31 Attribute Profile

属性协议：

Attribute Grouping

定义三个属性attribute type ： Primary Service», «Secondary Service» and «Characteristic»

Attribute Caching

attribute, attribute type,

Each attribute has an attribute type that identifies, by means of a UUID (Universally Unique IDentifier)

Each attribute has an attribute handle that is used for accessing the attribute on a server, as well as an attribute value