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The LL subsystem implements the Link Layer as defined in the Bluetooth core specification [1]. The LL API is designed to be compatible with the standard HCI specification for low energy controllers as also defined in [1]. In addition, the LL API is designed to interface efficiently to the HCI layer API of ARM's host stack.


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Ref. Author Date Title
[1] Bluetooth SIG Dec 06, 2015 "Specification of the Bluetooth System", Version 5.0
[2] ARM Oct 16, 2012 "Software Foundation API", 2009-0003, Revison 1.1


Term Definition
ACL Asynchronous Connectionless data packet
BLE Bluetooth Low Energy
HCI Host Controller Interface
LL Link Layer
WSF Wireless Software Foundation software service and porting layer
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