BT Designer: Glossary: A - E

This glossary includes acronyms and terms which may be encountered in the Bluetooth technology, and serves as a quick look-up guide.

2-in-1 Handset The situation where a subscriber handset is acting as a remote handset to a base unit which provides a network connection.

3G 3rd Generation The next generation of digital phone technology.

802.11 A Wireless LAN specification defined by a working group within the IEEE.

ABM Asynchronous Balanced Mode: the mode used by RFCOMM when connected.

Access Code Each baseband packet starts with an Access code, which can be one of 3 types, CAC, DAC & IAC. The CAC consists of a preamble, sync word and trailer, and its total length is 72 bits. When used as a self-contained message without a packet header, the DAC and IAC do not include thetrailer bits and are of length 68 bits.

ACK AC Knowledge: a bit used in Bluetooth wireless baseband packets to acknowledge that the last packet was received correctly.

ACL Asynchronous ConnectionLess: the links used by Bluetooth technology to send data. These links are also important to voice systems because SCO (voice) links can only be set up after an ACL (data) link has been set up between two devices to allow them to exchange control and configuration data.

ACO Authenticated Ciphering Offset.

Active Mode In the active mode, the Bluetooth wireless unit actively participates on the channel. The master schedules the transmission based on traffic demands to and from the different slaves. In addition, it supports regular transmissions to keep slaves synchronised to the channel. Active slaves listen in the master-to-slave slots for packets. If an active slave is not addressed, it may sleep until the next new master transmission.

ADPCM Adaptive Differential Pulse Code Modulation: an audio compression encoding scheme.

AG Audio Gateway: a device that transmits audio to a headset supporting the Bluetooth headset profile.

AM_ADDR Active Member Address. It is a 3 bit number.It is only valid as long as the slave is active on the channel. It is also sometimes called the MAC address of a Bluetooth unit.

ANSI American National Standards Institute: standards body with home page at http://www.ansi.org. ANSI administers and co-ordinates the private sector voluntary standardization system in the U.S.. ANSI does not develop standards itself, but facilitates their development by private-sector organisations.

AP Access Point.

AR_ADDR Access Request ADDRess. This is used by the parked slave to determine the slave-to-master half slot in the access window it is allowed to send access request messages in. It is only valid as long as the slave is parked and is not necessarily unique.

ARIB Association of Radio Industries and Businesses: a Japanese industry association.

ARQ Automatic Repeat reQuest: a bit in a Bluetooth wireless baseband packet which is used to request a retransmission of any packets received with errors.

ARQN Automatic Repeat reQuest Number is used as a 1-bit acknowledge indication to inform the source of a successful transfer of payload data with CRC.

ASIC Application Specific Integrated Circuit: silicon device used to perform a specific function.

ATM Asynchronous Tansfer Mode: a networking protocol.

ATS Abstract Test Suite: a method of describing tests which can be read by machines. It facilitates automatic testing.

Audio Gateway A device which connects to a Bluetooth headset and sends it a stream of audio information.

Authentication The process of verifying 'who' is at the other end of the link. Authentication is performed for devices. In Bluetooth technology, this is achieved by the authentication procedure based on the stored link key or by pairing (entering a PIN).

Authentication Device A device whose identity has been verified during the lifetime of thecurrent link based on the authentication procedure.

Authorisation A security procedure whereby a device is given permission to access a particular service.

AUX An ACL link packet type for data. An AUX1 packet resembles a DH1 packet except it has no CRC code. As a result it can can carry up to 30 info bytes.

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B

Baseband The part of the device which controls the radio.

BB BaseBand. The part of the device which controls the radio.

BCD Binary Coded Decimal: a way of representing numbers. Each decimal digit is represented by four binary digits.

BC flag BroadCast flag: identifies data in HCI packets as broadcast or point to point.

BCH Bose, Chaudhuri, Hocquenghem: a family of cyclic parity codes which when added to data before transmission allows the receiver to detect and correct errors. BCH codes improve the auto-correction properties in the Bluetooth wireless synchronization word.

BD Bluetooth device

BD_ADDR Bluetooth Device ADDRess. Each Bluetooth transceiver is allocated a unique 48-bit device address. It is divided into a 24-bit LAP field, a 16-bit NAP field and a 8-bit UAP field. The Bluetooth device address is also used in encryption and in generation of frequency hop sequencies.

BER Bit Error Rate : used to measure the quality of a link.

Blue unit A reference implementation of Bluetooth technology used as a standard during qualification.

Bluetooth A short-range wireless communication technology for voice and data. Bluetooth technology communicates via a frequency hopping transceiver in the ISM band. It is based on a low-cost short-range radio link facilitating protected ad hoc connections for stationary and mobile communication.

Bluetooth clock Every Bluetooth unit has an internal system clock which controls thetiming and hopping of the transceiver.

Bluetooth device A parameter that indicates the type of device and which types of servicesclass that are supported. The class is received during the discovery procedure.

Bluetooth service One or multiple services a device can provide to other devices. Thetype service information is defined in the service class field of the Bluetooth device class parameter.

BOM Bill Of Materials: component list and cost for a product.

Bonding A security procedure used to create a trusted relationship between two devices. When bonded devices encrypted information can be exchanged.

BPSK Binary Phase Shift Key: A data bit is signalled by two possible phase values.

BQA Bluetooth Qualification Body: reviews applications and test reports. May be a Test House or a manufacturer's in-house facility.

BQRB Bluetooth Qualification Review Board: Manages the qualification process. Can give compliance waivers.

BQTF Bluetooth Qualified Test Facility: Authorized test facility that provides test plan and test reports. May be a Test House or a manufacturer's in-house facility.

BRAN Broadband Radio Access to the Network: working group with ETSI looking at high-speed wireless access to core networks.

BTAB Bluetooth Technical Advisory Board: a forum for qualification and test issues.

BT Bluetooth (unofficial short form).

usiness card The electronic equivalent of a printed business card, like a file which can be exchanged between Bluetooth devices.

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C

CAC Channel Access Code

CC Call Control: the part of TCS which permits voice and data calls between Bluetooth devices to be set up and cleared down.

CCITT Comite Consultatif Internationale de Telegraphique et Telephonique: consultative committee on international telephone and telegraphy. Since 1993 the CCITT has been replaced by the ITU-T.

CCK Complementary Code Keying.

CDMA Code Division Multiple Access. CDMA is a digital cellular communications technology. Each call has a individual code to identify the call. Multiple calls can be grouped together on a single frequency.

CDMA uses spread-spectrum techniques for handling radio communications. CDMA is an improvement on AMPS and TDMA cellular service.

Channel A logical connection on the L2CAP level between two devices serving asingle application or higher layer protocol.

Channel (hopping) This is a pseudo-random sequence of 79 (23 for the 23MHz sequence system) frequencies, The frequency is calculated using the BD_ADDR of the master of the piconet. The phase in the sequence is derived from an estimate of the master's clock. The channel hopping sequence has a very long period length, does not show repetitive patterns over a short time interval, but which distributes the hop frequencies equally over the 79 (23 for the 23MHz system) MHz during a short time interval. See also Frequency sequence.

Circuit Switched The application of a network where a dedicated line is used to transmit information. Only one user may employ the resources of the line at a time.

CL ConnectionLess: a broadcast connection from a master to a number of slaves.

Class of device See Bluetooth device class. Also abbreviated as CoD.

Client A device which wishes to use the services of another device.

CLK Clock, typically the master device clock which defines the timing used in the piconet.

CLKE Clock Estimate, a slave's estimate of the master's clock, used to synchronise the slave device to the master.

CLKN Clock Native, the clock of the current Bluetooth Device

Cnf An abbreviation for Confirm. A suffix used on signals from lower layers to higher layers when responding to higher layer requests. An abbreviation for Confirm.

CO Connection-oriented.

COBS Consistent Overhead Byte Stuffing.

CODEC COder DECoder: a circuit used for processing voice signals.

CoD Class of Device.

COMAR Committee On Man And Radiation: an IEEE committee based in the U.S.A..

Connectable device A Bluetooth device, in range and connectable, that will respond to a page message, and possible for another device to make connection.

Connectionless Not tied to one particular device, i.e. a broadcast link is a connectionless link as it is not tied to a single device.

Convergence The process by which electronic devices, which used to be independent are merging in to one device solution.

Correlator A circuit that scans incoming data looking for a certain pattern. When it sees the pattern it is searching for it triggers and generates a signal.

CP Capability Provider. A Capability Provider is a module within the local device that provides a service to other modules. Protocol stack modules (RFCOMM, L2CAP) are Capability Providers. So are "application interface modules" such as OBEX and ESC-AT. In fact, any module that registers a port that other modules can connect to is a Capability Provider.

CR A Carriage Return character.

CRC Cyclic Redundancy Checksum. This is a 16-bit code added to the packet to determine whether the payload is correct or not. CRC data payloads can be carried only be DM, DH or DV packets. The

CRC code is generated by the CRC-CCITT polynomial 0x11021 (hex).

CRC-CCIT Used in RS232 transport layer: a CCIT scheme using a 16 bit checksum attached at the end of each packet before an endig delimiter of 0x7E.

CRLF Carriage Return character followed by a Line Feed.

CSMA Carrier Sense Multiple Access: A device listens to the channel before transmitting and then only transmits if the channel is not in use. Also known as Collision Avoidance.

CTP Cordless Telephone Profile.

CTS Clear To Send.

CVSD Continuous Variable Slope Delta modulation.

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D

DAC Device Access Code. It is used during page, page scan and page response substates. It is a code derived from the unit's BD_ADDR.

Daccess Time from beacon instant to first access slot.

D_ Timing of the first beacon slot (used for master to transmit to parked slaves.)

dBm deciBel Metres: a Bluetooth radio signal strength power rating.

DBPSK Differential Binary Phase Shift Keying: As BPSK, but it is the phase change which is significant.

D_sleep Timing of first beacon slave at which the slave wakes.

DC Direct Current.

DCE Data Circuit terminating Equipment: equipment at the end of the communications link which converts signals from the data terminal equipment and communications line.

DCI Default Check Initialisation. Within Bluetooth , the DCI is defined to be 0x00 (hexadecimal).

DCID Destination Channel Identifier, used as the device local end point for an L2CAP transmission. It represents the channel endpoint on the device receiving the message. It is a device local name only. See also SCID.

DECT Digital Enhanced Cordless Telephony. destination The Bluetooth device receiving an action from another Bluetooth device. The device sending the action is called the source. The destination istypically part of an established link, though not always (such as in inquiry / page procedures).

Device Discovery The mechanism to request and receive the Bluetooth address, clock, class of device, used page scan, and names of devices.

Device name See Bluetooth device name.

Device security level Access to a device can be denied based on the required device security level. There are two levels of device security: trusted device and untrusted device. See also service security level.

DH Data-High rate: a category of Bluetooth packets which achieves high rates by using reduced error checking.

DIAC Dedicated Inquiry Access Code, used when you wish to inquire for certain, specific types of devices.

DISC DISConnect: one of the low level RFCOMM command frames which is used to terminated an RFCOMM connection.

Discoverable device A Bluetooth device in range that will respond to an inquiry message.

DLC Data Link Connection: an RFCOMM channel.

DLCI Data Link Connection Identifier. This is a 6-bit value representing an ongoing connection between a client and a server application. It is used in the RFCOMM layer.

DM Data Medium Rate: An ACL link data packet type for medium rate data.

DM1 packets carry information data only, contining a 16-bit CRC code and up to 18 info bytes. They are encoded using 2/3 FEC and the packet can cover up to a single time slot. DM3 packets are the same except they can cover up to 3 time slots, and can carry up to 123 info bytes. DM5 packets are the same again except they can cover up to 5 time slots and can hold up to 226 info bytes. See also Bluetooth packet types.

DM Disconnect Mode: one of the low-level RFCOMM command frames.

DNS Domain Name Server: this provides mapping between test names and hosts and their numeric IP addresses.

DQPSK Differential Quadrature Phase Shift Keying.

DSP Digital Signal Processor: a microprocessor dedicated to real-time signal processing.

DSR Data Set Ready. A device sets an RS-232 DSR signal when it is ready to accept data.

DSS Digital Subscriber Signaling system: an ITU recommendation for signaling controlling calls on ISDN systems.

DSSS Direct Sequence Spread Spectrum: a modulation which spreads data across the entire transmission spectrum using a spreading code.

DT Data Terminal.

DTE Data Terminal Equipment: a device at the end of a communications link, i.e. a computer acts as a source and sink of data.

DTMF Dual Tone Multiple Frequency.

DUN Dial-Up Networking.

DUT Device Under Test.

DV Data Voice. A SCO link data packet type for data and voice. It is divided into a voice field of 80 bits and a data field of 150 bits. The voice field is not covered by FEC, but the data field is covered by 2/3 FEC. The voice and data fields are treated completely separate. The voice field is handled like normal SCO data and is never retransmitted; that is, the voice field is always new. The data field is checked for errors and is retransmitted if necessary. See also Bluetooth packet types.

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E

EDGE Enhanced Data rates for GSM: a specification for increased data rates over GSM by using a deeper modulation scheme.

ETSI European Telecommunications Standards Institute: the European standards organization which defined GSM and DECT specifications.

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