#1928: Problem with carrier sense in 802.11a? ----------------------------------+----------------------------------------- Reporter: [EMAIL PROTECTED] | Type: defect Status: new | Priority: major Component: madwifi: other | Version: v0.9.4 Keywords: | Patch_attached: 0 ----------------------------------+----------------------------------------- Problem with carrier sense in 802.11a?
Experiment Setup: ---------------- Madwifi Release 0.9.4: Two radios are transmitting simultaneously, saturating the channel @ 6Mbps PHY rate, 802.11a, channel 44. Both the radios use wlan0, with two virtual interfaces ath0 and ath1. ath0 is in Master mode and ath1 is in monitor mode. Acks are switched off using the setnoack ioctl. Observation: ----------- The radios don't share the channel for RSSI(s) as large as 28 and lesser, i.e., The received throughput at the nodes from the other is not close to typically expected (~ 2 Mbps). In fact it is very low, hardly any packets are received! However, the transmit rate at both the transmitters is consistently >5Mbps. It seems most packet transmissions end up in collisions. Note that the throughputs obtained when the radios are not transmitting simultaneously are as expected (>5Mbps). The radios do share the channel for RSSI(s) 44 and larger. It seems that Carrier sense is triggered only for large values of RSSI, as if only the energy based threshold for carrier sense was in place. The same setup works fine in 802.11g mode giving expected throughputs. -- Ticket URL: <https://madwifi.org/ticket/1928> madwifi.org <http://madwifi.org/> Multiband Atheros Driver for Wireless Fidelity ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Madwifi-tickets mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/madwifi-tickets
