Wi-Fi Overhead, Part 1: Sources of Overhead

Wi-Fi Overhead, Part 1: Sources of Overhead

By CWNP On 04/27/2011 - 26 Comments

Radio communication requires overhead. Network protocols require overhead. Unfortunately, wireless network protocols, like Wi-Fi, are loaded with overhead. Some amount of overhead is necessary for effective communications and interoperability; however, there are also times when overhead is unnecessary. Proper network design and deployment can minimize this overhead and improve network performance. This article kicks off a two-part post that will identify the sources of overhead (part 1) on WLANs and then provide some recommendations for reducing it (part 2).

Interference — In a very generic sense, all sources of interference (non-802.11 and 802.11) create overhead. 802.11 devices must perform a clear channel assessment (CCA) to determine whether the wireless medium is busy or idle. Whenever the medium is busy, Wi-Fi stations twiddle their thumbs and wait. Non-802.11 sources of RF (above a certain threshold) can be thought of as a source of overhead.

Interframe Spaces — Before every Wi-Fi transmission, there is an idle period on the medium. This idle period is called an interframe space (IFS). There are multiple different interframe space lengths; the purpose of an IFS is to regulate conversation flow and provide priority for certain types of transmissions.
Random Backoff —When 802.11 devices are contending for access to the wireless medium, they use a backoff algorithm that randomizes access to the medium. This process ultimately reduces collisions and is one way to achieve QoS prioritization. The random backoff time represents a number of “slots” (or, periods of time) that the wireless medium must be idle.

PHY Signaling — Radio communication peers must perform some type of synchronization for reliable reception of frames. The PHY Preamble is a series of bits used to perform this function. The PLCP Header follows the preamble and communicates the attributes of the following frame to the receiver so that the receiver knows how to process the data. In other words, the preamble and PLCP header are collectively the same as if a person were to say: “OK, I’m getting ready to say something. It’s going to take me 20 seconds to say it and I’m going to say it pretty quickly, so listen up. Here goes.”

MAC Header -- A complex protocol like Wi-Fi requires that stations can coordinate their operation. The MAC header is used to coordinate supported (or unsupported) features and functions. It is necessary, but it is still overhead. In data frames, the MAC header is so small (and usually transmitted at a high data rate) that it barely qualifies as overhead. In other frames, such as 802.11n beacons, the “overhead” designation is much more applicable.

Guard Intervals — Between each 802.11 symbol, there must be a quiet period, called a guard interval, on the medium to allow previous symbols to “settle.” Without this quiet period, a symbol may interfere with the previous symbol (inter-symbol interference). The normal guard interval setting for Wi-Fi is 800 ns.

Acknowledgements — Since wireless communication is inherently unreliable and lossy, many frame types require acknowledgement. Acks are overhead in and of themselves, and they also require an additional interframe space (i.e. SIFS).

Fragmentation (and small payloads) — While frames with small payloads are not an actual source of overhead, they are often an inefficient use of the medium, making the overhead problem more apparent. A similar problem exists when organizations enable frame fragmentation to attempt to reduce collisions (smaller frames are less likely to experience interference) in a noisy environment. Fragmentation is not used often in today’s networks because it rarely produces a benefit. Instead, it usually adds overhead.

Protection Mechanisms — Incompatible PHY formats (such as 802.11b and 802.11g) require protection for proper coexistence. Protection is usually achieved via an RTS/CTS exchange or a CTS-to-Self frame prior to the transmission of data. There are other types of protection (for 802.11n) that may be used as well. In addition to using these frame exchanges for protection, there are other times (such as when there are hidden nodes) when they may be enabled to attempt to improve overall network health.

Retransmissions — When a transmitted frame is not received properly by the intended recipient (or not acknowledged), a retransmission may be required. Transmitting a frame more than once is an obvious, and significant, source of overhead. When the frame is queued for retransmission, other sources of overhead (such as random backoff, IFS, etc.) are duplicated as well. Retransmissions represent one of the most problematic sources of overhead on our networks because they are one type of overhead that we can influence (with proper design).

Shall we go on? — If we wanted to extend the article, we could also break down the upper layers of the protocol stack as well, looking at the overhead inherent in each protocol. However, from the perspective of Wi-Fi (a Layer 1 and 2 protocol), the Layer 3-7 data is considered to be the payload. Complete reductionists might say that the application data is the only real payload that is not “overhead,” and I’d tend to agree. Since we’re focused only on Wi-Fi here, I won’t take it to that extreme.

Final Comments and Suggestions (FCS)
The Wi-Fi protocol is bloated with overhead. I don’t fault the engineers who designed the protocol for that. Any radio communication protocol will require some overhead. Broad WLAN adoption and use cases have made the 802.11 protocols very successful, but that success requires a lot of engineering complexity. Complexity requires coordination, and that coordination usually shows up as overhead. Network engineers should understand the sources of overhead on their networks and, within the limitations of their use case, seek to reduce overhead when possible.

A follow-up article will address the common network planning, design, and configuration strategies that will reduce unnecessary overhead.

Tagged with: Wi-Fi, half-duplex, overhead, contention, PHY rates, signaling rates, protection mechanisms, retransmissions, fragmentation, interframe spaces, random backoff

26 Responses to Wi-Fi Overhead, Part 1: Sources of Overhead

Subscribe by Email
karin johan Says:
06/09/2018 at 13:54pm
You really make it seem so easy with your presentation but I find this matter
to be really something which I think I would never understand.
It seems too complex and extremely broad for me.
I am looking forward for your next post, I’ll try to get the hang of it!
www.foodsolo.ga |

www.foodspree.ga |

www.foodcustom.ga |

www.foodebony.ga |

www.foodcanal.ga |

www.foodessence.ga |

www.foodcrown.ga |

www.foodavatar.ga |

www.foodpearl.ga |

www.foodiron.ga |

www.foodcrystal.ga |

www.foodbrowse.ga |

www.foodadaptive.ga |

www.foodloco.ga |

www.foodsignature.ga |

www.foodmatche.ga |

www.foodkayak.ga |

www.foodarrow.ga |

www.foodlucky.ga |

www.foodcrafter.ga |

www.foodcreativity.ga |

www.foodsurprise.ga |

www.foodthunder.ga |

www.foodoriginal.ga |

www.foodbuller.ga |

www.foodsedona.ga |

www.foodlimited.ga |

www.foodcheapest.ga |

www.foodbad.ga |

www.foodcheaper.ga |

www.foodlast.ga |

www.foodvariety.ga |

www.foodoffline.ga |

www.foodsuperhero.ga |

www.foodsunflower.ga |

www.foodnormal.ga |

www.foodjoker.ga |

www.foodbounce.ga |

www.foodsleuth.ga |

www.foodplatinum.ga |

www.foodcupcake.ga |

www.foodagenda.ga |

www.foodcommission.ga |

www.foodmillions.ga |

www.foodsilk.ga |

www.foodoneday.ga |

www.foodomega.ga |

www.foodrhino.ga |

www.foodgoddess.ga |

www.foodnature.ga |

www.foodsoldier.ga |

www.foodglamour.ga |

www.foodguerrilla.ga |

www.foodelectra.ga |

www.foodurban.ga |

www.foodglory.ga |

www.foodrapid.ga |

www.foodescrow.ga |

www.foodcamel.ga |

www.foodshuffle.ga |

www.foodprecision.ga |

www.foodflavor.ga |

www.foodverde.ga |

www.foodintergrity.ga |

www.foodgratis.ga |

www.foodepic.ga |

www.foodanchor.ga |

www.foodhandy.ga |

www.foodscribe.ga |

www.foodsouthbeach.ga |

www.foodouter.ga |

www.foodsustain.ga |

www.foodmeasure.ga |

www.foodClearance.ga |

www.foodNobel.ga |

www.foodEastside.ga |

www.foodhotrod.ga |

www.foodcorporation.ga |

www.foodfeature.ga |

www.foodcellar.ga |

www.foodplum.ga |

www.fooddivine.ga |

www.foodpronto.ga |

www.foodcarnival.ga |

www.foodeastbay.ga |

www.fooddodge.ga |

www.foodguerilla.ga |

www.foodwaterfront.ga |

www.foodgecko.ga |

www.foodyankee.ga |

www.foodprestige.ga |

www.foodrazor.ga |

www.foodatlantic.ga |

www.foodlowprice.ga |

www.foodhusky.ga |

www.foodnations.ga |

www.foodremarkable.ga |

www.foodnorthamerican.ga |

www.foodquantum.ga |

www.foodpeach.ga |

www.foodcourier.ga |

www.foodpresident.ga |

www.foodconstruct.ga |

www.foodsparkle.ga |

www.foodrainforest.ga |

www.foodfalcon.ga |

www.foodlightning.ga |

www.foodblod.ga |

www.fooddowntown.ga |

www.foodcurious.ga |

www.foodauthority.ga |

www.foodraven.ga |

www.foodafter.ga |

www.foodsalvage.ga |

www.foodpriority.ga |

www.foodovernight.ga |

www.foodmystical.ga |

www.foodpermanent.ga |

www.foodcaptive.ga |

www.foodamazing.ga |

www.foodtopsecret.ga |

www.foodabundant.ga |

www.fooddesigning.ga |

www.foodblender.ga |

www.foodimagine.ga |

www.foodsnapshot.ga |

www.foodhandsome.ga |

www.foodjust.ga |

www.foodlittle.ga |

www.foodsurreal.ga |

www.petcolor.ga |

www.petless.ga |

www.petbody.ga |

www.petdragon.ga |

www.petroll.ga |

www.petbrowser.ga |

www.petdir.ga |

www.petpipe.ga |

www.petcharts.ga |

www.petmarks.ga |

www.petwish.ga |

www.petflower.ga |

www.petdollar.ga |

www.petnight.ga |

www.petlion.ga |

www.petcaster.ga |

www.petpart.ga |

www.petgeo.ga |

www.petdollars.ga |

www.petopplis.ga |

www.petstick.ga |

www.petunder.ga |

www.petrates.ga |

www.petsonic.ga |

www.petflag.ga |

www.petclient.ga |

www.petover.ga |

www.petgrow.ga |

www.petcache.ga |

www.petfolder.ga |

www.petgun.ga |

www.petrex.ga |

www.petworth.ga |

www.petduck.ga |

www.petomatic.ga |

www.petblaster.ga |

www.petgang.ga |

www.petsplash.ga |

www.petmessenger.ga |

www.petvisual.ga |

www.petbattle.ga |

www.petchase.ga |

www.petfeedback.ga |

www.petkiss.ga |

www.petstamp.ga |

www.petgrab.ga |

www.petorama.ga |

www.petwinner.ga |

www.petmember.ga |

www.petdish.ga |

www.petrequest.ga |

www.petecho.ga |

www.petcollections.ga |

www.petcollector.ga |

www.petecono.ga |

www.petcalculator.ga |

www.petpure.ga |

www.petother.ga |

www.petminer.ga |

www.petexcel.ga |

www.petreps.ga |

www.petcircus.ga |

www.petmain.ga |

www.pethands.ga |

www.pettreasure.ga |

www.petnumber.ga |

www.petcharte.ga |

www.petcatch.ga |

www.petrail.ga |

www.petstreaming.ga |

www.petrally.ga |

www.peteagle.ga |

www.petcrawler.ga |

www.petfleet.ga |

www.petmetric.ga |

www.petnatural.ga |

www.petcounty.ga |

www.pethard.ga |

www.petopedia.ga |

www.petfame.ga |

www.petknight.ga |

www.petredhot.ga |

www.petclassy.ga |

www.petdraw.ga |

www.petslide.ga |

www.petcompanion.ga |

www.petbunny.ga |

www.petspicy.ga |

www.petvector.ga |

www.petbrite.ga |

www.petpride.ga |

www.petcollect.ga |

www.petsweet.ga |

www.petsearcher.ga |

www.petenvy.ga |

www.petpeace.ga |

www.petstrick.ga |

www.petlegacy.ga |

www.petrater.ga |

www.petcatcher.ga |

www.petcharm.ga |

www.petappeal.ga |

www.petsprint.ga |

www.petrunners.ga |

www.petshoot.ga |

www.pettreat.ga |

www.petnano.ga |

www.petsession.ga |

www.petturbo.ga |

www.petsample.ga |

www.petshadow.ga |

www.petphase.ga |

www.petfiesta.ga |

www.petseason.ga |

www.petpositive.ga |

www.petultra.ga |

www.petjackpot.ga |

www.petboulevard.ga |

www.petocity.ga |

www.petnational.ga |

www.petgrabber.ga |

www.petgorilla.ga |

www.petrule.ga |

www.petmuscle.ga |

www.petlastminute.ga |

www.petdestination.ga |

www.petdelta.ga |

www.petmeta.ga |

www.petpersonal.ga |

www.petjewel.ga |

www.petpremier.ga |

www.petpirates.ga |

www.petreadset.ga |

www.petgrace.ga |

www.petcrunch.ga |

www.petshake.ga |

www.petbeast.ga |

www.petvictory.ga |

www.petsolo.ga |

www.petunique.ga |

www.petspree.ga |

www.petcustom.ga |

www.petebony.ga |

www.petcanal.ga |

www.petpicker.ga |

www.petcrown.ga |

www.petavatar.ga |

www.petpearl.ga |

www.petiron.ga |

www.petcrystal.ga |

www.petbrowse.ga |

www.petadaptive.ga |

www.petloco.ga |

www.petsignature.ga |

www.petmatche.ga |

www.petkayak.ga |

www.petarrow.ga |

www.petlucky.ga |

www.petcrafter.ga |

www.petcreativity.ga |

www.petsurprise.ga |

www.petoriginal.ga |

www.petbuller.ga |

www.petsedona.ga |

www.petlimited.ga |

www.petcheapest.ga |

www.petbad.ga |

www.petcheaper.ga |

www.petlast.ga |

www.petvariety.ga |

www.petoffline.ga |

www.petsuperhero.ga |

www.petsunflower.ga |

www.petnormal.ga |

www.petjoker.ga |

www.petbounce.ga |

www.petsleuth.ga |

www.petplatinum.ga |

www.petcupcake.ga |

www.petagenda.ga |

www.petcommission.ga |

www.petmillions.ga |

www.petsilk.ga |

www.petoneday.ga |

www.petomega.ga |

www.petrhino.ga |

www.petgoddess.ga |

www.petnature.ga |

www.petpickup.ga |

www.petsoldier.ga |

www.petglamour.ga |

www.petguerrilla.ga |

www.petelectra.ga |

www.peturban.ga |

www.petglory.ga |

www.petrapid.ga |

www.petescrow.ga |

www.petcamel.ga |

www.petshuffle.ga |

www.petprecision.ga |

www.petflavor.ga |

www.petverde.ga |

www.petintergrity.ga |

www.petgratis.ga |

www.petepic.ga |

www.petanchor.ga |

www.pethandy.ga |

www.petscribe.ga |

www.petsouthbeach.ga |

www.petouter.ga |

www.petsustain.ga |

www.petmeasure.ga |

www.petClearance.ga |

www.petNobel.ga |

www.petEastside.ga |

www.pethotrod.ga |

www.petcorporation.ga |

www.petfeature.ga |

www.petcellar.ga |

www.petplum.ga |

www.petdivine.ga |

www.petpronto.ga |

www.petcarnival.ga |

www.peteastbay.ga |

www.petdodge.ga |

www.petguerilla.ga |

www.petwaterfront.ga |

www.petyankee.ga |

www.petprestige.ga |

www.petrazor.ga |

www.petatlantic.ga |

www.petlowprice.ga |

www.pethusky.ga |

www.petnations.ga |

www.petremarkable.ga |

www.petfighter.ga |

www.petnorthamerican.ga |

www.petquantum.ga |

www.petpeach.ga |

www.petcourier.ga |

www.petpresident.ga |

www.petconstruct.ga |

www.petsparkle.ga |

www.petrainforest.ga |

www.petfalcon.ga |

www.petlightning.ga |

www.petblod.ga |

www.petdowntown.ga |

www.petcurious.ga |

www.petauthority.ga |

www.petraven.ga |

www.petafter.ga |

www.petsalvage.ga |

www.petpriority.ga |

www.petovernight.ga |

www.petmystical.ga |

www.petpermanent.ga |

www.petcaptive.ga |

www.petamazing.ga |

www.pettopsecret.ga |

www.petabundant.ga |

www.petdesigning.ga |

www.petblender.ga |

www.petimagine.ga |

www.petsnapshot.ga |

www.pethandsome.ga |

www.petlittle.ga |

www.petsurreal.ga |

www.legalcolor.ga |

www.legalless.ga |

www.legalback.ga |

www.legalbody.ga |

www.legaldragon.ga |

www.legalroll.ga |

www.legalbrowser.ga |

www.legaldir.ga |

www.legalpipe.ga |

www.legalsend.ga |

www.legalcharts.ga |

www.legalmarks.ga |

www.legalwish.ga |

www.legalflower.ga |

www.legaldollar.ga |

www.legalnight.ga |

www.legallion.ga |

www.legalpart.ga |

www.legalgeo.ga |

www.legalpremium.ga |

www.legaldollars.ga |

www.legalopplis.ga |

www.legalunder.ga |

www.legalrates.ga |

www.legalletter.ga |

www.legalsonic.ga |

www.legalflag.ga |

www.legalwidget.ga |

www.legalclient.ga |

www.legalover.ga |

www.legalpatch.ga |

www.legalbuddies.ga |

www.legalcache.ga |

www.legalfolder.ga |

www.legalgroove.ga |

www.legalgun.ga |

www.legalrex.ga |

www.legalworth.ga |

www.legalduck.ga |

www.legalomatic.ga |

www.legalblaster.ga |

www.legalformula.ga |

www.legalgang.ga |

www.legalsplash.ga |

www.legalmessenger.ga |

www.legalvisual.ga |

www.legalscapes.ga |

www.legalbattle.ga |

www.legalchase.ga |

www.legalfeedback.ga |

www.legalkiss.ga |

www.legalstamp.ga |

www.legalgrab.ga |

www.legalorama.ga |

www.legalwinner.ga |

www.legalmember.ga |

www.legaldish.ga |

www.legalrequest.ga |

www.legalecho.ga |

www.legalcollections.ga |

www.legalcollector.ga |

www.legalecono.ga |

www.legalcalculator.ga |

www.legalpure.ga |

www.legalother.ga |

www.legalrings.ga |

www.legalexcel.ga |

www.legalreps.ga |

www.legalcircus.ga |

www.legalmain.ga |

www.legaltreasure.ga |

www.legalnumber.ga |

www.legalcharte.ga |

www.legalsugar.ga |

www.legalcatch.ga |

www.legalrail.ga |

www.legalstreaming.ga |

www.legalrally.ga |

www.legalcrawler.ga |

www.legalpassport.ga |

www.legalfleet.ga |

www.legalnatural.ga |

www.legalcounty.ga |

www.legalhard.ga |

www.legalopedia.ga |

www.legalfame.ga |

www.legalknight.ga |

www.legalredhot.ga |

www.legalclassy.ga |

www.legaldraw.ga |

www.legalslide.ga |

www.legalbunny.ga |

www.legalspicy.ga |

www.legalvector.ga |

www.legalbrite.ga |

www.legalpride.ga |

www.legalcollect.ga |

www.legalsweet.ga |

www.legalsearcher.ga |

www.legalenvy.ga |

www.legalpeace.ga |

www.legalstrick.ga |

muneer ahmed Says:
05/31/2018 at 04:57am
I think this is one of the most significant information for me. And i’m glad reading your article. But should remark on some general things, Iq option

Jack kevin Says:
05/09/2018 at 07:20am
The figuring incorporates the between outline dividing (utilizing WMM), physical layer prelude and header, MAC layer header, and information payload. It computes the measure of time required for Do My Essay balance of the bits over the air, however does not represent impacts or retransmissions.

Kevinogi jhome Says:
04/19/2018 at 21:12pm
I blame Cheap NFL Football Jerseys the cold weather. And testosterone. soccer jerseys And the time-honored baseball tradition that goes back to the days of Old Hoss Radbourn and King Kelly: an eye for an eye, blood will have blood. We had three flare-ups from nfl jerseys Wednesday's action, two in the Yankees-Red Sox tilt at Fenway and one at Coors Field, when Nolan Arenado charged the mound against the Padres with anger boiling in his veins. Worth noting: Both were intra-division episodes, which perhaps fueled the fires and custom nfl jerseys also means it might not be the last time we see these teams going at each other. Keep the Yankees in the Yard Can you nfl jerseys strike out the Yankees? It's your turn to pitch to Judge, Stanton and Sanchez. Play the game ? Let's start at Fenway, where the benches first emptied when Tyler Austin slid into second base and caught the back leg of Brock Holt with his spikes. Austin slid into the bag but sort of flipped his leg out as Holt stretched for the throw from third baseman Rafael Devers. The slide was in the gray area of being a slightly nba jerseys dirty play, especially considering Holt wasn't denver broncos jerseys trying to turn a double play. On the other hand, Cheap Jerseys Outlet if you see the replay from the left-field camera, Holt didn't stretch for carolina panthers jerseys the ball until Austin had started his slide. Holt also nhl jerseys should have done a better job of getting out of the way. But again, the spikes were up. That mlb jerseys led to an exchange of words and a more or less conventional emptying of the benches and bullpens, with phone numbers exchanged and dinner dates planned. Aaron Judge had a big grin on his face, although Austin seemed a bit too riled up for his own good and had to be restrained. Move ahead to the seventh inning. Joe Kelly throws high and tight and plunks Austin, who slams his bat down ncaa jerseys in disgust, and it's nike nfl jerseys on. I mean, it wasn't a 1970s or '80s brawl, but there was some pushing and shoving going on and Austin threw at least one punch that landed on Red Sox coach Carlos Febles. Kelly and Austin were ejected, and, really, it could have been much worse.


alice long Says:
02/06/2018 at 00:31am
QuickBooks +1 888 336 0774 the quintessential success story in the Silicon Valley software industry with a remarkable contribution in giving a makeover to old and worn QuickBooks Customer Service Numberout face of the 19th-century accountancy, has bestowed the with reducing the time-consuming paper-based and manual worksheets preparation job and making it a user-friendly digital phenomenon. Not too surprisingly, Intuit's or for that matter any Silicon Valley juggernaut's success QuickBooks Customer Service Phone Numberowes its growth to a rapid breakthrough in the Information technology.

alice long Says:
02/06/2018 at 00:25am
Quicken+1 888 336 0774 the quintessential success story in the Silicon Valley software industry with a remarkable contribution in giving a makeover to old and worn Quicken Customer Service Numberout face of the 19th-century accountancy, has bestowed the with reducing the time-consuming paper-based and manual worksheets preparation job and making it a user-friendly digital phenomenon. Not too surprisingly, Intuit's or for that matter any Silicon Valley juggernaut's success Quicken Customer Service Phone Numberowes its growth to a rapid breakthrough in the Information technology.

alice long Says:
02/06/2018 at 00:14am
Sage+1 888 336 0774 dawn of the internet and the spectacular advancements in the computer hardware paraphernalia like printers, fax during the era of baby boomers had marked the usher in of a new era for digital accounting. Intuit's astute Sage Technical Support Phone Numbercreators leveraged on the same and created what is today a $ 4.19 billion tech giant

Lucy Gray Says:
02/05/2018 at 00:44am
Sage Technical Support Phone Number takes a lion's offer in the bookkeeping programming promotes. The item is uniquely crafted for the new organizations, little and med estimated associations to manage accounting endeavors and joins business with extremely flexible course of action.Sage Customer Support Phone Number item is joined with grouping of utilitarian features to manage things, handle orders, customers, records and operations and gives vision on the most capable technique to abbreviate cost and administer improvement wants for the business.

Lucy Gray Says:
02/05/2018 at 00:34am
Whatever you require the Quicken Technical Support Number contact for, the telephone number on +1-844-454-7202 is the most ideal approach to begin. You may need to get hold of the Quicken Support on the web or be searching for opening hours for your nearby Quicken Customer Support Number Team. Calling +1-844-454-7202 will give you access to the Quicken client administrations group who are there to help you with any issue.

Lucy Gray Says:
02/05/2018 at 00:27am
Approach Quickbooks Customer Service Phone Number. Intuit QuickBooks Pro Support Phone Number QuickBooks Pro has infiltrations and dynamic capacities. On QuickBooks Pro, clients can find everything in a solitary spot, including records from your bookkeeper or amazing. Quickbooks Customer Support Phone Number and gives give bolster all day, every day and to QuickBooks authorities. Individually It's workable for you to use to get paid online pay now connect in bills.

anjilo smith Says:
02/03/2018 at 06:32am
Sage 50 Support Number +1-888-307-3506
Client can resolve every specialized issue of SAGE 50, SAGE 50 Payroll programming, Sage Support Number
Sage Support Phone Number SAGE 50 basics, SAGE 50 accounts experts, SAGE 50c, both SAGE 50c Professional and standard release. Get selective help for SAGE 50 2018 from specialists additionally Older adaptation SAGE 50, 2017, 2016, 2015, 2014, 2013 and other are likewise upheld. Settled all mistakes comes amid introducing, refresh, overhaul, setup, Customer Invoice, Email setup, Windows 7, 8, 8.1 and Windows 10.

anjilo smith Says:
02/03/2018 at 06:22am
Quicken Tech Support Phone Number +1-888-307-3506
Stimulate Support : 1-888-307-3506 Toll Free Quicken Support : Help in settling a Quicken Technical Support Phone Number
Quicken Customer Support Number wide range of availability issues with ease. errors when programming neglects to perceive the right record to be updated .Help in re-interfacing with the information document. Support in settling a wide range of network issues.Help in introducing/setting-up/re-introducing the product.

anjilo smith Says:
02/03/2018 at 05:54am
QuickBooks Customer Service Phone Number +1-888-307-3506
A group of master specialists will be constantly there for you to enable you with the objective to give you on the spot to cause and support to settle your Quickbooks Tech Support Phone Number
Quickbooks Technical Support Number QB specialized issues in a split second. You can get bolster from our technical support group all day, every day with the assistance of QuickBooks Support Number.

Olivia Smith Says:
02/02/2018 at 06:43am
Antivirus Customer Service Phone Number is here to help. Call +1888-451-1608 Norton Antivirus Support Phone Number for all kind of technical and support queries. Avg Antivirus Technical Support Phone Number But most of you, like myself, are not familiar with some of these details in the beginning, Mcafee Antivirus Tech Support Phone Number especially when you are first getting to know your computer and the technical aspects of what it takes to keep it running clean and safe.

Olivia Smith Says:
02/02/2018 at 06:19am
Microsoft Outlook Customer Support is here to help. Call +1-888-451-1608 Microsoft Outlook Support Phone Number for all kind of technical and support queries.Launch Outlook, click on the File tab, click on Info, select Account Settings, and then again choose Account Settings from the drop down list. Outlook Technical Support Phone Number When the Account Settings window opens up, click on the E-mail tab, select New, click on Email Account, and then click on the Next button.

Olivia Smith Says:
02/02/2018 at 06:14am
Aol Customer Support Number is here to help. Call +1-888-451-1608 for Mail correction, reset, forget password, account disable and unable, send or receive mail.You already know how to pop in the CD and run the installer, so go ahead and do that. You may want to know that there are two directories for program files on your new computer. Aol Technical Support Number One is called "Program Files" and one is called, "Program Files (x86)". You may have guessed that the first one holds the newer programs and the other one holds the old 32 bit programs. This information may be useful later, when you need to know where things are.

milan joy Says:
01/22/2018 at 06:22am
It is true that some amount of overhead is necessary for effective communications. This article provides in detail regarding the overhead on WLAN and also share some recommendations on reducing it. I am expecting more similar article from you.louvre tours

sameer sharma Says:
12/28/2017 at 22:56pm
Yes you heard right that we can play jigsaw puzzles online free and it has wonderful collection.

Says:
05/03/2011 at 02:42am
Marcus
For a data packet of 1500 bytes 26 bytes is not much of overhead, but for a voip packet of 160 bytes + ip headers, or even much less if high compression codecs are used, that is quite a lot.

Says:
05/02/2011 at 14:42pm
Great read Marcus ! thanks!

Says:
05/02/2011 at 13:48pm
Mericson, you may have to elaborate. For data frames, the maximum header size is 36 bytes, but is usually only 26 (no HT control or 4th address) bytes. At a solid data rate, that's a relatively small amount of time (about 4 usec at 54 Mbps or 2 usec at 130 Mbps).

Says:
05/02/2011 at 08:05am
For Voice frames the MAC header overhead is very significant.
Especially since the use of aggregated frames does not make any sense for voice!

Howard Higgins Says:
04/29/2011 at 13:28pm
Looking forward to part 2 :-)

Says:
04/29/2011 at 12:04pm
Good article.
I wonder if you could possibly make one step further and descend into gory details of physical-level modulation. Definitely, when you need to transmit 100bytes of L2 data, you transmit significantly more information on physical level. On the other hand, there's a coding rate which could help reduce some of the overhead. And all that varies depending on which rate/MCS you are...
Wikipedia "Bit Rate" article mentions that gross bitrate for 802.11a 54mbps datarate is 72Mbps "inclusive of error-correcting codes". Now recall how many actual goodput you receive on 54mbps datarate even if you're the single user in the air (which again depends on average packet size/etc) :) With 802.11n enhancements like MIMO and Space Division Multiplexing the whole thing becomes even more complicated.
I believe there's neither a straight answer nor a complicated formula to account for all possible scenarios, but some real-world measurement examples (even with just sending pings of various sizes) would be really nice to show how things like fragmentation, number of simultaneous transmissions/users, short guard, etc affect goodput. Especially, if someone has access to a nice Veriwave complex to exclude air factor (and then compare to real-world scenarios). :) Maybe, some of these test results were already published somewhere already?

Kees Pronk Says:
04/27/2011 at 12:34pm
Great article, can't wait for part number 2, which I imagine, like the Star Wars saga will be even better than the first part ;-) I hope the subject of data rates / airtime is also covered...
best regards, RU

<< 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