This post explains what Bluetooth profiles are and how they work. Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances using UHF radio waves in the ISM bands, from 2.402 to 2.48 GHz, and building personal area networks (PANs). It is mainly used as an alternative to wire connections, to exchange files between nearby portable devices, and connect cell phones and music players with wireless headphones.
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What is a Bluetooth profile?
A Bluetooth profile is a wireless interface specification for Bluetooth-based communication between devices, such as the Hands-Free profile. For a mobile device to connect to a wireless headset, both devices must support the Hands-Free profile.
Here are some Bluetooth profiles and how they work:
1. A2DP
The Advanced Audio Distribution Profile (A2DP) profile defines how high-quality audio can be streamed from one device to another over a Bluetooth connection. Android provides the BluetoothA2dp class, which is a proxy for controlling the Bluetooth A2DP Service.
2. Headset
The Headset profile provides support for Bluetooth headsets to be used with mobile phones. Android provides the BluetoothHeadset class, which is a proxy for controlling the Bluetooth Headset Service. This includes both Bluetooth Headset and Hands-Free (v1.5) profiles. The BluetoothHeadset class includes support for AT commands.
3. Health Device
Android provides support for the Bluetooth Health Device Profile (HDP). This lets you create apps that use Bluetooth to communicate with health devices that support Bluetooth, such as heart-rate monitors, blood meters, thermometers, scales, and so on.
4. Basic Imaging Profile (BIP)
This Bluetooth profile details how an imaging device can be remotely controlled, how it may print, and how it can transfer images to a storage device. This Bluetooth profile is naturally intended for cameras and other devices that can take pictures, including mobile phones now.
The Basic Image Profile, BIP defines two roles:
- Imaging Initiator: This is the device that initiates this feature.
- Imaging Responder: As the name implies, this is the device that responds to the initiator.
The overall profile may be considered to have the following actions:
- Image Push: This function allows the sending of an image from a device controlled by the user.
- Image Pull: This function within the Bluetooth profile allows browsing and retrieval of images from a remote device, i.e. pulling images from a remote source.
- Advanced Image Printing: This provides for the printing of images using a number of advanced options.
- Automatic Archive: This function enables the automatic backup of all new images from a target.
- Remote Camera: This function allows the remote control of a camera by an initiator.
- Remote Display: This allows for the Imaging Initiator to push images to another device for display
5. Basic Printing Profile (BPP)
This Bluetooth profile allows devices to send text, e-mails, v-cards, images, or other information to printers based on print jobs.
As would be expected from the Basic Printing Profile, BPP defines two roles:
- Printer: This is the device that manipulates the data to be printed. Typically this would be a physical printer.
- Sender: This is a device, possibly a mobile phone or another form of user equipment, UE, that needs to print some data, but without wanting the full overhead of a print driver.
The advantage of using the Basic Print Profile, BPP rather than the HCRP is that it does not need any printer-specific drivers. This makes it particularly applicable for use with embedded devices such as mobile phones and digital cameras.
6. Common ISDN Access Profile (CIP)
This Bluetooth profile details the way in which ISDN traffic can be transferred via a Bluetooth wireless connection. It is typically used in Bluetooth-enabled office equipment that is ISDN enabled.
The CIP defines two roles within the Bluetooth profile:
- Firstly; Access Point (AP): This node is connected to the external network and acts as an endpoint for it. It handles all the interworking associated with the external ISDN
- Secondly; ISDN Client (IC): This is the remote node accessing the Access Point via the Bluetooth wireless network or link
7. Cordless Telephony Profile (CTP)
This Bluetooth profile defines how a cordless phone can be implemented using Bluetooth. This Bluetooth profile is aimed at use for either a dedicated cordless phone or a mobile phone acting as a cordless phone when close to a CTP enabled base station. The aim of this Bluetooth profile was to allow a mobile phone to use a Bluetooth CTP gateway connected to a landline when within the home or office, and then use the mobile phone network when elsewhere.
Two roles are defined within this Bluetooth profile:
- Terminal (TL): This is the user equipment, and maybe a cordless phone or a mobile phone, etc.
- Gateway (GW): The gateway acts as the access point for the terminal to the landline or other network.
8. Dial-Up Network Profile (DUN)
This Bluetooth profile details a standard for accessing the Internet and other dial-up services via a Bluetooth system. This may be required when accessing the Internet from a laptop by when using a mobile phone, PDA, etc as a wireless dial-up modem.
This user Bluetooth profile defines two roles for the Bluetooth nodes:
- Gateway (GW): This is the Bluetooth node or device that provides the access to the public network and ultimately the Internet.
- Data Terminal (DT): This is the remote node that interfaces with the Gateway via the Bluetooth wireless link.
9. Fax Profile (FAX)
This Bluetooth profile defines how a FAX gateway device can be used. This Bluetooth profile may be needed when a personal computer uses a mobile phone as a FAX gateway to send a FAX.
There are two roles for this Bluetooth profile
- Firstly; Gateway (GW): This is the Bluetooth-enabled device that provides facsimile services.
- Secondly; Data Terminal (DT): This device connects via the Bluetooth wireless link to be able to send its FAX.
10. File Transfer Profile (FTP)
This Bluetooth profile details the way in which folders and files on a server can be browsed by a client device. This Bluetooth profile may be used for transferring files wirelessly between two PCs or laptops, or browsing and retrieving files on a server.
Two roles are defined for this Bluetooth profile:
- Client: This is the device that initiates the operation and pushes or pulls the files to or from the server.
- Server: This is the target device and it is remote from the device that pushes or pulls the files.
Those are some of the Bluetooth profiles and how they work.