TIDA-010024: 6LoWPAN Mesh, enabling SINGLE_FH_CHANNEL mode, debug_push_leaf does not connect if CONFIG_FH_CHANNEL_MASK and FH_ASYNC_CHANNEL_MASK are changed

I have assigned an expert to comment.

Hi Eirik,

Thank you very much!

I am continuing investigation of the issue with the resources I have available in the mean time and will update this thread if I find out any new information.

Hi Eirik,

I hope this thread has not been forgotten, I am sure everyone is busy.

I think I have found the issue here, it was not straight forward and I think somewhere there should be a note about this.

I would still appreciate an expert comment concerning if what I did is correct, will this cause any side effects to the FH logic???

I am worried a little of the side effects of this workaround/solution.

Are there ANY other problems with changing CONFIG_FH_CHANNEL_MASK and FH_ASYNC_CHANNEL_MASK that might cause issues?

Do sleepy leaf nodes not participate in frequency hopping (FH)?

Outside of this issue I am very happy with the 6LoWPAN mesh sample provided and am glad it is available.

Apparently when FH is enabled sleepy leaf nodes are still fixed to a specific channel.

This appears to be fixed to channel 0 in the idllc.c file, which is a frequency I excluded from the available FH channels.

I am providing the function Jdllc_init() in idllc.c, line 242

CONFIG_RX_ON_IDLE is set to zero for a sleepy leaf node, this drops us down to the else section of that if condition.

If you notice there are three lines that need to be changed to a frequency that the is not masked out, please correct me if I am wrong here.

The three zeros appear to stand for the channel number that a sleepy leaf node can use, they need to be a channel that is not masked.

In my case I only have channel 101 unmasked, so these need to be set to 101 in my case.

Please, please I do recommend and insist that there be a note added somewhere visible that if the CONFIG_FH_CHANNEL_MASK and FH_ASYNC_CHANNEL_MASK are changed in a way to exclude channel 0 that these three lines will need to be changed to an available channel.  This caused me a lot of frustration to track down.

            /* set PIB to enable fixed channel*/
            ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_unicastChannelFunction, 0);
            ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_broadcastChannelFunction, 0);

            /* set fixed channel in FH PIB */
            ApiMac_mlmeSetFhReqUint16(ApiMac_FHAttribute_unicastFixedChannel,0);

Below is the complete function, if it helps to see it in full context.

void Jdllc_init()
{

#if(IS_ROOT)
    uint16_t panid=CONFIG_PAN_ID;

    if((panid!=0x0000) && (panid!=0xFFFF))
    {
        devInfoBlock.panID=panid;
    }

    /* setup short address */
    /* not used for 6LoWPAN mesh stacks but requires for TI-15.4 */
    ApiMac_mlmeSetReqUint16(ApiMac_attribute_shortAddress,
                            CONFIG_SHORT_ADDR);

    /* Always set association permit to 1 for FH */
    //ApiMac_mlmeSetReqBool(ApiMac_attribute_associatePermit, true);
#endif
    ApiMac_mlmeSetReqBool(ApiMac_attribute_RxOnWhenIdle, true);

    if(CONFIG_FH_ENABLE)
    {
        uint8_t sizeOfChannelMask, idx;
        sizeOfChannelMask = sizeof(fhChannelMask)/sizeof(uint8_t);

        /* PIB for FH are set when we receive the IEs*/
        /* enable frequency hopping operation */

        ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_unicastDwellInterval,
                                 CONFIG_DWELL_TIME);
        ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_broadcastDwellInterval,
                                 CONFIG_DWELL_TIME);
        ApiMac_mlmeSetFhReqArray(ApiMac_FHAttribute_netName,
                                 (uint8_t*)&fhNetname[0]);
        /* set up the number of NON-sleep and sleep device */
        ApiMac_mlmeSetFhReqUint16(ApiMac_FHAttribute_numNonSleepDevice,
                                 FH_NUM_NON_SLEEPY_HOPPING_NEIGHBORS);
        //ApiMac_mlmeSetFhReqUint16(ApiMac_FHAttribute_numSleepDevice,
        //                          FH_NUM_SLEEPY_HOPPING_NEIGHBORS);

        /* if non sleepy FH device */
        if(CONFIG_RX_ON_IDLE)
        {
            uint8_t excludeChannels[APIMAC_154G_CHANNEL_BITMAP_SIZ];

            /* set PIB to enable channel hopping*/
            ApiMac_mlmeSetFhReqUint8(
                            ApiMac_FHAttribute_unicastChannelFunction,
                            JDLLC_FH_CHANNEL_HOPPPING);
            ApiMac_mlmeSetFhReqUint8(
                            ApiMac_FHAttribute_broadcastChannelFunction,
                            JDLLC_FH_CHANNEL_HOPPPING);

            /* set of Exclude Channels */
            if(sizeOfChannelMask > APIMAC_154G_CHANNEL_BITMAP_SIZ)
            {
                sizeOfChannelMask = APIMAC_154G_CHANNEL_BITMAP_SIZ;
            }
            memset(excludeChannels, 0, APIMAC_154G_CHANNEL_BITMAP_SIZ);
            for(idx = 0; idx < sizeOfChannelMask; idx++)
            {
                excludeChannels[idx] = ~fhChannelMask[idx];
            }
            ApiMac_mlmeSetFhReqArray(ApiMac_FHAttribute_unicastExcludedChannels,
                                     excludeChannels);
            ApiMac_mlmeSetFhReqArray(ApiMac_FHAttribute_broadcastExcludedChannels,
                                     excludeChannels);
        }
        else
        {
            /* set PIB to enable fixed channel*/
            ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_unicastChannelFunction, 0);
            ApiMac_mlmeSetFhReqUint8(ApiMac_FHAttribute_broadcastChannelFunction, 0);

            /* set fixed channel in FH PIB */
            ApiMac_mlmeSetFhReqUint16(ApiMac_FHAttribute_unicastFixedChannel,0);
        }

#if(!IS_ROOT)
        /* Start FH */
        ApiMac_startFH();
#endif
    }
}

EDIT: After knowing to search for the keyword "ApiMac_FHAttribute_unicastChannelFunction" I was able to find this similar question.

It appears that only one line needs to be changed, the other two is not the channel, but perhaps the algorithm used for FH mode.

This appears to fix the issue with the push_leaf configuration not able to connect.

This one line needs to be changed to reflect a channel on the white list it seems, please confirm.

/* set fixed channel in FH PIB */
ApiMac_mlmeSetFhReqUint16(ApiMac_FHAttribute_unicastFixedChannel,0);

Change this zero to, say, 102 for 922.6MHz.

Hi Eirik,

Has anyone been been able to find time to review this thread?

While the issue has been somewhat resolved I would like some confirmation about the solution here and if it there are any concerns about this method.

While this does not need to answered immediately it would be nice to have an expert comment as confirmation.

Hello Allan,

I am sorry for the delay. I am still searching for a subject matter expert.