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WPANSIEEE 802.15 : 

WPANSIEEE 802.15

Outline : 

Outline IEEE 802.15.1 – ”Bluetooth-Technical Specifications” IEEE 802.15.3 – High data rate WPAN IEEE 802.15.4 – Low data rate WPAN Recent WPAN Innovations

IEEE 802.15 - General : 

IEEE 802.15 - General Wireless Personal Area Networks (WPANs) Short Range Low Power Low Cost Small Networks Communication within a persons operating space

Serves as the backbone of any Wireless Personal Area Network. Bluetooth Special Interest Group(SIG) is the body that oversees the development of Bluetooth standards and licensing. Established in 1998. Nokia, Ericsson,Intel,IBM,Toshiba are some of founder members. 4

Bluetooth Stack : 

Bluetooth Stack A hardware/software/protocol description An application framework 5 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications

Interoperability & Profiles : 

Interoperability & Profiles A profile represents a default solution for a usage model Vertical slice through the protocol stack Basis for interoperability and logo requirements Each Bluetooth device supports one or more profiles 6

Slide 7: 

7 BLUETOOTH Technical Overview

Bluetooth Radio Specification : 

Bluetooth Radio Specification 8 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications

Slide 9: 

Radio Technology 9 Low Cost Single chip radio (minimize external components) Today’s technology Time divison duplex Low Power Standby modes Sniff, Hold, Park Low voltage RF Robust Operation Fast frequency hopping 1600 hops/sec Strong interference protection Fast ARQ Robust access code Forward header correction

Power Control Modes : 

Bluetooth 10 Power Control Modes Sniff Mode This is a low power mode in which the listening activity of the slave is reduced. In the sniff mode, the slave listens for transmissions only at fixed intervals Tsniff, at the offset slot Dsniff for Nsniff times. These parameters are given by the LMP in the master when it issues the SNIFF command to the slave. Hold Mode Slave temporarily (for Thold sec) does not support ACL packets on the channel (possible SCO links will still be supported). By this capacity can be made free to do other things like scanning, paging, inquiring, or attending another piconet. The slave unit keeps its active member address (AM_ADDR).

Power Control Modes (contd.) : 

Bluetooth 11 Power Control Modes (contd.) Park Mode This is a very low power mode with very little activity. The slave however, stays synchronized to the channel. The parked slaves regularly listen for beacon signals at intervals decided by the beacon structure communicated to the slave during the start of parking. The parked slave has to be informed about a transmission in a beacon channel which is supported by the master to keep parked slaves in synchronization and send them any other information. Any message to be sent to a parked member are sent over the broadcast channel. It also helps the master to have more than seven slaves.

Baseband : 

Baseband 12 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications

Connection Setup : 

Connection Setup 13 Inquiry - scan protocol to lean about the clock offset and device address of other nodes in proximity

Piconet formation : 

Piconet formation 14 Page - scan protocol to establish links with nodes in proximity

Addressing : 

Addressing 15 Bluetooth device address (BD_ADDR) 48 bit IEEE MAC address Active Member address (AM_ADDR) 3 bits active slave address all zero broadcast address Parked Member address (PM_ADDR) 8 bit parked slave address

Packet Format : 

Packet Format 16 Access code Header Payload 72 bits 54 bits 0 - 2745 bits Synchronization identification Filtering Address Packet Type Flow control ARQ SEQN HEC Error correction 1/3 rate FEC 2/3 rate FEC ARQ scheme for the data Smaller than an ATM cell ! Notice that there is no protocol type field

Piconet channel : 

Piconet channel 17 m s1 s2 625 ?sec f1 f2 f3 f4 1600 hops/sec f5 f6 FH/TDD

Multi slot packets : 

Multi slot packets 18 m s1 s2 625 ?sec f1 f4 f5 f6 FH/TDD Data rate depends on type of packet

Physical Link Types : 

Bluetooth 19 Physical Link Types Synchronous Connection Oriented (SCO) Point to Point Full Duplex between Master & Slave Established once by master & kept alive till released by Master Typically used for Voice connection ( to guarantee continuity ) Master reserves slots used for SCO link on the channel to preserve time sensitive information Asynchronous Connection Link (ACL) It is a momentary link between master and slave. No slots are reserved. It is a Point to Multipoint connection. Symmetric & Asymmetric links possible

Physical Link Types : 

20 Synchronous Connection Oriented (SCO) Link slot reservation at fixed intervals No ARQ, No CRC FEC (optional) 64 Kbps Physical Link Types Asynchronous Connection-less (ACL) Link Polling access method ARQ, CRC FEC (optional) Symmetric data rate 108 - 433 Kbps Asymmetric data rate up to 723 Kbps

Inter piconet communication : 

Inter piconet communication 21 Cell phone Cordless headset Cordless headset Cell phone

Scatternet : 

Scatternet 22

Link Manager Protocol : 

Link Manager Protocol 23 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications Setup and Management of Baseband connections Piconet Management Link Configuration Security

Link Manager Protocol : 

Link Manager Protocol Piconet Management Attach and detach slaves Master-slave switch Establishing SCO and ACL links Handling of low power modes ( Sniff, Hold, Park) 24 Link Configuration packet type negotiation power control Security functions Authentication Encryption

L2CAP : 

L2CAP 25 Logical Link Control and Adaptation Protocol L2CAP provides Protocol multiplexing Segmentation and Re-assembly Quality of service negotiation Group abstraction

RFCOMM : 

RFCOMM 26 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications Serial Port emulation on top of a packet oriented link Similar to HDLC For supporting legacy apps

Service Directory Protocol : 

Service Directory Protocol 27 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications

SDP(Service Discovery Protocol) : 

SDP(Service Discovery Protocol) Allows devices to discover what services each other support. What parameters to use to connect. E.g. – when connecting a mobile to Bluetooth headset, SDP will determine what profiles are supported by headset (Headset profile, Hands free profile etc.) 28

IP over Bluetooth V 1.0 : 

IP over Bluetooth V 1.0 Internet access using cell phones Connect PDA devices & laptop computers to the Internet via LAN access points 29 RF Baseband Audio Link Manager L2CAP RFCOMM SDP Applications GOALS

TYPES OF WPANs : 

TYPES OF WPANs HIGH DATA RATE WPANs LOW DATA RATE WPANs

IEEE 802.15.3 - Overview : 

IEEE 802.15.3 - Overview High data rate WPAN Potential future standard Motivation: The need for higher bandwidths currently supported with 802.15.1 100 Mpbs within 10 meter 400 Mpbs within 5 meter Data, High quality TV, Home cinema

IEEE 802.15.3 - Overview : 

IEEE 802.15.3 - Overview Dynamic topology Mobile devices often join and leave the piconet Short connection times High spatial capacity Multiple Power Management modes Secure Network

IEEE 802.15.3 - Overview : 

IEEE 802.15.3 - Overview Based on piconets Data Devices (DEV) establish peer-to-peer communication Includes also a Piconet Coordinator (PNC)

IEEE 802.15.3 - Topology : 

IEEE 802.15.3 - Topology

IEEE 802.15.3 - Superframe : 

IEEE 802.15.3 - Superframe

IEEE 802.15.3 - Beacon : 

IEEE 802.15.3 - Beacon BEACON Control information Allocates GTS Synchronization

IEEE 802.15.3 - CAP : 

IEEE 802.15.3 - CAP CONTENTION ACCESS PERIOD (CAP) Allows contention via CSMA/CD Command exchange between DEV and PNC File transfers from DEV without request

IEEE 802.15.3 - CFP : 

IEEE 802.15.3 - CFP CONTENTION FREE PERIOD (CFP) Time slot allocation specified in the beacon Reserved bandwidth for DEV MTS: Command, GTS: Data

IEEE 802.15.3 - GTS : 

IEEE 802.15.3 - GTS GTS RESERVATION DEV sends a Channel Time Request (CTR) to PNC Isochronous data: number and duration of slot(s) Asynchronous data: Total amount of data PNC allocates GTSs to DEV via CTA DEV is responsible of utilizing allocated GTSs

IEEE 802.15.3 - GTS : 

IEEE 802.15.3 - GTS Two types of GTSs Dynamic GTS Location within a superframe may change PNC can optimize channel utilization Pseudostatic GTS Only for isochronous data Fixed location within a superframe May be changed, but only after a series of notitications to the DEV

IEEE 802.15.3 : 

IEEE 802.15.3 Starting a piconet DEV scans the for the best channel and sends out beacons -> the DEV becomes PNC If no channels available: Establishes a child or neighbor piconet instead Requests a private GTS from parent PNC All communication takes place within assigned GTS

IEEE 802.15.3 - QoS : 

IEEE 802.15.3 - QoS QUALITY OF SERVICE : IEEE 802.15.3 supports both synchronous and asynchronous data CAP offers only best-effort The PNC will allocate resources in the CFP Through admission control Synchronous data: Based on number of time slots per superframe, duration of slot, priority and GTS type

IEEE 802.15.3 - QoS : 

IEEE 802.15.3 - QoS Asynchronous data: Based on total data and priority After performing admission control, GTSs may be allocated

Outline : 

Outline IEEE 802.15.1 – ”Bluetooth” IEEE 802.15.3 – High data rate WPAN IEEE 802.15.4 – Low data rate WPAN

IEEE 802.15.4 - Overview : 

IEEE 802.15.4 - Overview Low Rate WPAN (LR-WPAN) Simple Low cost Low power consumption E.g. Sensor networks Data rates: 20-250 kbps

IEEE 802.15.4 - DEVs : 

IEEE 802.15.4 - DEVs 2 or more DEVs form a PAN 2 different types of DEVs Full functional Device (FFD) Coordinator and simple node Any topology Talks to any device Reduced Functional Device (RFD) Simple node only, either source or desination Star topology only Talks to network coordinator only

IEEE 802.15.4 - Star : 

IEEE 802.15.4 - Star

IEEE 802.15.4 – Peer-to-Peer : 

IEEE 802.15.4 – Peer-to-Peer

IEEE 802.15.4 - Combined : 

IEEE 802.15.4 - Combined

IEEE 802.15.4 - QoS : 

IEEE 802.15.4 - QoS QUALITY OF SERVICE – 3 traffic types Periodic data: e.g. Sensor data Intermittent data: generated once a while, e.g. Ligth witch traffic Repetitive low latency data: E.g. Mouse device traffic Sophisticated QoS mechanisms may reside in upper layers

RECENT INNOVATIONS INWPANs : 

RECENT INNOVATIONS INWPANs

Recent Innovations: : 

Recent Innovations: Blue SNIPER: Its an antenna invented by group of hackers “Flexilis”. Successfully connected two bluetooth devices more than half a mile (800m) away. Used an Antenna and a scope attached to a rifle stock. Antenna attached to a Bluetooth card in a computer.

Recent Innovations: : 

Recent Innovations: BLUEDATING: Form of Dating which makes use of mobile phone and Bluetooth technology. Subscribers enter details about them and their ideal partner. When their mobile phone comes in the vicinity of that of another subscriber (10 meters) the phones exchange details of the two people. Vicinity can be pub, department store, beach called “blueplaces”.

Recent Innovations : 

Recent Innovations SKINPLEX: Skinplex, another PAN technology, transmits via the capacitive near field of human skin Works by sending a billionth of an amp (nanoamp) of current through the body, which is actually a thousand times less than the current generated by combing our hair. Skinplex can detect and communicate up to “1m” from a human body. It is already used for access control for door locks and jamming protection in convertible car roofs.

SKINPLEX : 

SKINPLEX

Thats all folks - Summary : 

Thats all folks - Summary IEEE 802.15.1: Bluetooth IEEE 802.15.3: High data rate WPAN IEEE 802.15.4: Low data rate WPAN