ZigBee Overview

1. Copyright 2002 The ZigBee Alliance, Inc. ZigBee Overview Modified from Adams 2003: http://www.zigbee.org/resources/documents/Adams-Heile_SensorsExpo_AnaheimSept03_V1_000.ppt Adams 2004: http://www.zigbee.org/resources/documents/IWAS_presentation_Mar04_Designing_with_802154_and_zigbee.ppt Karayanis (2003) �Emerging Wireless Standards, Understanding the Role of IEEE 802.15.4 & ZigBee� in AMR & Submetering,� AMRA 2003 International Symposium.

4. Copyright 2002 The ZigBee Alliance, Inc. Mission Statement

5. Copyright 2002 The ZigBee Alliance, Inc. The ZigBee Alliance Solution Targeted at home and building automation and controls, consumer electronics, PC peripherals, medical monitoring, and toys Industry standard through application profiles running over IEEE 802.15.4 radios Primary drivers are simplicity, long battery life, networking capabilities, reliability, and cost Alliance provides interoperability and certification testing

6. IEEE 802.15.4 & ZigBee In Context

7. Copyright 2002 The ZigBee Alliance, Inc. History

8. Copyright 2002 The ZigBee Alliance, Inc. Working Groups Architecture Application Framework Network Security Interoperability Marketing

9. Copyright 2002 The ZigBee Alliance, Inc. The Wireless Market

10. Copyright 2002 The ZigBee Alliance, Inc. Applications Future applications include Toys and Games, like consoles controllers, portable game pads (like gameboys), educational toys like leap frog stuff, and fun toys like RC (remote control) toys, etc.Future applications include Toys and Games, like consoles controllers, portable game pads (like gameboys), educational toys like leap frog stuff, and fun toys like RC (remote control) toys, etc.

11. Copyright 2002 The ZigBee Alliance, Inc. Development of the Standard ZigBee Alliance 50+ companies: semiconductor mfrs, IP providers, OEMs, etc. Defining upper layers of protocol stack: from network to application, including application profiles First profiles published mid 2003 IEEE 802.15.4 Working Group Defining lower layers of protocol stack: MAC and PHY scheduled for release in April

12. Copyright 2002 The ZigBee Alliance, Inc. Frequencies and Data Rates

13. Copyright 2002 The ZigBee Alliance, Inc. Stack Reference Model

14. Copyright 2002 The ZigBee Alliance, Inc. Protocol Stack Features Microcontroller utilized Full protocol stack <32 k Simple node-only stack ~4k Coordinators require extra RAM Node device database Transaction table Pairing table

15. Copyright 2002 The ZigBee Alliance, Inc. ZigBee and Bluetooth 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, hands-free audio, Mobile phones, headsets, PDAs, etc.

16. Copyright 2002 The ZigBee Alliance, Inc. Bluetooth is a cable replacement for items like Phones, Laptop Computers, Headsets Bluetooth expects regular charging Target is to use <10% of host power ZigBee and Bluetooth

17. Copyright 2002 The ZigBee Alliance, Inc. ZigBee is better for devices Where the battery is �rarely� replaced Targets are : Tiny fraction of host power New opportunities where wireless not yet used ZigBee and Bluetooth

18. Copyright 2002 The ZigBee Alliance, Inc. Air interface ZigBee DSSS- 11 chips/ symbol 62.5 K symbols/s 4 Bits/ symbol Peak Information Rate ~128 Kbit/second Bluetooth FHSS 1 M Symbol / second Peak Information Rate ~720 Kbit / second

19. Copyright 2002 The ZigBee Alliance, Inc. Protocol Stack Comparison

20. Copyright 2002 The ZigBee Alliance, Inc. ZigBee and Bluetooth

21. Copyright 2002 The ZigBee Alliance, Inc. ZigBee and Bluetooth

22. Copyright 2002 The ZigBee Alliance, Inc. An Application Example Wireless Light switch � Easy for Builders to Install A Bluetooth Implementation would either : keep a counter running so that it could predict which hop frequency the light would have reached or use the inquiry procedure to find the light each time the switch was operated.

23. Copyright 2002 The ZigBee Alliance, Inc. Light switch using Bluetooth Option 1: use counter to predict hop frequency reached by light The two devices must stay within 60 us (~1/10 of a hop) With 30ppm crystals, devices need to communicate once a second to track each other's clocks. Assume this could be improved by a factor of 100 then devices would need to communicate once every 100 seconds to maintain synchronization. => 900 communications / day with no information transfer + perhaps 4 communications on demand 99.5% Battery Power wasted

24. Copyright 2002 The ZigBee Alliance, Inc. Light switch using Bluetooth Option 2: Inquiry procedure to locate light each time switch is operated Bluetooth 1.1 = up to 10 seconds typical Bluetooth 1.2 = several seconds even if optimized Unacceptable latency

25. Copyright 2002 The ZigBee Alliance, Inc. Light switch using ZigBee With DSSS interface, only need to perform CSMA before transmitting Only 200 �s of latency Highly efficient use of battery power

26. Copyright 2002 The ZigBee Alliance, Inc. Conclusion ZigBee targets applications not addressable by Bluetooth or any other wireless standard ZigBee and Bluetooth complement for a broader solution

27. Copyright 2002 The ZigBee Alliance, Inc. Agenda What are IEEE 802.15.4 and ZigBee? IEEE802.15.4 � Packet Radio made simple ZigBee and the ZigBee Alliance Sensors and ZigBee, a natural pairing What�s Important Reliability and Robustness Cost, Size and Extreme Battery Life How it compares to other protocols Available Silicon and Platforms Motorola�s 802.15.4/ZigBee Platform Combo Summary / Q&A

28. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802.15.4 Standard

29. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802.15.4 Basics 802.15.4 is a simple packet data protocol for lightweight wireless networks Channel Access is via Carrier Sense Multiple Access with collision avoidance and optional time slotting Message acknowledgement and an optional beacon structure Multi-level security Three bands, 27 channels specified 2.4 GHz: 16 channels, 250 kbps 868.3 MHz : 1 channel, 20 kbps 902-928 MHz: 10 channels, 40 kbps Works well for Long battery life, selectable latency for controllers, sensors, remote monitoring and portable electronics Configured for maximum battery life, has the potential to last as long as the shelf life of most batteries

30. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802.15.4 standard Includes layers up to and including Link Layer Control LLC is standardized in 802.1 Supports multiple network topologies including Star, Cluster Tree and Mesh Channel scan for beacon is included, but it is left to the network layer to implement dynamic channel selectionChannel scan for beacon is included, but it is left to the network layer to implement dynamic channel selection

31. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802.15.4 MAC Overview Employs 64-bit IEEE & 16-bit short addresses Ultimate network size can reach 264 nodes (more than we�ll probably need�) Using local addressing, simple networks of more than 65,000 (2^16) nodes can be configured, with reduced address overhead Three devices specified Network Coordinator Full Function Device (FFD) Reduced Function Device (RFD) Simple frame structure Reliable delivery of data Association/disassociation AES-128 security CSMA-CA channel access Optional superframe structure with beacons GTS mechanism

32. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802.15.4 Device Types Three device types Network Coordinator Maintains overall network knowledge; most sophisticated of the three types; most memory and computing power Full Function Device Carries full 802.15.4 functionality and all features specified by the standard Additional memory, computing power make it ideal for a network router function Could also be used in network edge devices (where the network touches the real world) Reduced Function Device Carriers limited (as specified by the standard) functionality to control cost and complexity General usage will be in network edge devices All of these devices can be no more complicated than the transceiver, a simple 8-bit MCU and a pair of AAA batteries!

33. Copyright 2002 The ZigBee Alliance, Inc. Data Frame format One of two most basic and important structures in 15.4 Provides up to 104 byte data payload capacity Data sequence numbering to ensure that all packets are tracked Robust frame structure improves reception in difficult conditions Frame Check Sequence (FCS) ensures that packets received are without error Frame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination infoFrame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination info

34. Copyright 2002 The ZigBee Alliance, Inc. Acknowledgement Frame Format The other most important structure for 15.4 Provides active feedback from receiver to sender that packet was received without error Short packet that takes advantage of standards-specified �quiet time� immediately after data packet transmission Frame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination infoFrame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination info

35. Copyright 2002 The ZigBee Alliance, Inc. MAC Command Frame format Mechanism for remote control/configuration of client nodes Allows a centralized network manager to configure individual clients no matter how large the network Frame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination infoFrame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination info

36. Copyright 2002 The ZigBee Alliance, Inc. Beacon Frame format Beacons add a new level of functionality to a network Client devices can wake up only when a beacon is to be broadcast, listen for their address, and if not heard, return to sleep Beacons are important for mesh and cluster tree networks to keep all of the nodes synchronized without requiring nodes to consume precious battery energy listening for long periods of time Frame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination infoFrame control: + type of frame (4 types), format of address field, controls Ack, I.e. specifies how the frame looks and what it contains. The ACK and MAC command are lower level used for peer-to-peer Sequence number: and Frame check sequency: verifies the integrity of the MAC frame. A transmission is considered successful if the ack frame contains the same sequence number as the previous frame. FCS is a 16-bit cyclic redundancy check (CRC) Address field size: can contain both source and destination info

37. Copyright 2002 The ZigBee Alliance, Inc. MAC Options Two channel access mechanisms Non-beacon network Standard ALOHA CSMA-CA communications Positive acknowledgement for successfully received packets Beacon-enabled network Superframe structure For dedicated bandwidth and low latency Set up by network coordinator to transmit beacons at predetermined intervals 15ms to 252sec (15.38ms*2n where 0 ? n ? 14) 16 equal-width time slots between beacons Channel access in each time slot is contention free Three security levels specified None Access control lists Symmetric key employing AES-128 Carrier sense multiple access with collision avoidance CSMA-CACarrier sense multiple access with collision avoidance CSMA-CA

38. Copyright 2002 The ZigBee Alliance, Inc. ISM Band Interference and Coexistence Potential for interference exists in every ISM band, not just 2.4GHz IEEE 802.11 and 802.15.2 committees are addressing coexistence issues ZigBee/802.15.4 Protocol is very robust Clear channel checking before transmission Backoff and retry if no acknowledgement received Duty cycle of a ZigBee-compliant device is usually extremely low It�s the �cockroach that survives the nuclear war� Waits for an opening in otherwise busy RF spectrum Waits for acknowledgements to verify packet reception at other end

39. Copyright 2002 The ZigBee Alliance, Inc. PHY Performance

40. Copyright 2002 The ZigBee Alliance, Inc. IEEE1451.5 Sensor Group Wireless Criteria A survey was conducted mid-2002 on the characteristics of a wireless sensor network most important to its users In order of importance, these characteristics are 1. Data Reliability 2. Battery Life 3. Cost 4. Transmission Range 5. Data Rate 6. Data Latency 7. Physical Size 8. Data Security How would you modify these requirements, if at all?

41. Copyright 2002 The ZigBee Alliance, Inc. Reliability and Robustness throughout the stacks of IEEE 802.15.4 and ZigBee

42. Copyright 2002 The ZigBee Alliance, Inc. Reliability Consistently perform a given task to the desired result despite all changes of environmental behavior Without fail A necessary ingredient of trust �When the sensor measures its environment; the controller always knows that same value�

43. Copyright 2002 The ZigBee Alliance, Inc. Reliability The wireless medium is not a protected environment like the wired medium, but rather, it is fraught with degradations, disruptions, and pitfalls such as dispersion, multipath, interference, frequency dependent fading, sleeping nodes, hidden nodes, and security issues.

44. Copyright 2002 The ZigBee Alliance, Inc. Reliability Each of these degradations and disruptions can be mitigated by various mechanisms within the ISO layers; but not all mechanisms are compatible with all other mechanisms or may negatively impact critical performance attributes The system must be optimized for the best performance in a realistic environment

45. Copyright 2002 The ZigBee Alliance, Inc. Reliability In addition to the previous disruptions there is the case of sending messages to devices that are not receiving, e.g. they�re in the �sleep� mode. When this happens the message needs to be buffered by another device that is able to send the message when the sleeping device wakes up.

46. Copyright 2002 The ZigBee Alliance, Inc. Reliability

47. Copyright 2002 The ZigBee Alliance, Inc. Reliability IEEE 802.15.4 has built upon the successes of previous IEEE 802 standards by selecting those mechanisms proven to ensure good reliability without seriously degrading system and device performance.

48. Copyright 2002 The ZigBee Alliance, Inc. Reliability ISO Layers: PHY: Direct Sequence with Frequency Agility (DS/FA) MAC: ARQ, Coordinator buffering Network: Mesh Network (redundant routing) Application Support Layer: Security

49. Copyright 2002 The ZigBee Alliance, Inc. Reliability PHY Layers: Direct sequence: allows the radio to reject multipath and interference by use of a special �chip� sequence. The more chips per symbol, the higher its ability to reject multipath and interference. Frequency Agility: ability to change frequencies to avoid interference from a known interferer or other signal source.

50. Copyright 2002 The ZigBee Alliance, Inc. IEEE 802 Direct Sequence As can be seen from above, IEEE802.15.4/ZigBee has more processing gain (chips/symbol) than its predecessors

51. Copyright 2002 The ZigBee Alliance, Inc. Direct Sequence and Frequency Agility

52. Copyright 2002 The ZigBee Alliance, Inc. Reliability MAC: ARQ (acknowledgement request) is where a successful transmission is verified by replying with an acknowledge (ACK). If the ACK is not received the transmission is sent again Coordinator buffering is where the network coordinator buffers messages for sleeping nodes until they wake again

53. Copyright 2002 The ZigBee Alliance, Inc. Reliability Network: Mesh Networking: allows various paths of routing data to the destination device. In this way if a device in the primary route is not able to pass the data, a different valid route is formed, transparent to the user.

54. Copyright 2002 The ZigBee Alliance, Inc. Reliability: Mesh Networking

55. Copyright 2002 The ZigBee Alliance, Inc. Reliability Application Support Sub-layer(APS): Security: supports reliability by keeping other devices from corrupting communications. The APS configures the security emplaced in the MAC layer and also adds some of its own.

56. Copyright 2002 The ZigBee Alliance, Inc. Robustness Let�s define robustness as the ability to tolerate significant degrading phenomena in the physical medium Multipath and interference are probably the most significant degradations to the channel model.

57. Copyright 2002 The ZigBee Alliance, Inc. Robustness Frequency hopping is a method that allows the radio to periodically change channels to over time minimize the effect of a �bad� channel. While this technique is very effective in some circumstances it creates other problems such as latency, network uncertainty for sleeping nodes, loss of the product bandwidth x time, etc.

58. Copyright 2002 The ZigBee Alliance, Inc. Robustness Direct Sequence with Frequency Agility (DS/FA) combines the best features of DS and FH without most of the problems caused by frequency hopping because frequency changes aren�t necessary most of the time, rather they�re appropriate only on an exception basis.

59. Copyright 2002 The ZigBee Alliance, Inc. Robustness The 802.11 Working Group couldn�t agree upon which of the following PHYs was the best: FH, IR, or DS. So all three were standardized and left to the market to decide. Of the three PHYs; DS was the clear market winner. DS provided sufficient robustness with higher overall performance.

60. Copyright 2002 The ZigBee Alliance, Inc. Robustness Excess robustness does not achieve higher performance, rather it typically costs performance

61. Copyright 2002 The ZigBee Alliance, Inc. Conclusion IEEE 802.15.4/ZigBee have addressed reliability throughout the ISO stack with proven mechanisms to minimize the uncertainty of the wireless medium

62. Copyright 2002 The ZigBee Alliance, Inc. Examples

63. Copyright 2002 The ZigBee Alliance, Inc. Transceiver Comparisons Instantaneous Power Consumption 15.4 Transceivers are �similar� to Bluetooth Transceivers 802.15.4 OQPSK with shaping Max data rate 250kbps over the air 2Mchips/s over the air Direct Sequence Spread Spectrum (62.5ksps*32 spread) -90 dBm sensitivity 40ppm xtal Bluetooth FSK Max data rate 720kbps over the air 1Msps over the air Frequency Hop Spread Spectrum (79 channels @ 1600 hps) -85dBm sensitivity 20ppm xtal Instantaneous power consumption will be similar for the raw transceivers without protocol Bluetooth�s frequency hop makes it extremely difficult to create extended networks without large synchronization cost

64. Copyright 2002 The ZigBee Alliance, Inc. Protocol Makes the Difference 15.4 Protocol was developed for very different reasons than Bluetooth 802.15.4 Very low duty cycle, very long primary battery life applications Static and dynamic star and mesh network structures with potentially a very large number (>>65534) of client units, low latency available but not necessary Ability to remain quiescent for long periods of time without communicating to the network Bluetooth Moderate duty cycle, secondary battery operation where battery lasts about the same as master unit Wire replacement for consumer devices that need moderate data rates with very high QoS and very low, guaranteed latency Quasi-static star network structure with up to 7 clients (and ability to participate in more than one network simultaneously) Generally used in applications where either power is cycled (headsets, cellphones) or mains-powered (printers, car kits) Protocol differences can lead to tremendous optimizations in power consumption

65. Copyright 2002 The ZigBee Alliance, Inc. Applications Industrial Control/Monitoring Space Asset Management Basic identification Device ID, Device PN/SN, Device source/destination, etc. Asset �health� Temperature, humidity, shock, fuel levels, etc. Nearly any parameter can be monitored given an appropriate sensor Asset Tracking Location tracking through two-way communication Simplest form is communication/identification when passes a checkpoint Same as other RFID tagging systems More sophisticated �what other devices can it hear/communicate with?� Other options include ranging (time of flight) and SNR measurement Has the potential for very precise location measurement The wireless network uses protocol gateways to move command/monitor data between the end devices and the network data management center

66. Copyright 2002 The ZigBee Alliance, Inc. Warehouses, Fleet management, Factory, Supermarkets, Office complexes Gas/Water/Electric meter, HVAC Smoke, CO, H2O detector Refrigeration case or appliance Equipment management services & PM Security services Lighting control Assembly line and work flow, Inventory Materials processing systems (heat, gas flow, cooling, chemical) Product Examples

67. Copyright 2002 The ZigBee Alliance, Inc. Home & Diagnostics Examples Mobile clients link to PC for database storage PC links to peripherals, interactive toys PC Modem calls retailer, SOHO, Service Provider Gateway links to security system, temperature sensor, AC system, entertainment, health. Gateway links to field sales/service

68. Copyright 2002 The ZigBee Alliance, Inc. HID Scenario: Wireless Keyboard Scenario Parameters Battery-operated keyboard Part of a device group including a mouse or trackball, sketchpad, other human input devices Each device has a unique ID Device set includes a USB to wireless interface dongle Dongle powered continuously from computer Keyboard does not have ON/OFF switch Power modes Keyboard normally in lowest power mode Upon first keystroke, wakes up and stays in a �more aware� state until 5 seconds of inactivity have passes, then transitions back to lowest power mode

69. Copyright 2002 The ZigBee Alliance, Inc. Keyboard Usage Typing Rates 10, 25, 50, 75 and 100 words per minute Typing Pattern Theoretical: Type continuously until battery is depleted Measures total number of hours based upon available battery energy

70. Copyright 2002 The ZigBee Alliance, Inc. Wireless Keyboard Using 802.15.4 802.15.4 Operation Parameters Star network Non-beacon mode (CSMA-CA) USB Dongle is a PAN Coordinator Full Functional Device (FFD) Keyboard is a Reduced Function Device (RFD) Power Modes Quiescent Mode used for lowest power state First keystroke latency is approx 25ms Idle mode used for �more aware� state Keystroke latency 8-12 ms latency

71. Copyright 2002 The ZigBee Alliance, Inc. Wireless Keyboard Using 802.15.4 802.15.4 Chipset Parameters Motorola 802.15.4 Transceiver and HCS08 MCU Battery operating voltage 2.0 � 3.6 V All required regulation internal to ICs Nearly all available energy usable with end of life voltage at 2.0 volts

72. Copyright 2002 The ZigBee Alliance, Inc. Wireless Keyboard Using Bluetooth Bluetooth Operation Parameters Piconet network USB Dongle is piconet Master Keyboard is a piconet Slave Power Modes Park mode used for lowest power state 1.28 second park interval First keystroke latency is 1.28s Sniff mode used for �more aware� state 15ms sniff interval 15ms latency

73. Copyright 2002 The ZigBee Alliance, Inc. Wireless Keyboard Using Bluetooth Bluetooth Chipset Parameters CSR BlueCore 2 �External + Flash + Regulator Battery Operating Voltage 2.7 � 3.6 Vdc Requires external regulator for best performance Only 19 to 30 percent of available battery life usable with 2.7V cutoff voltage Power Consumption (estimated) Park Mode @ 1.28 s interval: 0.05mA avg Sniff Mode @ 15ms interval: 8mA avg NOTE: I do not assume a deep sleep mode since wake up time of 4 to 30 seconds seems unacceptable

74. Copyright 2002 The ZigBee Alliance, Inc. BT vs. 15.4 Keyboard Comparison

75. Copyright 2002 The ZigBee Alliance, Inc. Medical Sensor Scenario Assumptions Environment Battery-operated sensor body-worn with either body-worn or facility-mounted coordinator Sensor Running 100% of time Intelligent enough to output a digital waveform that at a minimum signals a detected heart beat For the course of this study, assume that only the leading edge of this pulse contains information (I.e., heartbeat event occurred) Power consumption is 10uA (WAG; immaterial to wireless connection but will consume wireless connection's battery) Network Coordinator Provides a regular RF beacon to which the sensor synchronizes Expect to hear from the sensor during communications windows relative to beacon interval Power Source Battery-operated if body-worn cellphone or other network access device Mains-powered if part of a hospital infrastructure

76. Copyright 2002 The ZigBee Alliance, Inc. 802.15.4/ZigBee Operation Mode 802.15.4/ZigBee Mode Network environment using Guaranteed Time Slot (GTS) Network beacons occurring either every 960ms or 61.44s (closest values to 1 and 60 s) Guaranteed time slot occurs at some predetermined point in the beacon interval Sensor has two ongoing processes Heartbeat time logging Transmit heartrate and other information (8 bytes total) Instantaneous heartrate (1/timeinterval between last two pulses,1ms precision) Running average heartrate (1/time interval between last twenty pulses, 1ms precision) Sensor average temperature (0.1C precision) Sensor average battery state (0.1V precision)

77. Copyright 2002 The ZigBee Alliance, Inc. Medical Sensor Scenario Low Power, Low Latency RF XCVR IC is essentially off (leakage currents predominating) in normal state MCU is capable of responding immediately to an interrupt MCU onboard 32kHz time clock is running Heartbeat sensor is capable of generating an interrupt signal for MCU System is in a multisensor environment where all sensors are assigned guaranteed timeslots (GTS) for communications Scenario 1 Beacon interval is 960ms (15ms*2^6) Scenario 2 Beacon interval is 61.44s (15ms*2^12) Assume that retries are not necessary due to GTS Reasonable if we assume RF environment is well-controlled

78. Copyright 2002 The ZigBee Alliance, Inc. General Schematic

79. Copyright 2002 The ZigBee Alliance, Inc. Sensor Battery Type Lithium coin primary battery Tadiran Lithium type TL-2186 http://www.tadiran.com/pdf/tl-2186.pdf 400 mAh nominal capacity (0.5mA constant to 2.0V) 3.6V BOL, 2.0V EOL

80. Copyright 2002 The ZigBee Alliance, Inc. Two Processes Process 1 Each heartbeat forces the MCU to respond to the sensor interrupt From MCU interrupt to completion of processing Approximately 980 microseconds Approximately 3E-8 mAh consumed per heartbeat Process 2 Each 960ms or 61.44s the system synchronizes to network and transmits the information From MCU beacon wakeup to completion of transmission Approximately 56ms (varies depending on beacon interval and assigned guaranteed time slot) Approximately 3E-4 mAh consumed per transmission event Constant Idle Currents 10 microamp sensor Leakage currents in RF XCVR IC and MCU oscillator/Time base reference (~ microamps)

81. Copyright 2002 The ZigBee Alliance, Inc. 802.15.4/ZigBee vs Bluetooth

82. Copyright 2002 The ZigBee Alliance, Inc. Conclusion Bluetooth and 802.15.4 transceiver physical characteristics are very similar Protocols are substantially different and designed for different purposes 802.15.4 designed for low to very low duty cycle static and dynamic environments with many active nodes Bluetooth designed for high QoS, variety of duty cycles, moderate data rates in fairly static simple networks with limited active nodes Bluetooth costs and system performance are in line with 3rd and 4th generation products hitting market while 1st generation 15.4 products will be appearing only late this year

83. Copyright 2002 The ZigBee Alliance, Inc. More Information ZigBee Alliance web site http://www.ZigBee.org IEEE 802.15.4 web site http://www.ieee802.org/15/pub/TG4.html Articles �Meet the ZigBee Standard�, Sensors Mag June 2003 http://www.sensorsmag.com/articles/0603/14/ �ZigBee Vital in Industrial Applications�, EETimes, 29 July 2003 http://www.eetimes.com/story/OEG20030727S0002

84. Copyright 2002 The ZigBee Alliance, Inc. Motorola 802.15.4/ZigBee� Platform for Low Data Rate Wireless

85. Copyright 2002 The ZigBee Alliance, Inc. System Simplicity and Flexibility

86. Copyright 2002 The ZigBee Alliance, Inc. Motorola 802.15.4 / ZigBee� solution Features 2.4 GHz Band, -90 dBm RX sensitivity at 1% PER IEEE spec is �85 dBm Power supply 2.0-3.6 V w/ on-chip regulator, logic interface 1.7 to 3.3 Runs off a single Li or 2 alkaline cells Complete RF transceiver data modem � antenna in, fully packetized data out Data and control interface via standard SPI at 4 to 8 MHz 802.15.4 MAC A large number of Motorola�s substantial line of HC08 MCUs will interoperate with the data modem chip Often 802.15.4 functionality can be added to existing systems simply by including the modem chip and reprogramming an existing MCU that may already be in the application HC08 RAM/FLASH configurations from 384B/4kB to 2kB/60kB depending upon application SW needs

87. Copyright 2002 The ZigBee Alliance, Inc. Motorola�s RF Data Modem Transceiver (1) Designed for the IEEE 802.15.4 and ZigBee� standards Operates in the 2.4 GHz ISM band available worldwide Cost effective CMOS design Low external components, no T/R switch required On-chip low noise amplifier 0dBm (1.0 mW) PA, step adjustable to �30dBm Integrated VCO, no external components Full spread-spectrum encoding and decoding compatible with 802.15.4 RX sensitivity of �90 dBm at 1% PER, better than specification Engineered to support 250 kBit/s O-QPSK data in 5.0 MHz channels, per the IEEE 802.15.4 specification No line-of-sight limitations as with infrared (IR)

88. Copyright 2002 The ZigBee Alliance, Inc. Motorola�s RF Data Modem Transceiver (2) Designed to run DIRECTLY off two alkaline AA or AAA cells, or one Lithium cell 2.0 to 3.6 V with on-chip voltage regulator Can use the full capacity of the battery (to end of life ~1.0V per cell) Buffered transmit and receive data packets for simplified use with low-end microcontrollers SPI data and control interface, operates up to 8MHz Designed to support peer to peer and star topologies On-board timers to support optional Superframe/Guaranteed Time Slots for low latency transfer Will support optional Zigbee� Network layer software Application-configurable power-saving modes that take best advantage of battery operation RX/TX > Idle > Doze > Hibernate > Off

89. Copyright 2002 The ZigBee Alliance, Inc. Scalability to Address Specific Needs 802.15.4 is a guest in existing microcontrollers

90. Copyright 2002 The ZigBee Alliance, Inc. Motorola�s 802.15.4 Platform Advantages Total System Solution Single source for platform solution Integrated Circuits, Reference Designs, Modules, Stack Software, Development Systems Key technology enhancements provide for a superior solution Adjacent channel rejection Improvements in noisy environment High Sensitivity Radio Solution 5 dBm beyond spec � longer range Extended Temperature Operating Range -40�C to +85�C for industrial and automotive applications Operating voltage range optimized for alkaline or lithium primary cells 2.0 Vdc to 3.6 Vdc, disposable Adjustable TX Output power Improved coexistence for short range applications, improved battery life IEEE and ZigBee� Alliance membership Technology and standards driver Early access to new technology

91. Copyright 2002 The ZigBee Alliance, Inc. Home/Light Commercial Spaces

92. Copyright 2002 The ZigBee Alliance, Inc. Industrial/Commercial Spaces Warehouses, Fleet management, Factory, Supermarkets, Office complexes Gas/Water/Electric meter, HVAC Smoke, CO, H2O detector Refrigeration case or appliance Equipment management services & Preventative maintenance Security services Lighting control Assembly line and work flow, Inventory Materials processing systems (heat, gas flow, cooling, chemical)

93. Copyright 2002 The ZigBee Alliance, Inc. Peel-n�-Stick Security Sensors Battery Operation 2 AA Alkaline or 1 Li-AA cell 802.15.4/ZigBee Mode Non-beacon network environment Sensor process RC Oscillator waking up MCU and doing network check-in at some interval Many security systems have between ~10 second and ~15 minute requirement On a sensor event, device immediately awakens and reports in to network

94. Copyright 2002 The ZigBee Alliance, Inc. Security Sensor Timing

95. Copyright 2002 The ZigBee Alliance, Inc. 802.15.4 Security Sensor

96. Copyright 2002 The ZigBee Alliance, Inc. Body-Worn Medical Sensors Heartbeat Sensor Battery-operated using CR2032 Li-Coin cell 802.15.4/ZigBee Mode Network environment using Guaranteed Time Slot (GTS) Network beacons occurring either every 960ms or 61.44s (closest values to 1 and 60 s) Sensor has two ongoing processes Heartbeat time logging Transmit heartrate and other information (8 bytes total) Instantaneous and average heart rate Body temperature and battery voltage

97. Copyright 2002 The ZigBee Alliance, Inc. Tracking Global Shipments Securely 1 High value consumer electronics shipment from Singapore to Chicago (sea leg) Container loaded with high-value electronics in Singapore, container�s transponder reads all the traditionally RFID-tagged material inside the container Loaded on ship at harbor, crane/ship communicates with container�s transponder confirming loading, contents and security and providing it information on ship�s network As ship proceeds across Pacific, environmental and security data regularly collected from container�s transponder, ensuring the safety of the contents and providing ability for shipper/contents owner to proactively respond to container malfunction/security breach Offloading at Long Beach, container transponder communicates with crane to validate contents/point of origin/container security and provides it information on train�s network

98. Copyright 2002 The ZigBee Alliance, Inc. Tracking Global Shipments Securely 2 High value consumer electronics shipment from Singapore to Chicago (rail leg) Transloaded onto COFC train at Los Angeles harbor, crane verifies contents, container ID and car number location match to train manifest and provides it information on train�s network Conveying flatcar establishes link with loaded container, communicates �loaded� status forward to locomotive computer Train leaves for Chicago; along way, locomotive continues to request and receive regular updates from container and relay entire train status to Ops Railroad provides the just-in-time information via internet to the shipper/receiver Train arrives Chicago, container offloaded at yard, crane communicates with container and verifies contents, source, and security and provides it information on truck�s network

99. Copyright 2002 The ZigBee Alliance, Inc. Tracking Global Shipments Securely 3 High value consumer electronics shipment from Singapore to Chicago (road leg) Road tractor/trailer combo moving container to final destination has transponder that communicates with container, and verifies contents, source, destination, and security Container arrives at destination (big box retail store distribution) where employees verify for the final time the contents, source, destination and container security before signing off on delivery Shipment protected at all times on journey Mishandling, smuggling, homeland security issues all contained with this simple yet very sophisticated system

100. Copyright 2002 The ZigBee Alliance, Inc. What security issues are there and how will they be solved? Security and data integrity Key benefits of the ZigBee technology ZigBee leverages the security model of the IEEE 802.15.4 RF standard Extends this capability with robust encryption options Can be tailored to the specific needs of the networked device

101. Copyright 2002 The ZigBee Alliance, Inc. How is ZigBee related to IEEE 802.15.4? ZigBee takes full advantage of A powerful physical radio specified by IEEE 802.15.4 ZigBee adds Logical network and application software ZigBee is based on the IEEE 802.15.4 RF standard, and the Alliance is working closely with the IEEE to ensure an integrated and complete solution for the market

102. Copyright 2002 The ZigBee Alliance, Inc. Non-Beacon vs Beacon Modes Non-Beacon Mode A simple, traditional multiple access system used in simple peer and near-peer networks Think of it like a two-way radio network, where each client is autonomous and can initiate a conversation at will, but could interfere with others unintentionally However, the recipient may not hear the call or the channel might already be in use Beacon Mode A very powerful mechanism for controlling power consumption in extended networks like cluster tree or mesh Allows all clients in a local piece of the network the ability to know when to communicate with each other Here, the two-way radio network has a central dispatcher who manages the channel and arranges the calls As you�ll see, the primary value will be in system power consumption

103. Copyright 2002 The ZigBee Alliance, Inc. Example of Non-Beacon Network Commercial or home security Client units (intrusion sensors, motion detectors, glass break detectors, standing water sensors, loud sound detectors, etc) Sleep 99.999% of the time Wake up on a regular yet random basis to announce their continued presence in the network (�12 o�clock and all�s well�) When an event occurs, the sensor wakes up instantly and transmits the alert (�Somebody�s on the front porch�) The ZigBee Coordinator, mains powered, has its receiver on all the time and so can wait to hear from each of these stations Since ZigBee Coordinator has �infinite� source of power it can allow clients to sleep for unlimited periods of time to allow them to save power

104. Copyright 2002 The ZigBee Alliance, Inc. Example of Beacon Network Now make the ZigBee Coordinator battery-operated also All units in system are now battery-operated Client registration to the network Client unit when first powered up listens for the ZigBee Coordinator�s network beacon (interval between 0.015 and 252 seconds) Register with the coordinator and look for any messages directed to it Return to sleep, awaking on a schedule specified by the ZigBee Coordinator Once client communications are completed, ZigBee coordinator also returns to sleep This timing requirement potentially impacts the cost of the timing circuit in each end device Longer intervals of sleep mean that the timer must be more accurate or Turn on earlier to make sure that the beacon is heard, increasing receiver power consumption, or Improve the quality of the timing oscillator circuit (increase cost) or Control the maximum period of time between beacons to not exceed 252 seconds, keeping oscillator circuit costs low