[802-20-GENERAL:] FW: IEEE 802.20 C802.20-05-36
TO: "Gal, Dan (Dan)" <dgal@lucent.com>
cc: "'Minako_kitahara@csg.kyocera.co.jp'"
<Minako_kitahara@csg.kyocera.co.jp>, "'cradhak@ktrc-na.com'"
<cradhak@ktrc-na.com>, STDS-802-MOBILITY@listserv.ieee.org
Re: IEEE 802.20 C802.20-05-36 (Document link: kazuhiro murakami)
Dear Mr. Dan Gel
Thank you for your information
I would like to review your information and new versions of G.108, G.113 and
G.175 and more
Now I am clarifying all kinds of parameters for E-model and investigate
wireless-releted parameters forMBWA.( delay , packet loss ,etc)
Also, I am investigating several codecs and the parameters for e-model (AMR,
iLBC, etc) for how to consider codec.
I will contribute the result of this intermediate revision and addition
before
next TEL conference, may be.
Thank you for your cooperation
Best regards
Kazuhiro Murakami
"Gal, Dan (Dan)" <dgal@lucent.com> 2005/08/23 04:47:21
??: "'kazuhiro_murakami@csg.kyocera.co.jp'"
<kazuhiro_murakami@csg.kyocera.co.jp>,
"'Minako_kitahara@csg.kyocera.co.jp'"
<Minako_kitahara@csg.kyocera.co.jp>, "'cradhak@ktrc-na.com'"
<cradhak@ktrc-na.com>
cc: STDS-802-MOBILITY@listserv.ieee.org
??: IEEE 802.20 C802.20-05-36
Dear Colleagues,
I have found your July 05 contribution very helpful and was motivated to
review
it again in the past few days, as well as to study the referenced ITU-T
G.xxx
Recommendations. I have noted that more recent versions of G.108, G.113 and
G.175 have since been published and you may want to update your
contribution, as
follows:
G.108: 03/2004
G.113: 02/2001
G.175: 05/2000
The current version of G.175, in particular, has some significant changes
which
the "E-Model" section in your contribution no longer agrees with. I would
urge
you to review G.175 (05/2000) carefully and update your contribution
C802.20-05/36.
Reflecting on the comments I made in the July 05 meeting, I am still
searching
for the right extent to which the E-Model approach can be applied to the
802.20
evaluation methodology. We need to keep in mind that the scope of the 802.20
standard will be limited to Layer 1 and Layer-2 of the air interface and
hence
it will have no control over the major portions of the end-to-end E-Model
values. In addition, we must also consider the fact that none of the
equipment-related parameters will be known at the 802.20 EC stage and, thus,
I
would suggest that we focus on a small (but critical) subset of the
prescribed
ITU-T E-Model parameters, namely, the air interface's contribution to:
Delay
Jitter
Packet Loss
It is clear that, in the 802.20 evaluation criteria, we would need to
analyze
and quantify the added transmission-impairments caused by a given proposed
air
interface when it operates in the defined mobility environments. Along these
lines, the actual impact on the voice quality is determined by the aggregate
end-to-end transmission impairments, including the effects of equipment
design
(such as the speech/audio codec) and the acoustic environments, which are
clearly out of scope for the 802.20 evaluation. Thus, we cannot include
these
non-air interface elements in our analysis and should consider narrowing the
usage-scope of the ITU-T E-Model and apply it with all but the above three
parameter-types set to some uniform, predefined typical values which would
make
sense for mobile wireless networks.
On the question of audio/speech codec:
-------------------------------------------------------------
The application of the E-Model involves determining the equipment impairment
factor, Ie which also depends on the choice of speech codec. Appendix I of
ITU-T
Recommendation G.113 (02/2001) provides provisional planning values for
codec-dependent Ie factor. We could choose from Table I.2 - "..Ie under
conditions of random packet loss, codecs G.729-A+VAD, G.723.1-A+VAD and GSM
EFR". As to the impact of the delay, we should consult ITU-T G.108
Amendment 2
(03/2004) and agree on similar E-Model Id parameter values. I am not sure
how to
handle the echo issue; we could agree on some typical values that would
reflect
the extra delay (when compared to wireline systems) introduced by mobile
wireless.
Thus, if we eventually decide to adopt the E-Model for the 802.20 EC, under
the
aforementioned constrains, technology proposals will not have to specify
their
actual codec and the EC should assume one uniform codec chosen from ITU-T
G.113
tables and the calculated R rating should be based on the Ie values which
correspond the % Packet Loss values derived from the individual proposal
simulation results.
Your thoughts and comments on these proposals will be greatly appreciated.
Best regards,
Dan