Hi Hasan Sorry about the misunderstanding. You want to increase the range of your application, am I correct? If so, which chip are you using? If you're using the nRF52840, you should be able to change the BLE_GAP_PHY setting to BLE_GAP_PHY_CODED, which is "long range mode", a test using this mode is described in this blog post. This mode outputs around 125kbps and is tested outdoors to work at ~1300 meters. If you're using an nRF52832, you could set the BLE_GAP_PHY to always be at BLE_GAP_PHY_1MBPS as well as increasing the TX power for the longest range possible. In both these cases, you should probably remove the change_PHY and PHY_UPDATE events from the main file in the image transfer demo. Best regards, Simon