28
Future Developments

When the Bluetooth SIG was originally formed, its aim was simply to produce version 1.0 of the Bluetooth specification. The plan was to dissolve the SIG at that point. As time went by, it became obvious that more could be done with Bluetooth in many ways:

• Version 1.0 was produced in a hurry and still needed corrections and clarifications.
• The list of profiles did not cover important areas, so there was scope for more profiles.
• There were proposals for enhancing Bluetooth to produce a version 2.0.

The Bluetooth SIG promoters announced that the SIG would continue in operation as long as Bluetooth devices were being made. The SIG reformed into a version 1.2 SIG, and members of the original SIG. Unlike the original SIG, the new version is incorporated as a U.S. not-for-profit organisation. The original SIG is now obsolete and its members have been asked to join the new SIG by signing up on-line at http://www.bluetooth.org.

To take the Bluetooth specification forward, the promoters also put in place working groups to continue enhancing and developing the Bluetooth specification.

28.1 Working Groups And New Bluetooth Profiles

A series of working groups continue the process of producing and refining the Bluetooth specification. An errata group considers corrections and clarifications to the specifications and includes reviewers who consider whether changes should be recommended. At present there is also an errata process group working under a BARB errata program manager; this group is formalising the errata process. Members of the Bluetooth SIG can submit and view errata at http://www.bluetooth.org/member/errata.htm.

At the time of publication, the remaining working groups were working on new profiles. The current list of profile working groups is as follows:

• AV, Audio/Video—CD quality audio, video suitable for conferencing.
• Ca—Produced the Hands-Free Profile (see Draft Post 1.1 Profiles chapter); the same group also has within its scope looking at diagnostics and positioning for cars.
• Coexist—Coexistence working group: working on coexistence of Bluetooth and other ISM band technologies.
• ESDP—Extended Service Discovery protocol: working on support for more discovery protocols such as Jini.
• HCI—This group is looking at extending the HCI part of the core specification.
• HID—Produced the Human Interface Device Profile (see Draft Post 1.1 profiles chapter).
• Imaging, Still Image—considers image exchange for storage display or forwarding. This group has produced the Basic Image Profile (see Draft Post 1.1 Profiles chapter).
• ISDN—Interoperability with ISDN services and applications.
• LP—Local positioning: aims to provide locationing information on Bluetooth devices to augment GPS services for indoor, underground, or builtup areas.
• PAN, Personal Area Networking—This group has produced the PAN profile and BNEP specification allowing Bluetooth to act as a bearer for IP based services (see PAN and BNEP chapter).
• Printing—Text document and image printing, this group has produced the Basic Printing Profile and Hardcopy Cable Replacement Profile (see Draft Post 1.1 profiles chapter).
• Radio—This group is looking at future versions of the Bluetooth specification aiming at best throughput for cost effective handhelds. It is split into two groups, one of which is looking at medium rate (Mb/s) and one at high rate (10 Mb/s).
• UDI—Unrestricted Digital Information protocol or UDI is a data system used in Japanese handsets. This group looks at interfacing Bluetooth to UDI systems.
• Security—This group is looking at improving and extending Bluetooth security procedures.

Additional groups will be formed as and when the need for new Bluetooth profiles emerges. Members of the Bluetooth SIG who are working on new products having usage models not covered by the current profiles are invited to submit ideas for new profiles.

28.2 Profile Working Groups

All Bluetooth profile working groups have some work in common. Every working group must consider:

• Issues of security, pairing, etc.
• Which features will be mandatory at various levels (LC, LM, etc.).
• How to define a service record for the profile.
• How to provide a royalty free specification wherever possible.
• How profiles will be tested.
• How to reuse existing work where possible.

In addition, each working group will address issues specific to the profile they are specifying.

The following sections look in more detail at the activities of some of the working groups.

28.2.1 Audio/Visual Profile

As Chapter 6 illustrated, the audio quality provided by Bluetooth SCO channels is inadequate for carrying music. However, the Bluetooth data links have a much higher bandwidth and could be used for carrying music, although the limited data rates of Bluetooth 1.0 and 1.1 mean that some form of compression technique is necessary to achieve transfer of video and high-quality audio.

As early as the first quarter of 2000 at CeBIT (the premier European consumer electronics showcase), there were several demonstrations of compressed video carried over Bluetooth. Although the bandwidth does not allow cinematic quality video, it is sufficient for many monitoring applications.

An audio/visual work group has been formed within the Bluetooth SIG to address issues involved in digital audio and sound distribution over Bluetooth’s data (ACL) links. The group is chaired by Philips and includes members from Ericsson, Nokia, Sony, and Toshiba.

The audio/visual work group aims to define formats and mechanisms for distributing video and high-quality audio over Bluetooth, reusing existing audio/visual standards wherever possible. The group aims to create the following profiles:

• Generic Distribution Profile—Mono and stereo CD-quality sound distribution.
• Advanced Audio Distribution Profile—Surround sound distribution.

• Remote Control Profile
• Video Conferencing Profile—video suitable for business use, this profile is not intended to provide video distribution for entertainment use.

The audio/visual profiles will be built upon L2CAP. They will include a security layer, which will aid with copy protection of material distributed over Bluetooth. Naturally with such high bandwidth applications, the profiles will use Bluetooth’s QOS facilities.

For displays, the work group may produce two sets of specifications: one which relies upon the data rates provided by Bluetooth 1.0, with display sizes limited to Zv VGA, and one using Bluetooth 2.0 radio data rates, which allow full VGA display.

To support their profiles, the Audio Video Group is working on two transports: the Distribution Transport protocol, and the Control Transport protocol.

28.2.2 Car Working Group Profiles

The Car working group has already produced the Hands-Free Profile which allows a Bluetooth enabled phone to work with a Hands-Free device such as might be used in a car. See Chapter 20 for more details of this Profile. A Phone Access Profile which adds extra functionality not provided in the Hands-Free Profile is currently being developed, as is a SIM Access Profile to govern communications with a Subscriber Identity Module (SIM).

The Car working group scope also covers other aspects of Bluetooth in the automotive environment. The applications for Bluetooth in cars are many and various. Within a car, Bluetooth devices can connect to one another and access services provided by the car.

The car can also communicate with the surrounding environment. Bluetooth 1.0 connection speeds do not allow a fast moving car to drive past a toll point, establish a connection, and transfer data before it is out of range, but there are many possible uses for a more static connection to a car. Car parking could be paid for over a Bluetooth link. Car diagnostics could be transferred to a unit in a garage or held by a mechanic. Tourist information points could transfer information to car navigation systems over Bluetooth. Fleet managers could extract information from vehicles using Bluetooth links. The list of applications goes on and on.

Even in advance of output from the Car working group, Bluetooth has received widespread interest from car manufacturers. BMW, SAAB, Ford, and Volvo are among the notable names from the automotive industry who have joined the Bluetooth SIG. A Car profile standardising the usage of Bluetooth in cars can only increase interest among manufacturers.

28.2.3 Extended Service Discovery Profile

The extended service discovery profile working group is looking at interoperability between the Bluetooth Service Discovery Protocol (SDP) and other service discovery protocols. The first specification being considered is UPnP (Universal Plug and Play). More information on UPnP can be found at http://www.upnp.org. Other service discovery profiles will be produced as and when a need for them is identified. Other profiles may be mapped to UPnP as part of the mapping effort.

28.2.4 Local Positioning Profile

The local positioning profile work group is examining how Bluetooth can be used to enable users to accurately find their position indoors and outdoors in builtup environments. The location information could be passed up the stack for use and display by applications. In particular, the information could be used with Web based applications.

Such capabilities could be useful in environments where GPS or cellular positioning systems do not perform well: inside buildings, underground, and in heavily builtup areas.

The working group will need to produce a descriptor, which can hold positioning information for passing to applications in a standardised format. This could be a new development or could reuse existing work from other specifications. Wherever possible, existing work will be reused.

Because locationing information is propagated between devices which may not be able to precisely identify one another’s location, it will need to incorporate some information on how much uncertainty there is in the location.

28.2.5 UDI—Bluetooth in Japanese 3G Handsets/UDI

Japan has different cellular phones from Europe and America, and the Japanese market often places different demands on the capabilities of handsets. Because of this, there is always a danger that specifications which meet with widespread acceptance in Europe and America will stumble in Japan. Therefore, a working group has been set up to explicitly consider issues related to using Bluetooth in Japanese third Generation (3G) handsets. This group will consider how to transport video over the Japanese 3G network and to generally resolve issues with incorporating Bluetooth into Japanese 3G handsets.

28.2.5 Further Profiles

The process of defining new profiles is open to any adopter company. The first step of course is to see if there is a real need for a new profile. Profiles are intended to aid inter-operation between products, so if an existing profile could be made to serve an application, then it makes more sense to use that profile than to invent a new one. This way, more devices will be available which support the profile and interoperability between devices will be higher. (There is of course the common sense argument of why invent something new if what you’ve got serves the purpose!)

If an application is not served by any existing profile, the next step is to ask if there is a sufficiently strong market to justify a new profile. In the cases where the profile would only serve a small specialised market, it may make more sense to implement a proprietary solution. Profiles are appropriate when there is a need for different manufacturers’ devices to interoperate. If it is a case where the market is so small that there will never be more than one manufacturer interested in serving it, interoperation is not a benefit.

When an application is identified which justifies a new profile, then a proposal for a new profile can be drawn up using the standard format followed by the other profiles. This is submitted to the core promoters group, and if it is seen as a useful and valid contribution to the Bluetooth specification, a working group is drawn up to consider the profile. The advantage of working groups is that many different companies have the opportunity to contribute their viewpoints. A profile drawn up by just one organisation may miss useful elements just because they are not useful to that particular group’s applications. A working group is likely to produce a more rounded, and more generally useful, profile.

At various stages during profile development the profile is reviewed by groups within the Bluetooth SIG to ensure that it fits in with other developments in Bluetooth and to ensure that it is testable. Finally, the work group outputs the finished profile it undergoes a legal review to ensure that it does not infringe intellectual property rights, and it can be incorporated into the Bluetooth specification after approval by the Bluetooth SIG Board of Directors.

28.3 Future Bluetooth Core Specifications

In addition to the profile working groups the SIG has working groups which are looking at improving and extending the core specification.

28.3.1 HCI Working Group

The HCI Working group formed in 2001 to look at extending the HCI part of the core specification. The group includes three subgroups: PCI, SD, and UART, each of which is considering a different transport. The UART group is looking at an alternative transport for serial lines: the existing UART protocol was intended for communication between chips on the same circuit board and has deficiencies when used with serial cables. For instance, it cannot correct for the bit errors occasionally encountered in a long serial cable. This group also helps to review HCI errata.

28.3.2 Coexistence Working Group

The coexistence working group (Coexist) is considering how Bluetooth can coexist with other wireless LAN standards in the ISM band. Bluetooth is not the only wireless telecommunications specification using the ISM band for communications, and it is possible that users may wish to use two ISM band protocols in the same device. For example, a user might want to install an 802.11b PCMCIA device in a notebook which already contains a Bluetooth module.

Already manufacturers and developers are investigating the development of baseband and radio devices that can work with more than one ISM band communications protocol. This, combined with hosts linked to more than one ISM band module, opens up the possibility of bridging devices which could link Bluetooth to 2.4 GHz WANs.

The working group considering coexistence with other ISM band devices will develop and recommend usage models for the ISM environment. To aid in this, they will work on interoperability issues in cross-industry groups and may suggest improvements to Bluetooth for incorporation in future specifications.

28.3.3 Radio Working Group

The radio working group is looking at an optional extension to the Bluetooth 1.0 radio. There will be two extensions: medium and high rate. The medium rate will be capable of data rates of around 2.0 Mb/s, the high rate offers around 10 Mb/s. The attractions are obvious; such high data rates would allow Bluetooth to carry hi-fi quality audio or even video and would align Bluetooth with 3G cellular systems.

The radio working group has been charged with maintaining the global availability of Bluetooth. This is likely to lead to the radio remaining confined to the ISM band. The constraints of the ISM band mean that the radio would have to use a more complex modulation scheme. The cost target is less than around $10 (USD), which will make complex modulation challenging for developers to implement.

Bluetooth 2.0 devices should preserve backwards compatibility with version 1.0 devices. This could mean having devices capable of handling two modulation schemes. The Radio 2.0 group is also looking at changing the inquiry mechanism to speed up the process of discovering Bluetooth devices. Finally, the Radio 2.0 group is also considering introducing an option for handover of Bluetooth voice and data calls. This will be particularly challenging, as established systems which implement handover between local groups of communicating devices use a backbone network to coordinate handover.

The very concept of handing over a call implies that there must be some backbone network taking the call. Handing over synchronisation of one cellular phone and PDA address book to synchronise with another’s address book makes no sense, but handing over a connection with one LAN access point to another LAN access point feeding into the same LAN makes perfect sense. The difference is that the PDA and cell phone were a self-sufficient piconet, but the LAN access points both feed into the same wider network, in this case a LAN, so somehow the roaming Bluetooth device must be coordinated with different access points supporting connection to the same wider area service.

Because Bluetooth connections are short range and involve mobile devices, it is possible to roam between piconets faster than the rate of cell switching normally expected on systems such as GSM. Fast acquisition of connections will be a requirement for handing over calls when devices are rapidly roaming between piconets. So the Radio 2.0 working group’s work on speeding up inquiry mechanisms could tie in with the work on handing over calls.

Some manufacturers have implemented scatternet capability, but up to version 1.1 it was not well supported by the specification, the radio group is investigating ways of better defining scatternet in the core specification.

Devices implementing future versions of the specification should be compatible with Bluetooth 1.0 and 1.1 devices. One proposal for achieving this is to have all devices connect in 1.0 mode, then negotiate a move to higher rate modes if all devices involved adhere to a higher rate specification.

28.4 Summary

The SIG has created a series of new working groups that are continuing development of the Bluetooth specification. The development is ongoing in three key areas: correction and clarification of the version 1.0 specification, the development of further profiles, and the development of an enhanced radio and baseband, which will lead to a new version 2.0 core specification.

The SIG has also provided a mechanism for Bluetooth adopter companies to propose further profiles.