Do current BLE modules support v4.1 or 4.2 of Bluetooth?

[Tester Testov]

I'm a new at BLE. So, as I know from bluetooth spec v 4.1 there is a opportunity to establish multiple connections to the same peripheral device from several central devices. Does any Nordic BLE module support this functionality? What vendors does this function support?

[Pål Håland]

Hi Tester Testov,

You are correct that it is possible for a peripheral to be connected to N number of devices and there is no limit except for the time it takes to maintain all the connections. The only limitation is the clock drift of the master/central that might make the listening window of the peripheral collide with other masters, thus it would be hard to maintain the connection. One way of working around this problem would be to have support for LL_CONNECTION_PARAM_REQ.

Regarding the network part of your question: I assume that you mean that the centrals connected to the peripheral cannot talk to each other, and this assumption is correct. The only way they could talk to each other is if the peripheral was configured to relay the packets it received.

If you would like to read a bit more about LE topology, you can have a look in Core Bluetooth 4.2 spec Volume 1, Part A, 4.1.2.

In the drawing there there is just one mode that our SoftDevices does not suppoert yet, and that is having two connections in the mode of a peripheral (Device O is connected to two centrals and is initiating a connection to a third device). (Having two centrals connecting to us) There might be other vendors out there that support this mode currently. We might release a SoftDevice with this functionality in the future, when is something that I don't know.

With the latest softdevice, released two days ago (s130 and s132 v2.0.0) we added configurable support for up to 8 central connections or 7 central and 1 peripheral connection, plus simultaneous broadcasting and scanning. You can also configure it to have 0 connection to save ram and only do scanning and broadcasting.

BR Pål

[Luis]

Thanks for the update. I believe the option of being able to have several peripheral connections is quite a popular request, am I wrong? This would add so much flexibility to my projects... Just wanted to say +1 to this request in future softdevices. :)