Professur Technische Informatik Prof. Dr. Wolfram Hardt. Network Standards. and Technologies for Wireless Sensor Networks. Karsten Knuth

Transcription

1 Network Standards and Technologies for Wireless Sensor Networks Karsten Knuth

2 Index 1. Motivation 2. Introduction 3. Bluetooth 4. ZigBee 5. nanonet 6. Roundup Network Standards 2

3 Motivation growing usage of sensor nets cars weather forecast Motivation Introduction Bluetooth how do the cells communicate? cable bound expensive in widespread applications hard to install error-prone static wireless easy to install fail-safe routing possibilities dynamic formation Network Standards 3

4 Introduction what technologies are available? acoustic transmission visible / non visible light Infrared short distance direct connection needed electromagnetic signals most frequencies need a licence normal radio not suitable for digital transmission WLAN or WiMAX high data rates high range but also high energy consumtion Motivation Introduction Bluetooth Network Standards 4

5 Bluetooth Introduction Bluetooth ZigBee developed by Bluetooth Special Interest Group version 2.1 usage for Wireless Personal Area Networks (WPANs) used in multimedia or as simple cable replacement headsets cordless keyboards version 1.1 and 1.2 and specified as IEEE Network Standards 5

6 IEEE Introduction Bluetooth ZigBee actual goal: compatibility between WPAN and WLAN devices showed to be infeasible base parts of Bluetooth specified as standard Radio Layer Baseband Link Manager L2CAP Layer Network Standards 6

7 IEEE Radio Layer uses Frequency Hopping Spread Spectrum (FHSS) several frequencies in the 2,4GHz band changes frequency 1600 times per second interference with and from other devices is reduced adapted hopping sequence Introduction Bluetooth ZigBee digital modulation uses Frequency Shift-Keying 1 higher frequency 0 lower frequency 3 power classes 1, 2,4 and 100mW Network Standards 7

8 IEEE Baseband connection point of Radio layer and the upper layers Introduction Bluetooth ZigBee 2 kinds of connections point to point point to many Piconet 1 master up to 7 active slaves many more sleeping slaves same hopping sequence Scatternet several Piconets that share the same device Network Standards 8

9 IEEE Baseband Introduction Bluetooth ZigBee every device has a unique 48 Bit long address is to be assigned by the IEEE 8 Bit company ID 24 Bit to be assigned by the company used for access codes which derive from the device address access codes device access code inquiry access code channel access code defined by the master Network Standards 9

10 IEEE L2CAP Introduction Bluetooth ZigBee connects to Bluetooth profiles to the lower layers channel multiplexing protocol multiplexing flow control error control and retransmission fragmentation and recombination quality of service Network Standards 10

11 Bluetooth Profiles Introduction Bluetooth ZigBee profiles are the essential part of Bluetooth determine what the device can do with whom and how it can communicate profiles sit upon the L2CAP layer profiles may require other profiles to work e.g. FTP Profile used for reading folder indexes, sending or getting files uses the OBEX Profile Network Standards 11

12 ZigBee Bluetooth ZigBee nanonet developed the ZigBee Alliance based on IEEE Low-Rate Wireless Personal Area Networks home automation automation technologies for the industry Network Standards 12

13 IEEE kinds of devices Full Function Device work as coordinator or device needs more resources due to routing requirements Reduced Function Device works as device low energy applications Bluetooth ZigBee nanonet 2 kinds of topologies star topology all communication goes via the PAN coordinator peer to peer topology devices may directly talk to each other Network Standards 13

14 IEEE PHY Bluetooth ZigBee nanonet 3 different frequency ranges MHz (Europe) MHz (North America) 2,400-2,483 GHz (worldwide) digital modulation 2,4 GHz range uses O-QPSK other ranges BPSK ASK O-QPSK Network Standards 14

15 IEEE PHY O-QPSK Bluetooth ZigBee nanonet Network Standards 15

16 IEEE MAC Bluetooth ZigBee nanonet supports joining and leaving a PAN uses CSMA-CA manages access to the Guaranteed Time Slots Network Standards 16

17 ZigBee Network Layer Bluetooth ZigBee nanonet data transport based on topology address management 16 Bit ZigBee addresses 64 Bit IEEE addresses initiate a new network joining, leaving networks neighbour discovery Network Standards 17

18 ZigBee Application Layer Bluetooth ZigBee nanonet communication between applications and network layer application framework gives application access to the hardware up to 240 hardware components addressable ZigBee Device Object initiates the parts of the application layer as well as the network layer initiates the Security Service Provider Network Standards 18

19 ZigBee Profiles Bluetooth ZigBee nanonet define functions and properties of ZigBee objects several profiles possible every device has to have the ZigBee Device Profile used for service and neighbourhood discovery 3 classes of profiles available private, released and public categorised by ZigBee Alliance with unknown requirements Network Standards 19

20 nanonet ZigBee nanonet Roundup developed by Nanotron Technologies uses 2,4 GHz range suitable for multimedia and sensor applications uses unique spread spectrum technique now standardised as IEEE a Network Standards 20

21 nanonet PHY ZigBee nanonet Roundup Chirp Spread Spectrum uses Chirps short impulses with changing frequency f = 80MHz Network Standards 21

22 nanonet PHY ZigBee nanonet Roundup On Off Keying (OOK) used as digital modulation no Signal meaning 0 Signal meaning 1 Upchirp/Off or Downchirp/Off Downchirp/Upchirp Downchirp meaning 0 Upchirp meaning 1 Folded-/Down-/Upchirp/Off possible to send 2 Bits within 1 Symbol Folded Chirp meaning 3 aso Network Standards 22

23 nanonet MAC ZigBee nanonet Roundup DA Master Slave usage master prompts slave to send CSMA-CA like IEEE TDMA Network Standards 23

24 Roundup ZigBee NanoNet Roundup Bluetooth ZigBee nanonet DECT WLAN WiMAX frequency range in GHz 2,4 0,868 0,915 2,4 2,4 1,8-1,9 2, data rate In MBit/s 2, , output power in mw 1 2,5 100 max. 100 max. 10 max range in m Network Standards 24

25 The End Thanks for your attention! Network Standards 25