title: Windows BLuetooth LE require pairing before connection?
body: <p>It seems from other posts (all quite old) that Windows 10 BLE requires (external) pairing before one can work with the device. </p>
  
  <p>Is this still true?
  Can I connect to a device without pairing and control the pairing myself (if needed)</p>
  
  <p>If Windows requires pairing to work with a device, that is bad because many BLE devices do not support pairing.</p>
  
  <p>My use case is remote patient monitoring, where a patient performs measurements with personal health medical devices. The patient needs to do as little as possible. On the Android I do the following and would like to do the same in Windows:</p>
  
  <ol>
  <li>Scan in the background for BTLE devices my app can work with
  (filtering on UUIDs; all devices that support the standard health
  thermometer, pulse ox, BP, Glucose, weigh scale, etc.).</li>
  <li><p>When a supported device is discovered, a popup appears and all user
  has to do is select connect or no.</p></li>
  <li><p>If the device needs pairing, it will be done automatically, either
      because the device sends a security request OR responds with an
      insufficient authentication error when I try to read/write/enable.</p></li>
  <li>If confirmation or passkey is needed, a second popup will occur.
      This is the most difficult part for the user.</li>
  <li>If pairing is not needed, it will never happen. I will never try to
      pair with a device that does not support it.</li>
  <li>If paired and bonded, the device is added to a list of known devices
      and when discovered, connection happens automatically with no user
      intervention.</li>
  <li>If unpairable, the device is still added to a list of known devices
      and when discovered, connection happens automatically with no user
      intervention. Of course I have to go through service discovery
      again.</li>
  </ol>
  
  <p>That is what I would like to emulate on Windows. The user shall need to know <em>nothing</em> about the device except how to use it and, unfortunately, make it pairable and/or connectable which is not standard and a big hurdle. The user should also have as little engagement as possible with the app. The minimum is a one time choice to connect (or not) and a pairing dialog (if needed).</p>
  
  <p>This works great on Android (barring Android's unstable BTLE).</p>