IEEE 802.11-20/1441r5 RU Restriction for 20MHz Operation Summary

September 2020 doc.: IEEE 802.11-20/1441r5 RU Restriction for 20MHz Operation Date: 2020-09-14 Authors: Name Affiliation Address Phone Email Eunsung Park esung.park@lge.com Dongguk Lim dongguk.lim@lge.com 19, Yangjae-daero 11gil, Seocho-gu, Seoul 137- 130, Korea LG Electronics Jinyoung Chun jiny.chun@lge.com Jinsoo Choi js.choi@lge.com Submission Slide 1 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 Introduction TGbe agreed to support the followings 20MHz operating channel width in 2.4GHz band mandatorily 20MHz only client in 2.4/5GHz band only Various small RU aggregation in each bandwidth New tone plan for 80MHz OFDMA transmission Similar to 11ax, we propose 11be supports that 20MHz operating / only STAs are assigned to certain RUs / MRUs in a wider bandwidth EHT OFDMA transmission Some RUs / MRUs in a wider bandwidth have some data tones which are located in tones corresponding to DC / guard of 20MHz operation due to the discrepancy in tone plan In each bandwidth, we also propose RU restriction for 20MHz operation considering the agreed RUs / MRUs and tone plans Submission Slide 2 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 Recap on RU restriction in 11ax [1] (1/2) 20MHz operating STAs (with corresponding Rx filtering) cannot receive some RUs without penalty in a wider bandwidth transmission The performance is badly hit, when the number of affected data tones* is more than 10% of data If those affected tones are not many, the performance is reliable Middle 26-tone RUs are not allocated to 20MHz operating STAs for wider bandwidth OFDMA PPDU *affected data tones: data tones modulated on DC/guard tone location of 20MHz operation Submission Slide 3 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 Recap on RU restriction in 11ax [1] (2/2) All 242-tone RUs in wider bandwidth have data modulated on the DC tone location of 20 MHz operating STAs This may cause RX DC (DL OFDMA) or TX LO leakage (UL OFDMA) to interfere w/ the data tones, further degrading performance The performance may depend on implementation UL OFDMA may be much more vulnerable to this factor because it needs more accurate synchronization It is optional whether all 242-tone RUs of 20 MHz operating STAs to be supported in wider bandwidth DL OFDMA 242-tone RUs shall not be allocated to 20MHz operating STAs in wider bandwidth for UL OFDMA Based on the rules used for 11ax, we propose RU restriction for 11be Submission Slide 4 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 RU Restriction for 40MHz (1/2) There are some MRUs as well as RUs which have tones affected by 20MHz operation 26_1 26_2 26_3 26_4 26_5 26_6 26_7 26_8 26_9 26_10 26_11 26_12 26_13 26_14 26_15 26_16 26_17 26_18 52_1 52_2 52_3 52_4 52_5 52_6 52_7 52_8 26+52_1 26+52_2 26+52_3 26+52_4 26+52_5 26+52_6 106_1 106_2 106_3 106_4 26+106_1 26+106_2 26+106_3 26+106_4 RUs in red They have more than 10% data loss* (12.5%), and thus, need to be not allocated to 20MHz operating STAs RUs in green They have less than 10% data loss (8.3%, 4.2%, 2%) The performance may be depending on MCS and Nss, and, severely degraded with 4K QAM and 16SS that 11be supports 20MHz operating STAs may use low MCS and small Nss basically, and thus, we can consider allocating these RUs to 20MHz operating STAs *data loss: ratio of # of affected data tones to # of data tones 242_1 242_2 Submission Slide 5 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 RU Restriction for 40MHz (2/2) Cont. 26_1 26_2 26_3 26_4 26_5 26_6 26_7 26_8 26_9 26_10 26_11 26_12 26_13 26_14 26_15 26_16 26_17 26_18 52_1 52_2 52_3 52_4 52_5 52_6 52_7 52_8 26+52_1 26+52_2 26+52_3 26+52_4 26+52_5 26+52_6 106_1 106_2 106_3 106_4 26+106_1 26+106_2 26+106_3 26+106_4 242_1 242_2 RUs / MRUs in blue They have less than 10% data loss (4.2%, 2.4%, 4%, 2.6%) but there are some data tones located in DC tones of 20MHz operation They can be optionally allocated to 20MHz operating STAs for DL OFDMA They need to be not allocated to 20MHz operating STAs for UL OFDMA From the scheduling perspective, middle 26+52/106 MRUs may not be useful for 20MHz operating STAs, and thus, these MRUs can be disallowed for both DL and UL OFDMA RUs / MRUs in white They can be allocated to 20MHz operating STAs Submission Slide 6 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 RU Restriction for BW 80MHz 40MHz tone plan is duplicated in 80MHz but some MRUs are not supported 26_1 26_19 26_2 26_3 26_4 26_5 26_6 26_7 26_8 26_9 26_10 26_11 26_12 26_13 26_14 26_15 26_16 26_17 26_18 26_20 26_21 26_22 26_23 26_24 26_25 26_26 26_27 26_28 26_29 26_30 26_31 26_32 26_33 26_34 26_35 26_36 52_1 52_2 52_3 52_4 52_5 52_6 52_7 52_8 52_9 52_10 52_11 52_12 52_13 52_14 52_15 52_16 26+52_1 26+52_2 26+52_3 26+52_4 26+52_5 26+52_6 26+52_7 26+52_8 106_1 106_2 106_3 106_4 106_1 106_2 106_3 106_4 26+106_1 26+106_2 26+106_3 26+106_4 242_1 242_2 242_3 242_4 RUs in red: more than 10% data loss, disallowed RUs in green: less than 10% data loss, allowed RUs / MRUs in blue: less than 10% data loss, data tones located in DC Optionally allowed for DL OFDMA Disallowed for UL OFDMA From the scheduling perspective, middle 26+52/106 MRUs can be disallowed for both DL and UL OFDMA RUs / MRUs in white: allowed All the above can apply to each 80MHz for BW 80MHz Slide 7 Submission Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 Summary Middle 26-tone RUs shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission 242-tone RUs may be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL OFDMA transmission but shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz UL OFDMA transmission As to middle 26 + 52/106 MRUs, it may be better to disallow them from being allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission 20MHz operating STAs shall support the tone mapping of the other RUs / MRUs with less than 242 tones for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission Submission Slide 8 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #1 Do you agree to add the following text to TGbe SFD? 11be supports that RUs / MRUs with less than or equal to 242 tones are allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission RU restriction is TBD 80+80 / 160+160 MHz is TBD This is for rel. 1 Y/N/A: // Submission Slide 9 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #2 Do you agree to add the following text to TGbe SFD? Middle 26-tone RUs shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission 80+80 / 160+160 MHz is TBD This is for rel. 1 Y/N/A: // Submission Slide 10 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #3 Do you agree to add the following text to TGbe SFD? 242-tone RUs may be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL OFDMA transmission but shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz UL OFDMA transmission 80+80 / 160+160 MHz is TBD Note: For downlink OFDMA, receiving 242-tone RUs is optional for 20MHz operating STAs This is for rel. 1 Y/N/A: // Submission Slide 11 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #3a Do you agree to add the following text to TGbe SFD? 242-tone RUs may be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL OFDMA 80+80 / 160+160 MHz is TBD Note: For downlink OFDMA, receiving 242-tone RUs is optional for 20MHz operating STAs Note: UL OFDMA case is TBD This is for rel. 1 Y/N/A: // Submission Slide 12 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #3b Do you agree to add the following text to TGbe SFD? 242-tone RUs shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz EHT TB PPDU This is for rel. 1 Y/N/A: // Submission Slide 13 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 Discussion for SP #3b 242-tone RU may be important for 20 MHz operating STAs because it is the largest RU available for them The current tone plan of 11be is more favorable to 242-tone RU usage of 20 MHz operating STAs than that of 11ax For 11be the maximum data loss is 2.56 % (4.27 % for 11ax) and there is no RU having tones overlapped with the adjacent 20 MHz channel However, we still have DC issues which may further degrade the performance and may need an additional implementation to reduce DC impacts Note that all the other RUs / MRUs which have tones overlapped with DC of 20 MHz operation have been disallowed Basically, 20 MHz operating STAs may have a small amount of data to transmit, and thus, a small size RU / MRU may be enough when transmitting the data For implementation simplicity, we suggest to disallow 242-tone RU for 20 MHz operating STAs in a wider bandwidth EHT TB PPDU Submission Slide 14 Eunsung Park, LG Electronics

August 2020 doc.: IEEE 802.11-20/1441r5 Straw Poll #4 Do you agree to add the following text to TGbe SFD? Middle 26 + 52/106 MRUs shall not be allocated to 20MHz operating STAs for 40 / 80 / 160 / 320 MHz DL / UL OFDMA transmission 80+80 / 160+160 MHz is TBD This is for rel. 1 Y/N/A: // Submission Slide 15 Eunsung Park, LG Electronics

September 2020 doc.: IEEE 802.11-20/1441r5 References [1] 802-11-16/0906r0 RU Restriction on 20MHz Operating STAs Submission Slide 16 Eunsung Park, LG Electronics