| Bluetooth is the name given to a new | | | | particular Bluetooth device is made for.The |
| technology standard using | | | | ACL Link: Bluetooth uses five logical |
| | | | channels to support |
| short-range radio links, intended to replace | | | | |
| the cable(s) connecting | | | | transferring of information between |
| | | | devices:Core Protocols in Bluetooth:Baseband: |
| portable and fixed electronic devices. The | | | | The Baseband and Link Control layer enables |
| standard defines a uniform | | | | the physical RF |
| | | | |
| structure for a wide range of devices to | | | | link between Bluetooth forming a piconet. It |
| communicate with each other.Its important | | | | provides two different |
| features of Bluetooth are robustness, low | | | | |
| complexity, | | | | kind of physical links with their |
| | | | corresponding baseband packets, |
| low power and low cost. Bluetooth is | | | | |
| considered a wireless PAN | | | | Synchronous Connection-Oriented and |
| | | | Asynchronous Connectionless which |
| technology that offers fast and reliable | | | | |
| transmission for both voice | | | | can be transmitted in a multiplexing manner |
| | | | on the same RF |
| and data. Bluetooth offers wireless access | | | | |
| to LANs, PSTN, the mobile | | | | link.Asynchronous Connectionless (ACL) |
| | | | packets are used for the |
| phone network and the Internet for home or | | | | |
| office and other hand held | | | | transmission of data only while Synchronous |
| | | | Connection-Oriented can |
| devices.A complete Bluetooth system will | | | | |
| require these elements:An RF portion for | | | | contain either audio or a combination of |
| collecting and sending data or information: | | | | audio and information.Link Manager Protocol: |
| | | | The link manager protocol is responsible for |
| A module with a baseband microprocessor for | | | | |
| processing function | | | | link set-up between Bluetooth devices. This |
| | | | includes setting up of |
| Memory module | | | | |
| | | | security functions like authentication and |
| An interface to the electronic device (such | | | | encryption by generating, |
| as a mobile phone, camera, or PC)The | | | | |
| lower-layer Bluetooth protocols are normally | | | | exchanging and checking of link and |
| embedded in the | | | | encryption keys and the control, |
| | | | |
| baseband module, and the host processor must | | | | negotiation of baseband packet sizes and |
| support the upper-layer | | | | duty cycles of the Bluetooth |
| | | | |
| protocols (like file transfer). In other | | | | radio device, and the receiving device on |
| words, the RF/baseband | | | | the other end.Logical Link Control and |
| | | | Adaptation Protocol: The Bluetooth logical |
| solution provides the means to communicate | | | | |
| with the host, but need to | | | | link control and adaptation protocol (L2CAP) |
| | | | adapts upper layer |
| implement a connection interface, as well as | | | | |
| any upper-layer | | | | protocols over the baseband. It can be |
| | | | thought to work in parallel |
| protocols, to use applications supported by | | | | |
| the final product.The higher/upper layers of | | | | with LMP in difference that L2CAP provides |
| the Bluetooth technology called as the | | | | services to the upper layer |
| | | | |
| Bluetooth profiles and these are nothing but | | | | when the payload data is never sent at LMP |
| a set of protocols. These | | | | messages.Service Discovery Protocol: Using |
| | | | SDP, device information, services |
| protocols are optimized for particular | | | | |
| applications. In the case of | | | | and the characteristics of the services can |
| | | | be queried and after that, |
| file transfer between two devices, it | | | | |
| requires interoperability among | | | | a connection between two or more Bluetooth |
| | | | devices can be established.Telephony and |
| devices. Each of the linked devices needs to | | | | Cable Replacement Protocol:Telephony Control |
| have similar applications | | | | protocol: Binary (TCS Binary or TCS BIN), a |
| | | | bit |
| ensures interoperability across a spectrum | | | | |
| of devices.The Bluetooth stack: It has the | | | | oriented protocol, defines the call control |
| following components:RF portion for reception | | | | signaling for the |
| and transmission | | | | |
| | | | establishment of speech and data calls |
| Baseband portion with micro controller | | | | between Bluetooth devices.RFCOMM:It is a |
| | | | serial line emulation protocol and is based |
| Link control unit | | | | on ETSI |
| | | | |
| Link manager to support lower-layer | | | | 07.10 ( European Telecommunications |
| protocols | | | | Standardization Institute ) |
| | | | |
| Interface to the host device | | | | specification. This protocol emulates RS-232 |
| | | | control and data signals |
| Host processor to support upper-layer | | | | |
| protocols | | | | over Bluetooth baseband, providing both |
| | | | transport capabilities for |
| L2CAP to support upper-layer protocolsThe | | | | |
| radio frequency (RF) portion provides the | | | | upper level services that use serial line as |
| digital | | | | transport mechanism.Adopted Protocols:PPP:PPP |
| | | | is the IETF Point-to-Point Protocol (Internet |
| signal-processing (DSP) component of the | | | | Engineering Task |
| system, | | | | |
| | | | Force, IETF Directory List of RFCs) and |
| and the baseband micro controller processes | | | | PPP-Networking is the means of |
| these signals. | | | | |
| | | | taking IP packets to/from the PPP layer and |
| The link controller handles all the baseband | | | | placing them onto the LAN.TCP/UDP/IP: TCP/IP |
| functions and supports | | | | PPP is used for the all Internet Bridge usage |
| | | | |
| the link manager. It sends and receives | | | | scenarios in Bluetooth 1.0 and for OBEX in |
| data, identifies the sending | | | | future versions. UDP/IP/PPP |
| | | | |
| device, performs authentication, and | | | | is also available as transport for WAP.OBEX |
| determines the type of frame to | | | | Protocol: IrOBEX (Short name is OBEX) is a |
| | | | session protocol developed |
| use for sending a transmissions. The link | | | | |
| controller also directs how | | | | by the Infrared Data Association (IrDA) to |
| | | | exchange data in a simple and automatic |
| devices listen for transmissions from other | | | | way.Advantages: Using peer-to-peer |
| devices and can move | | | | connectivity, Bluetooth technology |
| | | | |
| devices into sleep state in order to save | | | | simplifies personal area wireless |
| power.The link manager, located on top of the | | | | connections, enabling all digital |
| link controller, controls | | | | |
| | | | devices to communicate automaticaly. |
| setup, authentication, link configuration, | | | | Bluetooth technology also |
| and other low-level | | | | |
| | | | provides fast, secure voice and data |
| protocols. Together, the baseband and the | | | | transmissions. The range for |
| link manager establish | | | | |
| | | | connectivity is less than 10 meters, and |
| connections for the network.The host | | | | line of sight is not required. |
| controller interface (HCI) communicates the | | | | |
| lower-layer | | | | The Bluetooth radio unit can functions even |
| | | | in noisy radio environments, |
| protocols to the host device(Like mobile | | | | |
| phone, hand held PC etc).The host contains a | | | | ensuring audible voice transmissions in |
| processor.L2CAP: it supports the upper-layer | | | | severe conditions. It can |
| protocols and communicates with | | | | |
| | | | protect data by using error-correction |
| the lower layers. The Higher/upper-layer | | | | methods and provides a high |
| protocols consist of service-specific | | | | |
| applications | | | | transmission rate. It is possible encryption |
| | | | and authentication for |
| that must be integrated into the host | | | | |
| application as explained above. RFCOMM | | | | privacy in the transmitted data.In Bluetooth |
| protocol, which allows for the emulation of | | | | ad hoc networking enables personal devices to |
| serial ports over the L2CAP, which is also an | | | | |
| important part of Bluetooth.The Service | | | | automatically exchange information and |
| Discovery Protocol (SDP) gives the required | | | | synchronize with each other.Jith is an |
| services and the properties and | | | | Electrical and Electronic Engineer by |
| characteristic of the service that a | | | | profession from Southern india. |