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Submission Title: [What You Should Know about the Zig. Bee Alliance] Date Submitted: [24 September 2003 Source: [Jon Adams] Company [Motorola] Address [2100 E Elliott Rd, Tempe AZ 85254] Voice: [480 -413 -3439], FAX: [480 -413 -4433], E-Mail: [jta@motorola. com] Re: [Sensors Expo Workshop] Abstract: [Description of measures used to enhance reliability in IEEE 802. 15. 4/Zig. Bee] Purpose: [Point of discussion for the Sensors Expo] Notice: This document has been prepared to assist the Zig. Bee Alliance. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution will be posted in the member area of the Zig. Bee web site. Copyright 2002 The Zig. Bee Alliance, Inc.
What You Should Know about the “Wireless that simply works” Sensors Expo 24 September 2003 Anaheim Convention Center, Anaheim CA Copyright 2002 The Zig. Bee Alliance, Inc.
Sensors Expo September 24, 2003 Bob Heile, Chairman, Zigbee Alliance Copyright 2002 The Zig. Bee Alliance, Inc.
Mission Statement To enable reliable, cost-effective, lowpower, wirelessly networked, monitoring and control products based on an open global standard. Copyright 2002 The Zig. Bee Alliance, Inc.
The Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
History Proposals Proposal Zig. Bee Alliance formed Initial MRD RSI/TRD v 0. 2 to IEEE Zig. Bee IEEE 802. 15. 4 PAR Proposals 1998 1999 2000 2001 Copyright 2002 The Zig. Bee Alliance, Inc. Reviews 2002 Stand. Complete
Promoter Companies Copyright 2002 The Zig. Bee Alliance, Inc.
Membership Classes • Promoters – founding members of Zig. Bee, who form the Board of Directors. There are currently 5 promoters + 1 chairperson • Participants – members who generally wish to make technical contributions and/or serve on the Technical Group committees. These members have early access to specifications, and they may also chair working group subcommittees. They are in a position to help shape the Zig. Bee technology for industrial applications and the connected home. Copyright 2002 The Zig. Bee Alliance, Inc.
Working Groups • Architecture • Application Framework • Network • Security • Interoperability • Marketing Copyright 2002 The Zig. Bee Alliance, Inc.
The Wireless Market GRAPHICS INTERNET HI-FI AUDIO STREAMING VIDEO > LONG TEXT MULTI-CHANNEL VIDEO RANGE 802. 11 b LAN 802. 11 a/HL 2 & 802. 11 g Bluetooth 2 < SHORT DIGITAL VIDEO Zig. Bee PAN Bluetooth 1 LOW < DATA RATE > HIGH Copyright 2002 The Zig. Bee Alliance, Inc.
Applications security HVAC AMR lighting control access control BUILDING AUTOMATION patient monitoring fitness PERSONAL monitoring HEALTH CARE asset mgt process control environmental energy mgt CONSUMER ELECTRONICS TV VCR DVD/CD remote Zig. Bee Wireless Control that Simply Works INDUSTRIAL CONTROL RESIDENTIAL/ LIGHT COMMERCIAL CONTROL Copyright 2002 The Zig. Bee Alliance, Inc. PC & PERIPHERALS mouse keyboard joystick security HVAC lighting control access control lawn & garden irrigation
Development of the Standard APPLICATION ZIGBEE STACK SILICON • Zig. Bee Alliance – 50+ companies: semiconductor mfrs, IP providers, OEMs, etc. Customer – Defining upper layers of protocol stack: from network to application, including Zig. Bee application profiles Alliance IEEE – First profiles published mid 802. 15. 4 2003 • IEEE 802. 15. 4 Working Group – Defining lower layers of protocol stack: MAC and PHY scheduled for release in April Copyright 2002 The Zig. Bee Alliance, Inc.
Frequencies and Data Rates BAND 2. 4 GHz COVERAGE DATA RATE ISM Worldwide 250 kbps 16 Europe 20 kbps 1 Americas 40 kbps 10 868 MHz 915 MHz ISM Copyright 2002 The Zig. Bee Alliance, Inc. # OF CHANNEL(S)
Stack Reference Model End developer applications, designed using application profiles Application interface designed using general profile Topology management, MAC management, routing, discovery protocol, security management Channel access, PAN maintenance, reliable data transport Transmission & reception on the physical radio channel ZA 1 ZA 2 … ZAn IA 1 API IAn UDP IP Zig. Bee NWK 802. 2 LLC MAC (SSCS) IEEE 802. 15. 4 MAC (CPS) IEEE 802. 15. 4 PHY Copyright 2002 The Zig. Bee Alliance, Inc.
Protocol Stack Features • Microcontroller utilized • Full protocol stack <32 k • Simple node-only stack ~4 k • Coordinators require extra RAM – Node device database – Transaction table – Pairing table Customer APPLICATIONS APPLICATION INTERFACE SECURITY Zig. Bee Alliance NETWORK LAYER Star/Cluster/Mesh MAC LAYER PHY LAYER 2. 4 GHz 915 MHz Application Copyright 2002 The Zig. Bee Alliance, Inc. IEEE 802. 15. 4 868 MHz Zig. Bee Stack Silicon
Zig. Bee and Bluetooth Competitive or Complementary? Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Optimized for different applications • Bluetooth • Zig. Bee – Larger packets over small – Smaller packets over network large network – Ad-hoc networks – Mostly Static networks with many, – File transfer infrequently used – Screen graphics, pictures, devices hands-free audio, Mobile – Home automation, phones, headsets, PDAs, toys, remote controls, etc. Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Address Different Needs • Bluetooth is a cable replacement for items like Phones, Laptop Computers, Headsets • Bluetooth expects regular charging – Target is to use <10% of host power Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Address Different Needs • Zig. Bee is better for devices Where the battery is ‘rarely’ replaced – Targets are : • Tiny fraction of host power • New opportunities where wireless not yet used Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Zig. Bee Air interface Bluetooth • FHSS • DSSS- 11 chips/ symbol • 1 M Symbol / second • 62. 5 K symbols/s • Peak Information Rate • 4 Bits/ symbol ~720 Kbit / second • Peak Information Rate ~128 Kbit/second Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Voice Application Interface Network Layer Service Discovery Protocol (Serial Port) L 2 CAP Host Control Interface Link Manager MAC Layer Link Controller Baseband RF PHY Layer Zig. Bee Stack Fax Telephony OBEX Control RFCOMM Protocol Data Link Layer Silicon Dial-up Networking Application v. Message Intercom Headset Cordless Group Call v. Card v. Cal v. Note User Interface Application Silicon Zigbee Bluetooth Stack Applications Bluetooth Protocol Stack Comparison Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Timing Considerations Zig. Bee: • Network join time = 30 ms typically • Sleeping slave changing to active = 15 ms typically • Active slave channel access time = 15 ms typically Bluetooth: • Network join time = >3 s • Sleeping slave changing to active = 3 s typically • Active slave channel access time = 2 ms typically Zig. Bee protocol is optimized for timing critical applications Copyright 2002 The Zig. Bee Alliance, Inc.
Initial Enumeration Zig. Bee Bluetooth Coordinator Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth AIR INTERFACE PROTOCOL STACK BATTERY DEVICES/NETWORK LINK RATE RANGE Zig. Bee FHSS DSSS 250 kb 28 kb rechargeable non-rechargeable 8 255 1 Mbps 250 kbps ~10 meters (w/o pa) ~30 meters Comparison Overview Copyright 2002 The Zig. Bee Alliance, Inc.
An Application Example Battery Life & Latency in a Light Switch • 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. Copyright 2002 The Zig. Bee 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 30 ppm 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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Light switch using Zig. Bee • With DSSS interface, only need to perform CSMA before transmitting – Only 200 µs of latency – Highly efficient use of battery power Zig. Bee offers longer battery life and lower latency than a Bluetooth equivalent. Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee and Bluetooth Conclusion • Zig. Bee targets applications not addressable by Bluetooth or any other wireless standard • Zig. Bee and Bluetooth complement for a broader solution Copyright 2002 The Zig. Bee Alliance, Inc.
Agenda • What are IEEE 802. 15. 4 and Zig. Bee? – IEEE 802. 15. 4 – Packet Radio made simple – Zig. Bee and the Zig. Bee Alliance • Sensors and Zig. Bee, 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/Zig. Bee Platform Combo • Summary / Q&A Copyright 2002 The Zig. Bee Alliance, Inc.
A Primer to both 802. 15. 4 and Zig. Bee Jon Adams Director, Technology Strategy Motorola Wireless and Mobile Systems Tempe, Arizona Copyright 2002 The Zig. Bee Alliance, Inc.
IEEE 802. 15. 4 Standard Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Introduction to the IEEE 802. 15. 4 Standard • IEEE 802. 15. 4 standard released May 2003 – Semiconductor manufacturers • Sampling Transceiver ICs and platform hardware/software to Alpha Customers now – Users of the technology • Defining application profiles for the first products, an effort organized by the Zig. Bee Alliance Copyright 2002 The Zig. Bee 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 • Features of the MAC: Association/dissociation, ACK, frame delivery, channel access mechanism, frame validation, guaranteed time slot management, beacon management, channel scan • Low complexity: 26 primitives versus 131 primitives for 802. 15. 1 (Bluetooth) Copyright 2002 The Zig. Bee Alliance, Inc. Zig. Bee Application Framework Networking App Layer (NWK) Data Link Controller (DLC) IEEE 802. 15. 4 LLC IEEE 802. 2 LLC, Type I IEEE 802. 15. 4 MAC IEEE 802. 15. 4 868/915 MHz PHY IEEE 802. 15. 4 2400 MHz PHY
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 Copyright 2002 The Zig. Bee 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! Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 standardsspecified “quiet time” immediately after data packet transmission Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 » 15 ms to 252 sec (15. 38 ms*2 n 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Frequencies and Data Rates • The two PHY bands (UHF/Microwave) have different physical, protocol-based and geopolitical characteristics – Worldwide coverage available at 2. 4 GHz at 250 kbps – 900 MHz for Americas and some of the Pacific – 868 MHz for European-specific markets Copyright 2002 The Zig. Bee Alliance, Inc.
ISM Band Interference and Coexistence • Potential for interference exists in every ISM band, not just 2. 4 GHz • IEEE 802. 11 and 802. 15. 2 committees are addressing coexistence issues • Zig. Bee/802. 15. 4 Protocol is very robust – Clear channel checking before transmission – Backoff and retry if no acknowledgement received – Duty cycle of a Zig. Bee-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 Copyright 2002 The Zig. Bee Alliance, Inc.
PHY Performance 802. 15. 4 has excellent performance in low SNR environments Copyright 2002 The Zig. Bee Alliance, Inc.
IEEE 1451. 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. 2. 3. 4. 5. 6. 7. 8. Data Reliability Battery Life Cost Transmission Range Data Rate Data Latency Physical Size Data Security • How would you modify these requirements, if at all? Copyright 2002 The Zig. Bee Alliance, Inc.
Reliability and Robustness throughout the stacks of IEEE 802. 15. 4 and Zig. Bee Copyright 2002 The Zig. Bee 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” Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee Alliance, Inc.
Reliability Interferer Router Multipath XX Sleeping Node Network Coordinator Hidden Node Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee Alliance, Inc.
IEEE 802 Direct Sequence IEEE 802. 11 Chips/ 11 Symbol 11 b 15. 4 (900) 15. 4 (2. 4) 11 15 32 • As can be seen from above, IEEE 802. 15. 4/Zig. Bee has more processing gain (chips/symbol) than its predecessors Copyright 2002 The Zig. Bee Alliance, Inc.
Direct Sequence and Frequency Agility Interferer Over the Air 2. 4 GHz PHY Desired Signal After DS correlation Channels 11 -26 2. 4 GHz 5 MHz 2. 4835 GHz Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee Alliance, Inc.
Reliability: Mesh Networking Zig. Bee Coordinator (FFD) Zig. Bee Router (FFD) Zig. Bee End Device (RFD or FFD) Mesh Link Star Link Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee 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. Copyright 2002 The Zig. Bee Alliance, Inc.
Robustness • Excess robustness does not achieve higher performance, rather it typically costs performance Copyright 2002 The Zig. Bee Alliance, Inc.
Conclusion • IEEE 802. 15. 4/Zig. Bee have addressed reliability throughout the ISO stack with proven mechanisms to minimize the uncertainty of the wireless medium Copyright 2002 The Zig. Bee Alliance, Inc.
Examples Copyright 2002 The Zig. Bee Alliance, Inc.
Transceiver Comparisons • Instantaneous Power Consumption – 15. 4 Transceivers are “similar” to Bluetooth Transceivers • 802. 15. 4 – OQPSK with shaping – Max data rate 250 kbps over the air – 2 Mchips/s over the air Direct Sequence Spread Spectrum (62. 5 ksps*32 spread) – -90 d. Bm sensitivity – 40 ppm xtal • Bluetooth – FSK – Max data rate 720 kbps over the air – 1 Msps over the air Frequency Hop Spread Spectrum (79 channels @ 1600 hps) – -85 d. Bm sensitivity – 20 ppm 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 Copyright 2002 The Zig. Bee 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 Qo. S 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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Product Examples Warehouses, Fleet management, Factory, Supermarkets, Office complexes • • Gas/Water/Electric meter, HVAC Smoke, CO, H 2 O 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) Temp. Sensor Database Gateway Energy, diagnostics, e-Business services • Gateway or Field Service links to sensors & equipment – • Monitored to suggest PM, product updates, status changes Nodes link to PC for database storage – PC Modem calls retailer, Service Provider, or Corp headquarters remotely monitors assets, billing, energy management – Field Service or mobile worker Security Sensor Mfg Flow Back End Server Telephone Cable line Materials handling HVAC Copyright 2002 The Zig. Bee Alliance, Inc. Service Provider Corp Office Retailer
Home & Diagnostics Examples SOHO • Dealer Retailer Service Provider Customers • Back End Server Telephone Cable line Field Service AC or heat Pump • Gateway(s) 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 PC & peripherals Entertainment Temp. Sensor Body monitor Security Sensor Data Communication Two way Copyright 2002 The Zig. Bee Alliance, Inc. White goods
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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 25 ms – Idle mode used for “more aware” state » Keystroke latency 8 -12 ms latency Copyright 2002 The Zig. Bee Alliance, Inc.
Wireless Keyboard Using 802. 15. 4 • 802. 15. 4 Chipset Parameters • Motorola 802. 15. 4 Transceiver and HCS 08 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 Copyright 2002 The Zig. Bee 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. 28 s – Sniff mode used for “more aware” state » 15 ms sniff interval » 15 ms latency Copyright 2002 The Zig. Bee Alliance, Inc.
Wireless Keyboard Using Bluetooth • Bluetooth Chipset Parameters • CSR Blue. Core 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. 7 V cutoff voltage • Power Consumption (estimated) – Park Mode @ 1. 28 s interval: 0. 05 m. A avg – Sniff Mode @ 15 ms interval: 8 m. A avg – NOTE: I do not assume a deep sleep mode since wake up time of 4 to 30 seconds seems unacceptable Copyright 2002 The Zig. Bee Alliance, Inc.
BT vs. 15. 4 Keyboard Comparison Bad Hunt n’ Peck 802. 15. 4: Approx 38 days BT: Approximately 5 operating days By the way, Wireless. USB looks much like BT Copyright 2002 The Zig. Bee 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 10 u. A (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 Copyright 2002 The Zig. Bee Alliance, Inc.
802. 15. 4/Zig. Bee Operation Mode • 802. 15. 4/Zig. Bee Mode – Network environment using Guaranteed Time Slot (GTS) – Network beacons occurring either every • 960 ms or 61. 44 s (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, 1 ms precision) • Running average heartrate (1/time interval between last twenty pulses, 1 ms precision) • Sensor average temperature (0. 1 C precision) • Sensor average battery state (0. 1 V precision) heartbeat GTS Beacon time Copyright 2002 The Zig. Bee 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 32 k. Hz 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 960 ms (15 ms*2^6) • Scenario 2 – Beacon interval is 61. 44 s (15 ms*2^12) • Assume that retries are not necessary due to GTS – Reasonable if we assume RF environment is well-controlled Copyright 2002 The Zig. Bee Alliance, Inc.
General Schematic Vcc 802. 15. 4 XCVR SPI IRQ/ RESET 16. 000 MHz 4 SPI 3 Vdc MCU INT OSC 1 Plus about 10 -12 small value capacitors, resistors excluding any special components for heartbeat sensor) OSC 2 IRQ 32. 768 k. Hz Heartbeat Sensor Copyright 2002 The Zig. Bee Alliance, Inc.
Sensor Battery Type • Lithium coin primary battery – Tadiran Lithium type TL-2186 • http: //www. tadiran. com/pdf/tl-2186. pdf – 400 m. Ah nominal capacity (0. 5 m. A constant to 2. 0 V) – 3. 6 V BOL, 2. 0 V EOL Copyright 2002 The Zig. Bee 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 3 E-8 m. Ah consumed per heartbeat • Process 2 – Each 960 ms or 61. 44 s the system synchronizes to network and transmits the information – From MCU beacon wakeup to completion of transmission • Approximately 56 ms (varies depending on beacon interval and assigned guaranteed time slot) • Approximately 3 E-4 m. Ah consumed per transmission event • Constant Idle Currents – 10 microamp sensor – Leakage currents in RF XCVR IC and MCU oscillator/Time base reference (~ microamps) Copyright 2002 The Zig. Bee Alliance, Inc.
802. 15. 4/Zig. Bee vs Bluetooth At beacon interval ~60 s, 15. 4/Zig. Bee battery life approx 750 days 802. 15. 4/Zig. Bee superior at all beacon intervals greater than 0. 246 s Bluetooth 33 days (park mode @ 1. 28 s) At beacon interval ~1 s, 15. 4/Zig. Bee battery life nearly 136 days Copyright 2002 The Zig. Bee 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 Qo. S, 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 3 rd and 4 th generation products hitting market while 1 st generation 15. 4 products will be appearing only late this year Copyright 2002 The Zig. Bee Alliance, Inc.
More Information • Zig. Bee Alliance web site – http: //www. Zig. Bee. org • IEEE 802. 15. 4 web site – http: //www. ieee 802. org/15/pub/TG 4. html • Articles – “Meet the Zig. Bee Standard”, Sensors Mag June 2003 http: //www. sensorsmag. com/articles/0603/14/ – “Zig. Bee Vital in Industrial Applications”, EETimes, 29 July 2003 http: //www. eetimes. com/story/OEG 20030727 S 0002 Copyright 2002 The Zig. Bee Alliance, Inc.
Motorola 802. 15. 4/Zig. Bee™ Platform for Low Data Rate Wireless Jon Adams Director, Architecture and Systems Motorola American Association of Wireless and Railroads Automatic Equipment Broadband Identification Conference Systems Group Pittsburgh, PA 17 June Copyright 2002 The Zig. Bee Alliance, Inc. jta @
System Simplicity and Flexibility Motorola RF Packet Radio Motorola 8 -Bit MCU Copyright 2002 The Zig. Bee Alliance, Inc.
Motorola 802. 15. 4 / Zig. Bee™ solution • Features – 2. 4 GHz Band, -90 d. Bm RX sensitivity at 1% PER • IEEE spec is – 85 d. Bm – 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 HC 08 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 – HC 08 RAM/FLASH configurations from 384 B/4 k. B to 2 k. B/60 k. B depending upon application SW needs Copyright 2002 The Zig. Bee Alliance, Inc.
Motorola’s RF Data Modem Transceiver (1) • Designed for the IEEE 802. 15. 4 and Zig. Bee™ 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 0 d. Bm (1. 0 m. W) PA, step adjustable to – 30 d. Bm Integrated VCO, no external components Full spread-spectrum encoding and decoding compatible with 802. 15. 4 – RX sensitivity of – 90 d. Bm at 1% PER, better than specification – Engineered to support 250 k. Bit/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) Copyright 2002 The Zig. Bee 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. 0 V per cell) • Buffered transmit and receive data packets for simplified use with low-end microcontrollers • SPI data and control interface, operates up to 8 MHz • 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Scalability to Address Specific Needs 802. 15. 4 is a guest in existing microcontrollers RF Receiver RF Transmitter Digital Processing RF Transceiver IC RF Receiver RF Transmitter Application 15. 4 FFD MAC >32 k. B FLASH 8 -Bit Microcontroller SPI Digital Processing 32 k. B FLASH 8 -Bit Microcontroller Digital Processing Application 15. 4 RFD MAC 12 k. B FLASH 8 -Bit Microcontroller SPI Digital Processing Zigbee NWK 15. 4 RFD MAC SPI RF Transceiver IC RF Receiver Zigbee NWK Application RF Transceiver IC RF Receiver SPI Applicationspecific interfaces Application Direct SPI Calls 3 k. B FLASH (min) 8 -Bit Microcontroller Copyright 2002 The Zig. Bee Alliance, Inc. System Complexity and Cost 802. 15. 4 PHY Compliant Transceiver RF Transceiver IC
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 d. Bm 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 Zig. Bee™ Alliance membership – Technology and standards driver – Early access to new technology Copyright 2002 The Zig. Bee Alliance, Inc.
Copyright 2002 The Zig. Bee Alliance, Inc.
Backups Copyright 2002 The Zig. Bee 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 RFIDtagged 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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Associating and disassociating from a Zig. Bee network • PAN Coordinator – Enters enumeration or learn mode – allows new nodes onto the network for a defined amount of time (typical may be a few seconds) – If during this time there is a request to join the network, a new node will be able to do so Copyright 2002 The Zig. Bee Alliance, Inc.
Are gateway products available? • Gateway Products have high value for entry into established markets – Alliance companies are developing gateway products – Will enable interconnection between Zig. Bee networks and other home, building automation, and industrial networks Copyright 2002 The Zig. Bee Alliance, Inc.
What are the international regulations? • Zig. Bee-compliant products – Adhere to all relevant international standards, including FCC, ETSI and ARIB Copyright 2002 The Zig. Bee Alliance, Inc.
How reliable is the Zig. Bee technology? • Reliability is a combination of – RF Communications Link • Clear channel detection • Interference energy detection • Frequency agility – Protocol • • • Error detection/correction Collision avoidance Guaranteed Time Slots Packet data acknowledgement Packet data freshness – Standardized and open protocol that has strong certification and interoperability Copyright 2002 The Zig. Bee Alliance, Inc.
What are some examples of Zig. Bee applications? • Well suited to a wide range of applications in every industry • Any application that could benefit from interoperability, or that matches the fundamental RF characteristics of the IEEE 802. 15. 4 standard would benefit from a Zig. Bee solution. Examples include: – – – – Wireless home security Remote thermostats for air conditioner Remote lighting, drape controller Call button for elderly and disabled Universal remote controller to TV and radio Wireless keyboard, mouse and game pads Wireless smoke, CO detectors Industrial and building automation and control (lighting, etc. ) Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee vs. Proprietary Solutions • Main advantages – Product interoperability – Vendor independence – Expectation of increased product innovation as a result of the industry standardization of the physical radio and logical networking layers – No more having to invest resources to create a new proprietary solution from scratch every time – Companies now can leverage these industry standards to instead focus their energies on finding and serving customers Copyright 2002 The Zig. Bee Alliance, Inc.
Adding Zig. Bee technology to existing appliances • Yes! – Best suited to new design white goods • Brings communications functionality from the appliance to the manufacturer – Some existing white goods may not be adaptable to Zig. Bee application – The opportunities for adding value through integrating Zig. Bee into white goods is tremendous • Improving service after the sale with high visibility into product once sold • Improved warranty coverage with ongoing functionality data available to the manufacturer • Potential for reduced energy costs by controlling energy usage during peak periods Copyright 2002 The Zig. Bee Alliance, Inc.
What security issues are there and how will they be solved? • Security and data integrity – Key benefits of the Zig. Bee technology – Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
How is Zig. Bee related to IEEE 802. 15. 4? • Zig. Bee takes full advantage of – A powerful physical radio specified by IEEE 802. 15. 4 • Zig. Bee adds – Logical network and application software • Zig. Bee is based on the IEEE 802. 15. 4 RF standard, and the Alliance is working closely with the IEEE to ensure an integrated and Copyright 2002 The Zig. Bee Alliance, Inc.
When will products be available? • Timetable – IEEE 802. 15. 4 specification is expected to be ratified in 1 Q 2003 – Standards-based silicon (868/915 Mhz and 2. 4 GHz) available shortly thereafter – Zig. Bee members are building interoperable network, security and application profiles on top of the IEEE 802. 15. 4 standard and this important work is already underway Copyright 2002 The Zig. Bee Alliance, Inc.
How big is the low data rate wireless market expected to be? • The low data rate market is currently estimated at 150 M units per year, according to ABI – Market is completely proprietary, as no industry standard has existed before now that addressed the unique needs of this market – Impact of industry standardization on the hardware and software layers is expected to at least triple the size of the current market within a few years – Key market accelerators include an Copyright 2002 The Zig. Bee Alliance, Inc.
What are the advantages of joining the Zig. Bee Alliance? • Membership provides – Access to, and ability to influence, this emerging standard – Early access to the standard specifications and to other companies with complementary skills and capabilities – Ability to network with other leading edge companies committed to providing interoperable wireless products and networks Copyright 2002 The Zig. Bee Alliance, Inc.
How easy is it to develop Zig. Bee-compliant products? • Zig. Bee obviates the need for development of RF or protocol stacks – Physical solution is ready for integration into the end application – Easy and cost-effective embedding of Zig. Bee-compliant wireless networking capabilities into products through the introduction of small, low power, wireless modules – Availability of standards-based Copyright 2002 The Zig. Bee Alliance, Inc.
Who is supporting the Zig. Bee Alliance now? • A rapidly growing list of industry leaders worldwide has committed to providing Zig. Bee-compliant products and solutions • Five promoter companies – Honeywell, Invensys, Mitsubishi, Motorola and Philips • Nearly 40 (and growing every month) participant companies – Semiconductor manufacturers, Copyright 2002 The Zig. Bee Alliance, Inc.
History Proposals Proposal Zig. Bee Alliance formed Initial MRD RSI/TRD v 0. 2 to IEEE Zig. Bee IEEE 802. 15. 4 PAR Proposals 1998 1999 2000 2001 Copyright 2002 The Zig. Bee Alliance, Inc. Reviews Expected completion 2002
When will the preliminary specification become available? • The IEEE 802. 15. 4 specification – Physical, Media Access and Data Link Layers • Formal approval received in May 2003 • Zig. Bee Specification – Network, security and application profile layers • Preliminary drafts available now • Final specifications expected beginning in the summer of 2003 Copyright 2002 The Zig. Bee Alliance, Inc.
Development of the Standard • IEEE 802. 15. 4 Working Group – Defining lower layers of protocol stack: MAC and PHY scheduled for release in April • Zig. Bee Alliance – 50+ companies: semiconductor mfrs, IP providers, OEMs, etc. – Defining upper Copyright 2002 The Zig. Bee Alliance, Inc. APPLICATION Customer ZIGBEE STACK SILICON Zig. Bee Alliance IEEE 802. 15. 4
• How does Zig. Bee protocol compare to the Bluetooth protocol? Stack sizes – Zig. Bee stack is around 28 Kbyte – Bluetooth stack varies, but can be 250 K – Lower cost and lower power consumption • System ability for truly long-sleep times – Ultra-low power consumption is a key system design aspect of the Zig. Bee technology – Allows long lifetime non-rechargeable battery powered devices versus rechargeable devices for Bluetooth – Example: the transition from sleep mode to data transition is much faster in Zig. Bee than for Bluetooth • Networking capabilities – Zig. Bee can support at least 255 devices per network – BT up to 8 • Radios are “similar” Copyright 2002 The Zig. Bee Alliance, Inc.
How does Zig. Bee protocol compare to the Bluetooth protocol? • Range for Zig. Bee products – ~30 meters in a typical installation – compared to ~10 meters for Bluetooth products (without power amplifier) • Zig. Bee networks have very low duty cycles – Probability of interference and packet loss in Bluetooth networks is very low – If Bluetooth network causes the loss of a Zig. Bee packet, the Zig. Bee sender Copyright 2002 The Zig. Bee Alliance, Inc.
Why do we need both technologies? • Bluetooth wireless technology – Well focused towards voice applications and higher data rate applications (cell phones, headsets, etc. ) • The Zig. Bee technology – Best suited for control and monitoring applications – Low data rates – Low power – Low costs Copyright 2002 The Zig. Bee Alliance, Inc.
Comparing Zig. Bee to Existing Technologies • Other present offerings – Proprietary technologies or – Little or no networking capability • Requires regular readers positioned at strategic points • Tags cannot talk to similar devices • Tags cannot independently network – Asymmetric transceiving capability • Primary function is traditional RFID tag • Illuminate tag with plenty of RF, tag responds with ID, maybe some small amount of fixed data • Some tags now have simple transmitters and internal batteries, but functionality is very minimal • No practical sensors and little memory Copyright 2002 The Zig. Bee Alliance, Inc.
Choosing Zig. Bee technology over other protocols • Choose Zig. Bee when – Your application requires a standards-based wireless network solution – Simple to develop and deploy – Flexible networking that can automatically (or under network control) adjust to fit the physical plant characteristics – Optimized for applications requiring • • • Low cost Low data rate Long battery life Robust security High data reliability Product interoperability Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee Topology Models Mesh Star Zig. Bee coordinator Zig. Bee Routers Zig. Bee End Devices Cluster Tree Copyright 2002 The Zig. Bee 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 Copyright 2002 The Zig. Bee 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 Zig. Bee Coordinator, mains powered, has its receiver on all the time and so can wait to hear from each of these stations • Since Zig. Bee Coordinator has “infinite” source of power it can allow clients to sleep for unlimited periods of time to allow them to save power Copyright 2002 The Zig. Bee Alliance, Inc.
Example of Beacon Network • Now make the Zig. Bee 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 Zig. Bee 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 Zig. Bee Coordinator • Once client communications are completed, Zig. Bee 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 Copyright 2002 The Zig. Bee Alliance, Inc.
Growing the Network • • • In a beacon-environment, growing the network means keeping the overall network synchronized According to pre-existing network rules, the joining network’s PAN Coordinator is probably demoted to Router, and passes along information about its network (as required) to the PAN coordinator Beacon information passed from Zig. Bee Coordinator to now-Router, router knows now when to awake to hear network beacon Joining Network Existing network’s Coordinator Demoted to router New link established Copyright 2002 The Zig. Bee Alliance, Inc.
Zig. Bee Alliance Promoters Participants And more each month… Copyright 2002 The Zig. Bee Alliance, Inc.
Mission Statement Zig. Bee Alliance members are defining global standards for reliable, costeffective, low power wireless applications. The Zig. Bee Alliance is a rapidly growing, non-profit industry consortium of leading semiconductor manufacturers, technology providers, OEMs and end users worldwide. Copyright 2002 The Zig. Bee Alliance, Inc.
The Wireless Market GRAPHICS INTERNET HI-FI AUDIO STREAMING VIDEO DIGITAL VIDEO MULTI-CHANNEL VIDEO LAN TEXT 802. 11 a/HL 2 & 802. 11 g Zig. Bee < RANGE > 802. 11 b PAN Bluetooth 2 Bluetooth 1 LOW < DATA RATE > HIGH Copyright 2002 The Zig. Bee Alliance, Inc.
802. 15. 4 and the • IEEE 802. 15. 4 – Composed of many of the individuals and companies that make up the Zig. Bee Alliance – Developed the basic PHY and MAC standard with the requirement that 15. 4 be simple and manageable and that high-level functionality (networking, security key management, applications) be considered • The Zig. Bee Alliance is – 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 – Addresses application and interoperability needs of a substantial part of the market Copyright 2002 The Zig. Bee Alliance, Inc.
What is the Zig. Bee Alliance? • Organization defining global standards for reliable, cost-effective, low power wireless applications • A rapidly growing, worldwide, non-profit industry consortium of – – Leading semiconductor manufacturers Technology providers OEMs End-users • Sensors are one of the reasons for Zig. Bee! Copyright 2002 The Zig. Bee Alliance, Inc.
What is Zig. Bee technology? • Cost-effective, standards-based wireless networking solution • Developed for and targets applications that need – – Low to moderate data rates and low duty cycles Low average power consumption / long battery life Security and reliability Flexible and dynamic network topologies • Star, cluster tree and mesh networks – Interoperable application frameworks controlled by an industry alliance to ensure interoperability/compatibility Copyright 2002 The Zig. Bee Alliance, Inc.
The Zig. Bee Alliance Solution • Targeted at – – – Industrial and Commercial control/monitoring systems Wireless sensor systems Home and Building automation and controls Medical monitoring Consumer electronics PC peripherals • Industry standard through application profiles • Primary drivers – – – Simplicity Long battery life Networking capabilities Reliability Low cost • Alliance member companies provide interoperability and certification testing Copyright 2002 The Zig. Bee Alliance, Inc.
Why do we need Zig. Bee technology? • ONLY standards-based technology that – Addresses the unique needs of most remote monitoring and control and sensory network applications – Enables the broad-based deployment of wireless networks with low cost, low power solutions – Provides the ability to run for years on inexpensive primary batteries for a typical monitoring application Copyright 2002 The Zig. Bee Alliance, Inc.
What kind of battery life can a user expect? • Zig. Bee protocol was designed from the ground up to support – very long life battery applications • Users can expect – Near-shelf life in a typical monitoring application • Battery life is ultimately a function of – battery capacity and application usage • Many industrial applications are in harsh thermal environments – Batteries may include alkalines or Li-primaries – Other forms of power generation might include solar, mechanical, piezoelectric Copyright 2002 The Zig. Bee Alliance, Inc.
Part 3: The Application Space for 802. 15. 4/Zig. Bee monitors sensors automation control INDUSTRIAL & CONSUMER ELECTRONICS COMMERCIAL monitors diagnostics sensors TV VCR DVD/CD remote Zig. Bee PERSONAL HEALTH CARE consoles portables educational LOW DATA-RATE RADIO DEVICES TOYS & GAMES HOME AUTOMATION Copyright 2002 The Zig. Bee Alliance, Inc. PC & PERIPHERALS security HVAC lighting closures mouse keyboard joystick
Zig. Bee and The Zig. Bee Alliance Copyright 2002 The Zig. Bee Alliance, Inc.
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