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Re: [STDS-802-11-TGBE] Preamble Puncturing for OFDMA PPDUs, 11-20/483

Hi Oded,

Thanks for your email.

I agree with you that even if the puncture modes you proposed are accepted in the 11be, RU aggregations for those punctured modes in OFDMA are not allowed so far.   

My question is that for OFDMA, transmitter can puncture EHT portion arbitrarily, say, no user is assigned to a certain RU. But for puncture preamble, it is more complicated. For example, it is allowed that a 242 RU is not assigned to any user but the preamble corresponding to this 242 RU is still present, say, the primary 20MHz. So I am wondering how many preamble puncture modes we need to introduce to cover all the cases. I am OK with one hole puncture, but for two holes puncture, I am wondering how useful it is since punctures are mostly for avoiding radar and incumbent signals. 

Thanks,
Jianhan




On Tue, Apr 7, 2020 at 7:14 AM Oded Redlich (TRC) <oded.redlich@xxxxxxxxxx> wrote:

Hi Jianhan,

 

Following the last discussion about contribution 483 I feel that there were some misunderstandings regarding the SPs.

A reminder for SP1 (SP2 is the same except for the puncturing pattern which is 1010):

•       Do you agree to allow puncturing structure 1001 in a given 80MHz segment for OFDMA PPDUs transmitted to STAs operating at BW>=80MHz?

•       Assuming 2 content channels are used

•       Puncturing signaling may be different for different 80MHz channels

•       In 802.11ax in such cases the BW drops to 20MHz

 

You said that these patterns contradict with what is already defined in the SFD and that OFDMA puncturing patterns are defined as a subset of the non-OFDMA patterns.

Well, the only definition in the SFD regarding puncturing is that puncturing will be supported for both PPDUs transmitted to multi STAs and single STA (section 2.4.5)

Maybe you meant to say that large RU combination of 242+242 (either 1001 or 1010) are not supported in OFDMA and I agree with that.

But this has nothing to do with puncturing in OFDMA. These SPs do not suggest to allow multi RU of 242+242 to the same STA. They suggest to allow, for example (see figure below) one RU242 for one STA and another RU242 to a different STA (that’s why the SP discuss the OFDMA case only), hence no contradiction with the SFD.

 

I’m sure that allowing support for such preamble puncturing pattern will improve the channel utilization without any contradiction to other suggestions that are being discussed.

 

Please let me know what you think.

 

BR,

 

Oded

 

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