Formalizing WSON a bit with ITU-T definitions...

[Greg Bernstein <gregb@grotto-networking.com>]

Hello fellow CCAMPers and in particular those interested in WSON. Recent
discussions with ITU-T Study Group 15, Question 6 (Q 6/15) on 
impairments have
also pointed us to documents that can help in resolving some old issues 
in the
non-impairment case.

In particular we've had the following open issues:
(a) What should the optical signal that we are dealing with be called?
(b) Is there more than one type of optical signal?
(c) What parameters do we need to define this optical signal?

While we've all had a good notion of what we've meant by "light paths". The
problem is that CCAMP doesn't define physical layer signals so we need 
to point
to other documents. Our friends at Q6 pointed us at the following ITU-T
documents:

[1]     G.698.1 Multichannel DWDM applications with single-channel optical
        interfaces (12/2006)
[2]     G.698.2    Amplified multichannel DWDM applications with single 
channel
       optical interfaces (07/2007)
[3]    G.959.1    Optical transport network physical layer interfaces 
(03/2006)

For Wavelength Switched Optical Networks (WSONs), references [1] and [2] are
what we need since they specify single channel interfaces into multi-channel
WDM networks. They use definitions from reference [3].

From these we get the following definitions:
(1) Optical Tributary Signal [3] -- A single channel signal that is placed
   within an optical channel for transport across the optical network. 
This seems
   to be the "thing" that we are switching in WSONs.
(2) A variety of optical tributary signal classes based on modulation 
format and
   bit rate range [3]:
   (a) optical tributary signal class NRZ 1.25G
   (b) optical tributary signal class NRZ 2.5G
   (c) optical tributary signal class NRZ 10G
   (d) optical tributary signal class NRZ 40G
   (e) optical tributary signal class RZ 40G
(3) Although [1] and [2] are primarily concerned with impairments they 
specify a
   number of non-impairment related parameters:
   (a) Minimum channel spacing (incorporated into CCAMP G.694.1 labels)
   (b) Bit-rate/line coding of optical tributary signals. Note that [2]
       section 7.1.2 specifies that the exact bit rate needs to be
       specified.
   (c) FEC enabled
   (d) Minimum and Maximum central frequency in THz (we've got this in the
       WSON framework and info model, but we'll check the name).

We propose to update the WSON Framework (CCAMP WG) document
(draft-ietf-ccamp-rwa-wson-framework-02.txt) with this formalism and
definitions. Any comments, suggestions?

Best Regards

Greg, Young, and WSON co-authors

--
===================================================
Dr Greg Bernstein, Grotto Networking (510) 573-2237