Iprojekthi ye-OpenWifi ngokuphunyezwa kwetshiphu ye-Wi-Fi evulekileyo esekwe kwiFPGA kunye ne-SDR

Kwinkomfa yokugqibela yeFOSDEM ka-2020 thaca iprojekthi I-OpenWifi, ukuphuhlisa ukuphunyezwa kokuqala okuvulekileyo kwe-Wi-Fi 802.11a/g/n stack epheleleyo, imilo yesignali kunye nemodulation echazwe kwisofthiwe (SDR, Software Defined Radio). I-OpenWifi ikuvumela ukuba wenze ukuphunyezwa okulawulwa ngokupheleleyo kwawo onke amacandelo esixhobo esingenazingcingo, kubandakanywa iileya ezikumgangatho ophantsi, ezithi kwiiadaptha ezingenazingcingo eziqhelekileyo ziphunyezwe kwinqanaba leetshiphusi ezingenakuphicothwa. Ikhowudi amacandelo esoftware, kwakunye imizobo kunye neenkcazo iibhloko zehardware kulwimi lweVerilog yeFPGA zisasazwe phantsi kwelayisensi ye-AGPLv3.

Icandelo le-hardware yeprototype yokusebenza ebonakalisiweyo isekelwe kwi-Xilinx Zynq FPGA kunye ne-AD9361 i-universal transceiver (RF). I-OpenWifi isebenzisa i-architecture yeSoftMAC, ethetha ukuphunyezwa kwe-802.11 i-wireless stack (high-MAC) kwicala lomqhubi kunye nobukho be-low-MAC layer kwicala le-FPGA. Isitaki esingenazingcingo sisebenzisa inkqubo esezantsi ye-mac80211 enikezwe yiLinux kernel. Ukusebenzisana kunye ne-SDR kuqhutyelwa ngomqhubi okhethekileyo.

Izinto eziphambili:

• Inkxaso epheleleyo ye-802.11a/g kunye nenkxaso engaphelelanga ye-802.11n MCS 0~7 (PHY rx kuphela ngoku). Kukho izicwangciso zokuxhasa i-802.11ax;
• Ububanzi be-20MHz kunye noluhlu lwamaza ukusuka kwi-70 MHz ukuya kwi-6 GHz;
• Iindlela zokusebenza: I-Ad hoc (uthungelwano lwezixhobo zabaxumi), indawo yokufikelela, isikhululo kunye nokubeka iliso;
• Ukuphunyezwa kwe-link layer protocol kwicala le-FPGA I-DCF (Umsebenzi woNxibelelwano osasazwayo), usebenzisa indlela ye-CSMA/CA. Ibonelela ngexesha lokuqhuba isakhelo (SIFS) kwinqanaba le-10us;
• Iiparamitha eziphambili zofikelelo lwetshaneli: Ubude bexesha le-RTS/CTS, i-CTS-to-self, SIFS, DIFS, xIFS, ixesha lokungena, njl.
• Ukusika ixesha (Ixesha lokusika) ngokusekelwe kwidilesi ye-MAC;
• I-bandwidth eguquguqukayo ngokulula kunye namaxesha:
  I-2MHz ye-802.11ah kunye ne-10MHz ye-802.11p;

Okwangoku, i-OpenWifi ibonelela inkxaso Iiplatifti ze-SDR ezisekwe kwiFPGA
I-Xilinx ZC706 kunye ne-Analog Devices FMCOMMS2 / 3/4 transceivers, kunye ne-bundles (FPGA + RF) ADRV9361Z7035 SOM + ADRV1CRR-BOB kunye ne-ADRV9361Z7035 SOM + ADRV1CRR-FMC. Yenzelwe ukulayisha umfanekiso ogqityiweyo Amakhadi e-SD asekelwe kwi-ARM Linux. Kukho izicwangciso zokuxhasa i-ADRV9364Z7020 SOM + ADRV1CRR-BOB, Xilinx zed + FMCOMMS2/3/4, Xilinx ZCU102 + FMCOMMS2/3/4 kunye
Xilinx ZCU102 + ADRV9371. Iindleko zamacandelo abandakanyekayo kwiprototype yokuqala ye-OpenWifi yayimalunga ne-euro eyi-1300, kodwa ukuthunyelwa kwiibhodi ezingabizi kakhulu kuyaqhubeka. Umzekelo, iindleko zesisombululo esekelwe Izixhobo ze-Analog ADRV9364-Z7020 iya kuba 700 euro, kwaye ngokwesiseko ZYNQ NH7020 - 400 euro.

Ukuvavanya ukusebenza kokudibanisa umxhasi nge-TL-WDN4200 N900 i-adapter ye-USB kwindawo yokufikelela e-OpenWifi yasivumela ukuba sifezekise i-30.6Mbps (TCP) kunye ne-38.8Mbps (UDP) xa udlulisela idatha ukusuka kwindawo yokufikelela kumxhasi kwaye I-17.0Mbps (TCP) kunye ne-21.5Mbps (UDP) xa ihanjiswa ukusuka kumxhasi ukuya kwindawo yokufikelela. Kulawulo, izixhobo ezisemgangathweni zeLinux zinokusetyenziswa, njenge-ifconfig kunye ne-iwconfig, kunye nesixhobo esikhethekileyo se-sdrctl, esebenza nge-netlink kwaye ikuvumela ukuba ulawule ukusebenza kwe-SDR kwinqanaba eliphantsi (sebenzisa iirejista, tshintsha useto lwesilayi sexesha, njl.).

Phakathi kwezinye iiprojekthi ezivulekileyo ezizama i-Wi-Fi stack, sinokuqaphela iprojekthi WimeUkuphuhlisa i-IEEE 802.11 a/g/p ehambelanayo umthumeli isekelwe kwi-GNU Radio kunye nePC eqhelekileyo. Isoftware evulekileyo eyi-802.11 izitaki ezingenazingcingo nazo ziphuhlisa iiprojekthi Ziria и Sora (iMicrosoft Research Software Radio).

umthombo: opennet.ru