Application layer of Bluetooth low energy best bluetooth earbuds for phone calls

Above the controller and host is the application layer. The application layer specification (specification) defines three types: characteristic (characteristic), service (servicc) and specification (profle). These specifications are built on the generic attribute specification. The generic attribute specification defines attribute groupings for properties and services. Applications define protocols for using these property groups. www.bjbjaudio.com 

characteristic
An attribute is a small piece of data in a known format, tagged with a Universally Unique Identifier (UUID). Because the feature is required to be reusable, no behavior is involved in the design. As long as it is something with behavior added, its reusability is greatly reduced. There is something interesting about features. They are defined as computer-readable format, not human-readable text. This gives the computer the ability to download the relevant reading rules for the computer when it encounters a feature it has never met before. Used to display this feature to the user. www.bjbjaudio.com

Serve
A service is a human-readable set of characteristics and their associated behavioral specifications. A service only defines the behavior of the relevant feature located on the server. without defining the behavior of the client. for many services. The behavior of the client can be implicitly determined by the server behavior of the service. However, there are also services that may need to define complex behaviors on the client side that are defined by the normative non-service. A service can include other services. A parent service can only define its own contained services, it cannot change the characteristics or behavior of the contained services. However, including services should describe how multiple included services interact with each other. There are two types of services: primary services and secondary services, as described in Section 324 . Whether a service is essentially a primary service or a secondary service depends on the definition of the service, or can be determined by the specification document and the implementation of the specification document. The primary service characterizes what a given device primarily does. It is through these services that users learn what the device does. Secondary services are those that assist with primary business or other secondary services. The service itself does not dictate how devices are connected to each other, and how the service is discovered and used. Services only describe what exactly is done when reading and writing properties or notifying and indicating properties. The service does not describe what procedures the Generic Attribute Specification uses to find the service and the characteristics of the service, nor how the client uses the characteristics. www.bjbjaudio.com

specification
A specification is the final embodiment of a use case or application. A specification is a specification that describes two or more devices, each providing one or more services. The specification describes how to discover and connect devices to determine the required topology for each device. The specification also describes client behavior for discovering services and service characteristics, and using the service to implement the functionality required by a use case or application. There is a many-to-many mapping between specifications and services. A service can be used for many specifications: in order to implement the desired behavior on the device. At this point, the behavior of the service is independent of the specification for using the service. In the App Store, you can submit a list of all services supported by a device to find all the apps that use those services. This flexibility facilitates plug-and-play models, such as Universal Serial Bus. www.bjbjaudio.com