This is a tracking bug for Apple Radar 28814249

Radar contents:


[Chrome] Scanning for BLE peripherals reports fewer devices after 120 seconds

Area:
Bluetooth

Summary:
Chrome scans for BLE peripherals using -scanForPeripheralsWithServices:options: and sets the AllowDuplicates option to generate a discovery event each time a packet is received.  In an environment with several BLE beacons broadcasting simultaneously (about 10 beacons, each broadcasting every 700ms), the frequency of observed discovery events is observed to decrease when scanning for longer periods.

Steps to Reproduce:
This is easiest to observe by creating an app to scan for BLE peripherals and recording the number of discoveries per unit of time.

Expected Results:
The frequency of discoveries should be consistent for the duration of the scanning window.

Actual Results:
In our testing, the frequency is initially about 10 to 15 discoveries per second.
After 30 seconds, it drops to about 8 to 10 per second.
After 120 seconds, to drops to under 5 per second.

Version:
iOS 10.1

Notes:
GOOGLER:mattreynolds

Configuration:
iPhone 6s