Glossary

Glossary

Term/Acronym

Definition

ACL

A low-level Bluetooth data connection.

ADC

Hardware used to convert analog signals (such

as voice) into a digital format.

AG

A device that takes audio (for instance from a

telephone call), and sends it across a Bluetooth

link. For example, when a cellular phone is con-

nected to a Bluetooth headset, the cellular phone

is acting as an audio gateway.

API

A software interface designed specifically for

application programmers. APIs aim to present

features in easy-to-use ways.

ARM

A Cambridge, UK-based company that manufactures

a powerful range of processors. These have

proved popular for embedding in Bluetooth chips.

Authentication

A procedure whereby one Bluetooth device checks

that the link keys on another Bluetooth device

match its own link keys.

BD_ADDR

A unique address allocated to every Bluetooth

device on manufacture.

Bonding

A process where two Bluetooth devices which

share a secret PIN code connect, generate a link

key (which can later be used for authentication

and encryption), then disconnect.

CID

A number used by L2CAP to identify a logical

channel.

Codec

A hardware subsystem that converts audio

samples into a compressed data stream.

CVSD

An error tolerant Codec used in Bluetooth audio

systems.

DA

An agent that accumulates service information

and forms a repository of that information.

DAC

Hardware used to convert digital signals into an

analog format (such as voice).

DLCI

A number identifying one of the emulated serial

ports carried on an RFCOMM connection.

Encryption

A procedure whereby link keys are used to gen-

erate encryption keys, and the encryption keys are

then used to encode data so it cannot be read by

anyone who does not know the keys.

GAP

A profile that provides the basic operation rules

for all Bluetooth devices. For instance, it defines

the timing rules for inquiry and paging.

Glossary

Expanded

Term/Acronym

Acronym

Definition

GPL

Gnu General Public

A free license attached to much open source code.

License

HCI

Host Controller

An interface that allows a Bluetooth host to

Interface

communicate with a Bluetooth device. Various

transport layers are possible: UART, USB, and

RS232.

HID

Human Interface

A device used to interface between a human and

Device

a computer (for instance, a mouse, keyboard, joy-

stick, or tracker ball).

Hold mode

A device in hold mode is temporarily inactive until

a hold timer expires. A master might use hold

mode to allow slaves to save power if it knows it

will not communicate with them for a while—for

example, when it is connecting to a new slave.

IETF

Internet Engineering

The body that defines Internet specifications.

Task Force

Ioctl

Input output

An interface for controlling data transfer. There

control

are a set of standard ioctl control calls used in

UNIX and Linux.

IP

Intellectual Property

Designs, patents, and so forth, which are intan-

gible but have an owner.

IP

Internet Protocol

The higher layer networking protocol that runs on

Internet connections. Layered on TCP (Transmission

Control Protocol) for reliable communications, or

UDP (User Datagram Protocol) for unreliable com-

munications.

IPC

InterProcess

Usually First In First Out (FIFO) queues carrying

Communications

messages between processes.

IR

Infrared

Infrared light is used for optical communications

as another alternative to cabled connections.

IrDA

Infrared Data

An association which defines specifications for

Association

OBEX, vCal, vCard, and so on.

L2CAP

Logical Link Control

The part of a Bluetooth Protocol Stack that

and Adaptation

multiplexes several higher layer logical links onto

Protocol

one underlying physical link. L2CAP also provides

segmentation and reassembly to adapt large higher

layer packets onto the smaller packet sizes handled

by HCI and the lower layers.

LAP

LAN Access Point

Bluetooth-enabled device for accessing a LAN,

which supports the LAN Access Profile.

Glossary

Term/Acronym

Definition

LAP

Part of a Bluetooth device address, or other

Bluetooth access code (such as an inquiry access

code).

Ldisc

Line Discipline controls the format and rules you

use when reading input from a terminal (TTY) line.

Examples of line disciplines include: raw, cbreak,

select(), ioctl().

Link Key

Numbers up to 128 bits long which are used in

Bluetooth security procedures.

Link Manager

The layer that establishes and configures

Bluetooth connections. The Link Manager is usu-

ally implemented on a Bluetooth chip.

LMP

The protocol that two Link Managers use to

communicate when they are setting up and con-

figuring Bluetooth connections.

MMI

Input and output devices used by a human to

interface to a machine. For example, a keypad and

a display could make up an MMI.

MOS

A testing method used to assess audio quality—

because this is such a subjective quantity, it cannot

be measured by instrumentation, so users are sur-

veyed and asked to score the quality of signals.

The opinion scores of many users are taken and

the mean average is used to provide the MOS.

NetLib

The Palm OS library, which supports networking

functions.

OBEX

IrDA protocol which allows exchange of data

objects, as well as providing facilities for speci-

fying directories, and creating and deleting

objects and folders.

Park mode

A device in park mode has given up the active

member address that identifies it as part of a

piconet. It is inactive except for occasional beacon

slots when it wakes up to listen for unpark mes-

sages that can be used to reactivate it. Parked

devices are allocated special access window slots

in which they can request the master to reactivate

them by unparking.

Pairing

A process whereby two Bluetooth devices gen-

erate a link key that can be used later for authen-

tication and encryption. For devices to pair

successfully, they must have matching PIN codes.

PCM

A type of Codec used in Bluetooth, and also used

in cellular phones.

Glossary

Term/Acronym

Definition

PDA

A small handheld computing device such as a

Palm device.

PDU

A single package of information carrying a

message in a format specific to one protocol layer.

PDUs are used for peer-to-peer communication

between local and remote protocol entities. For

instance, SDP client and server communicate with

SDP PDUs.

Piconet

A network of Bluetooth devices consisting of a

master device and one to seven slave devices.

PIN

A number used for security procedures to verify

that the user is authorized to use a system.

PPP

An Internet protocol used for transporting

datagrams across point-to-point links.

PRC

A file containing a set of resources for a Palm OS

software module.

Profile

A set of instructions for how to use a protocol

stack to implement an end-user service. For

example, the Bluetooth Headset profile describes

how to use the Bluetooth protocol stack in a

headset.

PSM

A number used by L2CAP to identify which

protocol or service is connected to a channel.

PSTN

The networks provided by telephone service

providers to carry subscriber’s telephone calls.

RFCOMM

The serial port emulation layer of the Bluetooth

protocol stack.

SA

An agent that advertises information about a ser-

vice on behalf of the service.

SAFER+

The algorithm used by Bluetooth devices to

generate link keys used for authentication and

encryption.

SCO

A low-level Bluetooth duplex voice connection. To

set up a SCO connection, you must first set up an

ACL (data) connection.

SDAP

A profile that gives rules for using Service

Discovery Protocol in an application.

SDP

A peer-to-peer protocol that allows a client

Bluetooth device to ask a server device whether it

supports a service, or to browse through a list of

Glossary

Term/Acronym

Definition

SIG

A group that shares a common interest, and joins

together to pursue goals related to that interest.

The Bluetooth SIG shares an interest in Bluetooth.

Sniff mode

A low-power mode where a device only wakes up

to listen for data in periodic sniff slots.

TCS-Bin

A specification based on ITU-T Q.931, which

allows telephone calls to be transferred across

Bluetooth links.

TTY

The abbreviation that originally referred to tele-

types connected to mainframes. It is now used for

data terminals. (Linux has a TTY command that

prints the filename of the terminal connected to

standard input.)

UA

An agent that performs service discovery tasks for

a client.

UART

A device that supports transfer of data in a serial

bit stream.

UI

Also called MMI (Man Machine Interface).

Graphical User Interface (GUI) and Command Line

Interface (CLI) are both types of user interfaces.

UPnP

A system that allows wireless devices to find one

another, advertise services, and exchange status

monitoring and control information.

USB

A high-speed standard for data connections,

which allows many devices to be connected to

one hub device. USB is often used on PCs.

UUID

128-bit numbers that are guaranteed to be

unique across all space and time (or at least until

A.D. 3400).

VDRV

A Palm OS driver that provides virtual serial ports.