customer will try to pry open a shutter door that a connector may have.
Is the ONU’s mode of operation when it shuts down its laser when it sees no incoming signal a reasonable measure to classify higher-power optics as
class 1? My point is that this protection (a useful side-effect of MPCP, really) is done at a protocol level, way above PMD.
Can we somehow translate the 60825 requirements into a maximum limit for launch power at ONU?
Glen
Tom,
Good data. I am not sure why you were not able to post. I am forwarding this to the reflector (phone and e-mail from you signature were removed to
curb spam).
Glen
Glen, I tried posting to the listserv but I guess I’ve only got Lurking permissions. I have some awareness of laser safety as our test products use
Lasers up to 20 mw or so:
As one might expect Laser Safety is not a simple issue. Requirements are generally concerned about optical power density (mw/cm^2). I would guess
that an EDFA output at +20 dB (100 mW) could fall under class IIIB.
Revised system
In 2002 the system of Laser Classes was revised as part of a revision of the international laser safety standard, IEC 60825. The revision was based on
the greater knowledge of lasers that had accumulated since the original classification system was devised, and was intended to permit certain types of
lasers to be recognized as having a lower hazard than was implied by their placement in the original classification system. The revised system is
expected to be adopted for use in the US in the next revision of the ANSI Laser Safety Standard (ANSI Z136). The FDA, which regulates lasers offered
in commerce in the United States, does not object to its use on imported laser products' labels and markings.
class I
A class 1 laser is safe for use under all reasonably-anticipated conditions of use; in other words, it is not expected that the maximum permissible
exposure (MPE) can be exceeded. This class may include lasers of a higher class whose beams are confined within a suitable enclosure so that access to
laser radiation is physically prevented.
class IM
Class 1M lasers produce large-diameter beams, or beams that are divergent. The MPE for a Class 1M laser cannot normally be exceeded unless focusing or
imaging optics are used to narrow down the beam. If the beam is refocused, the hazard of Class 1M lasers may be increased and the product class may be
changed.
class II
A class 2 laser emits in the visible region. It is presumed that the human blink reflex will be sufficient to prevent damaging exposure, although
prolonged viewing may be dangerous.
class IIM
A class IIM laser emits in the visible region in the form of a large diameter or divergent beam. It is presumed that the human blink reflex will be
sufficient to prevent damaging exposure, but if the beam is focused down, damaging levels of radiation may be reached and may lead to a
reclassification of the laser.
class IIIR
A class 3R laser is a continuous wave laser which may produce up to five times the emission limit for Class 1 or class 2 lasers. Although the MPE can
be exceeded, the risk of injury is low. The laser can produce no more than 5 mW in the visible region.
class IIIB
A class 3B laser produces light of an intensity such that the MPE for eye exposure may be exceeded and direct viewing of the beam is potentially
serious. Diffuse radiation (i.e., that which is scattered from a diffusing surface) should not be hazardous. CW emission from such lasers at
wavelengths above 315 nm must not exceed 0.5 watts.
class IV
Class 4 lasers are of high power (typically more than 500 mW if cw, or 10 J/cm2 if pulsed). These are hazardous to view at all times, may cause
devastating and permanent eye damage, may have sufficient energy to ignite materials, and may cause significant skin damage. Exposure of the eye or
skin to both the direct laser beam and to scattered beams, even those produced by reflection from diffusing surfaces, must be avoided at all times. In
addition, they may pose a fire risk and may generate hazardous fumes.
(From The Physical and Theoretical Chemistry Laboratory Oxford University)[7]
Tom Durston
Product Development Manager
Greenlee / Textron
--------------------------------------------------------------------------------
From: Glen Kramer [mailto:glen.kramer@TEKNOVUS.COM]
Sent: Wednesday, November 01, 2006 1:21 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
David,
What about upstream launch power? I am not sure, but I’d guess the safety rules would be different for CO and for a household.
Are there any volunteers to make a short overview presentation on the topic?
Glen
--------------------------------------------------------------------------------
From: David Piehler [mailto:dpiehler@ALPHION.COM]
Sent: Wednesday, November 01, 2006 6:55 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
I don’t know the exact safety issues involved, but I do know that carriers deploying the video overlay do launch up to +20 dBm at 1550 nm into the
OSP fiber. Also in the CATV world, this type of launch power is not uncommon.
David Piehler
Alphion
mobile: +1 732 692 4581
--------------------------------------------------------------------------------
From: Glen Kramer [mailto:glen.kramer@teknovus.com]
Sent: Tuesday, October 31, 2006 11:49 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
Mike,
This is a great point. Could you provide some more info on class 1 safety? In general, what regulations apply to CPE side and to CO side? It would
be great to have a presentation in November covering this topic. It definitely should be part of the set of constraints that the high-split ad hoc
considers.
Glen
--------------------------------------------------------------------------------
From: Mike Dudek [mailto:mike.dudek@PICOLIGHT.COM]
Sent: Tuesday, October 31, 2006 11:35 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
Dear all,
One question related to the higher split ratio that I haven't seen discussed is related to laser eye safety. Is this a problem for EPON? For other
ethernet standards we've normally required class 1 eye safety. I think powers significantly higher than this are being considered here.
Regards,
Mike Dudek
Director Transceiver Engineering
Picolight Inc
1480 Arthur Avenue
Louisville
CO 80027
Tel 303 530 3189 x7533.
mike.dudek@picolight.com
--------------------------------------------------------------------------------
From: Hajduczenia, Marek [mailto:marek.hajduczenia@SIEMENS.COM]
Sent: Tuesday, October 31, 2006 1:06 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: [8023-10GEPON] 10GEPON ad hoc on higher split ratio - Conference Call Minutes
Dear all,
below please find the conference call minutes, taken down by Glen (thank You for the job well done)
please let me know if You find any irregularities in the minutes or if You have any comments on those.
*******************************************************************************
Attendees:
Haim Ben-Amram
Russell Davey
Glen Kramer
Marek Hajduczenia
Frank Chang
Silvia Pato
David Piehler
Harold Kamisugi
Bin Yeong Yoon
Dong Soo Lee
Wael Diab
Task 1: estimation of 1x64 and 1x128 port splitter power loss values
---------------------------------------------------------------------
Discussed Marek's presentation. Few questions about derivation of splitter loss. No objections. Task 1 is considered completed.
Task 2: non-linear effects in fiber channel
-------------------------------------------
Silvia gave brief overview of the paper on non-liner effects in 10GEPON. SBS seems like major impairment. Mentioned dithering technique for laser
sources.
Questions that need more research:
1) Can video-overlay even be supported on 1x128 PON? What power budget will be required?
2) Can we use high-power source for data wavelength and use video-overlay? Effects of Raman crosstalk due to high-power source.
AR: Silvia will finish sub-task 2.2 "estimate the maximum launch power into fiber which can be achieved without introducing non-linear effects" by
November 6th.
Task 3: TX/RX technology
----------------------
Bin Yeong Yoon and dong Soo Lee are in the process of compiling a survey of receivers, transmitters, and amplifiers available on the market today.
AR: Bin Yeong Yoon is to finish the first draft later this week. Then narrow down the viable configurations based on input from task 2.
Task 4: power margins in the EPON systems
-----------------------------------------
It seemed to be difficult to get this data from carriers. It was decided that for now we will reverse-calculate this data from insertion loss taken in
802.3ah. We later may update it with more accurate numbers based on carriers' responses to a wavelength/power survey.
AR: Marek is to calculate allocation for penalties and outside plant aging and repair margins later this week.
An additional conference call may be scheduled to discuss final drafts of the presentations.
*******************************************************************************
Best wishes
Marek Hajduczenia (141238)
(PhD Student - COM RD1)
SIEMENS Networks S.A. - IC
Rua Irmaos Siemens, 1
Ed. 1, Piso 1
Alfragide
2720-093 Amadora
Portugal
* Marek.Hajduczenia@siemens.com
http://marekhaj.easyisp.pl/index.php
(+351.21.416.7472 4+351.21.424.2082
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