direct advertising while having established connection

RE: direct advertising while having established connection

RK — Mon, 18 Jan 2016 09:25:08 GMT

I think that's exactly what you're going to see. Direct advertising is going to get as much time as the softdevice can give it but you aren't going to get it running at the no-connection rate when you have other connections. There's only so much one radio can do and connections have timing requirements that just must be kept. I don't think there's anything much you can do about that.

RE: direct advertising while having established connection

Matej — Mon, 18 Jan 2016 09:15:35 GMT

RK, thank you for your response and pointing me to specs (and yes thumbs up for nordic documentation –it's really great comparing with competition).

What I'm afraid of is inconsistent behavior of my system that direct advertiser, “advertise as much as possible/as soon as possible” – in case that I have no connection established, then I can direct advertise all the time and connection with smart device will be established very fast… In case that I have established connection with three devices (centrals) – there is less time to advertise and there is possibility that it takes longer that smart device receive advertise message in worst case can even happen that it won't receive advertise message in case that scan window and direct advertise message dismiss.

RE: direct advertising while having established connection

RK — Fri, 15 Jan 2016 12:53:49 GMT

There's a whole chapter on this in the softdevice spec, which goes into detail about which events get priority in different situations. It's chapter 14 and has a paragraph dealing with directed advertising when the device is also doing other things. It seems to me that you can do what you want, you may not send out all the advertising packets you would if there was nothing else running, but the device will still advertise as much as it can.

If you've not read that chapter - you should. This was the S132 V2 0.5 spec I was just looking at.

RE: direct advertising while having established connection

Matej — Fri, 15 Jan 2016 12:36:30 GMT

If i refer to BLE Relay example... Are we able to direct advertise to Collector if we already have established connection to Heart Rate Sensor or Running speed sensor?

Thank you

RE: direct advertising while having established connection

Matej — Fri, 15 Jan 2016 07:32:15 GMT

So is this advertising interval settable?
Is resolution of setting this advertising interval “big enough” that I can have established all three connections as central (there is still free one peripheral) and I can still direct advertise?

Thank you for clarifying – this feature is important to us that we can satisfy project requirements.

RE: direct advertising while having established connection

Matej — Fri, 15 Jan 2016 07:32:11 GMT

I edit my question -> nr5x is master so it's in central role... Regarding that S130 and S132 support 1 peripheral and 3 central connections this should work...

I'm a bit worried about timeslot scheduling -I'm a bit worried about timeslot scheduling – connectable undirected advertising has possibility to set advertising interval… Directed advertising has two duty cycle advertising (Refer to BLE Core Specs, Vol6, Link Layer Specifications, 4.4.2.4.1 and 4.4.2.4.2. -At high duty cycle directed advertising, time between two ADV_DIRECT_IND PDUs is less then 3.75ms and after 1.28s is advertising finished

At low duty cycle directed advertising time between two ADV_DIRECT_IND PDUs is less then 10ms. The advertising event shall be closed after advertising interval…

RE: direct advertising while having established connection

RK — Thu, 14 Jan 2016 23:23:33 GMT

I wouldn't think so - directed advertising is connectable and if you are in a connection already, the current softdevice only supports one peripheral connection, so any advertising would have to be non-connectable and hence not directed.

I guess that will change when the softdevice supports multiple peripheral connections.