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:

Server

• Contains the resources (data) to be monitored
  • Organized as an Attribute Database
• Receives requests from a client and sends responses back
• Typically associated with the Link Layer Slave and GAP Peripheral device roles

Client

• 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

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Example

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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