> Od: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> > Předmět: Re: [PATCH] wireless-regdb: Update regulatory rules for Czech Republic > (CZ) on 5GHz > Datum: 28.11.2008 11:09:02 > On Fri, 2008-11-28 at 01:11 +0100, Carlos Laué wrote: > > > OK, I thought we cannot guarantee the automatic power regulation, > > using lower values for now, it would be nice to implement the required > > mechanism to assure tx power regulation, but then how to define the > > two values? two tables, or a flag like "NO-APC -3" indicating that, > > without tx power regulation, there is a lower limit for tx power? > > No, it's not that trivial, needs more thought and a db change. > > johannes Yes, I'm aware of it. To make things clear and simple, I'll resume why we need such a feature: In Czech Republic, and maybe on other countries, one can transmit twice more eirp on 5GHz (on some frequencies) with automatic TX power management enabled than without such feature. For the Czech Republic,the limit is 3dB lower for devices without such feature(ie. half the output power). So it would be nice if users could use all available TX power, without breaking the law, and without having to bother. I'm using APC for automatic TX power management (as if one sets "iwconfig wlan0 txpower auto") on the text below. Perhaps the first thing we have to do is to change a little the DB and the parser. Adding a entry telling that, for the desired frequency, there can be "n" dB more TX power with APC enabled than without APC, or to define a second limit. The right thing to do would be to start at lower TX power settings, afterwards CRDA would check if the driver is capable of APC, and if it is, and it is enabled, than it could rise the TX power settings. That would assure that a driver unaware of APC "feature-enabled-feedback" won't get the higher tx power settings than is legal to use. Problems could arise when userspace tools i.e. iwconfig are used to disable APC, then the card should start transmitting with less power. We could just warn users about that, but to make things automatic would be nice. Maybe even the drivers will need a little touch to have them generating a udev event when APC settings changes, and then let CRDA make the right choice of max TX power setting. It seems that iwtxpower setting are now handled by mac80211. It would be nice to see this feature when it gets to cfg80211.... I'm downloading the wireless-testing git tree right now, but it will take a while at 18KB/s... Carlos Laué -- 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
