Iphrojekthi ye-OpenWifi ngokusetshenziswa kwe-chip ye-Wi-Fi evulekile esekelwe ku-FPGA ne-SDR

Engqungqutheleni yokugcina ye-FOSDEM 2020 kwethulwe iphrojekthi I-OpenWifi, ukuthuthukisa ukuqaliswa okuvulekile kokuqala kwesitaki esigcwele se-Wi-Fi 802.11a/g/n, umumo wesignali nokushintshashintsha okucaciswe kukho kusofthiwe (SDR, Software Defined Radio). I-OpenWifi ikuvumela ukuthi udale ukusetshenziswa okulawulwa ngokugcwele kwazo zonke izingxenye zedivayisi engenantambo, okuhlanganisa izendlalelo ezisezingeni eliphansi, okuthi kuma-adaptha angenawaya ajwayelekile asetshenziswe ezingeni lama-chips angafundeki. Ikhodi izingxenye zesofthiweFuthi imidwebo nezincazelo amabhulokhi wehadiwe ngolimi lwe-Verilog ye-FPGA asatshalaliswa ngaphansi kwelayisensi ye-AGPLv3.

Ingxenye yehadiwe ye-prototype esebenzayo ebonisiwe isekelwe ku-Xilinx Zynq FPGA kanye ne-AD9361 universal transceiver (RF). I-OpenWifi isebenzisa i-architecture ye-SoftMAC, okusho ukuqaliswa kwesitaki esikhulu esingenantambo esingu-802.11 (high-MAC) ohlangothini lomshayeli kanye nokuba khona kongqimba oluphansi lwe-MAC ohlangothini lwe-FPGA. Isitaki esingenantambo sisebenzisa isistimu engaphansi ye-mac80211 enikezwe i-Linux kernel. Ukusebenzisana ne-SDR kwenziwa ngomshayeli okhethekile.

Izici ezibalulekile:

• Usekelo olugcwele lwe-802.11a/g nosekelo oluyingxenye lwe-802.11n MCS 0~7 (PHY rx kuphela okwamanje). Kunezinhlelo zokusekela i-802.11ax;
• Umkhawulokudonsa ongu-20MHz kanye nebanga lemvamisa ukusuka ku-70 MHz ukuya ku-6 GHz;
• Amamodi okusebenza: Okukhethekile (inethiwekhi yamadivaysi amaklayenti), indawo yokufinyelela, isiteshi kanye nokuqapha;
• Ukuqaliswa kwephrothokholi yesendlalelo sesixhumanisi ohlangothini lwe-FPGA I-DCF (Distributed Coordination Function), kusetshenziswa indlela ye-CSMA/CA. Inikeza isikhathi sokucubungula uhlaka (I-SIFS) ezingeni 10us;
• Amapharamitha abalulekile wokufinyelela esiteshini: Ubude besikhathi se-RTS/CTS, i-CTS-to-self, SIFS, DIFS, xIFS, isikhathi se-slot, njll.
• Ukunciphisa isikhathi (Isikhathi sokusika) ngokusekelwe ekhelini le-MAC;
• I-bandwidth eguquguquka kalula kanye nemvamisa:
  2MHz kokungu-802.11ah no-10MHz kokungu-802.11p;

Okwamanje, i-OpenWifi iyahlinzeka ukwesekwa Amapulatifomu e-SDR asekelwe ku-FPGA
I-Xilinx ZC706 enama-Analog Devices FMCOMMS2/3/4 transceivers, kanye nezinqwaba (FPGA + RF) ADRV9361Z7035 SOM + ADRV1CRR-BOB kanye ne-ADRV9361Z7035 SOM + ADRV1CRR-FMC. Yakhelwe ukulayishwa isithombe esiqediwe Amakhadi e-SD asekelwe ku-ARM Linux. Kunezinhlelo zokusekela i-ADRV9364Z7020 SOM + ADRV1CRR-BOB, Xilinx zed + FMCOMMS2/3/4, Xilinx ZCU102 + FMCOMMS2/3/4 kanye
I-Xilinx ZCU102 + ADRV9371. Izindleko zezingxenye ezihilelekile kumfuziselo wokuqala we-OpenWifi zazicishe zibe ngama-euro ayi-1300, kodwa ukuthunyelwa kumabhodi ashibhile kuyaqhubeka. Isibonelo, izindleko zesixazululo ezisekelwe Amadivayisi e-Analog ADRV9364-Z7020 kuzoba ngama-euro angama-700, futhi ngokwesisekelo I-ZYNQ NH7020 - ama-euro angama-400.

Ukuhlola ukusebenza kokuxhuma iklayenti nge-adaptha ye-TL-WDN4200 N900 ye-USB endaweni yokufinyelela esekelwe ku-OpenWifi kusivumele ukuthi sifinyelele umthamo ongu-30.6Mbps (TCP) no-38.8Mbps (UDP) lapho sidlulisela idatha isuka endaweni yokufinyelela isiya kuklayenti futhi 17.0Mbps (TCP) kanye no-21.5Mbps (UDP) uma idluliswa isuka kuklayenti iye endaweni yokufinyelela. Ukuphatha, izinsiza ezijwayelekile ze-Linux zingasetshenziswa, njenge-ifconfig ne-iwconfig, kanye ne-sdrctl yensiza ekhethekile, esebenza nge-netlink futhi ikuvumela ukuthi ulawule ukusebenza kwe-SDR ezingeni eliphansi (phatha amarejista, shintsha izilungiselelo zocezu lwesikhathi, njll.).

Phakathi kwamanye amaphrojekthi avuliwe ahlola isitaki se-Wi-Fi, singaqaphela iphrojekthi WimeUkuthuthukisa ukuthobela i-IEEE 802.11 a/g/p umshini ngokusekelwe kumsakazo we-GNU kanye ne-PC evamile. Isoftware evulekile 802.11 izitaki ezingenantambo nazo zakha amaphrojekthi Ziria и Sora (I-Microsoft Research Software Radio).

Source: opennet.ru