Wireless personal area networks(PAN)

1. NGDT – II Wireless Personal Area Network “WPANs”

2. 2 IEEE definition of WPAN Wireless personal area networks (WPANs) are used to convey information over short distances among a private, intimate group of participant devices. Unlike a wireless local area network (WLAN), a connection made through a WPAN involves little or no infrastructure or direct connectivity to the world outside the link. This allows small, power-efficient, inexpensive solutions to be implemented for a wide range of devices.

3. WPANs 1. Bluetooth 2. Zigbee 3. Ultra Wide Band (UWB)

4. What is Bluetooth? • A cable-replacement technology that can be used to connect almost any device to any other device • Radio interface enabling electronic devices to communicate wirelessly via short range (10 meters) ad-hoc radio connections • a standard for a small , cheap radio chip to be plugged into computers, printers, mobile phones, etc

5. Products • Notebook PCs & desktop computers • Printers • PDAs • Other handheld devices • Cell phones • Wireless periperals: – Headsets – Cameras • Access Points • CD Player • TV/VCR/DVD • Telephone Answering Devices • Cordless Phones • Cars

6. What is Bluetooth? • Uses the radio range of 2.45 GHz • Theoretical maximum bandwidth is 1 Mb/s • Several Bluetooth devices can form an ad hoc network called a “piconet” – In a piconet one device acts as a master (sets frequency hopping behavior) and the others as slaves – Example: A conference room with many laptops wishing to communicate with each other

7. History • Harald Bluetooth : 10th century Danish King, managed to unite Denmark and Norway • Bluetooth SIG (Special Interest Group) : – Founded in 1998 by : Ericsson, Intel, IBM, Toshiba and Nokia – Currently more than 2500 adopter companies – Created in order to promote, shape an define the specification and position Bluetooth in the market place : Bluetooth 2.1

8. Bluetooth Architecture • Piconet – Each piconet has one master and up to 7 simultaneous slaves • Master : device that initiates a data exchange. • Slave : device that responds to the master • Scatternet – Linking of multiple piconets through the master or slave devices – Bluetooth devices have point-to-multipoint capability to engage in Scatternet communication.

9. Piconet • All devices in a piconet hop together – Master gives slaves its clock and device ID • Non-piconet devices are in standby MS S S P P SB SB M=Master P=Parked S=Slave SB=Standby

10. Scatternet • Devices can be slave in one piconet and master of another MS S SP P SB SB M S S SB P

11. Physical links • Between master and slave(s), different types of links can be established. Two link types have been defined: – Synchronous Connection-Oriented (SCO) link – Asynchronous Connection-Less (ACL) link

12. Physical links • Synchronous Connection Oriented (SCO) – Support symmetrical, circuit-switched, point-to-point connections – Typically used for voice traffic. – Data rate is 64 kbit/s. • Asynchronous Connection-Less (ACL) – Support symmetrical and asymmetrical, packet-switched, point-to-multipoint connections. – Typically used for data transmission . – Up to 433.9 kbit/s in symmetric or 723.2/57.6 kbit/s in asymmetric

13. Bluetooth Protocol Stack Bluetooth Radio Baseband LMP L2CAP Audio RFCOMM PPP IP UDP TCP WAP WAE OBEX vCard/vCal AT- Commands TCS BIN Host Controller Interface (HCI) Bluetooth Core Protocol Adopted Protocol Cable Replacement Protocol SDP Telephony Protocol

14. Bluetooth Protocol Stack • Bluetooth Radio : specifics details of the air interface, including frequency, frequency hopping, modulation scheme, and transmission power. • Baseband: concerned with connection establishment within a piconet, addressing, packet format, timing and power control. • Link manager protocol (LMP): establishes the link setup between Bluetooth devices and manages ongoing links, including security aspects (e.g. authentication and encryption), and control and negotiation of baseband packet size

15. Bluetooth Protocol Stack • Logical link control and adaptation protocol (L2CAP): adapts upper layer protocols to the baseband layer. Provides both connectionless and connection-oriented services. • Service discovery protocol (SDP): handles device information, services, and queries for service characteristics between two or more Bluetooth devices. • Host Controller Interface (HCI): provides an interface method for accessing the Bluetooth hardware capabilities. It contains a command interface, which acts between the Baseband controller and link manager

16. Bluetooth Protocol Stack • TCS BIN (Telephony Control Service): bit-oriented protocol that defines the call control signaling for the establishment of voice and data calls between Bluetooth devices. • OBEX(OBject EXchange) : Session-layer protocol for the exchange of objects, providing a model for object and operation representation • RFCOMM: a reliable transport protocol, which provides emulation of RS232 serial ports over the L2CAP protocol • WAE/WAP: Bluetooth incorporates the wireless application environment and the wireless application protocol into its architecture.

17. Connection Establishment States • Standby – State in which Bluetooth device is inactive, radio not switched on, enable low power operation. • Page – Master enters page state and starts transmitting paging messages to Slave using earlier gained access code and timing information. • Page Scan – Device periodically enters page state to allow paging devices to establish connections.

18. Connection Establishment States • Inquiry – State in which device tries to discover all Bluetooth enabled devices in the close vicinity. • Inquiry scan – Most devices periodically enter the inquiry scan state to make themselves available to inquiring devices.

19. Inquiry and Page Inquiry Page Inquiry scan Master response Inquiry response Page scan Slave response Connection Connection (1) ID packet (Broadcast) (2) FHS packet (3) Paging ID packet (4) ID packet (5) FHS packet (6) ID packet (7) ID packet Standby Standby Master Slave

20. Bluetooth Security • The following are the three basic security services specified in the Bluetooth standard: – Authentication • verifying the identity of communicating devices. User authentication is not provided natively by Bluetooth. – Confidentiality • preventing information compromise caused by eavesdropping by ensuring that only authorized devices can access and view data. – Authorization • allowing the control of resources by ensuring that a device is authorized to use a service before permitting it to do so.

21. ZigBee

22. Introduction • ZigBee is a technological standard designed for control and sensor networks • Based on the IEEE 802.15.4 Standard • Created by the ZigBee Alliance

23. Introduction • Operates in Personal Area Networks (PAN’s) and device-to-device networks • Connectivity between small packet devices • Control of lights, switches, thermostats, appliances, etc.

24. History • Developement started 1998, when many enginereers realized that WiFi and Bluetooth were going to be unsuitable for many applications • IEEE 802.15.4 standard was completed in May 2003

25. ZigBee Alliance • Organization defining global standards for reliable, cost effective, low power wireless‐ applications • A consortium of end users and solution providers, primarily responsible for the development of the 802.15.4 standard • Developing applications and network capability utilizing the 802.15.4 packet delivery mechanism

26. Characteristics • Low cost • Low power consumption • Low data rate • Relatively short transmission range • Scalability • Reliability • Flexible protocol design suitable for many applications

27. Security • Encryption specified for MAC, Network and APS layers • Encryprion/Authentication mode CCM(CTR +CBC-MAC) – CTR is a counter based encryption mode – CBC-MAC provides data integrity • All security is based on 128bit key and AES-128 block encryption method

28. Applications PERSONAL HEALTH CARE ZigBee LOW DATA-RATE RADIO DEVICES HOME AUTOMATION CONSUMER ELECTRONIC S TV VCR DVD/CD Remote control security HVAC lighting closures PC & PERIPHERAL S consoles portables educational TOYS & GAMES INDUSTRIAL & COMMERCIAL monitors sensors automation control mouse keyboard joystick monitors diagnostics sensors

29. ZigBee/IEEE 802.15.4 PHY 868MHz / 915MHz / 2.4GHz MAC Application Network Star / Mesh / Cluster-Tree Security 32- / 64- / 128-bit encryption API ZigBee Alliance IEEE 802.15.4 Customer ZigBee Alliance -“the software” -Network, Security & Application layers -Brand management IEEE 802.15.4 -“the hardware” -Physical & Media Access Control layers

30. IEEE 802.15.4 • IEEE 802.15.4 Architecture IEEE 802.15.4 868/915 MHz PHY IEEE 802.15.4 2400 MHz PHY IEEE 802.15.4 MAC IEEE 802.2 LLC Other LLC Data Link Controller (DLC) Networking App Layer ZigBee Application Framework

31. IEEE 802.15.4 Physical Layer • PHY functionalities: – Activation and deactivation of the radio transceiver – Energy detection within the current channel – Link quality indication for received packets – Clear channel assessment for CSMA-CA – Channel frequency selection – Data transmission and reception

32. PHY frame structure • PHY packet fields – Preamble (32 bits) – synchronization – Start of packet delimiter (8 bits) – shall be formatted as “11100101” – PHY header (8 bits) –PSDU length – PSDU (0 to 127 bytes) – data field Preamble Start of Packet Delimiter PHY Header PHY Service Data Unit (PSDU) 4 Octets 0-127 Bytes Sync Header PHY Payload 1 Octets 1 Octets Frame Length (7 bit) Reserve (1 bit)

33. ZigBee Network Topologies Star Mesh Cluster Tree PAN coordinator Full Function Device Reduced Function Device

34. ZigBee Network Topologies • Star Topology – Advantage • Easy to synchronize • Low latency – Disadvantage • Small scale

35. ZigBee Network Topologies • Mesh Topology – Advantage • Robust multihop communication • Network is more flexible • Lower latency – Disadvantage • Route discovery is costly • Needs storage for routing table

36. ZigBee Network Topologies • Cluster Tree – Advantage • Low routing cost • Allow multihop communication – Disadvantage • Route reconstruction is costly • Latency may be quite long

37. ZigBee and Bluetooth Comparison • Optimized for different applications – ZigBee • Smaller packets over large network • Mostly Static networks with many, infrequently used devices • Home automation, toys, remote controls, etc. – Bluetooth • Larger packets over small network • Ad hoc networks‐ • File transfer • Screen graphics, pictures, handsfree audio, Mobile phones, headsets, PDAs, etc.

38. ZigBee and Bluetooth Comparison Feature(s) Bluetooth ZigBee Power Profile days years Complexity complex Simple Nodes/Master 7 64000 Latency 10 seconds 30 ms – 1s Range 10m 70m ~ 300m Extendibility no Yes Data Rate 1 Mbps 250 Kbps Security 64bit, 128bit 128bit AES and Application Layer

39. ZigBee and Bluetooth ComparisonSHORT<RANGERANGE>LONG LOW < DATA RATEDATA RATE > HIGH PANPAN LANLAN TEXT GRAPHICS INTERNET HI-FI AUDIO STREAMING VIDEO DIGITAL VIDEO MULTI-CHANNEL VIDEO 802.15.1 Bluetooth1 802.15.1 Bluetooth 2 802.15.4 ZigBee 802.11b 802.11a/HL2 & 802.11g

40. 40 Ultrawideband Contents • Introduction • Why Ultrawideband • UWB Specifications • Why is UWB unique • Data Rates over range • How it works • UWB Characteristics • Advantages of UWB • Comparison with other technologies • Applications • Wireless USB • Challenges • Conclusion

41. 41 Introduction • Technology for short range Wireless radio communications • Bandwidth more than 25% of a center frequency or more than 1.5 GHz • Different from conventional narrowband and wideband systems

42. 42 Why Ultrawideband • Crunch in RF spectrum availability • Variations in RF spectrum from one country to next • Devices using RF Spectrum are more complex, cost more, and consume more power

43. 43 UWB Specifications • 3.1 -10.6 GHz assigned by FCC • 200 Mbps upto 10 meters • Limited transmit power of -41dbm/Mhz

44. 44 Why is UWB unique? • Simultaneously low power, low cost high data- rate wireless communications • 7.5 Ghz of “free spectrum” • Simple CMOS transmitters at very low power • “Moore’s Law Radio”

45. 45 Theoretical Data Rates Over Range • UWB shows significant throughput potential at short range

46. 46 How it works • Generation of extremely short digital pulses in the subnanosecond range. • Uses and extremely wide band of RF spectrum to transmit data

47. 47 UWB Characteristics • Extremely low transmission energy • Extremely difficult to intercept • Multipath immunity to fading • Follows Shannon’s channel capacity theorem

48. 48 Advantages of UWB • Does not use the traditional radio frequency carriers • UWB is not line-of-sight • Reduced Cost vs. Current Wireless Technology • Channelization: Frequency sharing with other applications • Transmission of data in large bursts • Can trade-off throughput for distance

49. 49 Comparison with other technologies • Faster than Bluetooth, Wi Fi • Data rate of 450Mbps instead of 1Mbps • Complementary to existing radio technologies like 802.11

50. 50 UWB Applications • Replacing IEEE 1394 cables with wireless connectivity • No. 1 High quality wireless video • Accurate Ranging information • Radar and Imaging

51. 51 Wireless USB • Wireless USB Promoter Group – define specifications • Backward Compatible • Targeted bandwidth – 480 Mbps • Connection-level security

52. 52 Challenges • Interference with other licensed bands • Tradeoffs with noise

53. 53 Conclusion • Well suited for high speed, short range WPAN • Supports multimedia data rates, and offers inherent data security. • Dominant player if FCC lightens the limitations

Wireless personal area networks(PAN)

Wireless personal area networks(PAN)

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