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Re: [802.3_EPOC] EPoC Bandwidth Discussion

Jorge-

My ballot comment and the response thereto can be found as:
    Comment # I-97
    On Page 29 of 41
in file: http://www.ieee802.org/3/bh/comments/P802d3_802d3_bh_D3p0_All_Clause.pdf
The comment was made during the initial Sponsor Ballot on the Revision of IEEE Std 802.3 (the entire existing standard) which is just finishing up. 

Best regards,
    Geoff Thompson

On 208//12 10:34 PM, Salinger, Jorge wrote:

Geoff,
Not to be a defense counsel for Marek, but I don't think Marek said that we are writing an amendment to the EPON spec. I think he was just agreeing with Matt.
And, I think we were converging on leaving the term "bandwidth" in the current spec text as-is. Or, from the other thread, are you suggesting that we make a wholesale change of "bandwidth" for "data rate"? If so, do we change DBA for DDRA?
Also, I did not understand the piece about "There is an oustanding DISAPPROVE vote on the current 802.3 revision project to split off the point-to-multipoint portions of the standard into a separate standard within the 802.3 family". Maybe I'm the only one not understanding what this meant. Could you explain what this meant? 

Thanks!
Jorge


*From*: Geoff Thompson [mailto:thompson@xxxxxxxx]
*Sent*: Tuesday, August 21, 2012 01:06 AM
*To*: STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx <STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx> 
*Subject*: Re: [802.3_EPOC] EPoC Bandwidth Discussion

Marek-
Matt is correct and you are incorrect.
We are writing an amendment to the 802.3 Ethernet standard not an amendment to EPON. If EPON terminology has flaws with respect to the rest of the Ethernet standard then they should get fixed. (This situation "could" be different. There is an oustanding DISAPPROVE vote on the current 802.3 revision project to split off the point-to-multipoint portions of the standard into a separate standard within the 802.3 family.) 

Best regards,
    Geoff

On 208//12 7:17 PM, Marek Hajduczenia wrote:


Matt,
You're 101% correct. We will be developing an amendment for EPoC and not a new spec, so some of the discussion, while technically correct, might be moot 

Marek

*From:* Matthew Schmitt [mailto:m.schmitt@xxxxxxxxxxxxx]
*Sent:* Tuesday, August 21, 2012 03:12
*To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
*Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion
Someone will correct me if I'm wrong, but if memory serves we won't be writing an EPoC spec; rather, we'll be generating amendments to the Ethernet spec. If so, rather than having to rewrite how a term is used throughout the entire existing spec (even if we could get away with it), might it be a good idea to use existing terms as they're already used? 

Matt
On Aug 20, 2012, at 7:17 PM, "Jain, Rajeev" <rajeevj@xxxxxxxxxxxx <mailto:rajeevj@xxxxxxxxxxxx>> wrote: 

    Thanks Hal.

    I dare say the "Bandwidth" for bit rate is a  marketing term that
    has crept in over the years -- salesmen in Best Buy can more
    easily convince the consumers they need "more bandwidth" to sell
    a higher speed router than "higher bit rate". "Bandwidth" has a
    feel good consumerism sound to it J

    Some of us are also old enough to recall  the similar confusion
    between baud rate and bit rate in the good old dial-up modem
    days. "Baud" was carried over from days of telegraph and it took
    a while with internet access to move from  baud to bit rate --
    and then we got that all mixed up with bandwidth.

    So EPoC may be a good chance to set the record straight and take
    the IEEE specs back to real engineering.

    Either way I do not have a strong opinion but concur with Marek
    that we need something unambiguous.

    Rajeev

    *From:* Hal Roberts [mailto:Hal.Roberts@xxxxxxxxx]
    <mailto:[mailto:Hal.Roberts@xxxxxxxxx]>
    *Sent:* Monday, August 20, 2012 6:06 PM
    *To:* Jain, Rajeev; STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* RE: [802.3_EPOC] EPoC Bandwidth Discussion

    I agree with Rajeev,

    Seems one can go with the traditional approach where bandwidth
    refers to spectrum or adopt the more recent use of bandwidth for
    data rate.

    I have to side with the traditional approach. The term
    "Band-Width" is pretty clear. There is a "band" (chunk of
    spectrum) and it has a width associated with it.

    It is unfortunate that the digital folks appropriated bandwidth
    for data rate.

    Just my opinion.

    *From:* Jain, Rajeev [mailto:rajeevj@xxxxxxxxxxxx]
    <mailto:[mailto:rajeevj@xxxxxxxxxxxx]>
    *Sent:* Monday, August 20, 2012 8:02 PM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Jorge, Marek,
    Sorry to come late to the party but my vote is for "spectrum
    bandwidth" in Hz when referring to the frequency bands in which
    we transmit  and "data rate" or "bit rate" in bps when referring
    the rate at which bits are transmitted in that frequency  band,
    assuming that is consistent with EPON. I have also found that
    bandwidth is used loosely and can be misconstrued when used in
    the context of digital data transmission -- data/bit rate is
    explicit is in this context. Adding the units to the definition
    will in any case remove any ambiguity.

    Cheers,

    Rajeev

    *From:* Salinger, Jorge [mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx]
    <mailto:[mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx]>
    *Sent:* Monday, August 20, 2012 5:43 PM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Sounds good. So, I think we are in agreement then. Let's use the
    term bandwidth to mean data capacity, and not use it to mean RF
    capacity. Instead, when referring to RF capacity we use the term
    spectrum.

    Does that make sense?

    Thanks!
    Jorge

    *From*: Marek Hajduczenia [mailto:marek.hajduczenia@xxxxxxxxx]
    <mailto:[mailto:marek.hajduczenia@xxxxxxxxx]>
    *Sent*: Monday, August 20, 2012 08:27 PM
    *To*: Salinger, Jorge; stds-802-3-epoc@xxxxxxxxxxxxxxxxx
    <mailto:stds-802-3-epoc@xxxxxxxxxxxxxxxxx>
    <stds-802-3-epoc@xxxxxxxxxxxxxxxxx
    <mailto:stds-802-3-epoc@xxxxxxxxxxxxxxxxx>>
    *Subject*: RE: [802.3_EPOC] EPoC Bandwidth Discussion

    Jorge,

    In EPON, we used term "bandwidth" in the meaning of "data rate" /
    "channel capacity", which in the retrospect perhaps was not the
    best idea. For example, we had statements like "Flexible
    architecture allowing dynamic allocation of *_bandwidth_*", which
    does not speak of spectrum allocation, but rather channel
    capacity allocation. I could produce more examples where it is
    used in this context, but I think you get the idea where it is
    going.

    In general, EPON we only spoke of wavelength / wavelength band
    allocation in Clause 75/60, which is effectively spectrum
    allocation. However, the term used was "wavelength" and
    "wavelength band/range".

    Does this help ?

    Marek

    *From:* Salinger, Jorge [mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx]
    <mailto:[mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx]>
    *Sent:* Tuesday, August 21, 2012 01:15
    *To:* Marek Hajduczenia; stds-802-3-epoc@xxxxxxxxxxxxxxxxx
    <mailto:stds-802-3-epoc@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Marek,

    I understand.

    So, how is the term bandwidth used in EPON parlance? I looked
    down in the thread and can't see an example, but maybe I missed it.

    Thanks!

    Jorge

    *From: *Marek Hajduczenia <marek.hajduczenia@xxxxxxxxx
    <mailto:marek.hajduczenia@xxxxxxxxx>>
    *Date: *Monday, August 20, 2012 8:08 PM
    *To: *"Salinger, Jorge" <Jorge_Salinger@xxxxxxxxxxxxxxxxx
    <mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx>>, EPoC Study Group
    <STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>>
    *Subject: *RE: [802.3_EPOC] EPoC Bandwidth Discussion

    Jorge,

    The only concern that I have with this is that multiple times we
    speak of "bandwidth" without other denominators, leaving it open
    to interpretation.

    While I can certainly understand where Geoff would like us to go,
    if we set different terminology from what was used in EPON
    before, we will create a rift and people who understand EPON,
    will have to get used to a different terminology for EPoC,
    something that I'd rather (personally) avoid.

    Marek

    *From:* Salinger, Jorge [mailto:Jorge_Salinger@xxxxxxxxxxxxxxxxx]
    *Sent:* Tuesday, August 21, 2012 01:04
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    All,

    No quite being an RF guy, but having worked in the cable industry
    for over 20 years... (for those thinking that I am old... I
    started when I was 19 years old ;-)

    My 2 cents...

    I would propose that when speaking of RF capacity we refer to it
    as spectrum. So, in the case of the discussion referenced by this
    Email thread, we say "spectrum for EPoC" or "EPoC spectrum".

    I think that the term bandwidth can be ambiguous unless it is
    used in a specific context, such as "the bandwidth of an analog
    cable channel is 6 MHz" and I also hear "the bandwidth of the
    highest HSD tier is 300 Mbps".

    Jorge

    *From: *Duane Remein <Duane.Remein@xxxxxxxxxx
    <mailto:Duane.Remein@xxxxxxxxxx>>
    *Reply-To: *Duane Remein <Duane.Remein@xxxxxxxxxx
    <mailto:Duane.Remein@xxxxxxxxxx>>
    *Date: *Monday, August 20, 2012 1:15 PM
    *To: *EPoC Study Group <STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>>
    *Subject: *Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Geoff,

    I see your point, could we at least agree to preface there term
    with "Spectra" when referring to RF (old habits, the only kind I
    have at this point, die hard)?

    Best Regards,

    Duane

    FutureWei Technologies Inc.

    duane.remein@xxxxxxxxxx <mailto:duane.remein@xxxxxxxxxx>

    Director, Access R&D

    919 418 4741

    Raleigh, NC

    *From:* Geoff Thompson [mailto:thompson@xxxxxxxx]
    *Sent:* Monday, August 20, 2012 1:04 PM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Colleagues-

    Just goes to show the extent to which Wikipedia is not an
    authoritative source.
The answer to this question is obvious within the word itself. Bandwidth is the width of the spectral band, i.e. it is an analog 
    measurement.

    The so called "digital bandwidth" is not a bandwidth it is
    "channel capacity" or "data rate" or "bit rate".

    To illustrate how silly it is to use the spectral term for the
    digital term just think of it in concrete terms.
    You would never use the term "pavement width" when you mean "cars
    per hour".

    I took a brief tour of older clauses of 802.3 and the term is
    mostly used correctly.  There are several instances (which are
    unfortunately duplicated in several places) where "bit rate"
    would have been more accurate.

    I would strongly prefer that we preserve its analog meaning and
    use other appropriate terminology for digital rate measurement
    (even if it means bucking current common terminology).

    Geoff Thompson

    On 208//12 9:22 AM, Hesham ElBakoury wrote:

    Jim,

    Wikipedia defines bandwidth as follows:

    *Bandwidth* has several related meanings:

        * Bandwidth (signal processing)
          <http://en.wikipedia.org/wiki/Bandwidth_%28signal_processing%29>
          or /analog bandwidth/, /frequency bandwidth/ or /radio
          bandwidth/: a measure of the width of a range of
          frequencies, measured in hertz
        * Bandwidth (computing)
          <http://en.wikipedia.org/wiki/Bandwidth_%28computing%29> or
          /digital bandwidth/: a rate of data transfer, bit rate or
          throughput, measured in bits per second (bps

    Hesham

    *From:* Jim Farmer [mailto:jfarmer@xxxxxxxxxx]
    *Sent:* Monday, August 20, 2012 8:50 AM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Unfortunately, as if often the case, we have multiple different
    definitions for the same term -- as an RF nerd myself, I had
    difficulty getting used to "bandwidth" referring to data.  But
    the data usage certainly is a common use of the term.  If we need
    to differentiate the two, I'd suggest the shorter term "RF
    bandwidth" when we need to differentiate the two.

    Thanks,

    jim

    Jim Farmer, K4BSE

    Chief System Architect,

    FTTP Solutions

    Aurora Networks

    1220 Old Alpharetta Rd.

    Ste. 370

    Alpharetta, GA 30005 USA

    678-339-1045 (office)

    678-640-0860 (mobile)

    jfarmer@xxxxxxxxxx <mailto:jfarmer@xxxxxxxxxx>

    *From:* Duane Remein [mailto:Duane.Remein@xxxxxxxxxx]
    *Sent:* Monday, August 20, 2012 11:32 AM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* Re: [802.3_EPOC] EPoC Bandwidth Discussion

    Steve,

    Your use ot the term "bandwidth" completely threw me, I've always
    associated this term with data bandwidth.

    Can I suggest we use something like Spectrum Channel Width --
    defined as a portion of RF spectrum dedicated to a transmission
    channel or sub-channel.

    Once we agree on such a term Marek can then add this to the
    definitions list.

    Best Regards,

    Duane

    FutureWei Technologies Inc.

    duane.remein@xxxxxxxxxx <mailto:duane.remein@xxxxxxxxxx>

    Director, Access R&D

    919 418 4741

    Raleigh, NC

    *From:* Shellhammer, Steve [mailto:sshellha@xxxxxxxxxxxx]
    *Sent:* Friday, August 17, 2012 6:42 PM
    *To:* STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx
    <mailto:STDS-802-3-EPOC@xxxxxxxxxxxxxxxxx>
    *Subject:* [802.3_EPOC] EPoC Bandwidth Discussion

    EPoC Group,

                   Several of us had a good discussion on EPoC
    bandwidth this morning.  I would like to see if there are other
    who would like to join us for future calls on Friday mornings (10
    AM Pacific Time).

                   If anyone else would like to join us, please send
    me an email and I will add you to the meeting invite.

                   Once we have some slides put together we will
    review them on the Monday AM calls, hosted by Comcast.

    Steve

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