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RE: stds-80220-requirements: Spectral Efficiency (4.1.2)



Title: Message
Joanne,
 
I have great concerns that while your proposal is likely suitable for systems whose adjacent block operators are utilizing the same technology and concur with the shared operation, it falls short of protecting such adjacent block operations that may be utilizing other technologies. The reality of field deployability dictates that emissions that fall outside of the authorized channel block(s) must conform to applicable regulatory constraints. As a consequence, guardbands must be incorporated into the channel bandwidth AND the spectral efficiency calculations. Channel bandwidth is then the sum of the "occupied bandwidth" (the 99% power bandwidth in your proposal) plus the required guardbands.
 
Walter Rausch
-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of Joanne Wilson
Sent: Thursday, December 04, 2003 2:50 AM
To: Humbert, John J [NTWK SVCS]; Requirements Reflector
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

John,
 
In light of my email message of November 24th, which received some support and no opposition, I  propose the following addition to the text in section 4.1.2: 
 
%%%%%%%%%%%%%%%%%%%%%% 
Proposal:
 
Add the following sentence to the end of section 4.1.2:
 
The calculation for spectral efficiency shall be determined within a fixed size block assignment and will include the use of sufficient
guard bands at the block edges to confine the transmitted signal energy to a 99% level within that fixed block. Additional 
details on how to calculate spectral efficiency will be addressed within the context of the evaluation criteria.

 Rationale:
 
This approach allows for a consistent comparison of the  spectral efficiency  in an arrangement that is consistent with general deployment practices. 
%%%%%%%%%%%%%%%%%%%%%%%
 
Best regards,
 
Joanne Wilson
 


 
-----Original Message-----
From: Humbert, John J [NTWK SVCS] [mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of Humbert, John J [NTWK SVCS]
Sent: Monday, December 01, 2003 3:59 PM
To: Requirements Reflector
Subject: FW: stds-80220-requirements: Spectral Efficiency (4.1.2)

The requirements CG seems to be blurring the lines between evaluation criteria and the requirements for an 802.20 system.  The difference between the two is that a requirement specifies the functionality that the widget, called 802.20, must or shall support. The evaluation criterion specifies how to determine if a proposal has met all of the requirements.

 

The discussion on whether or not guard bands should be included in the spectral efficiency calculation falls more into the how to measure it category rather than what the target should be category.  There are some really good points in the emails below, however I think that the issue of including or excluding guard bands is better addressed within the context of the evaluation team.

 

There needs to be a foot note added to this section stating how to treat the guard bands when calculating SE. This can be as simple as “The calculation for spectral efficiency [shall] [shall not] take into account the impact of guard bands located at the edge of the block assignment”. Additional details on how to calculate SE belongs in the evaluation criteria.

 

If for some reason the evaluation CG feels that this is insufficient then they are free to come back to the requirements CG to ask for further clarification.

 

John J. Humbert
6220 Sprint Parkway
Mailstop KSOPHD0504 - 5D276
Overland Park, KS 66251-6118
PCS (816) 210-9611

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Joseph Cleveland
Sent:
Tuesday, November 25, 2003 8:54 AM
To: 'Joanne Wilson'; '
Shively, David'; 'stds-80220-requirements@ieee.org'
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

 

Hi All,

 

I concur with Bob Love's advice to 'keep it simple' and with Joann that the bandwidth is the spectral width that contains 99% of the emitted power.  This is consistent with the FCC definition.

 

Joseph Cleveland

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Joanne Wilson
Sent:
Monday, November 24, 2003 11:48 AM
To: Shively, David; stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

David,

Since we agree that a consistent approach for all technologies is the way to go,  I think now we are just struggling a bit with the details of how to achieve it.   To some extent, this discussion has become as much about the evaluation process   (which is the purview of another CG) as it is about how to define "network-wide bandwidth". In keeping with Bob Love's good advice not to dive to deeply into the details at the requirements level, let's trust (or encourage) the Evaluation CG to create a process that provides a consistent approach to simulating the performance of the various proposals within a fixed block size (possibly 5 MHz, which seems to be preferred by many) and takes into consideration the need to confine the transmitted signal energy, say at the 99% level, to within that fixed block.  To calculate throughput in a specific scenario, the amount of spectrum that must be allocated to guardbands to meet that 99% level would be subtracted from the total available spectrum prior to multiplying by the calculated spectral efficiency.  I believe the 99% number guarantees that the variations in guardband requirements from one technology to the next won't be all that significant. It appears to me that this level of detail should be made  a proposal to the Evaluation CG and the definition of network-wide bandwidth in the Requirements document could be left as is, or at least it should be less detailed than the above.

Best regards,

Joanne

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of
Shively, David
Sent:
Wednesday, November 19, 2003 8:35 AM
To: stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

Hi Robert and Dave,

 

As Dave had pointed out:

---------------------------------

"There seemed last week some confusion about channelisation, freq. arrangements and the

tabular set of likely spectrum amounts to be entertained for viable deployments and all coupled

with the related issue of the evaluation criteria."

-----------------------------------------

 

I completely agree.  This what I was trying to clarify.  It doesn't make sense to discuss the

adoption of specific spectral efficiency values (e.g. 1 or 2 bps/Hz/sector) without a consistent

way to do the calculation.    Of course, this issue also comes up when performing comparisons

to other technologies. 

 

Best regards,

David Shively

Cingular Wireless

 

-----Original Message-----
From: Robert D. Love [mailto:rdlove@nc.rr.com]
Sent:
Tuesday, November 18, 2003 5:44 PM
To: djames@oak-global.com; 'Joanne Wilson'; '
Shively, David'; stds-80220-requirements@ieee.org
Subject: Re: stds-80220-requirements: Spectral Efficiency (4.1.2)

David, you have expressed my concern accurately.  As we get into the detailed evaluation phase it will become more apparent how we must modify our first set of evaluation criteria to fairly and accurately account for the range of variability that our candidate technologies exhibit.  Therefore, we should not attempt to drill down too far, nor be too exclusive of other options as we establish our initial requirements.

 

Best regards,

 

Robert D. Love
President, LAN Connect Consultants
7105 Leveret Circle       Raleigh, NC 27615
Phone: 919 848-6773   
Mobile: 919 810-7816
email: rdlove@ieee.org    Fax: 208 978-1187

----- Original Message -----

Sent: Tuesday, November 18, 2003 3:13 PM

Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

 

Joanne, and Dave et al:

Yes, you just beat me to the e-mail on this one.  This is really tricky, rather like determining the length of a piece of string, taking into account all the possible permutations.

 

On the latter point, I did not at last week's meeting also raise publicly the related question of suitable frequency bands for MBWA (I'd rather we called it PWDSL, for reasons I gave last week).  There are many other freq bands possible internationally, particularly if the WG can overcome the tendency to slip back into a mindset over always thinking in terms of 2G/3G spectrum.  Last week presentations were restricted to just PCS and similar bands (after all we were in USA).  But there is other spectrum, and there are many other new operators to emerge (I know, I am working with some ..).

 

As if that is not presenting enough permutations, there is also the issue we discussed some on what sort of "default" spectrum should be used for a sensible comparison (or set of such ?) for spec. efficiency. There seemed last week some confusion about channelisation, freq. arrangements and the tabular set of likely spectrum amounts to be entertained for viable deployments and all coupled with the related issue of the evaluation criteria. 

 

So my provocative suggestion is - as you imply - that the regulatory aspects be kept separate here, that the spec efficiency be defined in terms of "number of carriers deployed" (declared) "and the allocation block size"; that something like 10 MHz (TDD) or 2 x 5MHz (FDD) be taken as a baseline usage for all this for the purpose of assessment.   If folk want another higher (or lower) chunk of spectrum, so be it.  In any case, when it comes to evaluation of spec. efficiency this has to be assessed along with other related parameters which in turn relate to how one might have to determine and invoke guard bands or other measures (and here some bands have modest sharing rather than so-called co-existence issues).  Proposals will clearly have to explain how the spec. efficiency may or may not scale but may be piecewise incremented (pilots, BCH, correlation and other considerations etc)

 

So I'd agree with your text re "...defining the spectral efficiency ......... should be done based solely on the technology itself".  Of course that is not the end of it, one has to supply all the other material, too.  So again back to the notion: ".......unique carriers deployed in the network, including any required spacing between carriers. 

 

Certainly it seems to make things a lot simpler if one takes the aggregate DL, UL spec. efficiency /offered traffic rather than keep carrying the two separately, for there are so many other similar considerations and permutations for this, too. 

 

I think Bob Love made a valid point last week in this respect. There is endless pre-occupation in some quarters (and I can see why !) over pre-defining exactly how this calculation or that is to be done and under a thousand permuted scenarios.  I think his valid point was that we should move ahead more firmly, not try to settle each and every parameter prematurely; many are inter-related, and in the longer term the requirements, the baseline scenarios, the eval. criteria, the proposals, the assessment and discussed possible adjustment constitute a somewhat iterative process. (Bob, tell me if I misconstrue, please.)

 

BR, Dave

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Joanne Wilson
Sent:
18 November 2003 21:24
To: Shively, David; stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)



Dave,

 

It seems to me that the guardband requirements that you mentioned are probably that which

was needed to meet the spectral mask associated with a given frequency allocation.   Those are regulatory

matters that are outside of the purview of 802.20 to set and impossible for us to know without explicit

knowledge of the market and band of deployment.   For the purpose of defining the spectral efficiency

of the air interface, I believe it should be done based solely on the technology itself.  In your example,

you cite cdma2000 as having several different carrier bandwidths depending on the number of carriers

deployed and the allocation block size.  Based on that, I don't see how one could make a valid assessment

of cdma2000's spectral efficiency.  The PCS example may just be a deployment issue -- in a 5 MHz

block assignment they were able to deploy three 1.25 MHz carriers with 625 kHz guardbands on the edges.

A good  test case would then be to ask how many carriers could be deployed in a 10 MHz block assignment.

My guess (one of the cdma2000 suppliers or operators could provide a more definitive answer) is that

they could deploy more than 6 carriers -- in fact, probably 7 carriers with 625 kHz guardbands on the

edges.  In that case, by your method the cdma2000 carrier bandwidth would be about 2.14 MHz and not

2.5 MHz..

 

All this is to say that I think the guardband issue, at least with respect to adjacent block protection,

completely muddies the calculation of the spectral efficiency for the air interface.

 

Regarding UMTS, it was my understanding that ETSI had a specific work item to modify the UMTS

air interface so that it could be deployed with the US PCS allocation in a 5 MHz block size.   Again,

someone from that community can correct me if that was not the case.

 

Best regards,

 

Joanne Wilson

 

 

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of
Shively, David
Sent:
Tuesday, November 18, 2003 1:59 PM
To: stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

You are correct that my intention is to define a way to evaluate spectral efficiency in a consistent manner.

 

In the case of cdma2000, the individual channels can be placed directly adjacent to one another but there

is still a required guard band on either end of these channels.  For 1900 MHz systems, the guard band

on each end is typically 625 kHz, for a total of 1.25 MHz.  Thus, for a single cdma2000 carrier the total

spectrum requirement is 0.625 kHz + 1.25 MHz + 0.625 kHz = 2.5 MHz.   For 2 carriers, the total

spectrum requirement is 3.75 MHz and for 3 carriers the total is 5 MHz.  As you noted, the requirement

may be less at 450 MHz but there is still a clear requirement for some guard bands and this would impact

the calculation of spectral efficiency.

 

For UMTS, the chip rate is 3.84 Mcps so the basic bandwidth requirement is commonly quoted as 

3.84 MHz.  This would be the -3 dB bandwidth or, rather, the equivalent noise bandwidth.

I do not know what you refer to in terms of modifications for the US PCS bands.  The 3GPP standards

do include the definitions and specifications for the 5 MHz frequency blocks that are part of the bandplan

for the US PCS bands.  The 3.84 Mcps carrier completely fits into the 5 MHz block since there is "extra"

space on either side.   

 

The bottom line is that the spectral efficiency calculations should be done as consistently as possible.

From a network operator's perspective, what interests me is what spectrum efficiency can I get in a

certain amount of deployed spectrum (including guard bands).

 

The alternative approach would be do use only the carrier bandwidth without any guard bands.  However, 

in this case, for example, the UMTS bandwidth would be 3.84 MHz rather than 5 MHz.  

 

David Shively

-----Original Message-----
From: Joanne Wilson [mailto:joanne@arraycomm.com]
Sent:
Tuesday, November 18, 2003 12:38 AM
To: Shively, David; stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

Dave,

 

In principle, I agree with your underlying premise which I believe is that all proposals should state their overall

bandwidth requirements in a consistent way.  However, I don't think your example is quite correct.  For example,

I know that three cdma2000 carriers can be deployed in less than 2x5 MHz of spectrum (e.g. cdma450 deployments

which I believe are in about 2x4.5 MHz blocks) but W-CDMA cannot be deployed in less than 2x5 MHz and in fact,

I understand that it had to be modified to be deployable in the US PCS bands that are multiples of 2x5 MHz  block sizes.  So,

I don't believe that the 5 MHz W-CDMA channel bandwidth includes guardbands.

 

I believe it would be impossible to determine what would be the needed guardbands for protection of adjacent block licensees.

I think it would be make sense to include whatever spacing would be needed between multiple carriers in a single

deployment.

 

If you agree, how about the following approach?:

 "The network wide bandwidth is the total spectrum in use by  the unique carriers deployed in the network, including any 
required spacing between carriers." 

Agree?

 

Best regards,

 

Joanne 

 

-----Original Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org [mailto:owner-stds-80220-requirements@majordomo.ieee.org]On Behalf Of
Shively, David
Sent:
Monday, November 17, 2003 4:06 PM
To: stds-80220-requirements@ieee.org
Subject: RE: stds-80220-requirements: Spectral Efficiency (4.1.2)

 

Regarding these definitions, it should be clearly understood whether
or not guard bands are accounted for in the calculation of spectral
efficiency.  For UMTS (W-CDMA), the channel is usually quoted as being
5 MHz wide.  In this case the guard bands have been included.  However,
for cdma2000 1X (and IS-95) the channel is usually quoted as being
1.25 MHz wide which does not include the necessary guard bands.

I propose the following:

Network Wide Bandwidth:  The network wide bandwidth is the total spectrum in
use by the unique carriers deployed in the network, including any
required guard bands.

 

Best regards,
David Shively
-----------------------------------------------------------
Dr. David Shively
Cingular Wireless
5565 Glenridge Connector, Mail Stop 950
Atlanta, GA 30342
Phone:  404 236 5909
Mobile: 404 285 5731
FAX:    404 236 5949
email:  david.shively@cingular.com
pager:  dshively@imcingular.com



-----Original Message-----
From: Humbert, John J [NTWK SVCS] [mailto:JHumbe01@sprintspectrum.com]
Sent: Monday, November 17, 2003 12:08 PM
To: stds-80220-requirements@ieee.org
Cc: mike@arraycomm.com
Subject: stds-80220-requirements: Spectral Efficiency (4.1.2)

 

Below is the latest version of the text that was developed at the Plenary in Albuquerque along with a list of the open issues for this section.

*       4.1.2   System Spectral Efficiency (b/s/Hz/sector)
*       The system spectral efficiency of the 802.20 air interface shall be quoted for the case of a three sector baseline configuration [Footnote 1]. It shall be computed in a loaded multi-cellular network setting, which shall be simulated based on the methodology established by the 802.20 evaluation criteria group. It shall consider among other factors a minimum expected data rate/user and/or other fairness criteria, and percentage of throughput due to duplicated information flow. The values shall be quoted on a b/s/Hz/sector basis. The system spectral efficiency of the 802.20 air interface shall be greater than X b/s/Hz/sector.

*       Footnote 1: Since the base configuration is only required for the purpose of comparing system spectral efficiency, proposals may submit deployment models over and beyond the base configuration.

 

*       Definition:
*       System spectral efficiency - System spectral efficiency is defined as the ratio of the aggregate throughput (bits/sec) to all users in the system divided by the network wide bandwidth (Hz) and divided by the number of sectors in the system.

*       Aggregate Throughput: Aggregate throughput is defined as the total throughput to all users in the system (user payload only).

*       Network Wide Bandwidth:The network wide bandwidth is the total spectrum in use by the unique carriers deployed in the network.

 

*       Open items
-       Single value vs. multiple for uplink and downlink
-       X bits/sec/Hz [note 1 b/s/Hz -or- downlink > 2 b/s/Hz/(cell or sector?) @ 3km/hr ;uplink > 1 b/s/Hz/(cell or sector?) @ 3 km/hr].

-       Actual values of spectral efficiency at higher speeds
-       TDD/FDD

 

John J. Humbert
6220 Sprint Parkway
Mailstop KSOPHD0504 - 5D276
Overland Park, KS 66251-6118
PCS (816) 210-9611