802.11 PPDU Formats

802.11 PPDU Formats

By CWNP On 08/24/2007 - 9 Comments

There are three overall PPDU structures possible in an 802.11n network, one of which was previously defined by Clause 17.

 

— Non-HT format: frames of this format are structured according to the Clause 17 (OFDM) or 19 (ERP) specification.  Support for Non-HT Format is mandatory.

— HT mixed format: frames of this format contain a preamble compatible with the non-HT receivers.  The non-HT Short Training Field (L-STF), the non-HT Long Training Field (L-LTF) and the non-HT SIGNAL field are defined so they can be decoded by non-HT Clause 17 and 19 stations.  The rest of the frame cannot be decoded by Clause 17 or Clause 19 stations.  Support for HT mixed format is mandatory.

— HT greenfield format: HT frames of this format do not contain a non-HT compatible part.  Support for HT greenfield format is optional. An HT station that does not support the reception of an HT greenfield format frame must be able to detect that an HT greenfield format frame is an HT transmission (as opposed to a non-HT transmission).  In this case the receiver must decode the HT-SIG and determine if the HT-SIG cyclic redundancy check (CRC) passes.



Two NEW preamble formats are defined by 802.11n:

For HT mixed format operation (HT Mixed Mode preamble), the preamble has a non-HT portion and an HT portion.  The non-HT portion of the HT mixed format preamble enables detection of the PPDU and acquisition of carrier frequency and timing by both HT stations and stations that are compliant with Clause 17 and/or Clause 19.  The non-HT portion of the HT mixed format preamble also consists of the SIGNAL field defined in Clause 17 and is thus decodable by STAs compliant with Clause 17 and Clause 19, as well as HT stations.  The HT portion of the HT mixed format preamble enables estimation of the MIMO channel to support demodulation of the HT data by HT stations.  The HT portion of the HT mixed format preamble also consists of the HT-SIG field that supports HT operation, and the SERVICE field.  

For greenfield operation (HT Greenfield Mode preamble), compatibility with Clause 17 and Clause 19 STAs is not required.  Therefore, the non-HT portions of the preamble are not included in the greenfield format preamble.

9 Responses to 802.11 PPDU Formats

Subscribe by Email
neha gupta Says:
04/27/2018 at 04:25am
I wish more writers of this sort of substance would take the time you did to examine and compose so well. I am exceptionally inspired by your vision and knowledge.
Ludhiana call girls

neha gupta Says:
04/27/2018 at 04:13am
I extremely like your point you have composed incredibly. A debt of gratitude is in order for offering your data to everybody and keep posting.

Escorts in Chandigarh

neha gupta Says:
04/27/2018 at 04:00am
Its really phenomenal subject and you're making so awesome and you can give the honest to goodness portrayal about this point.
Chandigarh call girls

neha gupta Says:
04/26/2018 at 06:26am
Superior to anything normal post. I regard the tips. My course of action routine is shockingly like yours, neglecting the way that I expect I'm strolling along impressively more a tiny bit at a time than you.
Call Girls in Jaipur
Call Girls in Jaipur
Call Girls in Jaipur
Call Girls in Jaipur
Call Girls in Jaipur

neha gupta Says:
04/26/2018 at 06:03am
This post is amazingly stunning one! I was satisfied to take a gander at this, all that much key.
Call Girls in Goa
Call Girls in Goa
Call Girls in Goa
Call Girls in Goa
Call Girls in Goa

Kevinogi jhome Says:
04/18/2018 at 05:47am
Manfred said he didn't know that the Marlins' new owners planned to tear it washington nationals jersers down
In the early moments of atlanta braves jersers the interview, Le Batard asked Manfred whether he knew prior to the recent sale to the group oakland athletics jersers fronted by Bruce Sherman and Jeter whether the new owners planned to slash payroll. After some prodding (and Le Batard's saying that the commissioner was lying), Manfred answered, "We do not get involved in operating-level decisions in the ownership approval process."

"We did not have player-specific plans from the Miami Marlins or any other team that has been in the ownership miami marlins jersers process. Those are decisions that the individual owners make, and they do not have to be cleared by us or approved by us. ... Those are local decisions that really are not part of the approval process. Those are decisions that the individual owners make, and they do not have to be cleared with us or approved by us."

Manfred went on to say that he didn't receive a payroll plan from the Marlins until two days prior to his interview with Le Batard. More: "We don't get into, are you going to trade 'Player X' or 'Player Y' at a particular point in time, nor do we ask them to make a commitment to people before they even got in and made an evaluation of their talent level, their ability to win with the people that st. louis cardinals jersers they have. That's just not how the ownership process works."
wholesale baseball jersers

But some of that may not be true
Here's a key excerpt from a los angeles angels of anaheim jersers must-read Barry Jackson piece in the Miami Herald:

A source directly involved in the Marlins sales chicago white sox jersers process, after hearing the Le Batard cincinnati reds jersers interview, said, via text: "Commissioner said was not aware of [Jeter] plan to slash payroll. Absolutely not true. They request and receive the operating plan from all bidders.

"Project Wolverine [the name for Jeter's plan] called chicago white sox jersers on his group to reduce payroll to $85 million. This was vetted and approved by MLB prior to approval by MLB. Every [Jeter] investor and non investor has the Wolverine financial plan of slashing payroll to $85 million. Widely circulated."

First off, "Project Wolverine" is ludicrously self-important and sinister-sounding, as budget strategies go. That's the name of a secret NSA laboratory deep under the Caballo Mountains in New Mexico, not a financial schematic. Do better, Jeets. Anyhow, there's enough careful phrasing in Manfred's comments ("operating-level decisions," "'Player X' or 'Player Y'") to give him some plausible deniability. However, the idea that he didn't know about plans to engage in yet another demo job by Marlins owners strains credulity.

wiatmppgryar wiatmppgryar Says:
04/18/2018 at 03:43am
Computer chip Williams offers profitable residence work

Philadelphia Eagles Jerseys PHILADELPHIA -- The particular personal computer claims can be a infamous first-pitch swinger. Therefore it is not surprising in which Reds reliever used your pet any first-pitch splitting basketball inside the 9th inning Friday night time with Residents Lender Playground. Torrey Jones Jerseys Quackenbush needed Williams to be able to pursue, with the exception of now Williams failed to. Tommy McDonald Jerseys This individual as an alternative worked well themselves in to a 3-1 rely, just before this individual killed any fastball to be able to right-center-field to get a pinch-hit by yourself residence work in the 6-5 success.

Philadelphia Eagles It absolutely was the initial pinch-hit homer regarding Williams' job. Phillies better found his / her initial help save with the time of year using a scoreless ninth. Timmy Jernigan Jerseys Reds catcher struck his / her initial residence work with the time of year inside the next inning, tying the sport with 3. This individual has been powering the particular menu for your initial start of the time of year regarding southpaw, which authorized several works (a few attained) inside his / her a few innings regarding perform.   The particular Reds bullpen worked well several scoreless innings just before Quackenbush gave your home cost Williams. Terrence Brooks Jerseys OCCASIONS IN WHICH MATTEREDHoskins, Kingery hitter Reed: Phillies still left fielder struck any two-out, two-run residence cost still left industry inside the initial inning in opposition to Reed handy the particular Phillies any 2-1 direct. Stephen Tulloch Jerseys Newbie implemented using a by yourself residence cost still left inside the next, his / her initial Key Little league residence work, to produce that 3-1.

NFL Jerseys Kingery struck any 1-0 fastball slightly lower than 15 ins (1. twenty-two toes) over soil. Simply no Phillies person acquired struck any basketball reduced over soil given that struck a single lower than 9 ins (0. 73 toes) from your soil previous September. Ervin results, Hamilton will not: started out the particular sixth inning using a individual to be able to still left industry. Then he borrowed next that will put themselves inside credit scoring place. Stefen Wisniewski Jerseys Phillies catcher in fact used any explode to be able to next foundation -- clocked the particular chuck with 90. 0 mph -- yet Kingery have got to the particular carrier overdue and also acquired simply no possiblity to draw your pet. Sidney Jones Jerseys That proven expensive since Ervin afterwards have scored over a two-out chopper away from Phillies pitcher is the reason hands to be able to link the sport, 5-5. Alfaro appreciated several redemption overdue inside the inning any time Hamilton experimented with to be able to report coming from next over a outrageous toss. Stefen Wisniewski Jerseys Alfaro slid to be able to obtain the particular basketball powering the particular menu and also used any affect to be able to, which used on the particular basketball since Hamilton collided together with your pet for your next out there.

Kr Ashwin Says:
01/11/2018 at 05:08am
Every time you need to log in to see Bing Browser History and delete them.So guys if you are a Windows 10 operating system user then don't take tension,no one can see your search history.Follow this how to clear bing search history and able to know more from this station.Thank you.

Says:
08/24/2007 at 14:08pm
Although it seems unlikely that Greenfield (GF) packets would be used in a WLAN today because of the proliferation of legacy (abg) devices, some implementations will 'protect' the GF transmission with a CTS-2-Self or RTS-CTS.

<< prev - comments page 1 of 1 - next >>

Leave a Reply

Please login or sign-up to add your comment.
Success Stories

I literally just came out of the testing centre having taken the CWDP exam. The certification process opened my mind to different techniques and solutions. This knowledge can only broaden your perspective. Great job, CWNP, you have a great thing going on here.

-Darren
Read More

Working through the CWNP coursework and certifications helped not only to deepen my technical knowledge and understanding, but also it boosted my confidence. The hard work it took to earn my CWNE has been rewarding in so many ways.

-Ben
Read More

I want to commend you and all at CWNP for having a great organization. You really 'raise the bar' on knowing Wi-Fi well. I have learned a ton of information that is helping my job experience and personal career goals, because of my CWAP/CWDP/CWSP studies. Kudos to all at CWNP.

-Glenn
Read More