What is the iBeacon Bluetooth Profile
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What is the iBeacon Bluetooth Profile
I'd like to create my own iBeacon with some bluetooth low energy dev kits. Apple has yet to release a specification for iBeacons, however a few hardware developers have reverse Engineered the iBeacon from the AirLocate Sample code and started selling iBeacon dev kits.
So what is the iBeacon Bluetooth Profile?
Bluetooth Low Energy uses GATT for LE profile service discovery. So I think we need to know the Attribute Handle, Attribute Type, Attribute Value, and maybe the Attribute Permissions of the iBeacon attribute. So for an iBeacon with a UUID of E2C56DB5-DFFB-48D2-B060-D0F5A71096E0 a major value of 1 and a minor value of 1 what would the Bluetooth GATT profile service be?
Heres some assumptions I've made from the discussion on Apple's forums and through the docs.
You only need to see the profile service (GATT) of a Bluetooth peripheral to know it is an iBeacon.
The Major and Minor keys are encoded somewhere in this profile service
Heres some companies with iBeacon Dev Kits that seem to have this figure out already:
Hopefully in time we will have a profile posted on Bluetooth.org like these: https://www.bluetooth.org/en-us/specification/adopted-specifications
Answer by sandeepmistry for What is the iBeacon Bluetooth Profile
It seems to based on advertisement data, particularly the manufacturer data:
4C00 02 15 585CDE931B0142CC9A1325009BEDC65E 0000 0000 C5 - Apple Company Identifier (Little Endian), 0x004c
- data type, 0x02 => iBeacon
- data length, 0x15 = 21
- uuid: 585CDE931B0142CC9A1325009BEDC65E
- major: 0000
- minor: 0000
- meaured power at 1 meter: 0xc5 = -59
I have this node.js script working on Linux with the sample AirLocate app example.
Answer by davidgyoung for What is the iBeacon Bluetooth Profile
For an iBeacon with ProximityUUID E2C56DB5-DFFB-48D2-B060-D0F5A71096E0, major 0, minor 0, and calibrated Tx Power of -59 RSSI, the transmitted BLE advertisement packet looks like this:
d6 be 89 8e 40 24 05 a2 17 6e 3d 71 02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 52 ab 8d 38 a5
This packet can be broken down as follows:
d6 be 89 8e # Access address for advertising data (this is always the same fixed value) 40 # Advertising Channel PDU Header byte 0. Contains: (type = 0), (tx add = 1), (rx add = 0) 24 # Advertising Channel PDU Header byte 1. Contains: (length = total bytes of the advertising payload + 6 bytes for the BLE mac address.) 05 a2 17 6e 3d 71 # Bluetooth Mac address (note this is a spoofed address) 02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 # Bluetooth advertisement 52 ab 8d 38 a5 # checksum The key part of that packet is the Bluetooth Advertisement, which can be broken down like this:
02 # Number of bytes that follow in first AD structure 01 # Flags AD type 1A # Flags value 0x1A = 000011010 bit 0 (OFF) LE Limited Discoverable Mode bit 1 (ON) LE General Discoverable Mode bit 2 (OFF) BR/EDR Not Supported bit 3 (ON) Simultaneous LE and BR/EDR to Same Device Capable (controller) bit 4 (ON) Simultaneous LE and BR/EDR to Same Device Capable (Host) 1A # Number of bytes that follow in second (and last) AD structure FF # Manufacturer specific data AD type 4C 00 # Company identifier code (0x004C == Apple) 02 # Byte 0 of iBeacon advertisement indicator 15 # Byte 1 of iBeacon advertisement indicator e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 # iBeacon proximity uuid 00 00 # major 00 00 # minor c5 # The 2's complement of the calibrated Tx Power Any Bluetooth LE device that can be configured to send a specific advertisement can generate the above packet. I have configured a Linux computer using Bluez to send this advertisement, and iOS7 devices running Apple's AirLocate test code pick it up as an iBeacon with the fields specified above. See: Use BlueZ Stack As A Peripheral (Advertiser)
This blog has full details about the reverse engineering process.
Answer by slackhappy for What is the iBeacon Bluetooth Profile
Just to reconcile the difference between sandeepmistry's answer and davidgyoung's answer:
02 01 1a 1a ff 4C 00 Is part of the advertising data format specification [1]
02 # length of following AD structure 01 # <> AD Structure [2] 1a # read as b00011010. # In this case, LE General Discoverable, # and simultaneous BR/EDR but this may vary by device! 1a # length of following AD structure FF # Manufacturer specific data [3] 4C00 # Apple Inc [4] 0215 # ?? some 2-byte header Missing from the AD is a Service [5] definition. I think the iBeacon protocol itself has no relationship to the GATT and standard service discovery. If you download RedBearLab's iBeacon program, you'll see that they happen to use the GATT for configuring the advertisement parameters, but this seems to be specific to their implementation, and not part of the spec. The AirLocate program doesn't seem to use the GATT for configuration, for instance, according to LightBlue and or other similar programs I tried.
References:
- Core Bluetooth Spec v4, Vol 3, Part C, 11
- Vol 3, Part C, 18.1
- Vol 3, Part C, 18.11
- https://www.bluetooth.org/en-us/specification/assigned-numbers/company-identifiers
- Vol 3, Part C, 18.2
Answer by Senseful for What is the iBeacon Bluetooth Profile
If the reason you ask this question is because you want to use Core Bluetooth to advertise as an iBeacon rather than using the standard API, you can easily do so by advertising an NSDictionary such as:
{ kCBAdvDataAppleBeaconKey = ; } See this answer for more information.
Answer by Amit Shelgaonkar for What is the iBeacon Bluetooth Profile
It?s very simple, it just advertises a string which contains a few characters conforming to Apple?s iBeacon standard. you can refer the Link http://glimwormbeacons.com/learn/what-makes-an-ibeacon-an-ibeacon/
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