Connection parameter negotiation with iOS extremely slow

RE: Connection parameter negotiation with iOS extremely slow

Bjørn Kvaale — Tue, 16 Jul 2019 11:18:22 GMT

Very sorry for the super late reply. Does this only happen on iPhone 6S or have you noticed it on other phones too? I'm looking at this right now.

Looking at the sniffer trace again, the Rcvd Handle Value Notification is not important for the connection parameter update request. Once you receive the LL_CONNECTION_UPDATE_REQ opcode, you should be good to go.

RE: Connection parameter negotiation with iOS extremely slow

thefool — Tue, 16 Jul 2019 10:04:09 GMT

Any news on this?

RE: Connection parameter negotiation with iOS extremely slow

thefool — Thu, 20 Jun 2019 15:52:24 GMT

Alright, that's already good to know that it's at least 6 intervals. So the first 8 are just over 6, which I'll accept (grudgingly ;-)

but the extra 10 seconds really don't make much sense. I just checked again to make sure that it's nothing of our doing - but the delta time column definitely shows that the interval hasn't changed yet.

btw, we're using an nRF52382 with SDK 15.0, and the counterpart was an iPhone6s

RE: Connection parameter negotiation with iOS extremely slow

Bjørn Kvaale — Thu, 20 Jun 2019 10:08:53 GMT

These two devzone cases explain things quite well: link 1, link 2.

When doing a connection parameter update request, you need to wait at least 6 connection intervals before doing the update. Therefore, if you have a connection interval of 6 seconds, it will take a while to do the update. However, I am not quite sure while it takes another 10 seconds after the master sends the LL_CONNECTION_UPDATE_REQ. I will continue taking a look & get back to you soon.

RE: Connection parameter negotiation with iOS extremely slow

thefool — Sat, 15 Jun 2019 21:16:52 GMT

here you go - I've reduced the capture to the important parts. The write from the app to the device triggers the firmware in the device to wake up and renegotiate the speed. The notifications begin once the negotiation is complete.

devzone.nordicsemi.com/.../parameter_2D00_negotiation_2D00_960_2D00_to_2D00_30ms.pcapng

RE: Connection parameter negotiation with iOS extremely slow

Bjørn Kvaale — Sat, 15 Jun 2019 00:22:43 GMT

Could you please upload the whole sniffer log please? That should make it easier to debug.

RE: Connection parameter negotiation with iOS extremely slow

awneil — Thu, 13 Jun 2019 12:08:53 GMT

ISTR think there may be limitations in the BLE specs (and/or in mobile OSs) on re-negotiating the parameters ... ?