Project PDA

Bluetooth wireless technology, a protocol for the short range wireless transmission of data, has steadily grown in popularity as the application has been incorporated into more and more electronic devices. Bluetooth is a wireless radio technology that allows all of those products to "talk" to each other without wires, eliminating the need to "cradle" or connect wires between your devices to sync information. Bluetooth technology also allows the cell phone to serve as a wireless modem for your PDA. You can connect your PDA to your cell phone wirelessly with Bluetooth, then use the phone to dial into the Internet.

Bluetooth communicates on a frequency of 2.45 gigahertz, which has been set aside by international agreement for the use of industrial, scientific and medical devices (ISM). Currently, a Bluetooth enabled PDA allows a user to have the same portability to a 900 Megahertz phone in terms of data transfer. A user can potentially send a wireless beam at an optimized rate of up to 11 Mbp/s and is not hindered by walls or distance.

Bluetooth lets these devices communicate with each other when they are in range. The devices use a radio communications system, so they do not have to be in line of sight of each other, and can even be in other rooms, so long as the received transmission is powerful enough.

Using Bluetooth, devices can transfer up to 720 kbps. This bandwidth is restricted in comparison to those obtainable from 802.11 wireless technology, and while networking is one application of Bluetooth, it is not the primary application area.

This wireless technology allows you to swap data with other handheld procedure or some other Bluetooth facilitates appliance for instance a cell phone and headset or printer. Fax machine, laptop computer, and personal computer are also come in this category. The Bluetooth characteristic will permit you to insert an exterior keyboard. A Bluetooth-enabled mobile phone and a PDA that uses Bluetooth to connect to the phone and, through it, to the Internet and other connectivities. You can also use the Bluetooth connection to send data between the devices. Bluetooth-enabled devices bring convenience to communication while travelling.

The Bluetooth specification was first developed in 1994 by Sven Mattison and Jaap Haartsen, who were working for Ericsson Mobile Platforms in Lund, Sweden at the time http://www.information-age.com/article/2001/may/the_bluetooth_blues . The specifications were formalized by the Bluetooth Special Interest Group (SIG). The SIG was formally announced on May 20, 1998. Today it has over 6000 companies worldwide. It was established by Ericsson, Sony Ericsson, IBM, Intel, Toshiba and Nokia, and later joined by many other companies as Associate or Adopter members. Bluetooth is also known as IEEE 802.15.1.

Bluetooth 1.0 and 1.0B

Versions 1.0 and 1.0 B had many problems and the various manufacturers had great difficulties in making their products interoperable. 1.0 and 1.0B also had mandatory Bluetooth Hardware Device Address (BD_ADDR) transmission in the handshaking process, rendering anonymity impossible at a protocol level, which was a major setback for services planned to be used in Bluetooth environments, such as Consumerium.

Bluetooth 1.1

• Many errors found in the 1.0B specifications were fixed.
• Added support for non-encrypted channels.
• Received Signal Strength Indicator (RSSI)
  

Bluetooth 1.2

This version is backwards compatible with 1.1 and the major enhancements include:

• Adaptive Frequency-hopping spread spectrum (AFH), which improves resistance to radio frequency interference by avoiding the use of crowded frequencies in the hopping sequence
• Higher transmission speeds in practice
• extended Synchronous Connections (eSCO), which improves voice quality of audio links by allowing retransmissions of corrupted packets.
• Host Controller Interface (HCI) support for 3-wire UART
• HCI access to timing information for Bluetooth applications
  

Bluetooth 2.0

This version is backwards compatible with 1.x. The main enhancement is the introduction of
Enhanced Data Rate (EDR) of 3.0 Mbps. This has the following effects (Bluetooth SIG, 2004):

• 3 times faster transmission speed (up to 10 times in certain cases).
• 100 meter range
• Lower power consumption through a reduced duty cycle.
• Simplification of multi-link scenarios due to more available bandwidth.
• Further improved BER (bit error rate) performance.