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INTRODUCTION

Bluetoothwireless technology is a cable replacement technology that provides wireless communication between portable devices, desktop devices and peripherals. It is used to swap data and synchronize files between devices without having to connect each other with cable. The wireless link has a range of 10m which offers the user mobility. This technology can be used to make wireless data connection to conventional local area networks (LAN) through an access point. There is no need for the user to open an application or press button to initiate a process. Bluetooth wireless technology is always on and runs in the background. Bluetooth devices scan for other Bluetooth devices and when these devices are in range they start to exchange messages so they can become aware of each others capabilities. These devices do not require a line of sight to transmit data with each other. Within a few years about 80 percent of the mobile phones are expected to carry the Bluetooth chip. The Bluetooth transceiver operates in the globally available unlicensed ISM radio band of 2.4GHz. The ISM bands include frequency range at 902MHz to 928MHz and 2.4GHz to 2.484GHZ which do not require operator license from a regulatory agency. This means that Bluetooth technology can be used virtually anywhere in the world. Another type of wireless technology that is being used nowadays is infrared signals. The choice of using either one of the wireless technology will depend on the application for which it is being used. Bluetooth is an economical, wireless solution that is convenient, reliable, easy to use and operates over a longer distance than infrared. The initial development started in 1994 by Ericsson. Bluetooth now has a special interest group (SIG) which has 1800 companies worldwide. Bluetooth technology enables voice and data transmission in a short-range radio. There is a wide range of devises which can be connected easily and quickly without the need for cables. Soon people world over will enjoy the convenience, speed and security of instant wireless connection. Bluetooth is expected to be embedded in hundreds of millions mobile phones, PCs, laptops and a whole range of other electronic devices in the next few years. This is mainly because of the elimination of cables and this makes the work environment look and feel comfortable and inviting.

ORIGIN OF BLUETOOTH

In 1994, Ericsson Mobile Communication initiated a study to investigate the feasibility of a low power, low cost radio interface between mobile phones and their accessories. The aim of the study was to find a way to eliminate cables between mobile phones and PC cards, headsets, desktops and other devices. The study was part of a large project investigating how different communication devices could be connected to the cellular network via a mobile phone. Ericsson’s work in this area caught the attention of IBM, Intel, Nokia, and Toshiba. The companies formed the special interest group (SIG) in May 1998, which grew to over 1500 member companies by April 2000. The company jointly developed the Bluethooth 1.0 specifications, which was released in July 1999….

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EVOLUTION OF COMPUTER SYSTEMS

             Over the past four decades the computer industry has experienced four generations of development, physically marked by the rapid changing of building blocks from relays and vacuum tubes (1940-1950s) to discrete diodes and transistors
(1950-1960s), to small- and medium-scale integrated (SSI/MSI) circuits (1960-1970s), and to large- and very-large-scale integrated (LSI/VLSI) devices (1970s and beyond). Increases in device speed and reliability and reductions in hardware cost and physical size have greatly enhanced computer performance. However, better devices are not the sole factor contributing to high performance. Ever since the stored-program concept of von Neumann, the computer has been recognized as more than just a hardware organization problem. A modern computer system is really a composite of such items as processors, memories, functional units, interconnection networks, compilers, operating systems, peripherals devices, communication channels, and database banks.

             To design a powerful and cost-effective computer system and to devise efficient programs to solve a computational problem, one must understand the underlying hardware and software system structures and the computing algorithm to be implemented on the machine with some user-oriented programming languages. These disciplines constitute the technical scope of computer architecture. Computer architecture is really a system concept integrating hardware, software algorithms, and languages to perform large computations. A good computer architect should master all these disciplines. It is the revolutionary advances in integrated circuits and system architecture that have contributed most to the significant improvement of computer performance during the past 40 years. In this section, we review the generations of computer systems and indicate the general tends in the development of high performance computers.

 Generation of Computer Systems

             The division of computer systems into generations is determined by the device technology, system architecture, processing mode, and languages used. We consider each generation to have a time span of about 10 years. Adjacent generations may overlap in several years as demonstrated in the figure. The long time span is intended to cover both development and use of the machines in various parts of the world. We are currently in the fourth generation, while the fifth generation is not materialized yet….

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