User's Manual

Chapter 17: Bluetooth I/O
APx500 User’s Manual 143
vides “transport” controls such as Play, Pause,
Reverse, Forward, etc. Roles are Controller and Tar-
get.
Connect
Paired devices can connect using compatible pro-
files and roles. Connection enables exchange of
audio or control data. Each device can connect with
only one device at a time.
CVSD
is Continuously Variable Slope Delta modulation,
the codec used in HSP and legacy HFP profiles.
With HFP 1.6, higher data rates enable the use of a
higher quality codec called mSBC.
Device address
Every Bluetooth device has a unique 48-bit device
address, in APx500 displayed in hex format, such
as 00:f4:b9:c3:a0:cc.
Device class
A Bluetooth device class is a code that identifies
the type of device. Some Bluetooth devices will only
recognize devices of a certain class.
Discovery
Bluetooth devices that are not paired can discover
each other when they are in range. Some devices
allow users to make the device undiscoverable.
duplex
refers to a bi-directional audio channel, across
which speaking and listening can occur simultane-
ously.
eSCO
Extended SCO, available in the Bluetooth 1.2 speci-
fication. Adds new packet types (EV1, etc.) and
more flexibility in channel parameters, allows
retransmission of bad packets. Also see SCO.
EV1
First of a series of packet types available with
eSCO, as opposed to the HV1, etc. packet types in
SCO.
Friendly name
is an optional name for a Bluetooth device, more
easily understood and remembered than the device
address. An example is “iPhone”.
HF
is Hands Free, the duplex “phone” role in the HFP
profile.
HFP
is the Hands Free profile, intended to allow hands-
free device operation in an automobile. It is similar
to HSP, with more phone controls. Roles are AG and
HF.
HFP 1.6
is a revision of the HFP specification, which allows
new packet types and higher data rates compared
to legacy HFP. These data rates and newly sup-
ported codecs such as mSBC enable WBS (Wide-
band Speech) performance.
HS
is Head Set, the duplex “phone” role in the HSP pro-
file.
HSP
is the Head Set profile, intended to enable Blue-
tooth mobile phone use. Roles are AG and HS.
HV1
First of a series of packet types available with SCO,
as opposed to the EV1, etc. packet types in eSCO.
Link key
is a shared secret exchanged in pairing.
mSBC
is a monaural version of the SBC codec, optimized
for use in the HFP 1.6 profile. This codec and the
higher available sample rates enable Wideband
Speech operation.
Pair
Bluetooth devices that have discovered each other
can be paired by exchanging a link key to form a
bond. For some devices, pairing is automatic upon
discovery; for others, user interaction is required.
Pairing establishes a mutual, secure relationship
between devices that have at least one compatible
profile. Pairing is stored in non-volatile memory in
each device. Devices can pair with more than one
other device.
PIN code
A Personal Identification Number embedded in a
device or provided by a user that is exchanged in a
pairing negotiation.
Profile
One of a number of defined Bluetooth relationships
covering a range of devices and use cases. A device
can support more than one profile, and devices can
be paired acknowledging more than one profile.
role
A role is a defined use of a device within a profile. In
A2DP, for example, the roles are source and sink.
For HFP, the roles are AG and HF.
SBC
(Sub-band Codec), the mandatory codec for the
A2DP Profile. Other codecs are allowed.
SCO
is a synchronous connection oriented channel, a
full duplex data channel with 64 kbit/s data rate in
each direction. The CVSD codec is used, and the
three HV types of data packets are available. Also
see eSCO.