The following is a list of most of the terms used in the Bluetooth
technology, and serves as a quick look-up guide. This glossary is partly
based on the Glossary originally supplied in the Motorola
Bluetooth website, my thanks to them. However this glossary contains
much more lower layer information, removes the reams of superfluous terms,
and elaborates on many points. In effect it is a totally different list,
and (I think) much better and clearer.
- 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.
- Third generation. Refers to the next generation of digital
phone technology (such as UMTS). Also see 3G
- 802.11 WLAN
- A Wireless Lan specification defined by the IEEE.
Also see IEEE 802.11 Resource Center.
- 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 the trailer bits and are of length 68 bits.
- Asynchronous Connectionless Link.One of the two types of data
links defined for the Bluetooth Systems, it is an asynchronous
(packet-switched) connection between two devices created on the LMP
level. This type of link is used primarily to transmit ACL
packet data. The other data link type is SCO.
- Authenticated Ciphering Offset.
- Active Mode
- In the active mode, the Bluetooth 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.
- 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.
- Access Point.
- 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
- 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.
- The process of verifying 'who' is at the other end of the
link. Authentication is performed for devices. In Bluetooth,
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 the current link based on the authentication
- 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.
- The baseband describes the specifications of the digital
signal processing part of the hardware -- the Bluetooth link
controller, which carries out the baseband protocols and other
low-level link routines.
- Abbreviation of Baseband.
- Bluetooth device
- 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.
- Bit Error Rate
- An open specification for wireless communication of data and
voice. It is based on a low-cost short-range radio link
facilitating protected ad hoc connections for stationary and
mobile communication environments. Also see Bluetooth
- Bluetooth clock
- Every Bluetooth unit has an internal system clock which
determines the timing and hopping of the transceiver. It is
never adjusted or turned off. It can be implemented as a 28-bit
counter, with the LSB ticking in units of 312.5us, giving a
clock rate of 3.2kHz.
- Bluetooth device class
- A parameter that indicates the type of device and which types
of services that are supported. The class is received during the
- Bluetooth service type
- One or more services a device can provide to other devices.
The service information is defined in the service class field of
the Bluetooth device class parameter.
- Bluetooth (unofficial short form).
- business card
- The electronic date equivalent to a printed business card.
This electronic version of the business card is treated like a
file and can be exchanged between Bluetooth devices.
- Channel Access Code
- 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. Also see CDMA
- A logical connection on the L2CAP level
between two devices serving a single application or higher layer
- Channel (hopping)
- This is a pseudo-random sequence of 79 (23 for the 23MHz
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
- 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.
- Circuit Switched Bluetooth
- The application of a network where a dedicated line is used to
transmit bluetooth data.
- class of device
- See Bluetooth device class.
Also abbreviated as CoD.
- Clock, typically the master
device clock which defines the timing used in the piconet.
- Clock Estimate, a slave's estimate
of the master's clock, used to
synchronise the slave device to the master.
- Clock Native, the clock of the current Bluetooth Device
- Class of Device.
- connectable device
- A Bluetooth device in range that will respond to a page
message and set up a connection
- 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.
- Cyclic Redundancy Check. 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).
- Cordless Telephone Profile.
- Continuous Variable Slope Delta Modulation.
- 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.
- Default Check Initialisation. Within Bluetooth , the DCI is
defined to be 0x00 (hexadecimal).
- 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.
- The Bluetooth device receiving an action from another
Bluetooth device. The device sending the action is called the source.
The destination is typically 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.
- Data-High Rate. An ACL link data packet
type for high rate data. DH1 packets are similar to DM1
packets, except the info in the payload is not FEC
encoded. This means the DH1 packet can carry up to 28 info bytes
and covers a single time slot. The DH3
is the same except it can cover up to 3 time slots and contain
up to 185 info bytes. The DH5 packet is the same again except it
can cover up to 5 time slots and contains up to 341 info bytes
See also Bluetooth packet types.
- Dedicated Inquiry Access Code, used when you wish to inquire
for certain, specific types of devices.
- discoverable device
- A Bluetooth device in range that will respond to an inquiry
- 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
- 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
- Data Set Ready. A device sets an RS-232 DSR signal when it is
ready to accept data.
- Data Terminal.
- 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.
- European Telecommunications Standards Institute.
- Forward Error Correction. The purpose of the FEC scheme on the
data payload is to reduce the number of retransmissions. Within
Bluetooth , there are 2 versions of this, 1/3 FEC and 2/3 FEC.
1/3 FEC is a simple 3-times repetition of each info bit. 2/3 FEC
is a (15,10) shortened Hamming code.
- Frequency Hopping.
- Frequency Hopping Synchronization. This a special control
packet revealing, among other things, the BD_ADDR
and the clock of the source
device. It contains 144 info bits and a 16-bit CRC
code. The payload is coded with a rate 2/3 FEC
which brings the total payload length to 240 bits. The FHS
packet covers a single time slot. See also Bluetooth packet
- First In, First Out.
- Frequency Hopping
- Bluetooth is characterised by its system of fast frequency
hops. 10 different types of hopping sequences are defined, 5 of
the 79 MHz range/79 hop system and 5 for
the 23 MHz range/23 hop system. The
different range system's hopping sequences differ only in
frequency range 79MHz / 23MHz, and segment length : 32
hops(79MHz system) / 16 hops(23MHz system).
- The individual hopping sequences include the page
sequence and the page
response sequence, these are used in the page
procedure. Used in the inquiry
procedure are the inquiry
sequence and the inquiry
response sequence. Finally the main hopping sequence
used in the bluetooth system is the channel
- Generic Access Profile. This profile describes the mechanism
by which one device discovers and accesses another device when
they do not share a common application.
- Gaussian Frequency Shift Keying. This is the modulation used
in the radio layer of the Bluetooth system.
- General Inquire Access Code. The default inquiry code which is
used to discover all devices in range.
- Group Management.
- Generic Object Exchange Profile.
- Global System for Mobile communications. GSM
is a digital cellular communications technology that is
available in Europe and the US. GSM offers multiple services for
the subscriber such as short message service.
- Gateway. A Bluetooth enabled base-station
which is connected to an external network.
- Host Controller Interface. An (application-optional) layer
which provides a command interface to the LMP
and Baseband layers.
- A microphone and earpiece used to conduct conversations. Headsets
can be connected directly to a cellular device or remotely using
Bluetooth communications technology.
- Header-Error-Check. An 8-bit word normally generated by using
the UAP of the master
device. There are 2 exceptions: in the case of FHS
packets using the master page response, the slave UAP is
used and for FHS packets sent in inquiry response the DCI
value is used.
- hold mode
- Devices synchronised to a piconet can enter power-saving modes
in which device activity is lowered. The master
unit can put slave units into HOLD
mode, where only an internal timer is running. Slave units can
also demand to be put into HOLD mode. Data transfer restarts
instantly when units transition out of HOLD mode. It has an
intermediate duty cycle (medium power efficient ) of the 3 power
saving modes (sniff, hold
- Headset. Also see Bluetooth
- High quality Voice. A SCO link voice
packet. HV1 packets carry 10 info bytes, which are protected by
1/3 FEC. HV2 packets carry 20 info bytes, and
are protected by 2/3 FEC. HV3 packets carry 30 info bytes, and
not protected by FEC. HV packets do not have a CRC
or payload header.See also Bluetooth packet
- Inquiry Access Code. Used in inquiry
procedures, can be one of 2 types: Dedicated
IAC, for specific devices, or Generic IAC
for all devices.
- ID packet
- A 68-bit packet used in paging , inquiry and response
routines. It is essentially the device access code (DAC)
or inquiry access code (IAC). See also
Bluetooth packet types.
- Idle mode
- A device is in idle mode when it has no established links to
other devices. In this mode, the device may discover other
devices. In general, a device sends inquiry codes (GIAC,
DIAC to other devices. Any device that
allows inquiries will respond with information. The devices may
then decide to form a link.
- Institute of Electronic and Electrical Engineering. http://www.ieee.org/
- Inquiry Procedure
- The inquiry procedure enables a device to discover which
devices are in range, and determine the addresses and clocks for
the devices. The inquiry procedure involve a unit (the source)sending
out inquiry packets (inquiry
state) and then receiving the inquiry reply .The unit
that receives the inquiry packets (the destination),
will hopefully be in the inquiry
scan state to receive the inquiry packets. The
destination will then enter the inquiry
response state and
send an inquiry reply to the source. After the
inquiry procedure has completed, a connection can be established
using the paging procedure.
- Inquiry Response State
- When a device have received an inquiry packet, it can respond
with an inquiry reply packet (an FHS packet).
It will send this using the
inquiry response hopping sequence.
- Inquiry State
- When a device wishes to discover new devices , it enters the
inquiry state, where it broadcasts inquiry packets (ID
packets), containing the IAC, to all
devices in range. It will send these using the inquiry
hopping sequence. The device in the Inquiry state can also
receive inquiry replies (FHS packets),
however it will not acknowledge these packets.
- Inquiry Scan State
- When a device wishes to receive inquiry packets it enters the
inquiry scan mode. The scanning will follow the inquiry
- Inquiry (hopping)
- This is a sequence of 32 (16 for the 23MHz system)
frequencies, The frequency is calculated using the GIAC
LAP or the DIAC LAP. The phase in the
sequence is derived from the native unit's clock.
32 frequencies are calculated , the main centre
frequency and 31 other frequencies, these have an of offset
of +/- 16. A new centre frequency is calculated every 1.28s. To
handle all 32 frequencies , the inquiry hopping sequence
switches between 2 inquiry trains , of 16 frequencies each. See
also Frequency sequence.
(hopping) response sequence
- The inquiry response sequence covers 32 (16 for the 23MHz)
unique response frequencies that all are in an one-to-one
correspondence to the current inquiry
hopping sequence. The master and slave use different rules
to obtain the same sequence. See also Frequency
- Industrial, Scientific, Medical.
- International Telecommunication Union. http://www.itu.int
The ITU, headquartered in Geneva, Switzerland is an
international organization within the United Nations System
where governments and the private sector coordinate global
telecom networks and services.
- known device
- A device for which at least the BD_ADDR
- Logical Link Controller and Adaptation Protocol. This protocol
supports higher level protocol multiplexing, packet segmentation
and reassembly, and the conveying of quality of service
- Logical Channel.
- Local Area Network.
- LAN Access Point.
- Lower Address Portion. A 24-bit section of the BD_ADDR.See
also NAP & UAP.
- Link Controller. The Link Controller manages the link to the
other Bluetooth devices. It is the low-level baseband protocol
- LC Channel
- Link Control control channel. One of the 5 logical
channels defined for the bluetooth system. It is mapped onto
the packet header. It control low level link control info. The
LC is carried in every packet except the ID
packet which has no packet header.
- Linear Feedback Shift Register. Used in bluetooth to generate
the HEC and CRC.
- link key
- The authentication key used to establish a link between
devices. See also bonding.
- Link Manager. The Link Manager software entity carries out
link setup, authentication, link configuration, and other
- LM Channel
- Link Manager control channel. One of the 5 logical
channels defined for the bluetooth system. It carries
control info exchanged between the link managers of the master
and the slave(s). It can be carried
by either the SCO or ACL
- Link Manager Protocol. The LMP is used for link setup and
control. The LMP PDU signals are interpreted and filtered out by
the Link Manager on the receiving side and are
not propagated to higher layers.
- An LMP level procedure for verifying the
identity of a remote device. The procedure is based on a
challenge-response mechanism using a random number, a secret key
and the BD_ADDR of the non-initiating
device. The secret key used can be a previously exchanged link
key or an initialization key created based on a PIN (as used
- A LMP procedure that authenticates two
devices based on a PIN and subsequently
creates a common link key that can be
used as a basis for a trusted relationship or a (single) secure
connection. The procedure consists of the steps:
- 1: creation of an initialization key (based on a random
number and a PIN),
- 2: LMP-authentication based on the initialisation key
- 3: creation of a common link key.
- Logical Channel
- There are 5 logical channels defined for the Bluetooth system.
The LC & LM
control channels, and the UA, UI
& US user channels. The LC channel is
carried in the packet header, all other channels are carried in
the packet payload. See the individual sections for more
- Least Significant Bit.
- MAC Address
- 3-bit address to distinguish between units participating in
the piconet. Within Bluetooth, this is
the AM_ADDR .
- Metropolitan Area Network.
- master device
- A device that initiates an action or requests a service on a piconet.
Also the device in a piconet whose clock and hopping sequence
are used to synchronize all other devices in the piconet.See
- Mobile Station. A generic term for the mobile device in
question (GSM phone, Bluetooth
- Most Significant Bit.
- Message Sequence Chart.
- Mobile Terminal, same as Mobile Station.
- Multiplexing Sublayer. A sublayer of the L2CAP
- Name Discovery
- The mechanism to request and receive a device name.
- Non-significant Address Portion. A 16-bit section of the BD_ADDR.
See also LAP & UAP.
- non-connectable device
- A device that does not responds to paging is said to be
in non-connectable mode. The opposite of a non-connectable
device is a connectable device.
- non-discoverable device
- A device that cannot respond to an inquiry is said to be in
non-discoverable mode. The device will not enter the inquiry
response state in this mode.
- NULL packet
- A 126-bit packet consisting of the CAC and
packet header only. It is used to return link information to the
source. The NULL packet does not have to
be acknowledged .See also Bluetooth packet
- Object EXchange Protocol.
- Packet Format
Each packet consists of 3 entities, the access
code, the packet header and the
payload. Their are a number of
different packet types.
- Packet Header
- The header contains link control info and consists of 6
fields: AM_ADDR : active member address,
TYPE : type code , FLOW : flow control, ARQN
: acknowledge indication, SEQN : sequence
number & HEC : header error check. The
total size of the header is 54-bits.
- Packet Switched
- A network that routes data packets based on an address
contained in the data packet is said to be a packet switched
network. Multiple data packets can share the same network
- Packet type
- 13 different packet types are defined for the baseband layer
of the Bluetooth system. All higher layers use these packets to
compose higher level PDU's. The packets are ID,
FHS , DM1 ; these packets
are defined for both SCO and ACL
links. DH1, AUX1, DM3,
DH3, DM5, DH5
are defined for ACL links only. HV1, HV2,
HV3 , DV are defined for SCO
- Page (hopping) sequence
- This is a sequence of 32 (16 for the 23MHz system)
frequencies, Each frequency is calculated using the unit being
paged's BD_ADDR (this was obtained
earlier, such as an inquiry
operation ). The phase in the sequence is derived from an estimate
of the unit being paged's clock. Although it should be able
to theoretically calculate the predicated hop frequency of the
unit being paged, and page it straight away, inevitably clock
drift will occur. 32 frequencies are used to handle this, using
the calculated main centre frequency and 31 other
frequencies, these have an of offset of +/- 16. A new centre
frequency is calculated every 1.28s. To handle all 32
frequencies , the page hopping sequence switches between 2
paging trains , of 16 frequencies each. See also Frequency
- Page (hopping)
- The page response sequence covers 32 (16 for the 23MHz) unique
response frequencies that all are in an one-to-one
correspondence to the current page
hopping sequence. The master and slave use different rules
to obtain the same sequence. See also Frequency
- Page (Master)
- Step 1:When the source has received a reply to it's
original page message, it will enter this state. It will then
send an FHS packet to the destination device.
It will send this using the page
- Step 2:When the source has received the second reply (Page
Slave Response State: Step2), it knows that the
destination device has received the FHS packet the source sent
in Step 1. The source is now the master
of the destination (the slave).
- Page (Slave) Response
- Step 1: Once a destination
device has received its own DAC from the source
(in the ID packet), it will enter this
state. It will send a response message (its DAC again) to the
source .It will send this using the
page response hopping sequence.
- Step 2:Once the destination device has received the FHS
packet from the source ,(Page
Master Response State: Step 1), the destination will
send a reply to the source (an ID packet containing the
- Step 3: The destination will switch to the source's
channel params. The destination is now the slave
of the source (the master).
- Page Scan State
- A mode where a device listens for page trains containing its
own device access code (DAC). When a device
wishes to receive page packets it enters the page scan mode. The
scanning will follow the page
hopping sequence. If a device receives a page packet, it
will enter the slave
- Page State
- A mode that a device enters when searching for other devices.
The device sends out a page packet (ID
packet), using the page
hopping sequence, to notify other devices that it wants to
know about the other devices and/or their services.
- Paging Procedure
- With the paging procedure, an actual connection can be
established. The paging procedure typically follows the inquiry
procedure. Only the Bluetooth device
address is required to set up a connection. Knowledge about
the clock (clock estimate) will accelerate
the setup procedure. A unit that establishes a connection will
carry out a page procedure and will automatically be the master
of the connection. The procedure occurs as follows:
- 1: A device (the source)
pages another device (the destination
) : Page state
- 2: The destination receives the page : Page
- 3: The destination sends a reply to the
source. : Slave
Response state: Step 1
- 4: The source sends an FHS packet to the
destination : Master
Response state: Step 1
The destination sends it's second reply to the source. : Slave
Response state : Step 2
- 6: The destination & source then switch
to the source channel parameters :Master
Response state: Step 2 & Slave Response
state: Step 3
- pairable mode
- A device that accepts pairing, is said to be in pairable mode.
The opposite of pairing mode is non-pairable mode.
- The creation and exchange of a link key
between two devices. The devices use the link key for future
authentication when exchanging information.
- park mode
- In the PARK mode, a device is still synchronized to the piconet
but does not participate in the traffic. Parked devices have
given up their MAC (AM_ADDR) address and
occasional listen to the traffic of the master
to re-synchronize and check on broadcast messages. It has the
lowest duty cycle (power efficiency) of all 3 power saving modes
- payload format
- Each packet payload can have one of 2 possible fields, the
data field (ACL) or the voice field (SCO).
The different packets, depending on whether they are ACL
or SCO packets can only have one of these fields. The one
exception is the DV packets which have both.
The voice field has a fixed length field, with no payload
header. The data field consists of 3 segments: a payload header,
a payload body and a CRC code (with the
exception of the AUX1 packet).
- Pulse Coded Modulation.
- Protocol Data Unit. (i.e., a message.)
- Physical link
- A synchronized Bluetooth baseband-compliant
RF hopping sequence.
It is a baseband level association between two devices
established using paging. A physical link comprises a sequence
of transmission slots on a physical
channel alternating between master and
slave transmission slots.
- A collection of devices connected via Bluetooth technology in
an ad hoc fashion. A piconet starts with two connected devices,
such as a portable PC and cellular phone, and may grow to eight
connected devices. All Bluetooth devices are peer units and have
identical implementations. However, when establishing a piconet,
one unit will act as a master and
the other(s) as slave(s) for the
duration of the piconet connection. All devices have the same
physical channel defined by the master device parameters (clock
- Personal Identification Number. The Bluetooth PIN is used to
authenticate two devices that have not previously exchanged link
key. By exchanging a PIN, the devices create a trusted
relationship. The PIN is used in the pairing
procedure to generate the initial link that is used for further
- The PIN used on the baseband level.
The PIN(BB) is used by the baseband mechanism for calculating
the initialization key during the pairing
procedure. (128 bits)
- The PIN used on the user interface level. The PIN(UI) is the
character representation of the PIN that is entered on the UI
- Parked Member Address. It is a 8-bit member (master-local)
address that separates the parked slaves.The
PM_ADDR is only valid as long as the slave is parked.
- POLL packet
- Similar to the NULL packet, except
it requires a confirmation from the destination.
Upon reception of a POLL packet the slave must respond with a
packet. See also Bluetooth packet types.
- Point to Point Protocol.
- Pseudorandom Bit Sequence.
- A description of the operation of a device or application.
- Public Switched Telephone Network. The general phone network.
- Quality of Service.
- The Radio layer of the Bluetooth system, the lowest defined
layer. It details the requirements needed for a Bluetooth device
transceiver to operate in the Bluetooth radio band . 2 different
ranges have been defined for the radio layer, a 23MHz range and
a 79MHz range , both are in the 2.4GHz ISM band. The 23MHz range
is only used in certain countries (such as Spain, France) , that
have national limitations on the amount of frequencies
available. Different hop systems
are used for both.
- Radio Frequency.
- Serial Cable Emulation Protocol based on ETSI TS 07.10.
- A serial communications interface. Serial communication
standards are defined by the Electronic Industries Association (EIA).
- Received Signal Strength Indication. An optional part of the radio
layer, used to determine the link quality and thus whether
to increase broadcast power.
- RTX Timer
- The Response Timeout eXpired timer used in the
L2CAP layer to terminate the channel when the remote
endpoint is unresponsive to signalling requests. It is started
when a signalling request is sent to a remote device.
- Short for Slave. See slave device.
- Service Access Points (APs).
- Segmentation and Reassembly. A sublayer of the L2CAP
- Multiple independent and non-synchronized piconets
form a scatternet.
- Synchronous Connection Oriented link. One of the 2 bluetooth
data link types defined.A synchronous (circuit-switched)
connection for reserved bandwidth communications, e.g. voice,
between two devices created on the LMP level
by reserving slots periodically on a physical channel. This type
of link is used primarily to transport SCO packets (voice data).
SCO packets do not include a CRC and are
never retransmitted. It primarily supports time-bounded
information like voice. (Master to single slave.) SCO links can
be established only after an ACL link has
first been established. See also ACL.
- Source Channel Identifier. Used in the L2CAP
layer to indicate the channel endpoint on the device sending
the L2CAP message. It is a device local name only. See also DCID.
- Service Discovery Application Profile.
- Service Discovery Database.
- Service Discovery Protocol. It is a Bluetooth defined protocol
for provided for or available through a Bluetooth device.
Essentially provides a means for applications to discover which
services are available and to determine the characteristics of
those available services.
- SDP client
- The SDP client may retrieve information from a service record
maintained by the SDP server by issuing an SDP request.
- SDP server
- The SDP server maintains a list of service records that
describe the characteristics of services associated with the
- SDP Session
- The exchange of information between an SDP client and an SDP
server. The exchange of information is referred to as an SDP
- SDP Transaction
- The exchange of an SDP request from an SDP client to an SDP
server, and the corresponding SDP response from an SDP server
back to the SDP client.
- Security Mode 1
- A device will not initiate any security. A non-secure mode.
- Security Mode 2
- A device does not initiate security procedures before channel
establishment on L2CAP level This mode
allows different and flexible access policies for applications,
especially running applications with different security
requirements in parallel. A service level enforced security
- Security Mode 3
- A device initiates security procedures before the link setup
on LMP level is completed. A link level
enforced security mode.
- Sequential Numbering scheme. It provides a sequential
numbering scheme to order the data packet stream.
- Serial Interface
- An interface to provide serial communications. service This
term refers to a service that one device provides for others.
Examples are printers,
PIM. synchronization servers, modems (or modem emulators).
- Service (SDP layer)
- A service is any entity that can provide information, perform
an action, or control a resource on behalf of another entity. A
service may be implemented as software, hardware, or a
combination of hardware and software.
- Service Advisor
- The portion of the UI that handles BT services for the UI.
- Service Attribute
- Each service attribute describes a single characteristic of a service.
- Service Discovery
- See SDP.
- Service Class
- Each service is an instance of a
service class. The service class definition provides the
definitions of all attributes
contained in service records that
represent the instances of that class.
- Service Layer
- The group of protocols that provides services to the
application layer and the driver layer in a Bluetooth device.
- Service Record
- A service record contains all of the information about a
service that is maintained by an SDP
- Service Record Database
- A database that contains the service
- Service Record Handle
- A service record handle is a 32-bit number that uniquely
identifies each service record
within an SDP server.
- Special Interest Group. The Bluetooth SIG is located at www.bluetooth.com.
- slave device
- A device in a piconet that is not the
master.There can be many slaves per piconet.
- sniff mode
- Devices synchronized to a piconet can enter power-saving modes
in which device activity is lowered. In the SNIFF mode, a slave
device listens to the piconet at reduced rate, thus reducing its
duty cycle. The SNIFF interval is programmable and depends on
the application. It has the highest duty cycle (least power
efficient ) of all 3 power saving modes (sniff,
hold & park).
- The Bluetooth device initiating an action to another Bluetooth
device. The device receiving the action is called the destination.
The source is typically part of an established link,
though not always ( such as in inquiry
/ page procedures).
- Scan Repetition. A mode used in the baseband
layer to determine how long the device will continue to
scan for a page response
- Transport Control Protocol/Internet Protocol ( more...
- Telephone Control protocol Specification.
- A set of AT-commands by which a mobile phone and modem can be
controlled in the multiple usage models. In BT, AT-commands are
based on ITU-T recommendation v.250 and ETS 300 916(GSM 07.07).
In addition, the commands used for fax services are specified by
the implementation. TCS-AT will also be used for dial-up
networking and headset profiles.
- TCS Binary
- Bluetooth Telephony Control protocol Specification using
bit-Oriented protocol. It is also referred to as the TCS-BIN
system. TCS-BIN will be used for cordless telephony profiles.
- Time Division Duplex
- Timer used in the General Access Profile (GAP).
- time slot
- A single time slot in the Bluetooth system lasts 625us. It can
be though of as the time it takes to send one packet
from one Bluetooth device to another
- Tiny Transport Protocol between OBEX and
- UA Channel
- User Asynchronous data channel. One of the 5 logical
channels defined for the bluetooth system. The UA channel
carries L2CAP transparent asynchronous user
data. It is normally carried in the ACL link.
- Upper Address Portion. A 8-bit section of the BD_ADDR.
See also LAP & NAP.
- Universal Asynchronous Receiver Transmitter. A device which
converts parallel data into serial data for transmission, or it
converts serial data into parallel data for receiving data.
- User Control.
- User Datagram Protocol/Internet Protocol.
- UI Channel
- User Isochronous data channel. One of the 5 logical
channels defined for the bluetooth system. The UI channel
carries L2CAP transparent isochronous user
data. It is normally carried in the ACL link.
It is supported by timing start packets at higher levels
- Universal Mobile Telecommunications System. Also see 3G
- US Channel
- User Synchronous data channel. One of the 5 logical
channels defined for the bluetooth system. The US channel
carries transparent synchronous user data. It is carried
in the SCO link only.
- Universal Unique Identifier. Used in the SDP
- Wide Area Network.
- Wireless Local Area Network. Also see IEEE
802.11 Resource Center.