| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
|
Hello Vinko and Matt, Thanks for providing your opinions here. I think running this motion is a little bit early. Non-primary channel access topic is not new, we discussed
this again and again. Large BW could not be the reason, we introduced the 160MHz large bandwidth in 802.11ac, almost 10 years ago. This may not gain much as we expect. Please refer to the following points
1.
Complicate scenarios on unlicensed band. Not only WiFI devices operate on this band, that means it is difficult to get primary channel
busy time. So if the AP/STA goes to do channel access on the secondary channel in this case, the STA parking the primary channel could be out of the service, this is dangerous. Moreover, even if primary channel busy results from WiFi signal, The AP/STA may
also miss the preamble of WiFI PPDU or NAV could also be updated during the period when the AP/STA provides the service on the secondary channel.
2.
When the AP/STA intends to provide the service on the secondary channel, however, it does not know the status of that channel. If doing
channel access immediately, it will break the balance of that channel and cause a series of problems. Otherwise, “waiting” results in spectrum resource waste.
3.
We have PPDU preamble Puncture and Multi-link techniques now, both of these could alleviate or address the non-efficiency issue. Why not
need another complicate or immature technique.
4.
The solutions now are not clear, no full picture, no simulation evaluation. It is reasonable to have further discussion IMHO …. Best wishes Ming Gan 发件人: Vinko Erceg [mailto:00000c44f70266db-dmarc-request@xxxxxxxxxxxxxxxxx]
I would also like to add that 20+ year old WLAN channel access assuming primary being idle is very inefficient mechanism, especially for wide BWs
such 80MHz, 160Mhz and 320MHz. Since actual mechanisms are TBD, certainly can be made to fit within regulatory frameworks, LTE (NR-U) has mechanisms to exploit this already in an efficient way. Personally, I think that there is time for change, we should be
able to yield significant gains. And yes, any new amendment is better than the old one - wider BW, higher modulation, lower latency, etc. … then why not include also more efficient channel access? Thanks and Regards,
From: Matthew Fischer [mailto:00000959766b2ff5-dmarc-request@xxxxxxxxxxxxxxxxx]
Guogang, Here are some responses to your specific questions: 1. the proposal provides an optional behavior and the performance depends on the available unused bandwidth, so it is very scenario dependent,
but in any case, whenever it is used, it is taking advantage of BW that is otherwise unused, so it would be a net gain - whether that gain is worth the addition of the mechanism is an individualized tradeoff decision to be made by implementers, but we view
the extra effort for implementation as not far from what is already being done on other channels, and again, if you do not accept the tradeoff, you can opt out by not implementing the option 2. provided that the access rules incorporate some random access, it should be within regulations 3. STA that are members of the BSS and that do not support the transmission or reception on secondary channels should not be affected if
they are sharing the primary channel, as those devices would be shut out of access anyway - i.e. the secondary channel access only occurs when the primary is busy and some secondary channels are available - any STA that is legacy and therefore does not participate
in the secondary channel access will be completely unaffected because they are waiting for the end of the busy condition on the primary channel STAs that are OBSS and that do not support the transmission or reception on secondary channels that are not sharing the primary channel
might see more competitive pressure, but this is not much different than what they already experience from full BW transmissions from the same in-BSS - i.e. this proposal simply means that more of the transmissions from my competing BSS will become full BW,
but my BSS has the right to access the full BW already - this mechanism simply increases the number of TXOPs for which I exercise my full BW rights Matthew Fischer Nice Guy Broadcom Inc. +1 408 543 3370 office On Wed, Sep 16, 2020 at 7:58 AM huangguogang <huangguogang1@xxxxxxxxxx> wrote:
To unsubscribe from the STDS-802-11-TGBE list, click the following link:
https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1
To unsubscribe from the STDS-802-11-TGBE list, click the following link:
https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1
To unsubscribe from the STDS-802-11-TGBE list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGBE&A=1 |