BT Designer: Glossary: F - J

F | G | H | I | J

F Final bit: bit 5 in RFCOMM command field for frames carrying a response. Identifies whether a response to the frame is expected.

FCC Federal Communications Commission: U.S.A. regulatory body which sets regulations for type approval of radios.

FCon RFCOMM command used to switch on flow control.

FCoff RFCOMM command used to switch off flow control.

FCS Frame Check Sequence: used to check for errors in a packet.

FDM Frequency Division Multiplexing: dividing up a radio channel between users by allowing each user a different radio frequency.

FEC Forward Error Correction. The purpose of the FEC scheme on the data payload is to reduce the number of retransmissions. Within Bluetooth technology, 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.

FH Frequency Hopping.

FHS 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. Thepayload 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 types.

FHSS Frequency Hop Spread Spectrum: a modulations technique which spreads data across the entire transmission spectrum by transmitting successive data on different channels ("hopping").

FIFO First In, First Out.

Friendly Name A test device name which can easily be read by a human. Rather than the hexadecimal digits of a Bluetooth device address, "Joe's laptop" is easier to read.

Frequency Hopping Selection Bluetooth wireless technology 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 hopping sequence.

FSK Frequency Shift Keying: a type of modulation where values are represented by a change of frequency.

FW FirmWare: programs which are stored on a chip, such as programs in a Flash Memory, or boot PROMS.

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G

GAP 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.

Gateway A device that acts as an intermediary, allowing otherwise incompatible systems to communicate.

GFSK Gaussian Frequency Shift Keying. This is the modulation used in the radio layer of the Bluetooth wireless system.

GIAC General Inquire Access Code. The default inquiry code which is used to discover all devices in range.

GM Group Management.

GOEP Generic Object Exchange Profile.

GPRS General Packet Radio Service: a specification for providing packet data services over the GSM system.

GPSK Gaussian Phase Shift Keying: a modulation technique that represents a data bit by a shift in phase.

GSM 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.

GSM07.10 A standard for emulating multiple series cables used in a GSM system.

W Gateway A Bluetooth wireless enabled basestation which is connected to an external network.

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H

HA Host Application: software running on a Bluetooth host host on top of the Bluetooth stack.

HCI Host Controller Interface. An (application-optional) layer which provides a command interface to the LMP and Baseband layers.

HDLC High-level Data Link Control procedures: the HDLC layer ensures that data passed to higher layers has been received exactly as it was transmitted with no errors. It also looks after flow control. Headset A microphone and earpiece used to conduct conversations. Headsets can be connected directly to a cellular device or remotely using Bluetooth communications technology.

HEC 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.

HI Header Id: used in OBEX headers, this identifies the type of data being carried in a header.

HID Human Interface Device: i.e. a PC mouse.

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 & park).

Hop Sequence Bluetooth devices retune their radios on to a new frequency in a pseudo-random sequence called a hop sequence or frequency hop sequence.

Host A device implementing Bluetooth higher layers which controls a separate module providing the Bluetooth lower layers.

HRFWG Home RF Working Group: organization which defines home RF standards.

HS Headset.

HTML HyperText Markup Language: a language used to define world wide web pages.

HTTP HyperText Transfer Protocol: the protocol used to transfer web pages written in HTML. The protocol is used to follow links from one web page to another.

HV 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 types.

HW HardWare: the physical electronics part of a system, as opposed to software (programs).

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I

IAC Inquiry Access Code. Used in inquiry procedures, can be one of 2 types: Dedicated IAC, for specific devices, or Generic IAC for all devices.

ICS Information Conformance Statement: a statement of the capabilities of a Bluetooth device, and profiles which the device supports.

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.

IEC International Electrotechnical Commission: the international standards and conformity assessment body for electrotechnology (electricity, electronics, and related technologies).

IEEE Institute of Electronic and Electrical Engineering.

IETF Internet Engineering Task Force.

Ind A suffix used on signals from lower layers to higher layers when notifying higher layers of events happening in lower layers. Ind is an abbreviation of "Indication".

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 When a device have received an inquiry packet, it can respond with an State 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 hopping sequence.

Inquiry (hopping) This is a sequence of 32 (16 for the 23MHz system) frequencies, The Sequence 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.

IP Internet Protocol.

IP Intellectual Property: This usually refers to owned, or licensed or sold IP between companies, in the form of ideas, designs, and patents.

IPR Intellectual Property Rights.

IrCOMM Provides COM (serial or parallel) port emulation or connections using IrDA protocol.

IrDA Infrared Data Association: an organisation that defines the infrared communications protocol. A protocol used by many laptops and mobile cellular phones to exchange data at short ranges.

IRPA International Radiation Protection Association.

ISDN Integrated Services Digital Network: high bandwidth combined digital data and voice telephony service.

ISM Industrial, Scientific, Medical.

Isochronous Information which must be transferred within a fixed time; for instance, compressed video is isochronous, because its quality is affected if it is delayed by varying amounts.

ISR Interrupt Service Routine.

ITU International Telecommunication Union.

IUT Implementation Under Test.

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J

 

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