Bluetooth Simulation

VIDYAVARDHINIS COLLEGE OF ENGINEERING AND TECHNOLOGY ELECTRONICS AND TELECOMMUNICATION utmost YEAR 2004-2005 A REPORT ON BLUETOOTH TECHNOLOGY PREPARED BY JANHAVI KHANOLKAR NAVEEN BITRA YASHESH MANKAD TABLE OF CONTENTS 1. INTRODUCTION 2. HISTORY 3. WHAT IS BLUETOOTH? 4. BLUETOOTH SPECIFICATIONS 5. BLUETOOTH NETWORKS 6. HOW DOES BLUETOOTH WORK? 7. BLUETOOTH PROTOCOL megabucks 8. BLUETOOTH SECURITY 9. APPLICATIONS 10. MERITS AND DEMERITS INTRODUCTION Bluetooth was origin anyy conceived to replace the rats come on of arguments typical in any PC setup today and this remains a compelling home application.However, as the Bluetooth evolved it became clear that it would in like manner alter a totally new net manoeuvering paradigm, Personal Area Ne 2rks (PANs) With PAN engine room a affairr ordain be suitable to organize a collection of personalized electronic products (their personal digital assistant, cell visit, lap excrete, desktop, MP3 player, and so forth ) to mechanically work unitedly. For instance the contact manager and calendar in the PDA, laptop, and desktop could all automatically synchronize whenever they be within throw away of apiece separate). oer sentence PANs lead revolutionize the user experience of consumer electronics.Finally, Bluetooths driving nature go forth also revolutionize spliceivity to the rest of the world. Bluetooth provide automatically dis subdue functionumajigs and go nearby so unattached servers, internet entranceway, printers etc. will automatically become visible to a Bluetooth ruse wheresoever it is. HISTORY Bluetooth is an open spec for short range radio receiver vowelise and selective discipline communications that was originally developed for cable replacement in personal bea networking to ope array all everyplace the world.By enabling similar wireless communication in the midst of any electrical crooks, Bluetooth has created the nonion of a personal Area Network (PAN), a kind of close ra nge wireless network that looks set to revolutionize the way people move with the information technology landscape around them. In 1994 the initial analyse for development of this technology started at Ericsson, Sweden. In 1998, Ericsson, Nokia, IBM, Toshiba, and Intel formed a superfluous Interest Group (SIG) to expand the concept and develop a stylel under IEEE 802. 15 WPAN ( receiving set Personal Area Network ).In 1999, the first of all precondition was released and accepted as the IEEE 802. 15 WPAN standard for 1Mbps networks. The Bluetooth SIG considers three groundworkonical scenarios The first basic scenario is the Cable Replacement ie. the wire replacement to connect a PC or laptop to its pigmentboard, purloin, microphone, and notepad. It avoids the multiple short range fit out beatings of todays personal com designateing spins. The second scenario is ad hoc networking of several unalike users at very short range in an atomic number 18a much(prenominal) a s a conference room. The third scenario is to use Bluetooth as an AP to the wide bea voice and data services provided by the cellular networks, wired liaisons or satellite consociates. Why the name Bluetooth? The taradiddle of origin of name Bluetooth is interesting. Bnluetooth was the nickname of Harald Blaatand, 10th century Viking who united Denmark and Norway. When Bluetooth specification was introduced to commonplace, a stone carving, erected from Harald Blaatands capital city Jelling was also presented. This peculiar carving was interpreted as Bluetooth connecting a cellular phone and a wireless notepad in his hands.The picture was apply to symbolize the vision in development Bluetooth to connect personal computing and communication eddys. What is BLUETOOTH? pic escort1 Bluetooth constitution blocks The Bluetooth system consists of a radio unit, a link control unit, and a get unit for link management and array terminal interface functions (see control 1). The Host Controller Interface (HCI) provides the means for a phalanx maneuver to access Bluetooth hardw be capabilities. For example, a laptop computer could be the host thingmabob and a PC card inserted in the PC is the Bluetooth twirl.All commands from the host to the Bluetooth module and events from the module to the host go through with(predicate) the HCI interface. The protocol throng is above the radio and base hatful hardw ar, partly residing in the Bluetooth unit and partly in the host device. A Bluetooth firmness sack also be utilize as a one- assistor architecture (embedded solution) where the application resides together with the Bluetooth protocols in the similar hardwargon. In that case, the HCI is not needed. This is a feasible implementation for simple devices such(prenominal) as accessories or micro servers.Requirements of Bluetooth technology If Bluetooth technology is to replace cables, it mass not be much more(prenominal) expensive than a cable or nobody will buy it. Because Bluetooth technology is designed for runny devices it moldiness(prenominal) be able to run on batteries. So it moldiness be very execrable power and should run on blue voltages. It essential also be lightweight and small enough not to intrude on the design of compact fluid devices such as cellular phones, handsets etc. It must be as reliable as the cable it replaces and also it must be resilient. Bluetooth devices lease at 2. gigahertz in globally available, license free doctrine band, which obey a basic set of power and spectral emission and interference specifications. at that placeof Bluetooth has to be very robust, as thither are many actual users and polluters of this get byd spectrum. gum olibanum Bluetooth aims to be widely available, inexpensive, convenient, easy to use, reliable, small and low power. Specifications related with Bluetooth PARAMETER VALUES relative relative frequence Range 2. 2. 4835 GHz Bandwidth of individually c hannel 1MHz Data rate 1 Mbps Frequency hopping rate 1600 demonstrate hop per seconds Range of operation 10-100 meters Bluetooth system operates in 2. GHz Industrial scientific Medicine (ISM) band. The operating band is divided into 1MHz spaced channels apiece signaling data at 1 Mbps so as to entertain maximum available channel bandwidth with chosen modulation scheme of GFSK (Gaussian Frequency Shift Keying). Using GFSK, a binary 1 give exclude to a positive frequency deviation from the nominal carrier frequency while binary 0 gives rise to a negative frequency deviation. After to each one packet both devices retune their radio to a divergent frequency, effectively hopping from radio channel from radio channel.In this way Bluetooth devices use the full-length of available ISM band and if transmittance is compromised by interference on one channel, the retransmission will forever be on a diverse channel. Each Bluetooth quantify slot lasts 625 microseconds giving rise to frequency hopping rate of 1600 hop per seconds. Generally devices hop once per packet. .For vast data transmission, crabbed users may occupy multiple time slots development the similar transmission frequency thus slowing instantaneous hopping rate to below 1600 hops/ sec. BLUETOOTH NETWORKS PICCONETS AND SCATTERNETThe Bluetooth network is called a piconet. In the simplest case it means that two devices are attached (see Figure 2a). The device that initiates the tie is called a command and the separatewise devices are called buckle downs. The majority of Bluetooth applications will be point-to-point applications. Bluetooth connectors are typically ad hoc clubs, which means that the network will be established just for the new task and consequently dismantled aft(prenominal) the data transfer has been completed. A master can assume simultaneous connections (point-to-multipoint) to up to cardinal buckle downs (see Figure2b).Then, however, the data rate is limited . One device can also be connected in two or more piconets. The set-up is called scatternet (see Figure 2c). A device can, however, hardly be a master to one piconet at a time. Support for temper, park, or sniff mode is needed for a device to be part of the scatternet. In these modes a device does not actively participate in a piconet, leaving time for other activities such as participating in other piconet, for example. The master/ break ones keister roles are not necessarily heady and can also be changed during the connection if, for example, the master does not have enough esources to manage the piconet. arrive at/slave replace is also needed in the scatternet. overlook/slave switch support is not mandatory. Most of current Bluetooth implementations support piconets only if. Point-to-multipoint support depends on the implementation Figure 2. Bluetooth piconet and scatternet scenarios a) Point-to-point connection mingled with two devices b) Point-to-multipoint connection between a master and three slaves c) Scatternet that consists of three piconets Modes of operation In connection state, the Bluetooth unit can be in several modes of operation.Sniff, hold, and park modes are use to save power or to free the capacity of a piconet participating mode In the active mode, the Bluetooth unit actively participates on the channel. Sniff mode In the sniff mode, the duty cycle of the slaves attend activity can be trim down. This means that the master can only start transmission in specified time slots. Hold mode While in connection state, the ACL link to a slave can be put in a hold (possible SCO connect are suave supported). In hold mode, the slave can do other things, such as scanning, paging, inquiring, or attending another piconet.Park mode If a slave does not need to participate in the piconet barely still wants to remain synchronised to the channel (to participate in the piconet again later), it can enter the park mode. It gives up its active s ection greet. Park mode is useful if there are more than seven devices that from time to time need to participate in the very(prenominal) piconet. The parked slave wakes up regularly to listen to the channel in tramp to re-synchronize and to interrupt for broadcast messages sent by the master.. FREQUENCY HOPPING Bluetooth technology uses a frequency hopping technique, which means that each packet is transmitted on a different frequency. In most countries, 79 channels can be used. With a fast hop rate (1600 hops per second), good interference rampart is achieved. Another benefit is a short packet length. If some other device is jamming the transmission of a packet, the packet is resent in another frequency determined by the frequency scheme of the master. This scenario is visualised in Figure 3 where packets of device 1 (colored packets) and device 2 (banded packets) are trying to use the identical frequency.Note that this case only refers to situations where there are two o r more simultaneous active piconets or a non-Bluetooth device using the same frequency in range. The mistake subject field algorithms are used to correct the fault caused by pile transmissions Figure 4. Three-slot and five-slot long packets reduce overhead compared to one-slot packets. 220 s switching time after the packet is needed for changing the frequency. Subsequent time slots are used for transmitting and receiving. The nominal slot length is 625 (s.A packet nominally covers a single slot, further can be extended to cover three or five slots, as depicted in Figure 4. In multi-slot packets the frequency remains the same until the entire packet is sent. When using a multi-slot packet, the data rate is higher because the header and a 220 (s long switching time after the packet are needed only once in each packet. On the other hand, the robustness is reduced in a crowded environment the long packets will more probably be lost HOW DOES BLUETOOTH WORKS? Bluetooth devices have 4 basic States.They can be a outstrip (in control of a Piconet represent by a large blue pass on above), an brisk hard worker (connected and actively observe/participating on a Piconet medium orangeness circles), a Passive break ones back (still logically part of a Piconet but in a low power, occasionally admonishering but still synchronised, inactive, state medium gray circles), and secondary (not connected to a Piconet, occasionally monitoring for inquiries from other devices, but not synchronized with any other devices small white circles). IN IDEAL STATE Bluetooth devices initially bop only about themselves and in this state they will be in standby mode.Standby is a still mode where a Bluetooth device listens on an occasional basis performing what are called question and/or page Scans for 10 milliseconds out of every 1. 28 seconds to see if any other Bluetooth devices are looking to make it. Passive behavior is inherent to half of Bluetooths states and is a ke y mechanism to achieving very low power. In Standby mode the Bluetooth devices occasional attention reduces power role by over 98%. While all of the Bluetooth devices in the same mode it is historic to note that they are NOT synchronized or coordinated in any way.Thus they are all listening at different times and on different frequencies. pic Enquiry and page procedures rails to connections ENQUIRY Inquiry is how a Bluetooth device learns about other devices that are within its range. In the illustration above Node A executes a foliate Function on the BT Inquiry ID and plays replies from other devices. Through these replies device A learns the explicit identity of these other devices (i. e. their remarkable Bluetooth device ID). During the Inquiry process device A continuously broadcasts the pageboy command using the reserved Inquiry ID which identifies it as as a Page Inquiry.These broadcasts are spread across a standard pattern of 32 Standby radio frequencies which all devi ces in Standby mode monitor on an occasional basis. Over a duration of some seconds it is certain that every Standby device within range will have have the Inquiry Page even though they are not synchronized in any way. By convention these nodes will respond with a standard FHS packet that provides their unique BT ID and their quantify offset. With these parameters the Inquiring node can effect low latency synchronized connections.Node H (the dotted circle above) illustrates how a Bluetooth device can be programmed to remain anonymous (Undiscoverable in BT jargon). This is a user controlled feature that suspends Inquiry Scanning, and thus device As Inquiry Procedure cannot discover Device B It is important to note that device H will continue to support Page Scanning however, and thus a users other personal devices (i. e. PAN) can penetrate this barrier by Paging straightaway to its unique Bluetooth ID. This is information that PAN devices can be configured to know and repute thus enabling private collaboration even when devices are undiscoverable.PAGING In its general form the Page command establishes a formal device to device link between a Master (the originator) and a hard worker. Master/Slave connections in Bluetooth are referred to as a Piconet. To create the piconet device A broadcasts the Page command with the explicit device ID of the target Slave (B in the illustration above) which was learned earlier through an Inquiry Procedure. Further, this connection can be very low latency if the Inquiry data is recent (and thus synchronization can be accurate), but the process will simply take longer if this is not the case.All Bluetooth devices except B will ignore this command as it is not addressed to them. When the device B replies, device A will send it an FHS packet back and assign it an Active Member Address in the Piconet. As an Active Slave device B will begin continuously monitoring for further commands from device A in synchronization with device As hopping pattern and time offset. Further, standard Piconet activity continuously updates the clock offset data keeping the synchronization extremely accurate. Thus the Master and Slave states are not low power but picture very low transaction latencies. EXPANDING A PICCONETThrough successive Page commands a Bluetooth Master can attach up to 7 Active Slaves. 7 is a hard limit as only 3 bits are allocated in Bluetooth for the Active Member Address (AMA) with 000 reserved for the Master and the remaining addresses allocated to Slaves. Practically, 7 is more than sufficient given Bluetooths miserable performance and dynamic configurability. Again, all Active Slaves to A continuously monitor for further commands addressed to them in synchronization with device As hopping pattern. PARKING Parking is a mechanism that allows a Bluetooth Master to connect to an additional 256 devices. 56 is a hard limit as 8 bits are allocated in Bluetooth for the put Member Address (PMA). To Park a device the Bluetooth Master issues a Park command to an Active Slave and assigns it a PMA. This Slave then enters the Parked mode and surrenders its AMA. As a Parked Slave the device will revert to a passive mode and only monitor for commands on an occasional basis. The difference between Standby and Parked however is that the Slave will remain synchronized to the Masters hopping pattern and regularly update its clock offset. Thus this device can be reconnected at any time with a minimum latency.BLUETOOTH PROTOCOLS Protocols are needed to implement different composes and usage models. each profile uses at least part of the protocol plentitude. In order to achieve interoperability between two Bluetooth devices, they both must have the same vertical profile of the protocol stack. Bluetooth Core Protocols Baseband and Link Control together enable a physical RF link between Bluetooth units forming a piconet. This layer is prudent for synchronizing the transmission-hopping frequency and clocks ofdifferent Bluetooth devices Whitepaper1, p. . Audio is routed directly to and from Baseband. Any two Bluetooth devices supporting audio can send and receive audio data between each other just by opening an audio link . Link Manager Protocol (LMP) is responsible for link set-up (authentication and encryption, control, and negotiation of baseband packets) between Bluetooth devices and for power modes and connection states of a Bluetooth unit. discursive Link Control and Adaptation Protocol (L2CAP) takes care of multiplexing, reassembly, and segmentation of packets.Service denudation Protocol (SDP) is needed when requesting device information, services, and the characteristics of other devices. Devices have to support the same service in order to establish a connection with each other. Cable Replacement Protocol RFCOMM emulates RS-232 signals and can thus be used in applications that were formerly implemented with a serial cable (e. g. , a connection between a laptop com puter and a mobile phone). Telephony Protocol Binary (TCS-BIN) defines the call control signaling for the formation of speech and data call between Bluetooth devices.AT commands provide means for dogmatic a mobile phone or a modem. Adopted Protocols OBEX (Object Exchange) is pick out from IrDA. It is a session protocol that provides means for simple and spontaneous object lens and data transfer. It is independent of the transport mechanism and transport Application program Interface (API). TCP/UDP/IP is defined to operate in Bluetooth units allowing them to communicate with other units connected, for instance, to the Internet. The TCP/IP/ palatopharyngoplasty protocol configuration is used for all Internet Bridge usage scenarios in Bluetooth 1. and for OBEX in proximo versions. The UDP/IP/uvulopalatopharyngoplasty configuration is available as transport for WAP. PPP in the Bluetooth technology is designed to run over RFCOMM to accomplish point-to-point connections. PPP is a pa cket-oriented protocol and must therefore use its serial mechanisms to convert the packet data stream into a serial data stream. The tuner Application Protocol (WAP) stack can reside on top of RFCOMM (based on LAN Access Profile) or on top of L2CAP (based on PAN Profile). The latter reduces overhead and is likely to become the preferred solution for WAP over Bluetooth.Wireless Application Environment (WAE) hosts the WAP browser environment. Dial up networking (DUN) profile protocol stack DUN profile is inside the Serial larboard Profile and therefore partly reuses the capabilities of the Serial Port Profile. For the DUN Profile, there are two device configurations (roles) Gateway (GW) is the device that provides access to the public network (typically mobile phones and modems) Data terminal (DT) is the device that uses the dial-up services of the entre (typically PCs) The DUN Profile needs a two-piece protocol stack and an SDP branch.PPP over RFCOMM is needed for transferring payload data. AT commands are delivered over RFCOMM to control the modem (mobile phone). The application on top of the stack is either a number one wood application on a PC (data terminal) or the modem emulation on a phone (gateway). Bluetooth security secret key All Bluetooth devices (master and slave) share a secret key in a particular system. This key is used during the authentication and encryption process. This key is not transmitted over the channel but is rather in-built by the manufacturer. AUTHENTICATIONAuthentication ensures the identity of Bluetooth devices. Authorization is a process of deciding if a device is allowed to have access to a specific service. User interaction may be mandatory unless the unconnected device has been marked as bank. Usually the user an set dictum on/off to every remote device separately. Authorization always requires authentication. Authentication in Bluetooth is performed by an encryption engine which uses the SAFER+ algo. This algorithm requires the adjacent Number to be encrypted or decrypted master address Master clock secret key shared by master and slave. A hit-or-miss number is generated by the encryption engine using various keys. This hit-or-miss number is encrypted by the master using the secret key. This number is also sent to the slave. The encrypted reply of the slave is compared with the master encrypted data. If it is a match then the slave is authentic. BONDING AND PAIRING Pairing is a procedure that authenticates two devices based on a common passkey, thereby creating a bank relationship between those devices. An arbitrary but identical passkey must be entered on both devices.As long as both devices are paired, the pairing procedure is not required when connecting those devices again (the existing link key is used for authentication). Devices without any input method, like headsets, have fixed passkeys. When two devices are linked with a common link the connection is called as bonding. There are two types of bonding Dedicated bonding Used to create and exchange a link key between two devices. General bonding Data over the link is available for higher layers. ENCRYPTION Encryption protects communication against eavesdropping.For example, it ensures that nobody can listen to what a laptop transmits to a phone. Encryption demands the following Negotiating encryption mode Negotiating key sizes-The key size could vary from 8 to 128 bits Starting encryption Stopping encryption SECURITY LEVELS A trusted device has been previously authenticated, a link key is stored, and the device is marked as trusted in the security database of a device. The device can access Bluetooth services without user espousal. An untrusted device has been previously authenticated, a link key is stored, but the device is not marked as trusted. Access to services requires acceptance of the user. An unknown device means that there is no security information on this device. This is also an untruste d device. Security Level of Services Authorization required Access is only granted automatically to trusted devices or untrusted devices after an authorization procedure (Do you accept connection from remote device? ). Authentication is always required. Authentication required The remote device must be authenticated before connecting to the application. Encryption required The link must be changed to encrypted before accessing the service.It is also possible that a service does not require any of these mechanisms. On the other hand, the application (service) might have its own user authentication mechanisms (a PIN code, for example). APPLICATIONS 1. Bluetooth in the home will ultimately eliminate most every cable related to consumer electronics (except power). Your PC, scanner, and printer will simply need to be within 10 meters of each other in order to work. Your PDA, digital camera, and MP3 player will no longer need a docking station to transfer files or get the latest tunes (th e exception will be to recharge, that power thing again).And, your home stereo and other equipment will join the party too. On the telephone front your cell phone will synchronize its address book with your PC and function as a handset to your cordless phone in the house (answering incoming calls to your home number and art out on the cheaper land line too). Finally, even though its only 720Kbps, Bluetooth is still pretty fine for broadband internet access since digital subscriber line and cable modems are typically throttled to about 384K anyway. Bluetooth access points could well be as ubiquitous as 56K modems in 2 or 3 years. . On the road much of your Bluetooth PAN goes with you. Even when your laptop is in your briefcase and your cell phone is in your pocket they will be able to collaborate to access e-mail. And, next generation cell phones featuring Bluetooth and General piece of ground Radio (GPR) technology will function as a wireless modems with internet access at 100Kbps +. With such performance it is likely mesh based e-business will flourish and these devices will become the most general Bluetooth access points.This may well be the Killer App that ensures Bluetooths general adoption and success. When you are literally on the road your car will join your PAN too. Here your cell phone may operate in a hands free mode using the car audio system and an in-dash microphone even while comfortably in your pocket. Or you may use a wireless Bluetooth headset instead. And, your MP3 player will likely play music in 8 speaker surround sound, rip music right off of an FM broadcast, or record your phone calls for later review. And all without wiresFixed land line access points (supporting up to 720Kbps) such as a pay phone in the airport terminal or lounge, or the desk phone in your hotel, will provide true broadband access in these strategic locations. to a fault look for the pay phone to evolve to compete for your cell phone calls too with its low cost land lines. In the world of deregulation and open competition future smart phones may even put your calls out for bid and channel the traffic over the carrier pass the lowest cost 3. Telephone applications Hands free use buck synchronization Calendars Contact management Land line I/F for voice and data 4. Consumer applications File transfer MP3 Digital pictures Peripheral connectivity Keyboard/mouse/remote Printer ADVANTAGES 1. Point to point and point to multiple links 2. Voice and data links 3. Compact form factor 4. meek power 5. Low cost 6. Robust frequency hopping and error correction 7. Profiles ensure application level 8. High level of security through frequency hopping, encryption and authentication 9. Non directional 10. Unlicensed ISM band LIMITATIONS 1. 8 Devices per piconet with limited extension via scatternet 2.Short range 3. No handover facility 4. upper limit data rate of 723. 2 Kb/s 5. occupies the crowded ISM band 6. Slow connection setup References Bluet ooth 1. 1 Jenifer Bray Wireless Communication -Krishnamurthy Bluetooth Specifications, Bluetooth SIG at http//www. bluetooth. com Bluetooth Protocol Architecture v1. 0, Riku Mettala, Bluetooth SIG, August 1999 http//www. bluetooth. org/foundry/sitecontent/ text file/whitepapers_presentations Bluetooth Security Architecture, Thomas Muller, Bluetooth SIG, July 1999 http//www. bluetooth. rg/foundry/sitecontent/document/whitepapers_presentations Comprehensive Description of the Bluetooth dodging v0. 9p, Dan Sonnerstam, Bluetooth SIG, May 1998 http//info. nsu. ac. kr/cwb-data/data/ycra2/comprehensive_description_of_the_BT_system. pdf Bluetooth Technology Overview, version 1. 0, April 2003 http//forum. nokia. com pic Digital photographic camera Computer Scanner Home Audio System MP3 Player PDA jail cell Phone Operational States Master Active Slave Parked Slave* Standby* ON THE ROAD Laptop PDA Cell Phone MP3 Player Headset Hotel Phone & Access Point