Thread: [Madwifi-devel] driver Madwifi in mode 802.11b
Status: Beta
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From: makevuy <ma...@eh...> - 2007-05-30 15:26:03
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Hy, I'm a student research. I'm working with Madwifi over long distances. In concrete I'm studing 802.11e for using it over long distances in isolated areas. Recently, I've obtained laboratory results over Point to Point WiFi links of 3, 5, 10, 15, 20....until 90 km, using a emulated channel denominated propsim C8. Propsim C8 permits me to emulate long distance channels in laboratory, Wich is great!!!!. First, I've begun simulating over 802.11b (rate 2Mbps). Traffic was generated with the iperf tool sending UDP 1000- byte packets. The experimental results obtained, are the average of five runs of 60 s duration each, with 2 Mbps in both sides. Finally, I adapted Slottime in /proc/sys/dev/interface/slottime and ACK in /proc/sys/dev/interface/acktimeout, for each distance, asuming the next rules: Slottime=2Tp + 20 Acktimeout=distance (km)*8+40 Tp=distance(km)/0,3 (km/us) (integer value) The especifications of equipment used : * 2 Soekris with O.S voyage. Driver Madwifi 0.9.17.2. * 2 Proxim Orinoco b/g Cards I know that MadWifi implements short headers PLCP by default, and I compared the results gived by propsim C8, with results obtained with simulator Ns2.28., using the same especifications and applications CBR (UDP) with 1000 bytes. The results with Ns2.28 is quite different from propsim C8. Propsim C8 is quite optimistic than Ns2.28 in any case (over all with a distance more than 10 km), Approximately 0,1 Mbps better than Ns2. I am very surprised because experimental results are better than simulated results!!!!. Perhaps, Madwifi driver is improve the throughput, but I don't Know How. Any idea???? Thanks for all and regards. -- Sandra Salmerón Ntutumu <ma...@eh...> Tlf. Analog: +34 914888405 / Móvil: 653574298 Tlf. IP desde FWD: 656212. Ext: 10 / Tel. IP desde EHAS: 010010 Fundación EHAS: Enlace Hispanoamericano de Salud - www.ehas.org Telemedicina rural para zonas aisladas de países en desarrollo |
From: Paul P. <p_p...@in...> - 2007-05-30 18:55:02
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, > Perhaps, Madwifi driver is improve the throughput, but I don't Know How. Madwifi supports Atheros specific chipset extensions like FastFrames and Bursting. For more info check http://madwifi.org/wiki/ChipsetFeatures/SuperAG Regards, Paul Pichota - -- Please quote when answering. Short guideline on good quoting: http://www.massey.ac.nz/~tameyer/writing/quoting.html -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGXchqmH6TS/e/KAIRArpdAJ0bqBX/GMlCmVMPgamxDI5ZeygZdwCgtWZI fLP8GsQ7i3CiyFj7Lu0FoKs= =KDUq -----END PGP SIGNATURE----- |
From: Holger S. <hs...@ma...> - 2007-05-31 07:25:22
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> I am very surprised because experimental results are better > than simulated results!!!!. MAYBE it has to do with the calibration inside of madwifi. It might get calibrated differently in real-world than in your labortory. But of course this is wild guessing. Maybe if you want to dig VERY deep into the internal of madwifi, you should enable the register dump feature, see http://madwifi.org/changeset/2388 |