title: How to send service UUID
body: <p>We are developing an app which needs to scan for beacons in the background. This requires us for iOS to specify a service UUID while scanning. See <a href="https://developer.apple.com/library/ios/documentation/CoreBluetooth/Reference/CBCentralManager_Class/index.html#//apple_ref/occ/instm/CBCentralManager/scanForPeripheralsWithServices:options:" rel="nofollow">Apple documentation</a>:</p>
  
  <blockquote>
    <p>Apps that have specified the bluetooth-central background mode are allowed to scan while in the background. That said, they must explicitly scan for one or more services by specifying them in the serviceUUIDs parameter. The CBCentralManagerOptionShowPowerAlertKey scan option is ignored while scanning in the background.</p>
  </blockquote>
  
  <p>We are using a Raspberry Pi with a bluetooth adapter to send a beacon signal (conforming the AltBeacon spec). Unfortunately we are not able to find out how the service UUID should be set in the BLE Advertising PDU, is it part of the Bluetooth specification or part of the Manufacturer specific data structure? We did find examples for setting the service UUID for when you use an iOS device as beacon, but since we are using a generic bluetooth adapter we cannot use that.
  Could anyone clarify us how and where the service UUID should be set in the beacon transmission? </p>