Introduction Bluetooth technology is a global short-range standard which lets a wide range of devices that are electronic to connect and even communicate with one another. Bluetooth can also be viewed as an open wireless protocol that is used for data exchange on small distances by use of short radio waves form mobile and other fixed devices hence creating a personal area network. Bluetooth technology is generally a cable-replacement technology that allows various devices like MP3 players, PCs and peripherals, mobile phones, and headsets devices to connect. Bluetooth technology was created and launched in 1994 by a Swedish company, Ericson and introduced officially in 1998 (Garg 43).
Bluetooth Special Interest Group (SIG) is a group formed in 1998 and manages the Bluetooth technology. Bluetooth SIG founding members includes Nokia, Intel, Ericsson, Toshiba, and IBM. Bluetooth technology was initially designed in order to allow voice and data exchange at rates of up to 1Mbps/second. The initial range of Bluetooth coverage revolved around 5meters although after its expansion it attains a range of 10meters in 700-800kb bandwidth. Bluetooth specifications The Bluetooth transmission frequency sits between 2.4 to 2.4835GHz and a maximum speed of transfer of 2.0Mbps per second.
Bluetooth have improved with time from Bluetooth 2.1 to recently modified Bluetooth 3.0. The Bluetooth 3.0 is 160times faster than Bluetooth 2.1 model. The core system of a Bluetooth consists of a host and one or more controllers. A host is a computing device, peripheral, cellular telephone, access point to PSTN network or LAN etc. A host is defined as all the layers that are under the profiles and on top of the Host Controller Interface (HCI) (Muller 87).
The layers below HCI are usually defined as the controllers. Controllers are usually classified into two types including an alternate MAC/PHY (AMP) and a basic rate/enhanced data rate (BR/EDR). A basic rate/enhanced data rate (BR/EDR) controller includes baseband, radio, baseband, and HCI. An alternate MAC/PHY (AMP) controller includes AMP MAC, Protocol Adaptation layer (PAL), AMP PAL (protocol adaptation layer), and optionally HCI. Bluetooth is crucial as it allows data transfer without the use of wires. Bluetooth Core System Architecture The figure 1 shows the Bluetooth core system that consists of blocks.
They together provide services for supporting connections of various devices while exchanging application data within a short range links that are wireless. HCI (Host-Controller Interface) is an interface command to link manager and baseband controller giving a uniform method that access Bluetooth baseband abilities (Miller and Chatschik 123). RF and basebandThe block of RF has a role of transmitting as well as receiving information packets within the physical channel. The control path between the RF block and the baseband enables the baseband block manage the timing and frequency carrier of the RF block.
A stream of data is transformed to and from the physical channel and the baseband to the format that is required by the RF block. Link controllerLink controller has a role of decoding and encoding Bluetooth packets from the parameters and payload related to the logical transport, logical link, and physical channel. The link controller carries the protocol signalling of link control in a close combination with the scheduling function of the resource manager that is used to communicate flow control as well as retransmission, and acknowledgement of request signals.
The signals interpretation is usually characterized by the logical transport related with baseband packet. Control and interpretation of the link control signalling is usually related with the scheduler of resource manager (Miller and Chatschik 123).