Datasets:
kkboy1
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LeAudio

Dataset card Data Studio Files
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field size
octets description
length length of type and value fields
type service data uuid bit value ascs uuid x e
announcement type x general announcement
x targeted announcement
availableaudiocontexts availableaudiocontexts characteristic
from ascs
metadata length if there is additional metadata
otherwise
metadata varies metadata in ltv format
table ad values for targeted and general announcements
the common audio profile cap describes how initiators or commanders see section
below react to announcement s by defining two specific modes which helps explain when to
use each these are
inap the immediate need for audio related peripheral mode inap and
rap the ready for audio related peripheral mode rap
inap refers to the case where an initiator or commander wants to make a connection usually
due to a user action and needs to determine which acceptors are available to connect to if
it discovers an available acceptor it should connect or if it has discovered more than one
present the user with a range of available acceptors to let them make that choice the initiator
or commander would normally commence scanning at a higher rate to find acceptors when
ad data types are structures used in bluetooth advertisements to provide information about a
device or its capabilities they are defined the core specification supplement css
a uuid is a universally unique identifier defined in the b luetoo th bit uuids assigned
numbers document and used to identify a particular service or characteristic
section announcements
operating in the inap mode
in contrast when in rap mode the initiat or scans at a lower rate but will respond to a
targeted announcem ent from an acceptor by connecting
acceptors should only use targeted announcement s for a limited period of time when they
require an immediate connection
there is a further subtlety in announcements which is that they may or may not include a
context type value if they are used in relation to an audio stream they should include it
and are called bap announcements bap which contains an available audio context
field if the y are used for control purposes or scan delegation they do not they are then
called cap announcements cap
broadcaster s use announcements within their extended advertisement s to inform broadcast
receivers and broadcast assistant s see section that they have a broadcast stream
available these take two forms
broadcast audio announcements
broadcast audio announcements inform any scanning device that a broadcaster is
transmitting a group of one or more broadcast audio streams the ltv structure used for
broadcast audio announcements is shown below in table
field size
octets description
length length of type and value fields
type service data uuid bit value broadcast audio
announcement service uuid x
broadcastid a random id fixed for the life of the
broadcast isochronous group
supplementary announcement
service uuids varies optional uuids defined by top level
profiles
table ad values for targeted and general announcements
basic audio announcement
the confusingly similarly titled basic audio announcement is used in the periodic advertising
train by a broadcast source to expose the broadcast audio stream parameters through the
broadcast audio stream endpoint structure base its use is described in chapter
chapter new concepts in bluetooth le audio
remote controls commanders
bluetooth has always been a good candidate for remote control devices but these are almost
all simple remote controls which are essentially a bluetooth replacement for trad itional infra
red remote controllers hearing aids and earbuds make remote control an attractive option
as these devices are so small that they dont have room for many buttons and even where they
do manipulating a button that you cant see because it s on the side of your head or behind
your ear is a poor user experience as most earbuds are used with phones laptops or pcs
and the application generating the audio stream generally contains the controls that you use to
pause it answer a call or cha nge volume thats not a major issue however hearing aid users
also need to control the volume of their hearing aids when theyre just being used to amplify
ambient sound
to make it easier than fumbling for a button on the hearing aid the industry h as developed
simple keyfob like remote controls that allow a user to easily adjust the volume or change the
audio processing algorithms to suit their environments these are known as preset settings
even where a hearing aid contains bluetooth technology most of the time a user wont have
an active bluetooth link enabled and getting your phone out of a pocket or bag followed by
finding the appropriate app is an inconvenient way to adjust volume if you are troubled by a
loud noise its quic ker and easier to take your hearing aids out which is not a good user
experience
that is just the beginning of the problem the new broadcast capabilities of bluetooth le
audio will result in far more public infrastructure where a user will need to nav igate through
multiple different broadcasts and decide which to receive not only is that difficult to do on
a hearing aid or earbud it involves relatively power hungry scanning to address these issues
the concept of a separate device was developed wh ich could provide volume control discover
and display available broadcast source s discover keys for encrypted broadcasts and allow
hearing aid users to change their presets its also possible to use it to answer calls or control
a media player these devices take the commander role which is defined in cap but can
also use the broadcast assistant role from bap for discovering broadcasts as well as being
content control clients most top level profiles introduce further names for additional roles
that these devices can assume for the rest of the document ill use the commander
terminology unless its for the specific subset of a broadcast assistant
the commander is an important new addition to bluetooth topology the role can be
implemented on a phone either as a stand alone application or part of a telephony or audio
streaming app it can also be implemented in any device which has a bluetooth connection
to an acceptor or a coordinated set s of acceptors that means you can implement it in
dedicated remote controls smart watches wrist bands and even battery cases for hearing aids
and earbuds commanders can have a display to show textual information about broadcasts
to help you select them or just volume buttons commanders work on a fi rstcome first