Multiprotocol BLE/Thread

RE: Multiprotocol BLE/Thread

Krzysztof Loska — Fri, 14 Jul 2017 15:13:58 GMT

Hi,

Just remember that to benefit from MPL, you have to use Realm-Local address, NOT Link-Local address, which causes a single transmission.

RE: Multiprotocol BLE/Thread

Krzysztof Loska — Fri, 14 Jul 2017 13:05:17 GMT

Hi,

An assumption that "any CoAP server example should work" as a complementary side of "BLE UART and Thread MTD CoAP Client Example" is true. Quoted description which is part of nRF5 SDK for Thread documentation is misleading and will be changed.

RE: Multiprotocol BLE/Thread

wbober — Fri, 14 Jul 2017 12:42:06 GMT

Alain,

The assumption you're making in the second part of the question is correct: 15.4 packets will be dropped if the dual mode device is performing BLE activity.

There are, however, some mechanisms in the Thread stack that reduce the impact of such a situation: unicast packets use MAC layer acknowledgments and are retransmitted up to 3 times while multicast packets are disseminated using MPL (RFC 7731) which repeats each packet 3 times.

These mechanisms don't provide full reliability. This means that when you're using CoAP NONs you need to design your application in such a way that it can cope with message loss or introduce some reliability mechanism.

Note that a situation where a packet is lost isn't uncommon for 15.4 LLNs. In this respect the fact that a packet is dropped due to BLE activity doesn't differ that much from a situation where a packet is lost due to collisions or interference on 15.4.

Kind regards, Wojtek

RE: Multiprotocol BLE/Thread

Jørgen Holmefjord — Thu, 13 Jul 2017 12:55:05 GMT

The second board only needs to be a CoAP server, to test the receiption of data from CoAP Client (running on first board). In theory, any CoAP server example should work, but from the documentation it is mentioned that you can run BLE UART and Thread MTD CoAP Client Example with the following firmwares on second board:

This BLE-Thread dynamic multiprotocol example requires you to run the following example:

Simple CoAP Server example or/and

BLE Proximity and Thread CoAP Server Example

BLE Proximity and Thread CoAP Server Example is dynamic multiprotocol example running CoAP server on Thread concurrently with BLE.

Best regards,

Jørgen

RE: Multiprotocol BLE/Thread

Alain — Thu, 13 Jul 2017 12:15:05 GMT

Thanks a lot for your response.

In the example "BLE UART and Thread MTD CoAP Client Example" you need two nRF52840 boards. After reading your doc, it seems that both boards doesn't use the same firmware. The client (board 1) has a firmware which support BLE and Thread while the server (board 2) supports only Thread. Is it correct ? Is it possible to have the same kind of application with the Server supporting concurrently BLE and Thread and not only Thread. Thanks a lot, Best Regards,

RE: Multiprotocol BLE/Thread

Jørgen Holmefjord — Thu, 13 Jul 2017 12:01:20 GMT

I'm not sure I fully understand your question. There are multiple examples of dynamic multiprotocol in the SDK for Thread. Anyone of these examples support both BLE and Thread concurrently, and is capable of maintaining an established connection on both protocols. You can read more about how the multiprotocol support works on this page.