ZigBee

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ZigBee
Venkat BahlPhilipsBusiness Development
ManagerSemiconductors Division
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Market Application Landscape
Digital video
Graphics
Hi-Fi audio
Text
Multi-channel video
Internet
Streaming video
Long Range
GSM/CDMA
GPRS/3G
LMDS
Wi-Fi 802.11b
Wi-Fi5 802.11a/HL2
Bluetooth 2
ZigBee 802.15.4
Short Range
WiMedia 802.15.3
Bluetooth 1 802.15.1
Low Data Rate
High Data Rate
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Why ZigBee?

• Standard in a fragmented market
• Many proprietary solutions, interoperability
  issues
  
• Low Power consumption
• Users expect battery to last months to years!
• Low Cost
• High density of nodes per network
• Simple protocol, global implementation

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ZigBee -Target Markets
Industrial Commercial
Consumer Electronics

PC Peripherals
Low Data Rate Radio Devices
Personal Healthcare
Home Automation
Toys Games

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ZigBee Technology Adoption Curve
Gap
Technology Leaders
Evangelize
Early Adopters
Mature Market
Laggards
ZigBee today
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ZigBee Rate of Adoption
Market Matures
Home Control Adoption
Volume
Industrial Adoption
Initial Adoption
Time
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Standards Expectations
This will satisfy all requirements
Disillusionment
Everything is OK
Market Interest Builds
Market Expectations
Products start to ship
Obituaries Written
ZigBee today
Time
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Market Size Low Data Rate (No )
Source ABI, Dataquest, Internal
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Market Segmentation 2002 - 2006

• Industrial Applications will drive initial
• market
• Home Environment will become
• Important
• Over time, there will be varied
• Applications (Other)

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Some Details - Home Controls

• Energy Management is going to be a key aspect
• Even if we are to ignore the Building Auto and
  Industrial Markets for a few minutes.

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• Founding Members
• Cisco
• GM
• Invensys
• The NewPower Company
• Panasonic
• Sears
• Contributing Members
• Best Buy
• Sun

• Associate Members
• ADT Security Services
• Autco Distributing
• AVAD
• Coactive Networks
• CompUSA
• Connected Lifestyles
• Echelon
• emWare
• Gatespace
• Home Director
• Honeywell
• Info-linc

• Metering Technology
• N.E.W. Customer Service Companies
• Qubit Technology
• Reliant Energy
• Sage Systems
• Sempra Energy Connections
• Ucentric Systems
• Visteon
• Western Digital
• zBox

• The Connected Home
• The features of a connected home exist today
  they are not dreams of tomorrow. This home is
  connected in the sense that normally independent
  systems are linked to a centrally controlled
  system. In a connected home, your home computer,
  TV, lighting and heating controls, home security
  system and many appliances within the home can
  talk to each other via the Internet. These linked
  systems can be controlled through various
  devices, including your pager, cellular phone,
  TV, home PC, PDA, or even your automobile.
• More specifically, the connected home offers the
  following new forms of entertainment anywhere,
  anytime communication with family, friends and
  coworkers advanced home control and security
  new ways to buy over the Internet safe and
  secure e-mail and other communications and
  always-on, high speed Internet access - all from
  reliable providers.

Source Internet Home Alliance the Advantage
magazine.
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Internet Home Alliance Survey Findings Zigbee
can provide or help provide 3 of the 5 top
features customers want in a connected home
Interest in Individual Features of the Connected
Home

Zigbee use in thermostat simplifies wiring and
connectivity to the Internet
Zigbee sensors eliminate the need to run wires
throughout the house and make adding a new system
to an old house realistic
Zigbees technical characteristics and cost are
ideal for DAP applications
of respondents interested
Source Zanthus CEO interview, Internet Home
Alliance The Advantage magazine.
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Connected Home Pilot Programs
Energy Management
OnStar at Home

• To begin Q1 2002
• 100 households
• Integrated OnStars Virtual Advisor service with
  home security, control and telecommunications
  components
  
• Provides an easy to use, consistent interface to
  control home systems such as lighting,
  temperature and home security
  
• Homeowners will be able to control their home
  operations from any, PC, telephone, WAP phone or
  wireless PDA in addition to OnStars PCS service

• June to October 2001
• 300 households
• Tested the effectiveness of energy management
  systems
  
• NewPower initiated periodic energy curtailments
  (e.g. raising the temperature a few degrees
  during peak hours) to save money
  
• Individuals could override the curtailments
  manually or through a Web portal

Source Website, Mercer interview.
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Home NetworkingHome appliances will complement
additional Zigbee markets
Volume Comparison Between Home Appliances and CE
devices
(Unit shipments in the US in 2000)
Unit Shipments in 2000 (in millions)
Source US shipments in 2000 from Appliance
Magazine March 2001, Time Machine of the Year
2000.
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Market Requirements

• Global licence free ISM band operation
• Unrestricted geographic use
• RF penetration through walls ceilings
• Automatic/semi-automatic installation
• Ability to add or remove devices
• Possible voice support

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Market Requirements, cont...

• 10k-115.2kbps data throughput
• 10-75m coverage range (home/garden)
• Support for 32-255 nodes
• Support for 4 critical devices
• 4-100 co-located networks
• 0.5-2 year battery life
• Up to 5m/sec. (18kmph) permitted mobility
• Module cost 1.5-2.5 in 2004/5!

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ZigBee - General Characteristics

• Data rates of 250 kbps and 20 kbps
• Star topology, peer to peer possible
• 255 devices per network
• CSMA-CA channel access
• Optional Guaranteed Time Slot
• Fully handshaked protocol for transfer
  reliability
  
• Low power (battery life multi-month to years)
• Dual PHY (2.4GHz and 868/915 MHz)
• Extremely low duty-cycle (
• Range 10m nominal (1-100m based on settings)
• Location Aware Yes, but optional

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ZigBee Alliance - IEEE - Customer Relationship
Application
Customer
Application Interface
Network Layer
Data Link Layer
ZigBee Alliance
MAC Layer
MAC Layer
IEEE
PHY Layer
Silicon
ZigBeeStack
Application
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Range Estimation (Meters)
Using Firefly TRD/RSI propagation model
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Network Topology
Network coordinator
Network node
Communications flow
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Other Network Forms
Network coordinator
Ad-hoc network
Network node
Gateway
Communications flow
Gateway enabled network
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Supported Traffic Types

• Periodic data
• Application defined rate
• Intermittent
• Basic communication
• Repetitive low latency data
• Allocation of guaranteed time slots

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The Network Coordinator

• Transmits network beacons
• Sets up a network
• Manages network nodes
• Stores network node information
• Routes messages between paired nodes
• Receives constantly

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The Network Node

• Is generally battery powered
• Searches for available networks
• Transfers data from its application as
  necessary
  
• Determines whether data is pending
• Requests data from the network coordinator
• Can sleep for extended periods

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Stack System Requirements

• 8-bit ?C, e.g. 80c51
• Full protocol stack
• Simple node only stack 4k
• Coordinators require extra RAM
• node device database
• transaction table
• pairing table

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The ZigBee Alliance
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Some Participants
CompXs
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Standardization ChallengeHow do we make a
protocol a standard?

• ZigBee Alliance created with companies who share
  a common vision
  
• Alliance initiates need for low data rate W-PAN
  in IEEE, 802.15.4 is born
  
• Both MAC and PHY proposals win vote in IEEE
• Alliance is focussed on
• Upper Layers of stack
• Interoperability
• Marketing
• Keep initial participants limited until spec
  basics are defined

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ZigBee vs Bluetooth

• Competition or Complementary?

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Bluetooth is Best
But ZigBee is Better

• IF
• The Network is static
• Lots of devices
• Infrequently used
• Small Data Packets

• For
• Ad-hoc networks between capable devices
• Handsfree audio
• Screen graphics, pictures
• File transfer

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Air Interface

• Bluetooth
• FHSS
• 1 M Symbol / second
• Peak Information Rate
• 720 Kbit/second

• ZigBee
• DSSS
• 11 chips/ symbol
• 62.5 K symbols/s
• 4 Bits/ symbol
• Peak Information Rate
• 128 Kbit/second

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ZigBee Protocol Stack Size/Complexity
Application
Application Interface
Network Layer
Data Link Layer
MAC Layer
MAC Layer
PHY Layer
Silicon
ZigBeeStack
Application
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Bluetooth Protocol Stack Size/Complexity
User Interface
Voice
Intercom
Headset
Cordless
Group Call
vCard
vCal
vNote
vMessage
Dial-up Networking
Fax
Service Discovery Protocol
Telephony Control Protocol
OBEX
HOST
RFCOMM (Serial Port)
L2CAP
Host Control Interface
Link Manager
MODULE
Link Controller
Baseband
RF
Silicon
BluetoothStack
Applications
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Timing Considerations

• ZigBee
• New slave enumeration 30ms typically
• Sleeping slave changing to active 15ms
  typically
  
• Active slave channel access time 15ms
  typically

• Bluetooth
• New slave enumeration 3s
• Sleeping slave changing to active 3s
  typically
  
• Active slave channel access time 2ms typically

ZigBee protocol is optimized for timing critical
applications
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Initial Enumeration
ZigBee
Bluetooth
Coordinator
Coordinator
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Power Considerations

• Bluetooth
• Power model as a mobile phone (regular charging)
• Designed to maximise ad-hoc functionality

• ZigBee
• 2 years from normal batteries
• Designed to optimise slave power requirements

Application example of a light
switch with respect to latency and
power consumption ...
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Battery Life Latency in a Lightswitch

• Bluetooth 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.

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To reduce latency, Bluetooth would

• The two devices must stay within 60 us (1/10 of
  a hop)
  
• 30ppm crystals could increase at 60us per
  second.
  
• Devices communicate once a second to track each
  other's clocks.
  
• Possibly could be improved by a factor of 100.
• The devices would then need to communicate once
  every 100 seconds to maintain synchronisation.
  
• 900 communications / day with no information
  transfer
  
• perhaps 4 communications on demand
• 99.5 Battery Power wasted

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To reduce power consumption, Bluetooth would

• Undertake Bluetooth inquiry procedure when light
  switch operated
  
• May typically take 10 seconds using Bluetooth
  1.1 ?
  
• Much Better In Bluetooth 1.2
• possibly reduced to tens of ms BUT
• Not all requirements have been adopted yet

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Light switch Conclusion

• ZigBee radio using DSSS need only perform CSMA
  before transmitting, a delay of only 200 us
  (Radio wake up time)
  
• In the case of a light switch, ZigBee offers
  longer battery life and lower latency than a
  Bluetooth equivalent.

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Cost Standpoint

• ZigBee
• Minimum slave cost
• Minimum software and processing (80C51), no host
  platform
  
• System design for eventual single-chip
  antenna-to-application realisation

• Bluetooth
• Low added cost connectivity
• Take advantage of host processor power (ARM7)
• 802.11 functionality but with simplified r.f.
  specifications

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Solution Prices
Two different solutions optimised for different
applications...
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Conclusion

• ZigBee and Bluetooth are two solutions for two
  application areas

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ZigBee in Building Automation

• Existing solutions are either
• Power Line Carrier based (PLC)
• Expensive (15 - 40 BOM)
• Restricted to where there is existing power
  lines
  
• No mobility
• Interference from noisy inductance into the
  system (adding a fan, etc.)
  
• Security issues, PLC goes outside the home
• Interoperability is questionable
• Or proprietary
• Interoperability among various manufacturers
• Cost
• Existing RF solutions have limited capabilities

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ZigBee - Bluetooth - PLC Comparison
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Thank You