WLAN Data Link Layer

Cov ntaub ntawv txuas txheej ntawm WLAN yog siv los ua cov txheej txheem tseem ceeb rau kev xa cov ntaub ntawv.Txhawm rau nkag siab WLAN, koj kuj yuav tsum paub meej.Los ntawm cov lus piav qhia hauv qab no:
Hauv cov txheej txheem ntawm IEEE 802.11, nws MAC sublayer muaj cov txheej txheem nkag mus rau kev tshaj tawm ntawm DCF thiab PCF:
Lub ntsiab lus ntawm DCF: Distributed Coordination Function
Thaum DCF yog tus txheej txheem nkag yooj yim ntawm IEEE 802.11 MAC, uas siv CSMA / CA thev naus laus zis thiab koom nrog txoj kev sib tw, thaum lub node xa cov ntaub ntawv, nws yuav saib xyuas cov channel.Tsuas yog thaum lub channel tsis ua haujlwm nws tuaj yeem xa cov ntaub ntawv.Thaum cov channel tsis ua haujlwm, cov node yuav tos rau lub sijhawm teem sijhawm ntawm DIFS.
Yog hais tias kev sib kis ntawm lwm cov nodes tsis hnov ​​​​ua ntej kawg ntawm DIFS, lub sij hawm rov qab random yog xam, uas yog sib npaug rau teem lub sij hawm backoff timer;
Cov node pom cov channel txhua zaus nws ntsib lub sijhawm: yog tias nws pom tias cov channel tsis ua haujlwm, lub sijhawm rov qab mus txuas ntxiv mus;txwv tsis pub, lub sij hawm ntxiv ntawm lub sij hawm rov qab yog khov, thiab cov node tos dua rau cov channel kom tsis ua haujlwm;tom qab lub sij hawm DIFS dhau mus, cov node tseem suav los ntawm lub sijhawm ntxiv;Yog hais tias lub sij hawm ntawm backoff timer txo mus rau xoom, tag nrho cov ntaub ntawv yuav raug xa mus.Qhov no yog cov txheej txheem rectification ntawm cov ntaub ntawv xa mus.
PCF: Point Coordination Function;
PCF muab ib tus neeg saib xyuas cov ntsiab lus los ntsuam xyuas txhua qhov chaw xa lossis tau txais cov ntaub ntawv.Qhov no yog ib txoj kev tsis sib tw, yog li kev sib tsoo ncej yuav tsis tshwm sim, tab sis nws tsuas yog siv tau hauv wireless hauv cheeb tsam hauv cheeb tsam nrog qee qhov kev tsim kho.
Cov saum toj no yog cov kev taw qhia ntawm WLAN Data Link Layer coj los ntawm Shenzhen Haidiwei Optoelectronics Technology Co., Ltd. Shenzhen HDV Phoelectron Technology Co., Ltd. yog cov chaw tsim khoom tshwj xeeb hauv cov khoom siv kho qhov muag, thiab nws cov kev sib txuas luscov khoom.