Wireless Personal Area Networks (WPANs)OverviewWireless StandardsDistance vs. Data RateMobility vs. Data RateBluetooth ProductsBluetoothBluetooth: DetailsPiconetFrequency Hopping SequencesBluetooth Packet FormatBluetooth Operational StatesBluetooth Operational States (Cont)Energy Management in BluetoothPower per MBBluetooth Protocol StackBaseband LayerBluetooth Protocol Stack (Cont)Bluetooth Protocol Stack (Cont)Ultra-WidebandUltra-Wideband (UWB)UWBAdvantages of UWBDirect sequence (DS-UWB)Multi-Band OFDMZigBeeNetwork TopologySummaryReading AssignmentHomework 44-1©2006 Raj JainCSE574sWashington University in St. LouisWireless Personal Area Wireless Personal Area Networks (Networks (WPANsWPANs))Raj JainProfessor of CSE Washington University in Saint LouisSaint Louis, MO [email protected] slides are available on-line at:http://www.cse.wustl.edu/~jain/cse574-06/4-2©2006 Raj JainCSE574sWashington University in St. LouisOverviewOverview! Wireless Standards Overview! Bluetooth! Ultra-Wideband! ZigBee4-3©2006 Raj JainCSE574sWashington University in St. LouisWireless StandardsWireless Standards802.15.1Bluetooth802.15.3Personal Area Network (PAN)802.16/WiMAXFixed Wireless MANMetropolitan Area Network (MAN)802.11Wi-FiLocal Area Network (LAN)Wide Area Network (WAN)802.20Mobile2G, 2.5G, 3GCellular802.16eNomadic802.21Handoff802.15.4ZigBee802.22WRAN4-4©2006 Raj JainCSE574sWashington University in St. LouisDistance vs. Data RateDistance vs. Data RateData Rate (Mbps)RangeZigBee802.15.4802.15.3802.15.3a802.15.3cWPANWLANWMANWWANWiFi802.110.01 0.1 1 10 100 1000Bluetooth802.15.1IEEE 802.22WiMAXIEEE 802.16IEEE 802.20UWB4-5©2006 Raj JainCSE574sWashington University in St. LouisMobility vs. Data RateMobility vs. Data Rate802.15.3aUWB4-6©2006 Raj JainCSE574sWashington University in St. LouisBluetooth ProductsBluetooth Products! Printers, faxes, digital cameras…! 720 kbps to 10m! Competes with infrared, which has a range of 1m, requires line of sight and has a low data rateHeadsets Game Controller GPSAudio Keyboard4-7©2006 Raj JainCSE574sWashington University in St. LouisBluetoothBluetooth! Started with Ericsson's Bluetooth Project in 1994! Named after Danish king Herald Blatand(AD 940-981) who was fond of blueberries! Radio-frequency communication between cell phones over short distances! Intel, IBM, Nokia, Toshiba, and Ericsson formed Bluetooth SIG in May 1998! Version 1.0A of the specification came out in late 1999.! IEEE 802.15.1 approved in early 2002 is based on Bluetooth! Key Features:" Lower Power: 10 μA in standby, 50 mA while transmitting" Cheap: $5 per device" Small: 9 mm2single chips4-8©2006 Raj JainCSE574sWashington University in St. LouisBluetooth: DetailsBluetooth: Details! Frequency Range: 2402 - 2480 MHz (total 79 MHz band)23 MHz in some countries, e.g., Spain! Data Rate:1 Mbps (Nominal) 720 kbps (User) ! Channel Bandwidth:1 MHz! Range: Up to 10 m can be extended further! RF hopping: 1600 times/s ⇒ 625 μs/hop! Security: Challenge/Response Authentication. 128b Encryption! TX Output Power: " Class 1: 20 dBm Max. (0.1W) – 100m" Class 2: 4 dBm (2.5 mW) " Class 3: 0 dBm (1mW) – 10m! Ref: http://www.bluetooth.com/http://www.bluetooth.org/http://grouper.ieee.org/groups/802/15/index.html4-9©2006 Raj JainCSE574sWashington University in St. LouisPiconetPiconet! Piconet is formed by a master and many slaves" Up to 7 active slaves. Slaves can only transmit when requested by master" Up to 255 Parked slaves! Active slaves are polled by master for transmission! Each station gets a 8-bit parked address ⇒ 255 parked slaves/piconet! The parked station can join in 2ms.! Other stations can join in more time.! A device can participate in multiple piconets⇒ complex schedule4-10©2006 Raj JainCSE574sWashington University in St. LouisFrequency Hopping SequencesFrequency Hopping Sequences! 625 μs slots! Time-division duplex (TDD) ⇒ Downstream and upstream alternate! Master starts in even numbered slots only.! Slaves start in odd numbered slots only! lsb of the clock indicates even or odd! Slaves can transmit in one slot right after receiving a packet from master! Packets = 1 slot, 3 slot, or 5 slots long! The frequency hop is skipped during a packet.Frequency 1Frequency 2Frequency 34-11©2006 Raj JainCSE574sWashington University in St. LouisBluetooth Packet FormatBluetooth Packet Format! Packets can be up to five slots long. 2745 bits. ! Access codes: " Channel access code identifies the piconet" Device access code for paging requests and response" Inquiry access code to discover units! Header: member address (3b), type code (4b), flow control,ack/nack (1b), sequence number, and header error check (8b)8b Header is encoded using 1/3 rate FEC resulting in 54b ! Synchronous traffic has periodic reserved slots.! Other slots can be allocated for asynchronous trafficData PayloadAccess CodeBaseband/Link Control Header72b 54b 0-2745b4-12©2006 Raj JainCSE574sWashington University in St. LouisBluetooth Operational StatesBluetooth Operational StatesStandbyInquiry PageTransmitConnectedPark HoldSniffDisconnectedConnectingActiveLow Power4-13©2006 Raj JainCSE574sWashington University in St. LouisBluetooth Operational States (Cont)Bluetooth Operational States (Cont)! Standby: Initial state! Inquiry: Master sends an inquiry packet. Slaves scan for inquiries and respond with their address and clock after a random delay (CSMA/CA)! Page: Master in page state invites devices to join the piconet. Page message is sent in 3 consecutive slots (3 frequencies). Slave enters page response state and sends page response including its device access code.! Master informs slave about its clock and address so that slave can participate in piconet. Slave computes the clock offset.! Connected: A short 3-bit logical address is assigned! Transmit:4-14©2006 Raj JainCSE574sWashington University in St. LouisEnergy Management in BluetoothEnergy Management in BluetoothThree inactive states:! Hold: No ACL. SCO continues. Node can do something else: scan, page, inquire! Sniff: Low-power mode. Slave listens only after fixed sniff intervals.! Park: Very Low-power mode. Gives up its 3-bit active member address and gets an 8-bit parked member address.! Packets for parked stations are broadcast to 3-bit zero address.SniffPark4-15©2006 Raj JainCSE574sWashington University in St. LouisPower per MBPower per MB4-16©2006 Raj JainCSE574sWashington University in St. LouisBluetooth Protocol StackBluetooth Protocol Stack! RF =
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