Gazell device transmission timeout period

[rwyung]

Hi,

I am working with Gazell device and host example code from the Keil pack installer, using the default the data rate of 2MBit, so per Nordic's documentation the timeslot is set to 600 microseconds

How long does a device wait on a Tx transmission before considering it timing out? It certainly seems waiting for the duration of the timeslot (600 microsecond) seems a bit short, but the Gazell link layer user guide seems to agree (or I misunderstood the documentation)

Thanks Ray

Note on the side: I have a host and a device that is separated by about 3 feet away, and set the device's max number of Tx attempt to 1. Then I could see there are about 166 to 167 successful transmission (0 failed) per second, implying that a round trip time of 6 milliseconds.

[Hung Bui]

Hi Rwyung,

Most likely you have set the channel_selection_policy to NRF_GZLL_DEVICE_CHANNEL_SELECTION_POLICY_USE_SUCCESSFUL (this is the default one).

"By choosing the NRF_GZLL_DEVICE_CHANNEL_SELECTION_POLICY_USE_SUCCESSFUL policy, the Device will start sending packets on the channel it last had a successfully acknowledged transmission. This policy is the most robust against static interferers as once the Device finds a quiet channel it should be able to continue using this quiet channel."

This may explain why you have interval of 6 milliseconds. Please have a look in the documentation here.