Bluetooth technology

Bluetooth is the name of the new technology standard using
short-range radio link, intended to replace, connecting cable (y)
portable and fixed electronic equipment Standard defines a uniform.
structure for a wide range of devices to communicate with each other.

Its important features Bluetooth are robustness, low complexity,
low power and low cost. Bluetooth is a wireless network (PAN)
technology, which offers fast and reliable transmission of both voice
and Bluetooth offers data. wireless access to the LAN, PSTN, mobile
telephone networks and the Internet for home or Office and other hand held
device.

Complete the Bluetooth system will require the following elements:

RF part for collecting and submitting data or information:
Module with microprocessor transfers for processing functions

Memory module

Interface to electronic devices (like mobile phone, camera or PC)

Bluetooth lower-layer protocols are normally embedded in
traffic and processor module, a host must support the top layer
protocols (like file transfer). in other words, RF/baseband
solution provides the means to communicate with the host, but it should be
implement connection interfaces, as well as any top layer
protocols, to use applications that are supported by the finished product.

Higher/upper layers of the Bluetooth technology known as
Bluetooth profiles, and these are nothing but a set of These protocols.

protocols are optimized for specific applications.
transferring files between two devices, requires interoperability among
device.
Each connected device needs to have similar applications
provides interoperability across the spectrum of devices.

Bluetooth stack: Has the following components:

VF part for reception and transmission

Part transfers with micro controller


Link control unit



Link leading to lower-layer protocols support



Interface on the host device

Host processor supports the upper layer protocols




L2CAP supports the upper layer protocols

Part of the radio frequency (RF) provides digital
signal processing (DSP) component system
and micro controller handles the traffic signals.
Link Controller handles all the functions, transfers and supports
Reference Manager.Sends and receives data, identifies, TX
devices, performs validation and specifies the frame type
use to send traffic.Controller link also directs how
device to listen to the traffic from other devices and you can move
to sleep to conserve energy.

Manager links located above link controller controls
installation, configuration, verification, and other low-level links
protocols.Traffic Manager link Together and establish
network connectivity.

Host controller interface (HCI) communicates the lower layers
logs the host host device (Like mobile phone, hand held PC etc), The processor contains.

L2CAP: it supports the protocols the top layer and layer communicates snižší. higher-layer Protocols, top are composed of specific services must be integrated into aplikacíže host application as explained above RFCOMM Protocol., which allows you to emulate serial ports over the L2CAP, which is also an important part of Bluetooth.SDP (Service Discovery Protocol) provides the services and characteristics, and characteristics of the service, which is designed especially for Bluetooth.

ACL Link:Bluetooth uses five logical channels to support the transfer of information between devices:
Basic Bluetooth protocols:
Traffic: Traffic and Link Control layer allows physical RFlink between Bluetooth, forming a piconet.Offers two differentthe type of physical links to their corresponding packet transmissions, Connection Oriented synchronous and asynchronous appropriate thatmay be transmitted in the same RF multiplexing methodLink. Asynchronous appropriate ACL packets are used fortraffic only while focusing on synchronous connections can contain sound or a combination of sound and information.


Link Manager protocol:Is responsible for the management protocol referenceadvices link between Bluetooth devices.This includes zrízenízabezpecení acts like authentication and encryption through the generation,Exchange and link checking and encryption keys and the control of the packet size and duty cycles of the Bluetooth radio device and the receiving device at the other end.

Logical link control and adaptation protocol:Logical devices for controlling and adjusting Bluetoothprotokol reference (L2CAP) adapting the upper vrstvyprotokoly that It can understand traffic. work in the difference that LMP paralelnes L2CAP provides services to top vrstvuKdyž data payload sent never LMP message.

SSDP:By SDP, information about the device, the service may be služeba characteristics and then queried sespojení between two or more Bluetooth devices can be connected.
Telephone and cable replacement Protocol:
Telephony Control Protocol: a Binary field (binary, or TCS TCS BIN), the Protocol defines trochuorientovaný call control signaling prozrízení speech and data calls between Bluetooth devices.
RFCOMM:This is the Protocol emulation serial line and is based on ETSI
07.10 (European Telecommunications Standards Institute)
This Protocol specification. emulates RS-232 control and data signals
via Bluetooth transfers providing for both transport options
the top level of services as a transport mechanism to use serial line.

Adopted protocols:
PPP: PPP is Point-to-Point Protocol IETF (Internet Engineering Task
Force, IETF RFC Directory list) and PPP network is a means of
adoption of the IP packet layer of PPP and their introduction into the LAN.

TCP, UDP/IP:TCP/IP/PPP is used for all uses of the Internet Bridge
scenarios in Bluetooth 1.0 and future versions for OBEX. UDP/IP, PPP
It is also available as a transport for WAP.

Protocol OBEX:IrOBEX (short name for the OBEX) protocol is developed relaceod Infrared Data Association (IrDA) Exchange data simple and automatic way.
Advantages:
Using connect peer-to-peer technology, wireless personal area Bluetoothzjednodušuje, allowing all Default communication digitálnízarízení. Bluetooth taképoskytuje fast and secure voice and data traffic. Range prokonektivita is less than 10 metres, and the line is not required. Bluetooth radio Unit can even in noisy environments, radio acoustic voice transmissions in funkcezajištení adverse conditions It data using lzeochranu. methods of correction and provides vysokouprenosové speed., encryption and authentication proOchrana privacy of the data transmitted in ad hoc networks enables Bluetooth personal zarízeníautomaticky exchanging information and synchronize with each other.

Jith is Electrical and Electronic Engineer profession from South India. it has good experience in sensors, data acquisition systems, communications protocols, etc., and may contact via crsjith@gmail.com