RE: stds-80220-requirements: Frame Error Rate Requirement
Just to add to Mike's, and others before, point about the difficulty in
specifying a particular FER threshold. In addition to different applications
having different target FER vs latency tradeoffs, another issue is that the
extent of uncertainty in channel quality measurements (e.g. depending on the
SNR regime, rate of channel variation etc) can significantly impact the
transmitter's selection of appropriate transmission (e.g. coding and
modulation) parameters and corresponding FER targets under different
conditions. Consequently, it is probably best to not mandate a single FER
threshold.
Samir
-----Original Message-----
From: Michael Youssefmir [mailto:mike@arraycomm.com]
Sent: Wednesday, July 30, 2003 8:14 PM
To: Joseph Cleveland
Cc: 'Dorenbosch Jheroen-FJD007'; stds-80220-requirements@ieee.org;
Michael Youssefmir
Subject: Re: stds-80220-requirements: Frame Error Rate Requirement
Hi Joseph,
I see that this discussion is moving into specific design requirements
such as frame length instead of addressing functional requirements.
1) An FER requirement seems to be irrelevant absent the specifics of
the design and would have different performance implications for
different designs. As Jheroen pointed out a specific requirement
such as 1% will bias the requirement to shorter frames, and, as your
response indicates we rapidly have to go down the path of specifying
frame lengths to make the requirement have meaning. I think we are
far better off having the requirements document focus on high level
functional requirements and not specify specifics such as frame length.
2) As Jinweon pointed out tuning of FERs has performance
implications in trading off throughput and latency. For latency
insensitive data, the "FER can be less strict in order to maximize
throughput over the air", and for other data, the "FER needs to be
tightly controlled below a certain threshold". Again I therefore
think it is premature to define a specific FER.
For these reasons, I continue to believe that we should remove
the specific FER value and therefore delete the sentence:
"The frame error rate shall be less than 1 percent, with 95% confidence,
after channel decoding and before any link-level ARQ, measured under
conditions specified in Section xx."
Mike
ArrayComm, Inc.
On Tue, Jul 29, 2003 at 04:58:15PM -0500, Joseph Cleveland wrote:
> Hi All -- Yes, we need a frame length. This is why I asked what MAC layer
> "RLP" we intend to use.
>
> Joseph Cleveland
>
> -----Original Message-----
> From: Dorenbosch Jheroen-FJD007 [mailto:J.Dorenbosch@motorola.com]
> Sent: Tuesday, July 29, 2003 3:31 PM
> To: stds-80220-requirements@ieee.org
> Subject: RE: stds-80220-requirements: Frame Error Rate Requirement
>
>
> We seem to be converging.
>
> However, will it not be hard to specify a maximum error rate for a frame
> unless we have an idea of the length of the frame or of the number of
useful
> bits in a frame? A generic requirement could bias towards short frames.
>
>
> Jheroen Dorenbosch
>
> -----Original Message-----
> From: Joseph Cleveland [mailto:JClevela@sta.samsung.com]
> Sent: Tuesday, July 29, 2003 1:40 PM
> To: stds-80220-requirements@ieee.org
> Subject: stds-80220-requirements: FW: Frame Error Rate Requirement, 4.1.10
>
>
>
> Hi All: It seems that some are referring to a previous re-write of
4.1.10,
> Frame Error Rate. Several of the items noted were already addressed in
the
> latest version sent on 7/24, which is attached below. Please refer to the
> content in v0.2.1 so there is not wasted discussion.
>
> Regards
>
> Joseph Cleveland
>
> -----Original Message-----
> From: Joseph Cleveland
> Sent: Thursday, July 24, 2003 12:44 PM
> To: stds-80220-requirements@ieee.org
> Subject: Frame Error Rate Requirement, 4.1.10
>
> Hi All,
>
> Here is a revision to the wording on section 4.1.10 based on feedback from
> many of you. Thanks for the comments.
> <<frame_error_v0.2.1.rtf>>
> Joseph Cleveland
> Director, Systems & Standards
> Wireless Systems Lab
> Samsung Telecommunications America
> Richardson, TX 75081
> (O) 972-761-7981 (M) 214-336-8446 (F) 972-761-7909
>