BLE 기본 용어
Key terms and concepts
GATT (Generic Attribute Profile) :
-GATT 프로파일은 BLE 링크를 통해 "attribute"으로 알려진 짧은 데이터 조각을 송수신하기위한 일반적인 사양입니다. 현재의 모든 저에너지 애플리케이션 프로파일은 GATT를 기반으로합니다.
Attribute Protocol (ATT) :
-GATT is built on top of the Attribute Protocol (ATT).
-This is also referred to as GATT/ATT. ATT is optimized to run on BLE devices. To this end, it uses as few bytes as possible.
-Each attribute is uniquely identified by a Universally Unique Identifier (UUID), which is a standardized 128-bit format for a string ID used to uniquely identify information. The attributes transported by ATT are formatted as characteristics and services.
Characteristic :
A characteristic contains a single value and 0-n descriptors that describe the characteristic's value. A characteristic can be thought of as a type, analogous to a class.
Descriptor:
-Descriptors are defined attributes that describe a characteristic value.
For example, a descriptor might specify a human-readable description, an acceptable range for a characteristic's value, or a unit of measure that is specific to a characteristic's value
Service:
-service is a collection of characteristics.
-For example, you could have a service called "Heart Rate Monitor" that includes characteristics such as "heart rate measurement."
You can find a list of existing GATT-based profiles and services on bluetooth.org.
Roles and responsibilities
Central vs. peripheral.
GATT server vs. GATT client