Transcript ANT - 실시간 시스템 연구실 (Real Time System Lab.)

ANT Overview
Jae-hoon Woo
Kyungpook National University, Real Time System Lab
A Brief History of ANT
Dynastream foot-pod – Nike watch
• Body worn
• Battery operated on both sides of the link
• 1 year of battery operation
• Inexpensive
• Wireless
The Challenge
• 2032 coin cell battery can sustain 25uA / year
• 2.4GHz radio draws ~10mA
• Radio can be on for 0.25% of the time
The Solution
• Create a protocol that efficiently controls the radio
Kyungpook National University, Real Time System Lab
A Brief History of ANT
Dynastream incorporated in 1998
First product to Nike shipped in 2000
ANT developed with Suunto in 2004
First single chip released in 2005
Purchased by Garmin 2006
ANT+ alliance formed 2007
1ST million units shipped 2007
5TH million unit shipped 2009
Second Silicon Partner added 2010
12+ millionth node shipped by Sept 2010
Kyungpook National University, Real Time System Lab
What is ANT
ANT is an more light, more simple, more
efficient wireless protocol that operates in the
2.4GHz frequency spectrum for ultra-low power
networking applications
Kyungpook National University, Real Time System Lab
What is ANT
ANT is an more light, more simple, more
efficient wireless protocol that operates in the
2.4GHz frequency spectrum for ultra-low power
networking applications
Kyungpook National University, Real Time System Lab
What is ANT
ANT is an more light, more simple, more
efficient wireless protocol that operates in the
2.4GHz frequency spectrum for ultra-low power
networking applications
ANT was designed specifically to enable
communication between self powered devices in
an extensible network environment
Kyungpook National University, Real Time System Lab
What is ANT
• A silicon solution
• Delivered in chip form
• Ultra low power
• Several years life on coin cell
• Simple to implement
• ANT development tools
• ANT+ device profiles
• Scalable
• Supports advanced network topologies and ad hoc
reconfiguration
• Proven
• 3 million nodes shipped to date
• 4 million forecast to ship in the
next 12 months
Kyungpook National University, Real Time System Lab
WHY 2.4GHz ?
The Good …
• 2.4GHz is a license free ISM band worldwide
• The higher bandwidth means radio can be on for less time
Not So Good …
• This frequency band is shared by other technologies
• Absorbed by the body
Kyungpook National University, Real Time System Lab
What’s the difference between
ANT and ANT+?
ANT is a communication protocol
ANT+ is a managed network which enables
interoperability between devices
Together, they provide:
•
•
•
•
Ultra low power wireless,
High value at a low cost,
Ease of development,
Interoperability.
Kyungpook National University, Real Time System Lab
ANT+ Target Markets
ANT+ is focused on driving success in
personal wireless
sensor networks in two related target markets:
• Sport and Fitness
• Wellness and Home Health Monitoring
Kyungpook National University, Real Time System Lab
ANT+ Target Markets
•
•
•
•
•
Suunto
Garmin
Timex
wahoo
Sony Ericsson(Android)
Smartphone + Dongle
-> Fitness Device
Kyungpook National University, Real Time System Lab
How does ANT/ANT+ compare
with other wireless protocols
Kyungpook National University, Real Time System Lab
How does ANT/ANT+ compare
with other wireless protocols
Bluetooth
• Bluetooth classic compared with ANT/ANT+ is:
• 100 times larger protocol stack size
• 100 times greater power consumption
• 90%+ greater H/W cost
• It is not designed for large
WSNs.
Kyungpook National University, Real Time System Lab
How does ANT/ANT+ compare
with other wireless protocols
WSN parameter
Host resources
required(kByte)
Battery life
Over-the-air
transmission
rate(kbit/s)
Supported network
topologies
ANT(with
SensRcore)
ZigBee
2
100
3+ year
4 to 6month
1000
250
P2P, star, tree, mesh
P2P, star, tree, mesh
Kyungpook National University, Real Time System Lab
How does ANT/ANT+ compare
with other wireless protocols
Zigbee
• Zigbee compared with ANT/ANT+ is:
• 20x - 40x larger protocol stack size
(ZigBee’s protocol stack is less than a quarter the size of Bluetooth’s)
• 10x greater power consumption
• 60% greater H/W cost
(ANT is at least an order of magnitude smaller than ZigBee)
Kyungpook National University, Real Time System Lab
What networking topologies
does ANT support?
Kyungpook National University, Real Time System Lab
ANT Channel
•
•
•
Independent
- Self-managed
- Ad-hoc
- Adaptive
Master
Types
-
Bi-directional
Uni-directional
Shared
Etc …
Slave
Messages
- Broadcast
- Acknowledged
- Burst
Kyungpook National University, Real Time System Lab
ANT Channel
• Consists of:
–
–
–
–
2 nodes
Master endpoint (M)
Slave endpoint (S)
Nodes can have combinations of both
Kyungpook National University, Real Time System Lab
Master Endpoint
•
•
•
•
•
Master controls the channel
Communication initiator
Primary Transmitter
Can change on open channel between messages
RX window used for co-existence and receive
Kyungpook National University, Real Time System Lab
Slave Endpoint
• Communication acceptor
• Slave searches for and synchronizes to the
master
• Primary receiver
Kyungpook National University, Real Time System Lab
Co-Existence
• Ability of multiple independent channels to
co-exist in a common RF environment
• ANT channels achieve co-existence in the
time domain (TDMA)
Kyungpook National University, Real Time System Lab
Co-Existence
•
•
•
Probability means channels likely not to collide
Clocks not ideal
Adaptive technology allows detection and
correction
Kyungpook National University, Real Time System Lab
Data Messages
• Three types of messages supported
• Broadcast
• Acknowledged
• Burst
• All messages fully bi-directional
Kyungpook National University, Real Time System Lab
Broadcast
•
•
•
•
•
•
No acknowledgement
Default for master endpoint
The only message type supported on TX-only channels
8 bytes per message period
Best suited for sensor applications where loss of data is not
critical
Most ANT+ sensors use Broadcast messages
Kyungpook National University, Real Time System Lab
Acknowledged
•
•
•
•
•
Message is acknowledged
Fully bi-directional
8 bytes per message period
Best suited for control applications where sender must know
if data was received
Parts of ANT-FS protocol use acknowledged messaging
Kyungpook National University, Real Time System Lab
Burst
•
•
•
•
•
Optimized to send bulk data
Each packet re-tried up to 5 times
Maximum data rate is 20kbps, depends on:
- Serial port speed
- RF interference
8 bytes of data per packet
ANT-FS is heavily based on Burst messaging
Kyungpook National University, Real Time System Lab
Multi-cast channels
Multiple slaves synchronize to one master
Addressed by first two bytes in data payload
Can broadcast to all slaves using address 0
Can extend to auto-shared where each slave is assigned an
address as its joining the network
• Excellent for large network where latency is not a priority
•
•
•
•
Kyungpook National University, Real Time System Lab
Network Keys
Public Key
• All 0’s
• Open to every one
• Meant for development
Private Key
• Most secure
• Managed by purchasing company
Managed Key
• ANT+
• Managed by Dynastream
• Unique but identical for all ANT+ devices
Kyungpook National University, Real Time System Lab
Some other definitions
ANT-FS
- File transfer protocol
- Protocol extension of ANT
- Authenticated/Seamless operation
FIT
-
File format
Extensible and scalable
Forward and backwards compatible
End to end
Kyungpook National University, Real Time System Lab
ANTware II -Demo
•
•
•
C# .NET based
Full source available
Doesn’t crash
Kyungpook National University, Real Time System Lab
Development Kit
Contents:
•
•
•
•
•
•
•
•
AT3 module X 2
AP2 module X 2
Battery board X 2
IO Board X 2
USB Stick X 2
CR2032 battery X 2
CD-ROM (discontinued)
Quick Start Cards
Kyungpook National University, Real Time System Lab