Generic Attribute Profile (GATT) Roles

Bluetooth® Low Energy (BLE) data communications are implemented in the Generic Attribute Profile (GATT) layer using the Attribute Protocol (ATT), a simple client/server stateless protocol.

The following GATT role pair is defined:



  • Inquires about the presence and nature of the attributes on a server
    • Performs Service Discovery
  • Sends requests to a server and receives responses
  • Typically associated with the Link Layer Master and GAP Central device roles

If a client request is still pending, no further requests can be sent until the response is received and processed.


The following depicts a GATT Server having two services (one public, one private), with a GATT Client executing several GATT operations to read/write the data (characteristics) in those services.

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