1. doc.: IEEE 802.15-<doc#>
<month year>
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [DF08 Beamforming Related Comment Resolutions]
Date Submitted: [May. 12, 2009]
Source: [Junyi Wang, Zhou Lan, Chang woo Pyo, Chin-Sean Sum, Tuncer Baykas, Azizur Rahman, Ryuhei Funada, Fumihide Kojima, Hiroshi Harada, Shuzo Kato, Ismail Lakkis+]
Company [National Institute of Information and Communications Technology (NICT), Tensorcom, Samsung ]
Address1[3-4 Hikari-no-oka, Yokosuka-shi, Kanagawa , Japan;
10875 Rancho Bernardo Rd, #108, San Diego, CA ]
Voice1:[ ] , FAX1: [ ]
Re: []
Abstract: [Comment Resolutions related to Beamforming in DF08]
Purpose: [To be considered in TG3C baseline document.]
Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributors acknowledge and accept that this contribution becomes the property of IEEE and may be made publicly available by P
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2. Comment 67
Comment #
Subclause
Comment
Proposed Change 67
Bar
P162 L8
"For the SC PHY and HSI PHY, the ..training sequence shall be identical to the CMS preamble". since pCCADetectTime= 2 uS for SC / HSI Phy, wouldn't it be enough to send only J(d,r)/pCCADetectTime repetitions of a sector training sequence in the same direction ?
send only J(d,r)/pCCADetectTime
repetitions of a sector training sequence in the same direction
According to the clarification of commenter, the comment tries to use partial preamble for any of DEV receive directions. Or in the other words, it means that if the only one time training for multiple receive direction and if use CCA as basic time, what is the basic length for training sequences.
Reject. To estimate LQI to decide the best directions, the estimation shall be conducted after coarse synchronization. So the training sequences for any one of directions shall at least contain SYNC sequence and CES . Furthermore CMS preamble used for sector level training may be useful for sector level training if DEVs are 10 meter away.
(may resolve as “Accept in principle ”if 116 is resolved)

3. Comment 69 Accept in principle.
Subclause
Comment
Proposed Change 69
Bar
P163 L10
Isn't it a protocol violation to send successive Announce command, each Imp-ACK request?
clarify
Accept in principle.
Add the following sentence in L11, p 163; L50, p165,
For more than one feedback CMD frame, only last feedback is sent with Imp-ack,　while previous feedback frames are sent with No-ACK mode
To find the start of SIFS easily, add 1 octets in the beamforming Feedback IE specified as following fields
Total number of feedbacks : 4 bits
Index of the current feedback: 4 bits
Revise Figures and related text : Figure 225, Figure 226 (related text in L35, p163 only), Figure 227, Figure 232, Figure 233 (related text in L11, p166 only ), Figure 234, Figure 241 (related text in L39, p169 only ), Figure 242, Figure 247 (related text in L9, p172) and Figure 248 as follows
Eliminate Imp-ack for Feedback from DEV1 to DEV2 but use Feedback announce command from DEV2 to DEV1 as Imp-ack.
Set Feedback announce command from DEV2 to DEV1 ACK policy as Imm-ack
Set Mapping announce command ACK policy as Imm-ack

4. Current
Revised

5. Comments 70, 71 and 73 Comment # Subclause Comment Proposed Change 70
Bar
7.4.28
P35 L16
In AAS, The direction of Imm-ACK for associate Request CMD in association S-CAP, should be defined using the "best PNC Tx Q-omni direction index" IE, but there is no mapping for Q-omni direction only to sectors and beams ( From which direction the Imm-ACK shall be sent)
define IE for Q-Omni direction mapping
The commenter agree to resolve it as comment 71. 71
13.5
P161 L1
According to 15.3b ( page 78) The PNC shall acknowledge all correctly received Association Request commands, by
sending an Imm-ACK. The direction of the PNC Imm-ACK, as I understand it, shall be in one of the PNC Q-omni direction. Since the device trained his RX with the PNC TX during beacon section, the device knows what this direction should be. In AAS, the direction of Imm-ACK for associate Request CMD in association S-CAP, should be defined using the "best PNC Tx Q-omni direction index" IE, but the procedure is not defined. Other option is to use no-ACK policy and keep sending Association Request commands until Association Response is received. ( From which direction the Imm-ACK shall be sent)
define procedure for direction association using Q-omni pattern 73
Associate Response CMD is sent using no-ack policy, w/ ATP. This is tricky since a DEV did not train the PNC yet, so the PNC does not know what S-CAP to use, and sending response in multiple direction may cause races w/ the time out counter.This could be avoided since best Q-omni direction information is avaliable to the device (should be the direction of the association S-CAP the PNC ACKed the first associate Request CMD). but the procedure is not defined (to send Asso Res with the same direction of Imm-ACK)

6. Agree but no change required for the procedure.
The text of mentioned procedure are already in
The DEV sends multiple of Association Request Commands with information of PNC's best Q-omni transmit pattern indicated in the field “Response Tx sector”.
The Imm-ACK shall be send in the assocaiton S-CAP from the best PNC Q-omni transmit pattern indicated in “Response Tx sector”
Association response command is also sent from PNC best Q-omni transmit pattern indicated in “Rsponse Tx sector”.
The mentioned field is the same as “Response Tx sector” defined in Suggest to rename the field as “best PNC Tx Q-omni pattern”.

7. Comment 122
Comment #
Subclause
Comment
Proposed Change
122
Tuncer 13
There should be a distinction between a DEV beamforming capability and what degree of beamforming it wants to do before communicationg with another DEV. For example DEV1 might want to perfrom a level 1 only beamforming with DEV2 before communication although DEV1 is capable of 2 levels. Or DEV1 might be omni capable and does not want to do any beamforming. after 1st level
When DEV1 requests a CTA from the PNC to perform beamforming with DEV2 it should tell the PNC the number of levels it wants to perform during this CTA.
Accept in principle. However instead of exchange this information during CTA request. It is suggested to add a field “End of training” in feedback IE defined in
Change Figure 48q- Feedback information element format from To
Add the following statement in
The field “End of training” is used to indicate the end of the training stage. Any DEV who wants to terminate the training stage at the end of sector level training may set this field from 0 to 1 during sector level training period. However if one of DEVs (say DEV1) sets the field to 1 but the other (say DEV2) does not, DEV1 shall help DEV2 to finish beam level training by using DEV1 ‘s best transmit and receive sectors.

8. Reserve values 0xFB and redefine 0xFC in stream index to enable DEVs to start beamforming from sector level training or to continue its beam forming from beam level training
Add or revise following sentence in 7.2.5
0xFB reserved for beamforming starting from sector level training
0xFC reserved for beamforming starting from beam level training
Add the following statement in L15, 153 in 13.1
If a CTA is allocated with stream index 0xFB, the beamforming starts from sector level training, while if allocated with stream index 0xFC, the beamforming starts directly from beam level training. However a DEV shall not request CTA with stream index 0xFC without finishing sector level training.

9. Comment 187 Accept. Unify them in ms. Change as follows
Subclause
Comment
Proposed Change
187
James
7.4.28
P36, L11
The values in the table increase by a factor of 2 except for 1000 to 1001, which increases by a factor of 2000
The tracking period should probably all be in units of ms or in units of microseconds. I would think that ms is what makes sense.
Accept. Unify them in ms.
Change as follows
64 us -> 0.064ms
128 us -> 0.128ms
256 us ->0.256 ms
512 us -> ms

10. Comment 62
Comment #
Subclause
Comment
Proposed Change 62
Bar
P162 L8
"For the SC PHY and HSI PHY, the ..training sequence shall be identical to the CMS preamble, .. For the AV PHY, the .. training sequence shall be identical to the HRP preamble", so if Beam Tracking field is set to one in (beacon) PHY header, what is the value of IFS to the training sequense? ( in drwaing appears unspecified parameter GT)
define GT
Accept in principle. The GTs appeared in Figure 125b in and Figure 125e in shall be specified as BSIFS.
Change the following statement in L41, p153 from
Beam forming sector level IFS (BSIFS) = 1728 SC PHY chips (1 μs) To
Beam forming sector level IFS (BSIFS) = 880 SC PHY chips (0.5 μs)
Replace all GTs in Figure 125b in and Figure 125e in into BSIFS

11. Comment 66
Comment #
Subclause
Comment
Proposed Change 66
Bar
P162 L8
"For the SC PHY and HSI PHY, the ---training sequence shall be identical to the CMS preamble, --- For the AV PHY, the .. training sequence shall be identical to the HRP preamble, so if Beam Tracking field is set to one in (beacon) PHY header, does it overwirtes preamble type field in and ?
clarify
No change required. The usage of beamtracking field indicates whether there are training sequences following data frame in beam tracking stages. On the other hand, the usage of preamble type field indicates the preamble used in the next frame. They serve different purposes and are not overlapped.

12. Comment 68
Comment #
Subclause
Comment
Proposed Change 68
Bar
P163 L10
what is the IFS between Announce command in different directions during the AAS DEV1 to DEV2 feedback?
set IFS to MIFS
Accept in principle. since a DEV may receive multiple training sequences from different directions, it may need time to process the receive signal. Add BSIFS/BBIFS in between announce commands of training sequences in different directions.
Add BSIFS in Figure 221 and Figure 230
Add BBIFS in Figure 237 and Figure 239

13. Comment 74 Withdrawn by the commenter Comment # Subclause Comment
Proposed Change 74
13.5
in SAS there is no need for feedback for training, but such procedure is not defined
define procedure for SAS training w/o feedback , where each DEV trains its peers by sending repetitions of training sequence in each direction.
Withdrawn by the commenter