nrf51 BTLE frequency hopping certification

RE: nrf51 BTLE frequency hopping certification

Janek Mann — Fri, 01 Dec 2017 08:11:41 GMT

BTW, for full BT stack testing, like what it sounds like your lab is trying to do, there is special test equipment which can simulate the peer device. That's probably what your lab should be using, if they are trying to fulfil the test protocol from the BT SIG for example. Someone from Nordic would probably be able to add a lot of details on this...

RE: nrf51 BTLE frequency hopping certification

Maycon Kruger — Fri, 24 Nov 2017 22:19:35 GMT

I am developing this test for certification in Brazil, so the requirements are slight different from FCC. I too, find it weird that the lab is requesting this kind of test. But I wanted to make sure the required test was not possible to develop before challenging the lab. Anyway, thank you for your help! I will contact the lab to double check the tests requirements.

RE: nrf51 BTLE frequency hopping certification

endnode — Fri, 24 Nov 2017 22:11:46 GMT

Guess what: no it wouldn't;) There is no entry point to speak to LL inside the SD so what is expected to come over radio must vome over radio;)

RE: nrf51 BTLE frequency hopping certification

Maycon Kruger — Fri, 24 Nov 2017 22:09:14 GMT

Ok so , wouldn't it be possible to modify the ble_central example to emulate responses from the slave device by software , instead of listening for actual radio responses? Like, make the central believe it is connected to a slave device, but the slave device is really emulated by software.

RE: nrf51 BTLE frequency hopping certification

endnode — Fri, 24 Nov 2017 22:05:58 GMT

Yes, SD needs valid peer to operate Link Layer (as it is BT LE certified it's kind of logical that it doesn't provide non-standard feature). Footnote: I went through several BTSIG and FCC certifications and I've never seen such request. If it is some usual certification like one of these then I would challange the lab why exactly they demand this (what criteria/limit they want to test by this) and I would crosscheck with some trusted reference.

RE: nrf51 BTLE frequency hopping certification

Maycon Kruger — Fri, 24 Nov 2017 21:51:57 GMT

I see, so in summary that would no be achieavable with nordic SD. The problem is the lab is requesting a test that uses the SD, so it could test the device under normal operation.

RE: nrf51 BTLE frequency hopping certification

endnode — Fri, 24 Nov 2017 21:36:08 GMT

You can do it but not with off-the-shelf BLE stack such as Nordic Soft Device, that's kind of logical;) The stack has just GAP layer functions such as "advertise", "scan", "connect", disconnect" and without having both observer and broadcaster first the stack won't enter central/peripheral mode. Then you could theoretically (after first packet exchange) cut the Slave power and just observe Master PDUs how they hop over the spectrum but that will end by Supervision timeout (and you still need the second device during the initialization so why to shut it down later?)

Other solution is to develop it on your own without Soft Device (e.g. based on DTM or radio test examples) or go with other stack (e.g. Zephyr) and customize it (if it's open source).

RE: nrf51 BTLE frequency hopping certification

Maycon Kruger — Fri, 24 Nov 2017 21:22:30 GMT

Yes, I already delivered a DTM example alongside with a radio sweep test to the lab. But they are really insisting on a BTLE hopping frequency test.

"connects to Slave by sending CONNECT_REQ to some connectable ADV_XXX" So I would have to have a slave device, to maintain connection? Could I just use the master to continuously send data without a slave device?

RE: nrf51 BTLE frequency hopping certification

endnode — Fri, 24 Nov 2017 21:07:44 GMT

Otherwise indeed you don't need anything from Security Manager layer such as pairing or bonding, simply Master (GAP Central if you implement GAP) connects to Slave by sending CONNECT_REQ to some connectable ADV_XXX packet and the rest is just managed by Link Layer (there will be normally pair of PDUs exchanged on one channel each connection event). And until higher (GAP/APP) layer doesn't say so such Link can be maintained by Link Layer (including mandatory channel hopping) until the end of the universe.

RE: nrf51 BTLE frequency hopping certification

endnode — Fri, 24 Nov 2017 21:05:30 GMT

Are you sure they mean real link and not some sort of DTM or simple radio test mode where you "sweep" along the frequency band?

RE: nrf51 BTLE frequency hopping certification

Maycon Kruger — Fri, 24 Nov 2017 20:17:54 GMT

By hopping mode,I mean frequency hopping. Which is used for comunication once two devices are connected.

RE: nrf51 BTLE frequency hopping certification

shibshab — Fri, 24 Nov 2017 20:09:55 GMT

What is 'hopping mode'?