title: Best approach for transfering large data chunks over BLE
body: <p>I'm new to BLE and hope you will be able to point me towards the right implementation approach.</p>
  
  <p>I'm working on an application in which the peripheral (battery operated) device continuously aggregate sensor readings.
  On the mobile side application there will be a "sync" button, upon button press, I would like to transfer all the sensor readings that were accumulated in the peripheral to the mobile application.
  The maximal duration between sync's can be several days, hence, the accumulated data can reach a size of 20Kbytes.</p>
  
  <p>Now, I'm wondering what will be the best approach to perform the data transfer from the peripheral to the central application.
  I thought about creating an array of characteristics where each characteristic will contain a fixed amount of samples (e.g. representing 1hour of readings).</p>
  
  <p>Then, upon sync, I will:</p>
  
  <ol>
  <li>Read the characteristics count (how many 1hours cells).</li>
  <li>Then read the characteristics (1hour cells) one by one.</li>
  </ol>
  
  <p>However, I have no idea if this is a valid approach ?</p>
  
  <ol>
  <li>I'm not sure if this is the most "power efficient" way that I can
  use. </li>
  <li>I'm not sure if Characteristic READ is the way to go, or maybe
  I need to use indication instead.</li>
  </ol>
  
  <p>Any help here will be highly appreciated :) </p>
  
  <p>Thanks in advance, Moti.</p>