Hi, 2017-10-23 15:00 GMT+02:00 Andrzej Kaczmarek <andrzej.kaczmarek@xxxxxxxxxxx>: >> >>> Is there any point in using extended version if we can only do >> >>> 1Mbit/s, is there any practical difference? Is there any reason we are >> >>> not trying 2 Mbit/s phy as well? >> >>> >> >> >> >> The idea is to first implement the extended version with no functionality >> >> change (ie with PHY as 1M). We are planning to expose kernel >> >> interface so that user can select the PHY for the connection. We can add >> >> other PHYs accordingly during the implementation of the interfaces. >> > >> > There is nothing here suggesting what sort of interface we will use >> > for switching between 1-2 MBit/s, >> >> I am planning to raise separate patch for the interfaces. >> >> > usually, for BR/EDR we choose the >> > best possible (or let the controller do so) we will continue with the >> > same logic the phy policy will reside in the kernel anyway. Are there >> > any reasons why we cannot request 2MBit/s? >> >> My thinking was to select 1M, 2M or LR based on the user selection. >> Whether we need 2M or LR would be based on the usecase i think. >> But i understand your point that we can have 2M instead of 1M if both >> controller supports. But i am not sure whether any power consumption >> issues (i may be dumb here) will be there wherein some use cases 1M is >> preferred over 2M (Usecases where data rate is not relevant). But otherwise >> as you said we can add 2M also in the PHYs by default. > > We cannot just have 2M instead of 1M since scanning on primary > advertising channels in only possible on 1M or LR - so 1M is perfectly > fine here. > The only reason to include 2M here is to specify default connection > parameters in case connection is established on 2M (which is still > possible) and we want them to be different than for 1M (which are used > if 2M is not specified). > > IMO having 1M only is just fine until we have proper support for other > PHYs in place. > 2 MBit/s consumes around half the energy since it does everything in half the time with the same radio power consumption. But I wouldn't be surprised if the range is worse compared to 1 MBit/s. /Emil -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
