Bluetooth

Bluetooth
Bluetooth is an open specification for short-range wireless voice and data communications
that was originally developed for cable replacement in personal-area networking
and intended for worldwide use. In 1994 the initial study for development of this
technology began at Ericsson, Sweden. In 1998, Ericsson, Nokia, IBM, Toshiba, and
Intel formed a special interest group (SIG) to expand on the concept and to develop a
standard under IEEE 802.15 WPAN. In 1999, the first specification, v1.0b, was released
and then accepted as the IEEE 802.15 WPAN standard for 1-Mb/s networks. At the
time of this writing, over 2000 companies participate as members of the Bluetooth
SIG, and a number of companies all over the world are developing Bluetooth chip sets. Marketing forecasts indicate penetration of Bluetooth in more than 100 million
cellular phones and several millions of other consumer devices. As noted in earlier paragraphs,
the IEEE 802.15 group is also studying coexistence among and interference
between Bluetooth and IEEE 802.11 products operating at 2.4 GHz.
Bluetooth is the first popular technology for short-range ad hoc networking that is
designed for integrated voice and data applications. Compared with WLANs, Bluetooth
has a lower data rate, but it has an embedded mechanism to support voice applications.
Unlike 3G cellular systems, Bluetooth is an inexpensive personal area ad hoc network
operating in unlicensed bands and owned by the user.
The Bluetooth SIG considers three application-based scenarios that are shown in
Fig. 2.5. The first scenario is the wire replacement for connecting a personal computer
or laptop to its keyboard, mouse, microphone, and notepad. As the name of the scenario
indicates, it avoids multiple short-range wiring surrounding today’s personal computing
devices. The second scenario is ad hoc networking of several different users within
very short range of each other, such as in a conference room. As we saw earlier in the
chapter, WLAN standards and products also commonly address this scenario. The third
scenario is use as an access point to the wide-area voice and data services provided
by cellular networks, wired connection, or satellite links. The 802.11 community also
considers this overall concept of the access point. However, the Bluetooth access
point is used in an integrated manner to connect to both voice and data backbone
infrastructures. A more detailed discussion of Bluetooth, its protocol structure, and its
relationship to IEEE 802.11 may be found in [Pah02a].
At this writing, Bluetooth-enabled devices have not yet established a position in
the mainstream wireless market, but they are poised to take that next step. Bluetooth
technology may well find its first significant market in the automobile industry,
where hands-free regulations are helping to drive the movement toward the safety and
convenience of cordless headsets.