Bluetooth information

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• Introduction
• Bluetooth basics
• Connecting Bluetooth devices
• Technical definitions
• Software / firmware
• Bluetooth organisation
• Summary
• Table of profiles
• Back to Dongle

1. Introduction

   This document describes the basic functionality and requirements for Bluetooth.

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2. Bluetooth basics
   
   
    
   2.1 What is Bluetooth?
   
   At the start of the Bluetooth development, Bluetooth was designed for communication between separate electronic devices. Most important functionality items are:
   • Bluetooth is a standard wireless technology. It uses Radio Frequency (RF) for communication.
   • Bluetooth has the possibility of secure communication.
   • Bluetooth communication is possible at longer distances without using cables.
   • Bluetooth communication definitions for devices are defined in profiles/services. From now on we will mention it as profiles in this document.

    

   2.2 What is required for Bluetooth?
   
   The minimum requirements for Bluetooth products are:
   1. The used devices need Bluetooth wireless functionality.
   2. The used devices need to be in each other's maximum range.
   3. The used devices need to have Bluetooth functionality switched on.
   4. The used devices need to be paired and/or connected.
   5. The used devices need to have matching Bluetooth profiles (which is a description of the Bluetooth functionality, profiles will be described later in this document).

    

   2.3 How to connect?
   
   Generally there are 5 steps for making a connection between 2 Bluetooth devices:
   1. One device has to be made discoverable/searchable (this is called slave device).
   2. One device has to search for the other (discoverable/searchable) device (this is called master device).
   3. Most of the time the slave device has to be paired with PIN-code.
   4. Select the right functionality for connection.
   5. Connect the slave device with the master device to the right profile for right functionality.

    

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3. Connecting Bluetooth devices
   
   
    

   This chapter will discuss the basic principles and steps of how to connect Bluetooth devices with each other.

   3.1Discoverable and searching mode
   
   When Bluetooth devices want to connect with each other then:
   1. Bluetooth devices must have the Bluetooth functionality turned on.
   2. Bluetooth (master) device has to search for the discoverable/searchable (slave) device.

   Most used connection method for Bluetooth slave devices is a pairing/connection button on the device.
   There are several ways for master devices, which are used for searching the slave devices:

   1. Pairing/connection button on easy to use Bluetooth (master) devices.
   2. Pairing/connection menu's for searching in more complex Bluetooth (master) devices (for example: mobile phones, Bluetooth USB adapters for computers).

    

   Note: The method, for putting Bluetooth devices in discoverable/searchable states and turning on Bluetooth functionality, varies by device and by manufacturer. The method should be described in the user's manual of the used Bluetooth products.

    

   3.2 Pairing with PIN-code
   
   To prevent strangers from accessing or connecting your Bluetooth devices, Bluetooth has built in security options. Some products require security pin-codes (sometimes called pass-codes). For example, when you use your Bluetooth USB adapter for networking between more computers, you don't want to allow strangers to access your important data on your computer freely. The security can take place in several ways. Sometimes Bluetooth devices have build-in personal identification numbers (PIN-code), which must be entered by the master Bluetooth device for pairing (see Fig. 1).
    
   
   
   Fig. 1

    

   For example: our Trust Bluetooth modem has a built in PIN-code (which is mentioned on product itself). When this modem is used with our Bluetooth USB adapters, this code must be entered when the Bluetooth modem is 'paired' with the Bluetooth USB adapter (see Fig. 2)
    

   
   
   Fig. 2

    

   Sometimes Bluetooth devices have not a built in PIN-code, but these devices require pairing (see Fig. 3). A pin-code can be freely chosen by end-users and must be entered in master and slave device.
    

   
   
   Fig. 3

    

   For example: a Bluetooth mobile phone has no built in pin-code, when it's 'paired' with a computer it needs a pin-code. The pin-code can be randomly chosen by end-user. This chosen pin-code must be typed in the computer, same as in mobile phone (see Fig. 4).
    

   
   
   Fig. 4

    

   It's possible to disable this security option in some products. However, this is depending if all used Bluetooth products have functionality of turning off the built-in security.
   For example:
   The Trust Bluetooth headset has a fixed built-in pin-code. It's not possible to disable the security, because it's fixed into the Bluetooth headset's hardware.
   Depending on the manufacturers implementation of Bluetooth, the Bluetooth devices sometimes are connected automatically after pairing. See chapter 3.3 for more information about connecting.

   3.3 Selecting functionality and connecting
   
   After Bluetooth devices have paired, sometimes the functionality of the communication has to be chosen in the master devices.
   This functionality for the Bluetooth communication is described in profiles. Profiles will be described in chapter 4.1.

    

   For example, a Bluetooth USB adapter with software can connect with a Bluetooth mobile phone (see Fig. 5)
   The phone supports several Bluetooth functions, such as:

   1. Connecting to the Internet with dial-up networking.
   2. Synchronising calendar items and contact items.
   3. Faxing.

    

   To use these different functions, the right functionality item must be connected.
   How to configure the functionality is described in the Bluetooth device manual.
   When the functionality is chosen you are connecting the Bluetooth devices with each other.

   
   
   Fig. 5

    

   Some Bluetooth products have only one main purpose for use. This means no functionality has to be chosen.
   For example: The Trust Bluetooth Headset. It has one function for wireless audio communication with for example, mobile phones or computers.

   The connecting of different Bluetooth devices with each other is also depending on the manufacturers implementation.
   Most of the time the Bluetooth devices are connected with each other
    

   1. Directly after pairing.
   2. Automatically after turning the power on of both Bluetooth devices.
   3. After pushing the pairing/connect button on both devices.
   4. When computer is used, when accessing/double clicking the Bluetooth functionality.

    

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4. Technical definitions
   
   
   4.1 Profiles
   A profile is a list of options, features or functionality for a specific Bluetooth device.
   Bluetooth devices, which want to communicate with each other, need similar profiles to be in.

    

   Important: it's important for all used Bluetooth devices to support similar profiles for them to work together

   Bluetooth wireless technology is used for much different type of applications. Profiles are descriptions of how these applications should work together.
    

   1. For example: mobile phone with Bluetooth needs the Bluetooth headset profile to communicate with a Bluetooth headset.
   2. An example of devices, which won't work together: A mouse, which is a typically Human Interface Device (HID-profile), will not work with a Bluetooth washer and dryer, because it's not a 'logical' combination. The Bluetooth washer and dryer don't support HID-profile. (FYI: Toshiba has washer and dryer with built-in Bluetooth, for automatically connecting to a washer dryer service company, when servicing is necessary).

    

   A table of profiles and functionality description is available in chapter 8.
   This is not a final list of profiles, because profiles are being added during the development of Bluetooth

    

   Example of expected functionality and mismatching profiles:
   Bluetooth mobile phone with a Bluetooth headset: It's expected the mobile phone should work with the Bluetooth headset.
   The Bluetooth headset has the Headset profile built-in. This headset profile is standardised in Bluetooth version 1.1.
   Some Bluetooth mobile phones only have the newer Handsfree profile built-in, which is not specified in Bluetooth v1.1, but is added as an extra profile (which is growing to Bluetooth version 1.2).
   So the Bluetooth mobile phone does not work, with the Bluetooth headset. (See Fig. 6)
    

   
   
   Fig. 6

    

   Possible solutions for this problem:
    

   1. Mobile phone manufacturer could build in the Headset profile next to Handsfree profile
   2. Headset manufacturer could build in the Handsfree profile next to Headset profile

    

   4.2 Wireless range
   The class of a Bluetooth device is a definition of maximum wireless range of possible Bluetooth communication.
   It's divided in 3 classes:
    

   1. Class I - communication possible with maximum distance of 100 meter.
   2. Class II - communication possible with maximum distance of 10 meter.
   3. Class III - communication at very short distance (this is rarely used).

    

   The maximum communication distance between 2 Bluetooth devices is depending on the devices with the lowest class.
   See Fig. 7, Fig. 8 and Fig. 9. This is caused by the lowest transmission power of the lower used class.
    

   
   
   Fig. 7
   
    
   
   
   Fig. 8
   
    
   
   
   Fig. 9

    

   Bluetooth is a Radio Frequency Technology. So it is not necessary for Bluetooth devices to be 'in sight' of each other.
   The radio frequency can pass through objects, like walls, ceilings, etc. Keep in mind: the maximum distance will be decreased when objects are in between.
   For example when a ceiling is between 2 class I Bluetooth products, the maximum communication distance can decrease to 50m (depending on ceiling material).

   4.3 Bluetooth 'network' structures
   A Bluetooth connection always has a master and slave configuration.
   A master Bluetooth device can connect to a maximum of 7 slave devices. It's possible to connect 2 masters to each other. One of the masters will become a slave to the other master.
   The device that initiates the connection automatically becomes the master.
   A Bluetooth network can exist in 3 ways (see Fig. 10):
    

   1. Point-to-point (example: Bluetooth mobile phone with Bluetooth headset).
   2. Point-to-multipoint, this is called a piconet (example: Fig. 11).
   3. Linked point-to-multipoint, this is called a scatternet (this is rarely used).
   
   
   Fig. 10

    

   Example of a 'less' complex Point-to-multipoint piconet (see Fig. 11)
    

   
   
   Fig. 11

    

   Configuration:
   Computer with Bluetooth is master.
   Bluetooth Tablet, Bluetooth USB printer adapter and Bluetooth mobile phone are slaves.
   The Tablet is used as a mouse and for editing the picture. With the tablet/mouse functionality it's possible to control your computer system and access the mobile phones pictures with Windows Explorer. These pictures can be printed directly to the printer using the Bluetooth USB printer adapter.

   Example of a linked point-to-multipoint 'scatternet' (see Fig. 12)
    

   
   
   Fig. 12

    

   Configuration:
   One computer is master and accessing different slave Bluetooth devices, such as Bluetooth printer, Bluetooth digital camera, etc. The master computer is also connected to another master computer. The other master computer is slave to the 'central' master computer. But, this slave computer is master to his Bluetooth networking slave computers.

   4.4 Speed
   The approximate speed of Bluetooth products to work with is: 720 kbps

   4.5 Bluetooth versions
   Bluetooth version 1.0 is 1st version of Bluetooth. This version is rarely being used at this moment.
   The Bluetooth standard version at this moment is 1.1 and is 'growing' to Bluetooth version 1.2.
   The difference between current Bluetooth v1.1 and later Bluetooth v1.2 is:
    

   1. Adding of profiles/services.
   2. Upgrading hardware functionality for better Bluetooth communication (backwards compatible to previous versions of Bluetooth).
   3. New Enhance Data Rate transfer for transferring speed of data up to 2.1 Mbps.
   4. Bluetooth v1.2 will have over 30 profiles (v1.1. only has 13 profiles defined*)

    

   * Some of the future Bluetooth version 1.2 profiles are already used in Bluetooth version 1.1 products. Not all Bluetooth version 1.1 products support these profiles. This is reason why it must be determined which profiles the Bluetooth products have build in. Knowing the supported profiles, is more important than knowing if the Bluetooth product is version 1.1 compatible.

    

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5. Software / firmware
   
   
   Bluetooth is developed in software. The hardware of Bluetooth has been defined already; only the new Bluetooth version 1.2 will have some minor hardware changes, and must be backwards compatible to Bluetooth version 1.1.
   Since Bluetooth is mainly software, it's possible for manufacturers to add Bluetooth functionality each time after developing with software.
   Hardware Bluetooth products, like Bluetooth mobile phones have a build-in chip with software, this software is called firmware.
   Examples of Bluetooth features that can be build in, in later stadium in the software/firmware:
    
   • Security can be upgraded.
   • Automatically reconnect can be integrated.
   • Bluetooth profiles can be added.

    

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6. Bluetooth organisation
   
   
   The features and upgrades from the Bluetooth functionality have to be tested by the Bluetooth Special Interest Group. Added profiles are 'controlled' by this special Bluetooth organisation.
   Before a manufacturer can put the official Bluetooth logo on his Bluetooth product, the manufacturer has to be a member of the Bluetooth organisation.
   This organisation offers the possibility to have the Bluetooth products certified in the Bluetooth Qualification program. The product gets a Bluetooth Qualification Body (BQB), when it's fully Bluetooth compatible.
    

    

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7. Summary
   
   
   Most important reminders are:
    
   • For Bluetooth wireless communication, it's needed all used devices need Bluetooth build-in functionality.
   • Bluetooth products need to be in each other range before connecting.
   • Bluetooth products need to have the Bluetooth functionality switched on.
   • Bluetooth products need to be discoverable/searchable and searched for before connecting.
   • Most Bluetooth products need to be paired before connecting.
   • Bluetooth products need similar profiles to communicate with each other.

   Hints:
    

   • Before trying to connect Bluetooth products with each other, find out if the Bluetooth devices have similar profiles/services build-in.
   • Read the manuals of all used Bluetooth products before trying to connect.

    

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8. Table of profiles
   
   
    

   Acronym	Profile name	Description
   A2DP	Advanced Audio Distribution Profile	Specifies the protocols and procedures that define the distribution of high quality audio content.
   AVRCP	Audio Video Remote Control Profile	Specifies the features and procedures that ensure interoperability between Bluetooth devices with audio/video control functions.
   BIP	Basic Imaging Profile	Defines the requirements for Bluetooth devices necessary to support the Basic Imaging Profile usage models.
   BPP	Basic Printing Profile	Defines requirements for Bluetooth enabled printers.
   CIP	Common ISDN Access Profile	Defines provision of ISDN services over Bluetooth in a way that allows application interfaces to be implemented without loss of backward compatibility to existing (legacy) ISDN applications.
   CTP	Cordless Telephony Profile	Forwarding telephone calls to Bluetooth devices.
   DUN	Dial Up Networking Profile	A Bluetooth link to a modem.
   ESDP	Extended Service Discovery Profile	Defines how devices with Bluetooth wireless communications can use the Bluetooth Service Discovery Protocol (SDP) initially to discover other devices that support UPnP services and retrieve information about these services.
   FAX	Fax Profile	Defines how to transfer a fax over Bluetooth
   FTP	File Transfer Profile Specification	Transferring files between Bluetooth devices.
   GAP	Generic Access Profile	Defines the basic rules for using the protocol stack and is the foundation for all other profiles.
   GAVDP	Generic Audio Video Distribution Profile	Generic definition used in a Bluetooth device for the distribution of audio/video content using an ACL channel.
   GOEP	Generic Object Exchange Profile	A set of rules for using OBEX, which supports file transfer, object push and synchronization profiles.
   HCRP	Hard Cable Replacement Profile	Includes printing and scanning of documents.
   HFP	Hands Free Profile	Defines the interactions for hands free devices, for example cellular phone with a Bluetooth in-car kit. This profile provides means for both remote control of the device and voice connections.
   HID	Human Interface Device Profile	Defines the protocols, procedures, and the features that shall be used by Bluetooth Human Interface Devices, such as keyboards, pointing devices, gaming devices, and remote monitoring devices.
   HP	Headset Profile	A duplex link to a headset, controlled by an audio gateway, such as mobile phone.
   ICP	Intercom Telephony Profile	Short-range voice connections between Bluetooth devices.
   LPP	Local Positioning Profile	Defines a mechanism and formats for the transfer of position related data over Bluetooth. The profile supports position determination and location awareness.
   OPP	Object Push Profile	Pushing objects from a Bluetooth enabled server to a client.
   PAN	Personal Area Network Profile	Makes two or more Bluetooth enabled devices form an ad-hoc network and access a remote network through a network access point with the same mechanism.
   SDAP	Service Discovery Application Profile	Defines the features and procedures for an application in a Bluetooth device to discover services registered in other Bluetooth devices and retrieves any desired available information pertinent to these services.
   SIM	SIM Access Profile	Defines protocols and procedures used to access a SIM card via a Bluetooth link.
   SPP	Serial Port Profile	Defines how RFCOMM's serial port emulation should be used in Bluetooth products
   SYNCH	Synchronization Profile	Synchronizing objects between Bluetooth devices.
   UDI	UDI Profile	Defines the protocols and procedures that shall be used by devices implementing the UDI part of the usage model called "UDI for the 3rd generation (3G) mobile phone systems". UDI is a bearer service for telephony, which provides synchronous data communication.
   VCP	Video Conferencing Profile	Defines the requirements for Bluetooth devices necessary for support video conferencing.
   VDP	Video Distribution Profile	Defines the requirements for Bluetooth devices necessary for support of video distribution.
   WAP	WAP Over Bluetooth	Defines how Bluetooth enabled devices can access WAP services over the PAN Profile. The profile also defines how WAP servers can Push WAP services to Bluetooth enabled devices.

   Table 1

    

   Trust products and supported profiles Q4, 2004

   Item no	Product name	Bluetooth profiles
   14117	BT446 Wireless Bluetooth Tablet	HID
   14107	BT310 Bluetooth USB Printer Adapter	HCRP, SPP
   13854	56K V92 Bluetooth Wireless Modem	DUN, FAX, SPP
   13853	BT180 class1 USB Bluetooth Adapter	DUN, FAX, FTP, HCRP, HEADSET, LAN, OPP, PAN, SPP, SYNCH
   13428	BT120 USB Bluetooth Adapter	DUN, FAX, FTP, HCRP, HEADSET, LAN, OPP, PAN, SPP, SYNCH
   13909	BT210 Bluetooth Headset	HEADSET
   14219	BT220 Headset	HEADSET, HANDSFREE
   14271	HS-8100 Bluetooth Car Kit	HEADSET, HANDSFREE
   14182	MI-5500X Bluetooth Optical Mouse	HID
   14298	MI-5400X Bluetooth Optical Mouse	HID
   14231	MI-5300M Bluetooth Optical Mouse	HID
   14377	BT-1300Tp Bluetooth USB Adapter	DUN, FAX, FTP, HCRP, HEADSET, LAN, OPP, PAN, SPP, SYNCH,BIP,GAVDP,A2DP,AVRCP

   Table 2  
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