Kendrick, yes, Apple is limiting throughput by restricting the number of packets sent to 4 per connection event (officially 6 - see http://stackoverflow.com/questions/10354613). My measurements at 37.50ms connection interval are as follows: Indications / Read / Write With Response : ~4 kbit/s Notifications / Write Without Response: ~20 kbit/s Graph for Notifications: http://www.scriptreactor.com/conn_interval-throughput.pdf When you go with Notifications / Write Without Response you need your own protocol to offer reliability, as such packets may be dropped at any time. Depends also on range and angles in which you hold the device. Etan On 14.06.2013, at 03:53, Kendrick Taylor <kendrick@sano.co> wrote:

I'm running some performance tests on Core Bluetooth for a project I'm working on. It seems like apple is rate limiting the BLE connection, even when the app is in the foreground. I've tried reading a characteristic repeatedly and the throughput drops from a max of 400 bytes a second, to 10 bytes a second after 12 seconds. This is repeatable if I use indications, instead of reading a characteristic repeatedly. Anyone have any insight on this issue? I may need higher continuous throughput in bursts over 12 seconds for my project, but not consistently.

Thanks for any insight.

Kendrick Taylor

-- Kendrick Taylor Sano kendrick@sano.co sano.co 703.855.5608 _______________________________________________ Do not post admin requests to the list. They will be ignored. Bluetooth-dev mailing list (Bluetooth-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/bluetooth-dev/kissling%40oberon.ch

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