REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA Redes Inalámbricas – Tema 2.B Wireless PANs: Bluetooth  Bluetooh Acknowledgments: Foo Chun Choong, Ericsson Research / Cyberlab Singapore, and Open Source Software Lab, ECE Dept, NUS

REDES INALÁMBRICAS MIC 2009/2010 IEEE Working Group for WPAN  IEEE Std ™ Mb/s WPAN/Bluetooth v1.x derivative work  ™- Recommended Practice for Coexistence in Unlicensed Bands  ™ Mb/s High Rate WPAN for Multimedia and Digital Imaging  a™ Mb/s Higher Rate Alternative PHY for  ™ kb/s max for interactive toys, sensor and automation needs  ZigBee 2

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Market  Installed base of Bluetooth enabled products reached 1 Billion devices in November of  Every week, 13 million Bluetooth units are shipped. (~675 million per year or 21 every second)  Every working day, more than five new Bluetooth enabled products are qualified. (~1300 per year)  Broad surveys have shown that the Bluetooth brand is recognized by more than 75% of respondents world-wide. (Millward Brown internet survey for Bluetooth SIG: Bluetooth.org) 3

REDES INALÁMBRICAS MIC 2009/2010 The Bluetooth Wireless Experience  Replaces cables connecting portable and/or fixed devices while maintaining high levels of security,  Robust, low power, low cost solution,  Any Bluetooth enabled device, almost everywhere in the world, can connect to other Bluetooth enabled devices in proximity,  Bluetooth enabled devices with common profiles work together to provide a uniform user experience.  LUETOOTHI_FUNCTIONALITY.htm 4 HEADSETPRINTINGTRANSFERMUSIC HID

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth history  De facto standard - open specifications.  publicly available on Bluetooth.com:  Bluetooth specs developed by Bluetooth SIG.  February 1998: The Bluetooth SIG is formed promoter company group: Ericsson, IBM, Intel, Nokia, Toshiba  May 1998: The Bluetooth SIG goes “public”  July 1999: 1.0A spec (>1,500 pages) is published  December 1999: ver. 1.0B is released  December 1999: The promoter group increases to 9 3Com, Lucent, Microsoft, Motorola  February 2000: There are 1,500+ adopters  Versions:  0.7  0.9  1.0A  1.0B  1.1  …  November 2003: release 1.2  November 2004: release 2.0+EDR  (EDR or Extended Data Rate) triples the data rate up to about 3 Mb/s  July 2007: release 2.1+EDR  April 2009: release 3.0+HS 5

REDES INALÁMBRICAS MIC 2009/2010 Versions  The 1.2 version, unlike the 1.1, provides a complementary wireless solution to co-exist Bluetooth and Wi-Fi in the 2.4 GHz spectrum without interference between them.  uses the technique "Adaptive Frequency Hopping (AFH), which runs a more efficient transmission and a more secure encryption.  offers voice quality (Voice Quality - Enhanced Voice Processing) with less noise, and provides a faster configuration of communication with other Bluetooth devices within range of reach.  Version 2.0, created to be a separate specification, mainly incorporates the technique "Enhanced Data Rate (EDR)” that allows you to improve transmission speeds up to 3Mbps while trying to solve some errors specification

REDES INALÁMBRICAS MIC 2009/2010 Release 2.1  Near Field Communication (NFC) Technology  NFC may also be used in the new pairing system, enabling a user to hold two devices together at a very short range to complete the pairing process.  Lower Power Consumption Reduced power consumption means longer battery life in devices like mice and keyboards. Bluetooth Specification Version EDR can increase battery life by up to five times.  Improved Security For pairing scenarios that require user interaction, eavesdropper protection makes a simple six-digit passkey stronger than a 16-digit alphanumberic character random PIN code. Improved pairing also offers "Man in the Middle" protection that in reality eliminates the possibility for an undetected middle man intercepting information. 7

REDES INALÁMBRICAS MIC 2009/2010 Release 3.0  It supports theoretical data transfer speeds of up to 24 Mbit/s.  Its main new feature is AMP (Alternate MAC/PHY), the addition of as a high speed transport.  Two technologies had been anticipated for AMP: and UWB, but UWB is missing from the specification.  Alternate MAC/PHY  Enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth Radio is still used for device discovery, initial connection and profile configuration, however when lots of data needs to be sent, the high speed alternate MAC PHY (802.11, typically associated with Wi-Fi) will be used to transport the data.  And also:  Unicast connectionless data  Read encryption key size  Enhanced Power Control 8

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Power Class Table 9

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Network Topology  Bluetooth devices have the ability to work as a slave or a master in an ad hoc network. The types of network configurations for Bluetooth devices can be three.  Single point-to-point (Piconet): In this topology the network consists of one master and one slave device.  Multipoint (Piconet): Such a topology combines one master device and up to seven slave devices in an ad hoc network.  Scatternet: A Scatternet is a group of Piconets linked via a slave device in one Piconet which plays master role in other Piconet. 10 M S i) Piconet (Point-to- Point) M S S S S ii) Piconet (Multipoint) M SSS M SS Master/Slave iii) Scatternet The Bluetooth standard does not describe any routing protocol for scatternets and most of the hardware available today has no capability of forming scatternets. Some even lack the ability to communicate between slaves of one piconet or to be a member of two piconets at the same time.

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Protocol Stack: Transport Protocol Group  Radio Frequency (RF)  Sending and receiving modulated bit streams  Baseband  Defines the timing, framing  Flow control on the link.  Link Manager  Managing the connection states.  Enforcing Fairness among slaves.  Power Management  Logical Link Control & Adaptation Protocol (L2CAP)  Handles multiplexing of higher level protocols  Segmentation & reassembly of large packets  Device discovery & QoS  The Radio, Baseband and Link Manager are on firmware.  The higher layers could be in software.  The interface is then through the Host Controller (firmware and driver).  The HCI interfaces defined for Bluetooth are UART, RS232 and USB. 11 Source: Farinaz Edalat, Ganesh Gopal, Saswat Misra, Deepti Rao BLUETOOTH SPECIFICATION, Core Version 1.1 page 543

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Protocol Stack: Middleware Protocol Group 12 RF Baseband Audio Link Manager L2CAP Data SDP RFCOMM IP Control Applications Middleware Protocol Group Additional transport protocols to allow existing and new applications to operate over Bluetooth. Packet based telephony control signaling protocol also present. Also includes Service Discovery Protocol. Source: Farinaz Edalat, Ganesh Gopal, Saswat Misra, Deepti Rao  Service Discovery Protocol (SDP)  Means for applications to discover device info, services and its characteristics.  TCP/IP  Network Protocols for packet data communication, routing  RFCOMM  Cable replacement protocol, emulation of serial ports over wireless network

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Protocol Stack: Application Group 13 Application Group RF Baseband Audio Link Manager L2CAP Data SDP RFCOMM IP Control Applications Consists of Bluetooth aware as well as un-aware applications. Source: Farinaz Edalat, Ganesh Gopal, Saswat Misra, Deepti Rao

REDES INALÁMBRICAS MIC 2009/2010 SCO (Synchronous Connection-Oriented) payload types  Bluetooth offers two types of links:  Synchronous connection-oriented link for classical telephone (voice) connections: HV (High quality Voice), DV (Data and Voice)  Asynchronous connectionless link for typical data applications: DM1 (Data Medium rate) and DH3 (Data High rate) with 3 slots 14 payload (30) audio (30) audio (10) HV3 HV2 HV1 DV FEC (20) audio (20)FEC (10) header (1)payload (0-9)2/3 FECCRC (2) (bytes)

REDES INALÁMBRICAS MIC 2009/2010 ACL (Asynchronous connectionless Link) Payload types 15 payload (0-343) header (1/2)payload (0-339)CRC (2) header (1)payload (0-17)2/3 FEC header (1)payload (0-27) header (2)payload (0-121)2/3 FEC header (2)payload (0-183) header (2)payload (0-224)2/3 FEC header (2)payload (0-339) DH5 DM5 DH3 DM3 DH1 DM1 header (1)payload (0-29) AUX1 CRC (2) (bytes)

REDES INALÁMBRICAS MIC 2009/2010 Channel access  Bluetooth devices use a Time-Division Duplex (TDD) scheme  Channel is divided into consecutive slots (each 625  s)  One packet can be transmitted per slot  Subsequent slots are alternatively used for transmitting and receiving  Strict alternation of slots b/t the master and the slaves  Master can send packets to a slave only in EVEN slots  Slave can send packets to the master only in the ODD slots 16 Source: Farinaz Edalat, Ganesh Gopal, Saswat Misra, Deepti Rao

REDES INALÁMBRICAS MIC 2009/2010 Multi-slot packets 17 Single slot Three slot Five slot f n f n+1 f n+2 f n+3 f n+4 f n+5

REDES INALÁMBRICAS MIC 2009/2010 Mixed Link Example 18 MASTER SLAVE 1 SLAVE 2 SLAVE 3 ACL SCO ACL

REDES INALÁMBRICAS MIC 2009/2010 Throughput 19

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Connection States  There are four Connection states on Bluetooth Radio:  Active: Both master and slave participate actively on the channel by transmitting or receiving the packets (A,B,E,F,H)  Sniff: In this mode slave rather than listening on every slot for master's message for that slave, sniffs on specified time slots for its messages. Hence the slave can go to sleep in the free slots thus saving power (C)  Hold: In this mode, a device can temporarily not support ACL packets and go to low power sleep mode to make the channel available for things like paging, scanning etc (G)  Park: Slave stays synchronized but not participating in the Piconet, then the device is given a Parking Member Address (PMA) and it loses its Active Member Address (AMA) (D,I) 20 E A G H C D I H C B F Master Bluetooth Connection States

REDES INALÁMBRICAS MIC 2009/2010 Bluetooth Forming a Piconet  Inquiry: Inquiry is used to find the identity of the Bluetooth devices in the close range.  Inquiry Scan: In this state, devices are listening for inquiries from other devices.  Inquiry Response: The slave responds with a packet that contains the slave's device access code, native clock and some other slave information.  Page: Master sends page messages by transmitting slave's device access code (DAC) in different hop channels.  Page Scan: The slave listens at a single hop frequency (derived from its page hopping sequence) in this scan window.  Slave Response: Slave responds to master's page message  Master Response: Master reaches this substate after it receives slave's response to its page message for it. 21 Master Inquiry Inquiry Scan Inquiry Response Page Page Scan Slave Response Master Response Connection Slave Forming a Piconet Procedures

REDES INALÁMBRICAS MIC 2009/2010 Inquiry time 22

REDES INALÁMBRICAS MIC 2009/2010 SDP - Service Discovery  Focus  Service discovery within Bluetooth environment  Optimized for dynamic nature of Bluetooth  Services offered by or through Bluetooth devices  Some Bluetooth SDP Requirements (partial list)  Search for services based upon service attributes and service classes  Browse for services without a priori knowledge of services  Suitable for use on limited-complexity devices  Enable caching of service information  How it works?  Establish L2CAP connection to remote device  Query for services Search for specific class of service, or Browse for services  Retrieve attributes that detail how to connect to the service  Establish a separate (non-SDP) connection to use the service 23

REDES INALÁMBRICAS MIC 2009/2010 Bluez 24

REDES INALÁMBRICAS MIC 2009/2010 Usage models  A number of usage models are defined in Bluetooth profile documents. A usage model is described by a set of protocols that implement a particular Bluetooth-based application. Some examples are shown on the following slides:  File transfer  LAN access  Wireless headset  Cordless (three-in-one) phone. 25

REDES INALÁMBRICAS MIC 2009/2010 File transfer application 26 Using the file transfer profile: A Bluetooth device can browse the file system of another Bluetooth device, can manipulate objects (e.g. delete objects) on another Bluetooth device, or - as the name implies - files can be transferred between Bluetooth devices. SDP RFCOMM OBEX File transfer application L2CAP

REDES INALÁMBRICAS MIC 2009/2010 LAN access application 27 Using the LAN profile: A Bluetooth device can access LAN services using (for instance) the TCP/IP protocol stack over Point-to- Point Protocol (PPP). Once connected, the device functions as if it were directly connected (wired) to the LAN. SDP RFCOMM PPP LAN access application L2CAP TCP/IP (e.g.)

REDES INALÁMBRICAS MIC 2009/2010 Wireless headset application 28 Using the headset profile: According to this usage model, the Bluetooth-capable headset can be connected wirelessly to a PC or mobile SDPRFCOMM Headset application L2CAP Audio phone, offering a full- duplex audio input and output mechanism. This usage model is known as the ultimate headset.

REDES INALÁMBRICAS MIC 2009/2010 Cordless (three-in-one) phone application 29 Using the cordless telephone profile: A Bluetooth device using this profile can set up phone calls to users in the PSTN (e.g. behind a PC acting as voice base SDPTCS BIN Cordless phone application L2CAP Audio station) or receive calls from the PSTN. Bluetooth devices implementing this profile can also communicate directly with each other.