https://devzone.nordicsemi.com/f/nordic-q-a/14751/can-gazel-keep-communicate-and-frequency-hopping-without-ackI was able to setup gazell frequency hopping communication between a device and a host. Device:nrf51822+PA/LNA(RFX2401);Host:nrf51822+PA/LNA; They can communicate at a long distance about 300m+. In order to simplify the design and lower the cost, I wanten-USTelligent Community 13Mon, 27 Jun 2016 10:48:28 GMThttps://devzone.nordicsemi.com/thread/56320?ContentTypeID=1Mon, 27 Jun 2016 10:48:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:60839169-efe3-4bcd-a28d-8a3978b2b4eaHung Bui<p>Hi Chenyu,</p> <p>Yes they can.</p> <p>You can disable re-transmission by setting nrf_gzll_set_max_tx_attempts(0).</p> <p>The device will be always out of sync since there will be no ACK received. Frequency hopping will still work but will not be as effective as when the device can be in sync. You can set the sync_lifetime to 0. You should set timeslots_per_channel_when_device_out_of_sync lower than the timeslot per channel on the Host. This is to avoid the 2 devices using wrong channels all the time if you set the timeslot per channel on 2 device equally.</p><div style="clear:both;"></div>