Alex Wegznek Chris Griffis EEL 4514 Communications System

 ZigBee Overview  Purpose of ZigBee  History of ZigBee  How ZigBee works  Pros & Cons  Regulations & Standards  Stack & Protocol  Comparisons

 Specification for communication protocols based upon IEEE standard  Wireless sensor monitoring and control  Designed to be: ◦ Highly reliable ◦ Cost-effective ◦ Low-power ◦ Highly secure ◦ Low-data rate cience.smith.edu%2F~jcardell%2FCourses%2FEGR390%2FReadings%2FZigBee- Tutorial.ppt&ei=S45vUL2MIpOY9QS164GADQ&usg=AFQjCNFTM-NOUd01KZbHOteELxu737imrQ

 Provide reliable and cost effective solution for WPANs  Designed specifically for sensor networking and automation  Intended to fit on 8-bit microcontrollers with 16 and 32-bit solutions available  Low power leads to extended battery life

 Conceived around 1998  Grew out of the realization that Wi-Fi and Bluetooth were unsuitable for many applications  The first IEEE standard was finished in 2003  ZigBee PRO (new standard) was finished in 2007  ZigBee PRO has extra features: multi-casting, many-to-one routing, and more

 Formed in 1997 with 8 original promoter companies and now has over 200 members  Maintains and publishes the ZigBee standard

 Home Control ◦ Automation, smart lighting, security, temperature control  Commercial Building Automation  Wireless Sensor Networks  Industrial Control  Embedded Sensing

 Mesh networking ◦ Ad-hoc network ◦ Nodes can forward data to other nodes which is called hopping ◦ Multi-hopping can give the network extended range as well as avoid barriers  Tree and star routing also available

Low PowerLow-Data Rate Due to low cost/power 250 kbps maximum Actual throughput comes out closer to 25 kbps Transceivers are half duplex – Can only receive or transmit at one time Devices have low duty cycle No constant contact Allows devices to operate for the entire shelf life of the battery Leads to low data rates Ideal for sensor networks harvesting/resources/articles/Ultra-Low-Power-MCUs.html

National Institute of Standards and Technology (NIST) Advanced Encryption Standard (AES) AES-128 bit block cipher algorithm ZigBee both encrypts and authenticates packets High Level of SecurityHigh Reliability Carrier sense multiple access with collision avoidance (CSMA-CA) 16 bit cyclic redundancy check (CRC); parity bit Mesh network finds route and acknowledges each hop End-to-end data arrival acknowledgements

Direct-sequence spread spectrum (DSSS) Binary Phase-Shift Keying (BPSK) Offset Quadrature Phase-Shift Keying (OQPSK) 868 and 915 MHz band Simplest form of phase shift keying, also the most robust Takes the highest level of noise/distortion to cause an incorrect decision by the demodulator Only able to modulate at 1 bit/symbol (slow data rate) 2.4 GHz band Uses 4 different values of the phase to transmit Offset reduces any unwanted amplitude fluctuation Transmits twice the data rate in a given bandwidth as compared to BPSK

– High reliability – Low cost – Ultra Low power – Highly secure – Open global standard – Remote operation – Easy to implement – Self healing networks – Low data rate – Relatively small transmission range if hopping is not used ( m) ProsCons

 IEEE low rate WPAN standard  Uses the ISM bands  OQPSK - 2.4GHz band  BPSK – lower bands  250 kbps, 40 kbps, and 20 kbps

 16 channels: 5 MHz of BW each  All 16 channels because low BW protocol  Interference tolerant  Fc = ( (5*ch))MHz where ch = 11,12,…26

 Lower protocol specifications  IEEE defines how to: ◦ Discover networks ◦ Form & join networks ◦ Change channels ◦ Detect interference ◦ Single hop, broadcast and data-packet delivery method bwrc.eecs.berkeley.edu/people/grad_students/.../zigbee%2 0master.ppt

 Simple Stack – easy for user  Physical layer - direct sequence, cheap, high integration  MAC layer – several topologies, works with many devices  Network layer – control, communication, and monitoring the nodes architecture.php

 MAC and PHY layers are under IEEE control  The physical layer is the circuitry  The MAC layer allows networks to form and for data transfer  ZigBee assures security, multi-hops, and interoperability  ZigBee’s security differs from IEEE  The APS layer has tables to keep track of which nodes it can accept data from  User only worries about task ZigBee Wireless Networking, Drew Gislason

 Star, Peer-to-Peer, & Mesh  ZigBee network layer has 3 device types: coordinator, router, and end device  Network layer deals with network discovery, formation, address allocation, message routing, network wide security  The APS layer uses the address tables to act as a filter characterstics.php

 Coordinator ◦ Forms network ◦ Monitor/establish/maintains network ◦ Chooses channel ◦ Acts as the trust center ◦ Can act as a router  Router ◦ Finds and joins networks ◦ Pushes broadcasts along ◦ Maintains routes ◦ Stores data for sleeping end devices

 End devices ◦ Most often sleeping ◦ Periodically wake to check if their parent nodes have anything for them ◦ They perfom their tasks ◦ Send data if necessary ◦ Back to sleep ◦ Orphaned nodes will find new parents

 Fully reliable hand-shake data transfer protocol  Error detection and retransmission  ZigBee communicates similar to us ◦ Collision avoidance ◦ Cannot listen and talk at same time  Designed to minimize time the radio is on  Beaconing (asleep)  Non-beaconing (always on) 00mg-zigbee-network-layer-technical-overview.pdf

 Infrequent, small data packets  Many nodes  Timing is critical ◦ 30 ms to add a new slave ◦ 15 ms to wake up  Lots of devices &ISSUE=1209&RELTYPE=blog&PRODCODE=000000&PRODLETT=ES& CommonCount=0

   =0CB8QFjAA&url=http%3A%2F%2Fwww.science.smith.edu%2F~jcardell%2FCo urses%2FEGR390%2FReadings%2FZigBee- Tutorial.ppt&ei=S45vUL2MIpOY9QS164GADQ&usg=AFQjCNFTM- NOUd01KZbHOteELxu737imrQ =0CB8QFjAA&url=http%3A%2F%2Fwww.science.smith.edu%2F~jcardell%2FCo urses%2FEGR390%2FReadings%2FZigBee- Tutorial.ppt&ei=S45vUL2MIpOY9QS164GADQ&usg=AFQjCNFTM- NOUd01KZbHOteELxu737imrQ  Zigbee.org  bwrc.eecs.berkeley.edu/people/grad_students/.../zigbee%20master.ppt