IEEE P802.11 Wireless LANs Resolutions for Comments related to Extended Range Beacon Date: 2017-04-06 Tomoko Adachi Toshiba 1, Komukai Saiwai-ku, Kawasaki, Japan +81 44 549 2283 tomo.adachi@toshiba.co.jp Narendar Madhavan Toshiba Yongho Seok Newracom Po-Kai Intel Robert Stacey Intel Revision Notes r1: changed 17/XXXX in resolution column to show this document number. r2: changed resolution that says “Approve” to “Accept”. Added resolutions for CIDs 5165, 5905, 6554, 6560, 7977, 9561, and 9868 and updated the number of CIDs in the abstract. Discussion HE ER SU PPDU Beacon The baseline spec has the following: “10.7.5.1 Rate selection for non-STBC Beacon and non-STBC PSMP frames If the BSSBasicRateSet parameter is not a non-STBC PSMP frame or a non-STBC Beacon frame shall be transmitted in a non-HT PPDU using one of the rates included in the BSSBasicRateSet parameter. If the BSSBasicRateSet parameter is empty, the frame shall be transmitted in a non-HT PPDU using one of the mandatory PHY rates.” With this, up to now, a Beacon other than sent in STBC is always sent in non-HT PPDU for operation in the legacy band. Based on this basic rule, we can assume that all the STAs associated with the AP are within the coverage of non-HT PPDU frames from the AP. As all the STAs other than only supporting DSSS can receive and decode the non-HT PPDU, which means the STAs can set NAV by frames transmitted in non-HT PPDU, the AP can use non-HT PPDU to achieve robust protection.
BSS". It is a matter of perspective. Perhaps better to say, expanding the BSS coverage or something like that. 6223 John Coffey 6.50 3.2 The definition of an HE dual beacon starts with an action: "A BSS transmits beacons in two PHY modes ...". This is very unclear. The BSS shall transmit beacons in two PHY modes? Or the BSS may transmit beacons in two PHY modes? And either way, what is this doing in a definitions section? Rewrite the definition so that it defines the term purportedly being defined. In particular, if or when a BSS uses HE dual beacons, are both beacons "HE dual beacons", or is only the one transmitted in HE_EXT_SU PY format a dual beacon? Or is it the case that neither is, and instead the BSS is in "HE dual beacon mode"? And isn't it normally the case that beacons are transmitted by an "AP", not a BSS? Clarify. Revised. See proposed change in doc. 11-17/0576r2. 6917 Joseph Levy 6.50 3.2 The definition of high efficient dual beacon is a bit odd as it is not really a beacon but an operating mode that allow for the transmission of both a non-HE formatted rewrite the definition of the HE Dual Beacon to be for the HE Dual Beacon Mode. Revised. See proposed change in doc. 11-17/0576r2. 6918 Joseph Levy 6.50 3.2 The term: high efficient dual beacon, HE dual beacon, or high efficient (HE) dual beacon does not appear in this amendment anywhere accept the in definitions Either add the term to some clauses in the amendment or delete the definition. Revised. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 9.4.2.219
7997 Massinissa Lalam 92.36 9.4.2.219 It seems to me that the Dual Beacon subfield does not "indicate" the TBTT offset of the Beacon frame in HE extended range SU PPDU format. This offset is fixed and defined in subclause 11.1.3.10. Delete the sentence "The Dual Beacon subfield also indicates the TBTT offset of Beacon frame in HE extended range SU PPDU in 11.1.3.10 (Beacon generation in an HE BSS)." Add the sentence "The TBTT offset of Beacon frame in HE extended range SU PPDU is defined in 11.1.3.10 (Beacon generation in an HE BSS)." after "The subfield is set to 1 if the HE AP transmits beacons in an HE extended range SU PPDU and a non-HE PPDU.". Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 9562 Yonggang Fang 91.00 9.4.2.219 In order to improve the deployment flexibility, it may require to independently control legacy beacon and HE beacon transmission. Increase the size Dual Beacon field to 2 bits as in the comment Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 9563 Yonggang Fang 92.30 9.4.2.219 Modify the definition of Dual Beacon field. 00: Legacy Beacon only, 01: HE beacon only, 10: L+HE beacon with duplicated system info. 11: L+HE with non-duplicated system info Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 9.4.2.220 5393 Geonjung Ko 93.14 9.4.2.220 When an AP uses the Dual Beacon, a non-AP STA that receives RAPS elements from both Beacon frames of two PPDU formats When an AP uses the Dual Beacon, the RAPS element should be included only in one format of Beacon frame between two Revised. The Dual Beacon mechanism is deleted.
would initialize its OBO counter twice. Then the STA may have less probability to access the random access RU than a STA that receives one Beacon frame. formats of Beacon frames. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 9.4.2.222 5391 Geonjung Ko 95.24 9.4.2.222 When an AP uses the Dual Beacon, even if the STA receives any Beacon frame between Beacon frames of two PPDU formats, all STAs in the BSS shall start to use the BSS Color at the same time. e.g. at the TBTT of non-HE format Beacon frame. Need a clarification on a setting of the Color Switch Countdown field. When an AP uses the Dual Beacon, a value of 0 indicates that the switch occurs at the current TBTT if the element is carried in a format Beacon frame or at the next TBTT of a non-HE format Beacon frame if the element is not carried in a nonHE format Beacon frame. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 11.1.3.10 3055 Abhishek 141.00 11.1.3.10 Only HE STAs can understand an HE Beacon in Extended PPDU format. Such beacon need not carry information that is relevant to non-HE/legacy STAs. This will help reduce the size of HE Beacon. Add a sentence which implies that an HE beacon may not include fields/IEs that apply only to legacy STAs. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 5797 Huizhao Wang 141.50 11.1.3.10 Need detail description of different element sets may be included in beacons in non-HE and HE_EXT_SU PPDUs formats. If they are carrying different set of elements, then in order to avoid any ambiguity, need to list out which elements may differ, and the Please add detail description Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2.
reasons behind them. 5905 James Yee 141.50 11.1.3.10 Rather than stating different elements may be carried, it should be specified what are identical elements and contents that must be carried in both types of Beacon frames. As suggested. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 7961 Mark RISON 141.37 11.1.3.10 For dual beacons to work w.r.t. both non-HE STAs and distant HE STAs, group-addressed traffic needs to be sent twice, once after each of the beacon types After "When Beacon frames are transmitted in two PHY formats, the HE AP shall transmit Beacon frames in non-HE format and in HE_EXT_SU format." add "The HE AP shall transmit buffered non-GCR-SP group addressed BUs twice, once immediately after each of these Beacon frames, when they are DTIM Beacons frames (see 11.2.3.4)." Also add a bit to HE Operation to indicate which kind of beacon it is (cf. STBC Beacon in 802.11-2016 page 953) Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 7978 Mark RISON 141.44 11.1.3.10 "The Beacon frame transmitted in HE extended range SU PPDU has TBTT at the TSF value 0 plus the TBTT offset which value is a half of the value of the Beacon Interval field of the Beacon frame sent in non-HE format." is unclear Change to "The TBTT for the Beacon frame transmitted in HE extended range SU PPDU format shall be offset by half of a beacon interval from the TBTT of the Beacon frame transmitted in PPDU format." Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2.
7979 Mark 141.50 11.1.3.10 "The non-HE format and HE EXT_SU PPDU format Beacon frames may contain different set of elements." is far too loose Change to "Except for the setting of the TIM field and TSF field, all other fields inside the Beacon frame transmitted in HE extended range SU PPDU format shall be identical to the Beacon frame transmitted in non-HE PPDU format." At 141.41 delete "as indicated in the Beacon frame transmitted in PPDU format" and change "Beacon interval" to "beacon interval". At 141.48 delete "as indicated in the Beacon frame transmitted in the HE extended range SU PPDU." Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 9334 Tomoko Adachi 141.30 11.1.3.10 When the AP transmits beacons in an HE_EXT_SU PHY format, it uses the dual beacon mechanism. However, the dual beacon mechanism is deprecated in the baseline (see Table 9-168 and subclause 11.1.3.2 in 802.11-2016). There is no need to reintroduce this again. Just allowing the beacons to be transmitted in an HE_EXT_SU PHY format is enough. Add in subclause 10.7.5.3 a condition to allow beacon frames and group addressed frames to be transmitted in an HE_EXT_SU PHY format if the BSSBasicRateSet, the Basic HT-MCS Set, and the basic VHT-MCS and NSS set are all empty and only the Basic HE MCS And NSS Set is not empty. Delete subclause 11.1.3.10, delete the definition of high efficient (HE) dual beacon from subclause 3.2, replace the Dual Beacon subfield in the HE Operation Parameters field to reserved and delete the Revised. See proposed change in doc. 11-17/0576r2.
description of the Dual Beacon subfield in subclause 9.4.2.219. 5165 Dorothy Stanley 141.36 11.1.3.10 We had in 11n with STBC. Noone implemented it. Why are we introducing yet another Delete this to reduce complexity in the spec. as in comment Revised. Agree in principal. See proposed change in doc. 11-17/0576r2. 5905 James Yee 141.50 11.1.3.10 Rather than stating different elements may be carried, it should be specified what are identical elements and contents that must be carried in both types of Beacon frames. As suggested. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 6554 John Coffey 141.32 11.1.3.10 Inconsistent usage of defined terms: here we have "beacon frames", whereas everywhere else in the drfat, including several places in the same section, we have "Beacon frames". Change "beacon frames" to "Beacon frames". Revised. The related subclause is deleted. See proposed change in doc. 11-17/0576r2. 6560 John Coffey 141.51 11.1.3.10 Inconsistent use of defined term: here we have "HE EXT_SU", whereas everywhere else in the draft we have "HE_EXT_SU". Change "HE EXT_SU" to "HE_EXT_SU". Revised. The related subclause is deleted. See proposed change in doc. 11-17/0576r2. 7977 Mark RISON 141.39 11.1.3.10 "The Beacon frame transmitted in PPDU format has TBTT at the TSF value 0." is unclear Change to "Time 0 is defined to be a TBTT for the Beacon frame transmitted in PPDU format (see 11.1.3.2)." Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 9561 Yonggang Fang 141.44 11.1.3.10 Using a half value of Beacon Interval of legacy beacon frames as offset of HE beacon may not as in the comment Revised. The Dual Beacon mechanism is deleted.
be flexisible in deployment. Suggest to add HE Beacon Offset in the HE Operation element, or remove this restriction. See proposed change in doc. 11-17/0576r2. 9868 Young Hoon Kwon 141.38 11.1.3.10 When Beacon frames are transmitted in two PHY formats, it says one of the format shall be format. However, as baseline spec. says the beacon frame to be carried in (duplicate) format, it shall be non-HT format instead of non-HE format. As in the comment. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 27.5.2.6.2 5392 Geonjung Ko 173.31 27.5.2.6.2 When an AP uses the Dual Beacon, a non-AP STA that receives RAPS elements from both Beacon frames of two PPDU formats would initialize its OBO counter twice. Then the STA may have less probability to access the random access RU than a STA that receives one Beacon frame. When an AP uses the Dual Beacon, the STA should use the RAPS element from one format of Beacon frame. Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. 9415 Woojin Ahn 173.31 27.5.2.6.2 A STA might receive both normal Beacon and Dual Beacon. If both of the two beacons included RAPS elements, the STA might reset its OBO and OCW twice. If a STA receives a normal Beacon and a Dual beacon including RAPS elements, it shall initialize its OBO and OCW only for the normal Beacon Revised. The Dual Beacon mechanism is deleted. See proposed change in doc. 11-17/0576r2. Related Comments in Subclause 27.16.2 6179 Jin-Sam Kwak 206.39 27.16.2 In case that an AP uses the Dual Beacon, all of STAs associated with the AP should identify the same BSS Please define the BSS Color change TBTT to be the same to all of STAs in a BSS when the BSS Revised. The Dual Beacon mechanism is deleted.