[ath5k-devel] RSSI (or SNR) for IEEE 802.11a and b/g
Hi, i'd list to ask the members of this list regarding the value rs-rs_rssi ath5k reports in the ath5k_receive_frame function. I use a monitor node (its interface set to promiscuous mode) and i collect the rssi values (rs-rs_rssi) in a per packet basis (i' vemodified base.c). I use an interferer (this is an IEEE 802.11 compatible node working in adjacent channels) and i monitor the rssi of the packets sent by an access point . Whenever i work in IEEE 802.11a, i can see that RSSI (or SNR) drops when interferer is on. However, whenever i work in IEEE 802.11g there are no SNR drops, although the interferer succesfully jams the channel. I've repeated the experiments with ANI disablesd but still SNR does not drop in g. Any ideas? Thanks, Alex ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] RSSI (or SNR) for IEEE 802.11a and b/g
Have you also added a hook or two to monitor what's going on to the noise floor? IIRC, atheros radios report RSSI as an offset from the current NF; if the NF raises but the signal doesn't, RSSI will decrease. Adrian On 3 March 2011 11:50, Alex alfr...@gmail.com wrote: Hi, i'd list to ask the members of this list regarding the value rs-rs_rssi ath5k reports in the ath5k_receive_frame function. I use a monitor node (its interface set to promiscuous mode) and i collect the rssi values (rs-rs_rssi) in a per packet basis (i' ve modified base.c). I use an interferer (this is an IEEE 802.11 compatible node working in adjacent channels) and i monitor the rssi of the packets sent by an access point . Whenever i work in IEEE 802.11a, i can see that RSSI (or SNR) drops when interferer is on. However, whenever i work in IEEE 802.11g there are no SNR drops, although the interferer succesfully jams the channel. I've repeated the experiments with ANI disablesd but still SNR does not drop in g. Any ideas? Thanks, Alex ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] RSSI (or SNR) for IEEE 802.11a and b/g
I'll try this thanks. Another thing i've noticed is that whenever Ath5k works in g mode, it reports no PHY or CRC errors, although inteferer is running. This is not the case when the driver is in 802.11a mode. Alex On 3/3/2011 9:59 ??, Adrian Chadd wrote: Have you also added a hook or two to monitor what's going on to the noise floor? IIRC, atheros radios report RSSI as an offset from the current NF; if the NF raises but the signal doesn't, RSSI will decrease. Adrian On 3 March 2011 11:50, Alex alfr...@gmail.com mailto:alfr...@gmail.com wrote: Hi, i'd list to ask the members of this list regarding the value rs-rs_rssi ath5k reports in the ath5k_receive_frame function. I use a monitor node (its interface set to promiscuous mode) and i collect the rssi values (rs-rs_rssi) in a per packet basis (i' vemodified base.c). I use an interferer (this is an IEEE 802.11 compatible node working in adjacent channels) and i monitor the rssi of the packets sent by an access point . Whenever i work in IEEE 802.11a, i can see that RSSI (or SNR) drops when interferer is on. However, whenever i work in IEEE 802.11g there are no SNR drops, although the interferer succesfully jams the channel. I've repeated the experiments with ANI disablesd but still SNR does not drop in g. Any ideas? Thanks, Alex ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org mailto:ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] RSSI (or SNR) for IEEE 802.11a and b/g
Well, the first thing that immediately springs to mind there is 11g == OFDM and CCK, but 11a == OFDM only. You may find the CCK stuff behaves differently in the presence of noise. You could also try fiddling with ANI (is there ani in ath5k?) which has some parameters for controlling CCK sensitivity/threshold/trigger levels. HTH, Adrian On 3 March 2011 12:24, Alex alfr...@gmail.com wrote: I'll try this thanks. Another thing i've noticed is that whenever Ath5k works in g mode, it reports no PHY or CRC errors, although inteferer is running. This is not the case when the driver is in 802.11a mode. Alex On 3/3/2011 9:59 μμ, Adrian Chadd wrote: Have you also added a hook or two to monitor what's going on to the noise floor? IIRC, atheros radios report RSSI as an offset from the current NF; if the NF raises but the signal doesn't, RSSI will decrease. Adrian On 3 March 2011 11:50, Alex alfr...@gmail.com wrote: Hi, i'd list to ask the members of this list regarding the value rs-rs_rssi ath5k reports in the ath5k_receive_frame function. I use a monitor node (its interface set to promiscuous mode) and i collect the rssi values (rs-rs_rssi) in a per packet basis (i' ve modified base.c). I use an interferer (this is an IEEE 802.11 compatible node working in adjacent channels) and i monitor the rssi of the packets sent by an access point . Whenever i work in IEEE 802.11a, i can see that RSSI (or SNR) drops when interferer is on. However, whenever i work in IEEE 802.11g there are no SNR drops, although the interferer succesfully jams the channel. I've repeated the experiments with ANI disablesd but still SNR does not drop in g. Any ideas? Thanks, Alex ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
