BLE Advertisement switch interval & advertising interval

Question

I want to be able to switch between two advertising data using one bluetooth adapter, what is the optimal advertising switch interval and the advertising interval for it to be recognized immediately without much delay by iOS? (I want to switch between iBeacon and GATT Service advertisement). Right now I am using 1.5s switch interval with advertising interval of 200ms. I am wondering if 200 ms is too much.

Thanks

Answer 1

The fastest I have been able to reliably switch between two BLE advertisements on iOS is 1 second. See my answer and sample code here.

The standard iOS iBeacon advertising frequency is 30 Hz, but in my experience, you only need to transmit an iBeacon advertisement every 900ms for fastest detection. More frequent advertisements are still useful for more accurate distance measurements, as iOS uses samples of RSSI from the iBeacon advertisements to make this estimate every second when ranging.