Editing Bluetooth (section)

=== {{Anchor|v5}}Bluetooth 5.1 ===
The Bluetooth SIG presented Bluetooth 5.1 on 21 January 2019.<ref>{{Cite web |last=Woolley |first=Martin |date=28 January 2019 |title=Bluetooth Core Specification v5.1 |url=https://www.bluetooth.com/wp-content/uploads/Files/Specification/1901_Feature_Overview_Brief_FINAL.pdf |access-date=23 February 2023 |website=bluetooth.com |edition=1.0.1 }}{{Dead link|date=March 2025 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

The major areas of improvement are:
* [[Angle of arrival]] (AoA) and Angle of Departure (AoD) which are used for locating and tracking of devices
* Advertising Channel Index
* GATT caching
* Minor Enhancements batch 1:
** HCI support for debug keys in LE Secure Connections
** Sleep clock accuracy update mechanism
** ADI field in scan response data
** Interaction between {{abbr|QoS|Quality of service}} and Flow Specification
** Block Host channel classification for secondary advertising
** Allow the SID to appear in scan response reports
** Specify the behavior when rules are violated
* Periodic Advertising Sync Transfer

Features added in Core Specification Addendum (CSA) 6 – integrated in v5.1:
* Models
* [[Bluetooth mesh#Mesh models|Mesh-based model]] hierarchy

The following features were removed in this version of the specification:
* Unit keys