CC1352P: Running OpenThread based protocol at 868/915 MHz

Part Number: CC1352P

Hi,

I understand that OpenThread does not (officially) support 868/915 MHz, while IEEE 802.15.4 does.

From the OpenThread CC1352 Github repository I even see that the example code would throw the error: Platform cc1352 doesn't support configuration option: OPENTHREAD_CONFIG_RADIO_915MHZ_OQPSK_SUPPORT

Even though there is no support and there are no available products on the market for this:

1) Would it still be possible to create an OpenThread based private network at 868/915 MHz (e.g. using this referenced example, removing the check)?
2) I take it I would have to take care about e.g. the 868 MHz bands duty-cycle myself in the application layer?
3) Are there other issues with running this at 868/915 MHz, timing related or otherwise?

Kind regards, Jorick

  • Hi,

    1) Would it still be possible to create an OpenThread based private network at 868/915 MHz (e.g. using this referenced example, removing the check)?

    Yes, this is possible, but changes to radio.c would be additionally required to make use of sub-1 g radio commands.

    2) I take it I would have to take care about e.g. the 868 MHz bands duty-cycle myself in the application layer?

    Duty cycling to meet regulatory requirements is platform-related. This can be done in application layer, but the openthread stack itself initiates radio transmissions (e.g. advertisements), so some lower-layer may be the best place (e.g. radio.c).

    3) Are there other issues with running this at 868/915 MHz, timing related or otherwise?

    Data rates for Sub-1 GHz are typically lower than in 2.4 GHz.

    Thanks,
    Toby

  • Dear Toby,

    Based on the answer above we went ahead and purchased 6 evaluation boards to prepare a proof of concept.
    We have OpenThread working at 2.4 GHz but getting something similar at 915 MHz it is a bit harder.

    Unfortunately it looks like making changes to radio.c is not enough.

    It does not appear that the CC1352P supports O-QPSK or anything else with DSSS at 915 MHz?
    Is that something that will change in the future?

    So am I correct that the only CC1352 IEEE 802.15.4 modulation available at 915 MHz would be SimpleLink long range or 2-GFSK with frequency hopping?

    Kind regards,

    Jorick

  • The sub-1 PHYs supported can be found in smartrf studio:

    For sub1 PHY for 802.15.4, you can also refer to the ti154stack examples:

    (in the project's .syscfg file: "RF STACKS" --> "TI 15.4 STACK" --> Radio)

    The GFSK PHY should be specified in a later revision of 802.15.4 (e.g. 2015).

    Can you share what issues you are running into?