A SemBeacon is a Bluetooth Low Energy transmitter that advertises a namespace and instance identifier and a Uniform Resource Indicator (URI) linking to a RDF resource on the web describing the beacon's location and other information relevant to this location.

Bluetooth Specification

SemBeacon Flags

The specification provisions 1-byte for flags. These flags provide more context to the installation of the beacon so applications scanning for a beacon can decide wether or not they want to retrieve the semantic data for these beacons.

Bit (MSB)DescriptionExample
0Indicates if the beacon has a position.0 = Unsure, 1 = Yes
1Indicates if the beacon is private.0 = Public, 1 = Private
2Indicates if the beacon is attached to a moving object.0 = No, 1 = Yes
3Indicates if the beacon has a positioning system.0 = No, 1 = Yes
4Indicates if the beacon has telemetry data.0 = No, 1 = Yes
5 - 7Reserved for future use.

Resource URI

The resource URI should resolve to a semantic description of the beacon. Depending on the BLE version this resource URI needs to be shortened to fit in the advertisement data.

URI Shorteners

  • tinyurl.com
  • bitly.com
  • s.sembeacon.org (only available in the SemBeacon app)

BLE 4.x Specification

SemBeacon Bluetooth 4.x specification

BLE 5.x Specification

SemBeacon Bluetooth 5.x specification