submission page 1 october 2001 doc.: ieee 802.11-01/542r0 andrew myles, cisco systems a discussion...

Andrew Myles, Cisco Systems

Submission Page 1

October 2001

doc.: IEEE 802.11-01/542r0

A discussion of 802.11h scope for theTGh teleconference on 10 October 2001

Andrew Myles (Cisco Systems)

9 October 2001


Submission Page 2

October 2001

doc.: IEEE 802.11-01/542r0

This presentation explores issues, questions, answers and outcomes relating to the scope of TGh’s PAR

• Some voters believe:

– all elements of D1.0 exceeding the PAR’s scope should be removed

– all elements of D1.0 exceeding the PAR’s scope should at least be identified

– the PAR should be revisited and, possibly, the whole selection process restarted

• The issue of scope raised by the voters suggests a series of questions

• The aim of this presentation is to explore the answers to these questions, leading to an outcome, which could include some combination of:

– Continue comment resolution and proceed to next LB

– Remove functionality exceeding the PAR

– Rewrite the PAR

– Restart the selection process

• The author will avoid expressing a personal view until the last two slidesExecutive summary


Submission Page 3

October 2001

doc.: IEEE 802.11-01/542r0

Some voters believe all elements of D1.0 exceeding the PAR’s scope should be removed

Voter Comment summary Recommended change summary

David Bagby • The PAR limits scope to satisfying European regulations

• Various elements of D1.0 exceed the PAR’s scope

• “Spirit of goodness” argument is flawed

• Remove all functionality not related to the PAR

Jon Rosdahl • Various elements of D1.0 exceed the PAR’s scope


Andrew Myles • Various elements of D1.0 exceed the PAR’s scope

• Replace D1.0 with revised draft (provided) focused on the PAR requirements

Robert Miller, Harry Worstell,David Skellern

• Hidden station reporting in D1.0 exceeds the PAR’s scope

• Remove hidden station reporting

Amar Ghori,Bobby Jose

• Various elements of D1.0 have an impact on work in 802.11e

• Liase with 802.11e; OR


Note: author apologises for any misinterpretation of LB comments

Voter comments


Submission Page 4

October 2001

doc.: IEEE 802.11-01/542r0

Some voters believe all elements of D1.0 exceeding the PAR’s scope should at least be identified

G Srikantar • Various elements of D1.0 not related to ERC

• Identify functionality not related to ERC

M Venkatraman • Aim of D1.0 is to gain European regulatory approval

• Identify functionality related to aim



Voter comments


Submission Page 5

October 2001

doc.: IEEE 802.11-01/542r0

Some voters believe the PAR should be revisited and, possibly, the whole selection process restarted

John Kowalski • In favour of hidden station detection, but it is not clear hidden station detection is required by PAR’s scope.

• Modify the scope to allow hidden station detection.

Baruch Altman • Various elements of D1.0 exceed the PAR’s scope

• Group (or 802.11 chair) should formally determine whether D1.0 and/or the original proposal exceed the PAR’s scope

• Fix process, possibly change PAR, remove functionality not related to the PAR and possibly restart process



Voter comments


Submission Page 6

October 2001

doc.: IEEE 802.11-01/542r0

The issue of scope raised by the voters suggests a series of questions and outcomes

What is the scope of the TGh PAR?

Does D1.0 meet the PAR?

Is D1.0 allowed to exceed the PAR?

Should we remove functionality exceeding the PAR?

Continue comment resolution and proceed to next LB

Restart the selection process

Remove functionality exceeding the PAR

Agreed scope

No, list of functionality exceeding scope

No

No

Yes

Yes

Yes

Should we rewrite the PAR?

No

Yes

Questions & outcomes

Rewrite the PAR


Submission Page 7

October 2001

doc.: IEEE 802.11-01/542r0









Agreed scope


No

No

Yes

Yes

Yes


No

Yes


Rewrite the PAR


Submission Page 8

October 2001

doc.: IEEE 802.11-01/542r0

The 802.11 WG established a PAR for TGh; but should the PAR be interpreted narrowly or broadly?

Is a narrow interpretation correct?

• A strict reading of TGh’s PAR suggests TPC and DFS facilities with limited functionality are all that are required or allowed

• Debate at the time the TGh’s PAR was approved suggests a narrow interpretation was intended

• The purpose section of the PAR cannot be used to justify a broad interpretation

• Acceptance of the original proposals in Orlando by 90% and the LB by 60% cannot be used to justify a broad interpretation

Is a broad interpretation correct?

• A broad reading of TGh’s PAR suggests TPC and DFS facilities with wide functionality are possible

802.11 WG established a PAR for TGh related toTPC and DFS extensions for the 5GHz band in Europe



Submission Page 9

October 2001

doc.: IEEE 802.11-01/542r0

802.11 WG established a PAR for TGh related to TPC and DFS extensions for the 5GHz band in Europe

Project scope (what?) Project purpose (why?)

• Enhance the 802.11 Medium Access Control (MAC) standard and 802.11a High Speed Physical Layer (PHY) in the 5GHz Band supplement to the standard;

– To add indoor and outdoor channel selection for 5GHz license exempt bands in Europe.

– And to enhance channel energy measurement and reporting mechanisms to improve spectrum and transmit power management (per CEPT and subsequent EU committee or body ruling incorporating CEPT Recommendation ERC 99/23).

• To enhance the current 802.11 MAC and 802.11a PHY with network management and control extensions for spectrum and transmit power management in 5GHz license exempt bands, enabling regulatory acceptance of 802.11 5GHz products.

• Provide improvements in channel energy measurement and reporting, channel coverage in many regulatory domains, and provide Dynamic Channel Selection and Transmit Power Control mechanisms.

Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, for Spectrum and Transmit Power Management extensions in the 5 GHz band in Europe

Project title

What is the scope of the TGh PAR? – TGh PAR

Source: 0301r38w-SMa SG-Draft-PAR.doc


Submission Page 10

October 2001

doc.: IEEE 802.11-01/542r0

A strict reading of TGh’s PAR suggests TPC and DFS facilities with limited functionality are all that are required and allowed

The scope section of the TGh PAR implies specific goals

• Applies only to the 5GHz license exempt band

• Applies only to Europe (CEPT countries)

• DFS and TPC facilities are only required to satisfy the needs of ERC 99/23 and any subsequent revisions

ERC 99/23 implies simple requirements for TPC and DFS

• TPC must define a maximum transmit power by channel

• TPC must define an average transmit power mitigation (currently 3dB)

• DFS must avoid licensed users in all channels

• DFS must provide channel spreading over defined number of channels (330MHz)

• DFS must disallow outdoor use in certain channels

What is the scope of the TGh PAR? – Narrow - Scope


Submission Page 11

October 2001

doc.: IEEE 802.11-01/542r0

Debate at the time the TGh’s PAR was approved suggests a narrow interpretation was intended

• David Bagby recalls that debate explicitly limited 802.11h’s scope to TPC and DFS facilities required to obtain European regulatory approval:

– “As a key participant in the debate leading up to the approval of the TGH PAR, and (if memory serves) the maker of several motions in Plenary that modified the proposed PAR to explicitly limit the scope of TGH to exactly TPC and DFS as they are required by European regulatory requirements, I conclude that the TGH draft does exceed the TGH PAR authorization. It certainly exceeds the intention of the restrictions adopted when the PAR was proposed and later approved.”, source: LB29, comment no. 3

• The approved version of the PAR excluded wide geographical applicability, which was present in an an earlier version:

– “IEEE P802.11 will correspond with regulatory bodies worldwide in order to try to assure that the proposed extension will be applicable geographically as widely as possible. “, source: 0301r18W-SMa SG-Draft-PAR.doc

What is the scope of the TGh PAR? – Narrow - Debate


Submission Page 12

October 2001

doc.: IEEE 802.11-01/542r0

Acceptance of the original proposals in Orlando by 90% and the LB by 60% cannot be used to justify a broad interpretation

• Claims have been made that the current broad approach can be justified by its wide acceptance in two votes

– The original proposal achieved a “yes” vote of >90%

– D1.0 achieved a “yes” vote in the LB of >60%

• However, there are alternative and more compelling explanations for these overwhelming “yes” votes

– People voted overwhelming “yes” on one original proposal to get the TGh process moving forward; a positive step to get 802.11a into Europe

– People voted “yes” on the LB to maintain voting rights, because they simply did not care or because they did not have time; indeed, given that D1.0 is missing essential information, it is hard to explain any “yes” vote in the LB

What is the scope of the TGh PAR? – Narrow - Voting


Submission Page 13

October 2001

doc.: IEEE 802.11-01/542r0

The purpose section of the PAR cannot be used to justify a broad interpretation

The purpose section of the TGh PAR implies broad goals …

• Gain regulatory acceptance in many domains (in 5GHz band)

• Provide general channel measurement and reporting

• Provide effective channel coverage (is this sophisticated channel planning based on TPC and DFS?)

… but the scope section tells us what should be in the standard

• “The purpose is why you believe that this standard needs to exist”

• “The scope is what you are trying to cover in the standard”

• Source:http://standards.ieee.org/guides/companion/part2.html#structure

What is the scope of the TGh PAR? – Narrow - Purpose


Submission Page 14

October 2001

doc.: IEEE 802.11-01/542r0

A broad reading of the TGh PAR suggests TPC and DFS facilities with wide functionality are possible

The scope section of the TGh PAR implies broad goals:

• The scope is open ended in that 802.11h needs to satisfy future regulations that are currently unknown

• The only way to satisfy unknown goals with reasonable confidence is to include facilities with wide functionality

What is the scope of the TGh PAR? – Broad - Scope


Submission Page 15

October 2001

doc.: IEEE 802.11-01/542r0

Can we agree on a narrow scope for the TGh PAR with some expandability to cater for future regulatory changes?

Proposed interpretation of scope:

• Applies only to the 5GHz license exempt band

• Applies only to Europe (CEPT countries)

• DFS and TPC facilities are only required to satisfy the needs of ERC 99/23 and any subsequent revisions

Assumed needs of ERC 99/23

• TPC must define a maximum transmit power by channel

• TPC must define an average transmit power mitigation

• DFS must avoid licensed users in all channels

• DFS must provide channel spreading over defined number of channels

• DFS must disallow outdoor use in certain channels

Assumed needs of revisions

• TPC and DFS must be expandable to meet likely future regulatory requirements only

What is the scope of the TGh PAR? – Agreement?


Submission Page 16

October 2001

doc.: IEEE 802.11-01/542r0

Does the original proposal and D1.0 meet the PAR?








Agreed scope


No

No

Yes

Yes

Yes


No

Yes


Rewrite the PAR


Submission Page 17

October 2001

doc.: IEEE 802.11-01/542r0

Aspects of both TPC and DFS in D1.0 exceed the scope of the PAR; the extent of the problem in DFS is unclear


Protocols related to dynamic TPC and power capability in D1.0 exceed the

scope of the PAR

Protocols related to at least some measurement requests and reports in

DFS in D1.0 exceed the scope of the PAR

D1.0 exceeds

the scope of the TGh

PAR

It is difficult to evaluate parts of DFS in D1.0 against the scope of the PAR


Submission Page 18

October 2001

doc.: IEEE 802.11-01/542r0

Protocols related to dynamic TPC and power capability in D1.0 exceed the scope of the PAR

Within scope of PAR

• Use of Country elements to define the maximum transmit power by channel

• Use of Power Constraint elements to define mitigation requirements by channel (by channel provides for the future)

Outside scope of PAR

• Use of support mechanisms for dynamic TPC including:

– Transmit power in Service field

– Hidden station reporting

• Use of Power Capability elements to assist range control procedures

Status (relative to scope of PAR) subject to debate

• Use of Country and Power Constraint elements for range control

Does D1.0 meet the PAR? - TPC


Submission Page 19

October 2001

doc.: IEEE 802.11-01/542r0

It is difficult to evaluate parts of DFS in D1.0 against the scope of the PAR

• At least some voters believe the DFS description in D1.0 cannot be properly evaluated in its current state

– “DFS is incompletely, unclearly and ambiguously specified. There is insufficient clear consistent detail to allow equipment to be designed to the letter of the language contained in the draft text”, source: Carlos Rios in a LB comment

– The author of this document made a similar LB comment

• The motivation and usage of many DFS facilities are not included in either the protocol description or accompanying notes, e.g.

– BSS bit, QBSS bit, ToDS bit, FromDS bit

– Power Level Adjustment, Own Beacon RSSI fields

– Total/Unknown RSSRI histogram

• It is not clear that some DFS facilities will actually assist in detecting licensed users, as required by the regulators, e.g.

– Periodicity bit

– CCA Busy Fraction/Duration/Interval

Does D1.0 meet the PAR? – DFS evaluation


Submission Page 20

October 2001

doc.: IEEE 802.11-01/542r0

Protocols related to at least some measurement requests and reports in DFS in D1.0 exceed the scope of the PAR

Within scope of PAR

• Channel switch announcements

• Specification of requirement for channel spreading

• Some of the DFS measurement request and report components

Outside scope of PAR

• Some of the DFS measurement request and report components including:

– Extended BSS Reports

Status (relative to scope of PAR) subject to debate

• Supported channel announcements

• Many of the DFS measurement request and report components

– QBSS

– ToDs/FromDS

– Foreign PLCP Header

– Periodicity

– Extended CCA Report

– Power Level Adjustment

– Own Beacon RSSI

– Total RSSI histogram

Does D1.0 meet the PAR? - DFS


Submission Page 21

October 2001

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Agreed scope


No

No

Yes

Yes

Yes


No

Yes


Rewrite the PAR


Submission Page 22

October 2001

doc.: IEEE 802.11-01/542r0

D1.0 should probably not significantly exceed the scope set by the PAR

• The IEEE standards guide emphasises the importance of the PAR as a legal description of the work of TGh

– “The PAR is a legal document, signed by the working group chair and the sponsor. It is the means by which the working group gains the umbrella of indemnification from the IEEE. As such, it should never be forgotten”

– Source: http://standards.ieee.org/guides/companion/part2.html#PAR

• Bob O’Hara (parliamentarian) believes there is only limited flexibility to exceed the scope of the PAR

– “To a degree I think that going beyond the strict interpretation of the PAR is OK. However, adding functionality that is not even hinted by the PAR is probably going a bit too far”

– Source: private e-mail, with permission



Submission Page 23

October 2001

doc.: IEEE 802.11-01/542r0









Agreed scope


No

No

Yes

Yes

Yes


No

Yes


Rewrite the PAR


Submission Page 24

October 2001

doc.: IEEE 802.11-01/542r0

Removing functionality from D1.0 that exceeds the PAR is a strategic decision with advantages, disadvantages and risks

Advantages

• Simplifies draft considerably, which:

– should shorten the definition and approval process

– will increase the probability of a correct standard

• Avoids need to rewrite PAR, and potentially restart entire selection process, which would cause a long delay

Risks

• Could be forced to restart selection process anyway because the original proposals also exceeded the PAR

Disadvantages

• Will lose some useful functionality, potentially forever

• Another TG will need to be formed to redefine removed useful functionality, thus causing a long delay until this functionality is available

• The work of any new TG may be constrained by design decisions made by TGh, thus reducing overall system effectiveness



Submission Page 25

October 2001

doc.: IEEE 802.11-01/542r0









Agreed scope


No

No

Yes

Yes

Yes


No

Yes


Rewrite the PAR


Submission Page 26

October 2001

doc.: IEEE 802.11-01/542r0

Rewriting the PAR is a strategic decision with advantages, disadvantages

Advantages

• Allows functionality beyond current PAR to be efficiently integrated

• Avoids need for another TG to define the functionality beyond current PAR, potentially reducing time until all functionality available

Disadvantages

• Increases complexity of draft, which:

– will lengthen the definition and approval process, thus delaying 802.11a entry into Europe

– will decrease the probability of a correct standard

• Will require the entire selection process to be restarted, which would cause a long delay



Submission Page 27

October 2001

doc.: IEEE 802.11-01/542r0

The author has a personal view of the answers to the posed questions; what do other members of TGh think?








Agreed scope


No

No

Yes

Yes

Yes


No

Yes

Personal and group views?

Adoption of the author’s proposed revision (11-01-543r0) OR an equivalent alternative

provides the shortest path to enabling 802.11a in Europe

Rewrite the PAR


Submission Page 28

October 2001

doc.: IEEE 802.11-01/542r0

Adoption of the author’s proposed revision or an equivalent alternative provides the shortest path to enabling 802.11a in

Europe

The authors revision (11-01-543r0) addresses most issues raised in LB29 …

• Removes features exceeding PAR– Removes tx power in Service field

– Removes hidden station reporting

– Removes extended BSS reports

• Adds features required to satisfy PAR– Adds simple version of DFS in an IBSS

– Adds flexibility providing for future changes to the regulations in both DFS and TPC

• Corrects various protocol errors

• Improves text description using style and layout compatible with 802.11 traditions

• Includes templates for unwritten sections

… and yet remains broadly compatible with the original proposals

Advantages of adopting author’s proposed revision or an equivalent alternative

• Provides opportunity of moving forward quickly to a standard meeting the PAR– The revision is simple

– The revision exists

• Does not break the development process – the revision is mostly a superset of the original

proposal, except where the original proposal exceeded the PAR

• Avoids changing the PAR, thus reducing risk of having to restart selection process

Disadvantages of adopting author’s proposed revision or an equivalent alternative

• Some people feel that the revision or an alternative cannot be adopted without a major delay

• …?

Personal and group views?

submission page 1 october 2001 doc.: ieee 802.11-01/542r0 andrew myles, cisco systems a discussion...

Documents

par slide

scope of tghs par

tgh par

par note

issue of scope

h scope

pars scope group

pars scope fix process