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Baseband

​​Assigned numbers for Baseband identifies the Inquiry Access codes and Class of Device/Service (CoD) fields.

Bluetooth® Baseband

The General- and Device-specific Inquiry Access Codes (DIACs)

The Inquiry Access Code (IAC) is the first level of filtering for finding Bluetooth devices and services. The main purpose of defining multiple IACs is to limit the number of responses when scanning devices within range.

#LAP ValueUsage
00x9E8B33General/Unlimited Inquiry Access Code (GIAC)
10x9E8B00Limited Dedicated Inquiry Access Code (LIAC)
2 630x9E8B01-0x9E8B32, 0x9E8B34-0x9E8B3FRESERVED FOR FUTURE USE

Table 1: Inquiry Access Codes

The Limited Inquiry Access Code (LIAC) is to be used only for limited periods in scenarios where both sides have been explicitly caused to enter this state, usually by user action. For further explanation of the use of the LIAC, please refer to the Generic Access Profile.

In contrast, it is allowed to continuously scan for the General Inquiry Access Code (GIAC) and respond whenever inquired.

The Class of Device/Service field

The Class of Device/Service (CoD) field has a variable format. The format is indicated using the "Format Type field" within the CoD. The length of the Format Type field is variable and ends with two bits different from "11." The version field starts at the least significant bit of the CoD and may extend upward.

In the "format #1" of the CoD (Format Type field = 00), 11 bits are assigned as a bit-mask (multiple bits can be set), each bit corresponding to a high-level generic category of service class. Currently, seven categories are defined. These are primarily of a "public service" nature. The remaining 11 bits are used to indicate device type category and other device-specific characteristics.Any reserved but otherwise unassigned bits, such as in the Major Service Class field, should be set to zero.

Major Service Classes

The Major and Minor Service classes define the general families of devices with which Bluetooth SIG members want their applications to be associated. No assumptions about the specific functionality or characteristics of any application should be based solely on its inclusion within a Major or Minor device class.

Bit No.Major Service Class
13Limited Discoverable Mode [Ref #1]
14(reserved)
15(reserved)
16Positioning (Location identification)
17Networking (LAN, Ad hoc, ...)
18Rendering (Printing, Speakers, ...)
19Capturing (Scanner, Microphone, ...)
20Object Transfer (v-Inbox, v-Folder, ...)
21Audio (Speaker, Microphone, Headset service, ...)
22Telephony (Cordless telephony, Modem, Headset service, ...)
23Information (WEB-server, WAP-server, ...)

Table 2: Major Service Classes

[Ref #1: See Generic Access Profile (please refer to the Generic Access Profile within the respective Core Specification)]

Major Device Classes

The Major Device Class segment is the highest level of granularity for defining a Bluetooth device. A device's main function determines its Major Class assignment. There are 32 major classes. The assignment of this Major Class field is defined in the table.

12111098Major Device Class
00000Miscellaneous [Ref #2]
00001Computer (desktop, notebook, PDA, organizer, ... )
00010Phone (cellular, cordless, pay phone, modem, ...)
00011LAN /Network Access point
00100Audio/Video (headset, speaker, stereo, video display, VCR, ...
00101Peripheral (mouse, joystick, keyboard, ... )
00110Imaging (printer, scanner, camera, display, ...)
00111Wearable
01000Toy
01001Health
11111Uncategorized: device code not specified
XXXXXAll other values reserved

Table 3: Major Device Classes

[Ref #2: Used where a more specific Major Device Class code is not suitable (but only as specified in this document). A device that does not have a major class code assigned can use the all-1 code until "classified."]

The Minor Device Class field

The Minor Device Class field (bits 7 to 2 in the CoD) is interpreted only in the context of the Major Device Class (but independently of the Service Class field). Thus, the meaning of the bits may change, depending on the value of the Major Device Class field. When the Minor Device Class field indicates a device class, then the primary device class should be reported – e.g., a cellular phone that can also work as a cordless handset should use "Cellular" in the Minor Device Class field.

Minor Device Class field - Computer Major Class

765432Minor Device Class bit no. of CoD
000000Uncategorized, code for device not assigned
000001Desktop workstation
000010Server-class computer
000011Laptop
000100Handheld PC/PDA (clamshell)
000101Palm-size PC/PDA
000110Wearable computer (watch size)
000111Tablet
XXXXXXAll other values reserved

Table 4: Sub-device Class field for the "Computer" Major Class

Minor Device Class field - Phone Major Class

765432Minor Device Class bit no. of CoD
000000Uncategorized, code for device not assigned
000001Cellular
000010Cordless
000011Smartphone
000100Wired modem or voice gateway
000101Common ISDN access
XXXXXXAll other values reserved

Table 5: Sub-device Classes for the "Phone" Major Class

Minor Device Class field - LAN/Network Access Point Major Class

765Minor Device Class bit no. of CoD
000Fully available
0011% to 17% utilized
01017% to 33% utilized
01133% to 50% utilized
10050% to 67% utilized
10167% to 83% utilized
11083% to 99% utilized
111No service available
XXXAll other values reserved

Table 6: The LAN/Network Access Point Load Factor field

The exact loading formula is not standardized. It is up to each LAN/Network Access Point implementation to determine what internal conditions to report as a utilization percentage. The only requirement is for the number to reflect an ever-increasing utilization of communication resources within the box. As a recommendation: a client locating multiple LAN/Network Access Points should attempt to connect to the one reporting the lowest load.

432Minor Device Class bit no. of CoD
000Uncategorized (use this value if no others apply)
XXXAll other values reserved

Table 7: Reserved sub-field for the LAN/Network Access Point

Minor Device Class field - Audio/Video Major Class

765432Minor Device Class bit no. of CoD
000000Uncategorized, code not assigned
000001Wearable Headset Device
000010Hands-free Device
000011(Reserved)
000100Microphone
000101Loudspeaker
000110Headphones
000111Portable Audio
001000Car audio
001001Set-top box
001010HiFi Audio Device
001011VCR
001100Video Camera
001101Camcorder
001110Video Monitor
001111Video Display and Loudspeaker
010000Video Conferencing
010001(Reserved)
010010Gaming/Toy
XXXXXXAll other values reserved

Table 8: Sub-device Classes for the "Audio/Video" Major Class

Minor Device Class field - Peripheral Major Class

76Minor Device Class bit no. of CoD
00Not Keyboard / Not Pointing Device
01Keyboard
10Pointing device
11Combo keyboard/pointing device

Table 9: The Peripheral Major Class keyboard/pointing device field

Bits six and seven independently specify mouse, keyboard or combo mouse/keyboard devices. These may be combined with the lower bits in a multifunctional device.

5432Minor Device Class bit no. of CoD
0000Uncategorized device
0001Joystick
0010Gamepad
0011Remote control
0100Sensing device
0101Digitizer tablet
0110Card Reader (e.g. SIM Card Reader)
0111Digital Pen
1000Handheld scanner for bar-codes, RFID, etc.
1001Handheld gestural input device (e.g., "wand" form factor)
XXXXAll other values reserved

Table 10: Minor Class bits two to five for Peripheral Major Class

Minor Device Class field - Imaging Major Class

7654Minor Device Class bit no. of CoD
XXX1Display
XX1XCamera
X1XXScanner
1XXXPrinter
XXXXAll other values reserved

Table 11: The Imaging Major Class bits four to seven

Bits four to seven independently specify display, camera, scanner or printer. These may be combined in a multifunctional device.

32Minor Device Class bit no. of CoD
00Uncategorized, default
XXAll other values reserved

Table 12: The Imaging Major Class bits two and three

Bits two and three are reserved

Minor Device Class field - Wearable Major Class

The Minor Class segment is the lowest level of granularity for defining a Bluetooth Device. There are 64 different possible minor classes.

765432Minor Device Class bit no. of CoD
000001Wristwatch
000010Pager
000011Jacket
000100Helmet
000101Glasses
XXXXXXAll other values reserved

Minor Device Class field - Toy Major Class

765432Minor Device Class bit no. of CoD
000001Robot
000010Vehicle
000011Doll / Action figure
000100Controller
000101Game
XXXXXXAll other values reserved

Minor Device Class field - Health

765432Minor Device Class bit no. of CoD
000000Undefined
000001Blood Pressure Monitor
000010Thermometer
000011Weighing Scale
000100Glucose Meter
000101Pulse Oximeter
000110Heart/Pulse Rate Monitor
000111Health Data Display
001000Step Counter
001001Body Composition Analyzer
001010Peak Flow Monitor
001011Medication Monitor
001100Knee Prosthesis
001101Ankle Prosthesis
001110Generic Health Manager
001111Personal Mobility Device
XXXXXXAll other values reserved
 
Specification