physical channel
BR/EDR physical channels:
Basic piconet channel,Adapted piconet channel,Inquiry scan channel,Page scan channel,Synchronization scan channel
LE physical channels:
LE piconet physical channel,Advertising physical channels,Periodic physical channel,LE Isochronous physical channel
AMP physical channel:
physical link:
A physical link is always associated with exactly one physical channel.
logical links:
Each logical link is associated with a logical transport
Logical transports
L2CAP channel
L2CAP提供了一个多路复用的角色，允许许多不同的应用程序共享一个ACL-U、ASB-U、LE-U或AMP-U逻辑链路。应用程序和服务协议使用一个面向通道的接口与L2CAP连接，以创建到其他设备上等效实体的连接。
