https://devzone.nordicsemi.com/f/nordic-q-a/24217/ble-send-data-failnow, i have a question: i have a buffer 100byte data to send, when i send data package via sd_ble_hvx() continus,delay 20ms after each send ,but it will lost some data , i must keep the speed to send ,because my buffer is refresh. now , i want send dataen-USTelligent Community 13Thu, 10 Aug 2017 08:34:51 GMThttps://devzone.nordicsemi.com/thread/95352?ContentTypeID=1Thu, 10 Aug 2017 08:34:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:77a2bcae-b098-4851-b30d-be07ba087a6aendnode<p>Sorry, this still doesn&#39;t make sense with how BLE normally works on GATT layer. There should be no &quot;delays&quot; as your application is living out of sync from what is happening on lower (LL) layer with it&#39;s own timing (connection interval). Simply put as many (G)ATT packets through SD API to the stack as possible and let it do its job to transfer it over the link (reliably). Once you are running out of buffers in the stack you need to wait for TX_COMPLETE event and then try it again. If you are starting to have bigger queue in your application data buffer than in SD buffers then you have problem with bandwidth and there is not much you could do. Use all tricks to increase it (MTU extension, PDU extension, connection interval as short as possible) but indeed it relies on your peer. If peer device (mobile phone?) doesn&#39;t support it there is no help.</p><div style="clear:both;"></div>