On IRC, Johannes, Felix and I talked about how to indicate the noise level towards user-space. Noise is not really a property of the link, althought derived values like SNR are. It can be nice to debug stuff. However, what hardware value hardware says is a noise level variues. For ath5k, it's internal, thermal noise. For ath9k, it's external medium noise. Some hardware can determine noise only while in a connection, others can do it at any time. However, noise is only one property of a channel, a wider approach would be to define a "site survey API". This could include hw cycle counters, e.g. to find out the channel utilization. The idea is to have one API call "do site survey", where you tell the driver to scan on specified/all channels to determine those values. And then there's an API call to retrieve this information. For hardware where you cannot really scan (e.g. Libertas, Orinoco), you can simply call the "retrieve site survey" call without the prior scanning and you just get what the hardware knows anyway. This makes the retrieve systeam call "cheap" in order to only get the noise level, but the API rich in case the hardware has much more versatile capabilities. We did not yet come up with a clear API definition for this. My idea for an initial "retrieve site survey" response is: NL80211_CMD_NEW_SURVEY_RESULTS NL80211_ATTR_GENERATION NL80211_ATTR_IFINDEX NL80211_BSS_FREQUENCY NL80211_BSS_NOISE_MBM Of course this will extend over time, but that is easy due to nl80211. -- M&N Solutions GmbH Ein Unternehmen der Datagroup AG Holger Schurig Raiffeisenstr. 10 61191 Rosbach Tel: 06003/9141-15 Fax 06003/9141-49 http://www.mn-solutions.de/ Handelsregister Friedberg, HRB 5903 Geschäftsführer: P.Schrittenlocher -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
