ZigBee
Low
-
power networking protocol
Presented by:
Leif Millar
David Jackson
Chase Casgrain
1
Overview
•
What is
ZigBee
?
•
Pros and Cons
•
Mesh Networking
•
Security
•
Demo
•
Questions
2
•
Named after the wiggle dance a bee does when it returns to
the hive.
•
Wireless communication protocol typically utilized by
small embedded radios
.
•
Developed to meet demand for ad
-
hoc personal networks.
•
Demand speculated by engineers around 1998
•
ZigBee
Alliance started in 2002
•
Based on the 802.14.5 wireless networking protocol
.
•
Uses: Electric Meters, Thermostats, Security Systems, Light
Switches, Traffic Management, 373 Projects?
What is
ZigBee
?
3
Why
ZigBee
?
•
Low Power, Cost, and Size
•
Straightforward
configuration
•
Good support and documentation
•
Lots of products already on the market
•
Mesh
Networking
•
Lends itself well to many different applications
•
Very low wakeup time
•
30mS (
Zigbee
) vs. up to 3S (Bluetooth)
4
•
Competes with Wi
-
Fi for bandwidth..
Only
four usable bands in Wi
-
Fi intensive scenarios
•
Low speed and throughput
•
< 100kbps
Or maybe not…
Image & Data Source
<http://fosiao.com/system/files/misc/zigbee.wifi_.channel.jpg>
5
Comparison
Diagram obtained from :
<
http://
www.telegesis.com/downloads/general/Evoluon%20Zigbee%20Presentation.pdf>
6
What is a Mesh Network, and why do I care?
A mesh network consists of a series of nodes.
Each node must acquire and transmit
its own data, as well as act as a relay for
other nodes to propagate data.
ZigBee
devices often form Mesh Networks.
Examples: Wireless light switching, Music school
practice rooms.
7
Image Source:
<http://kf5czo.blogspot.com/2012/03/ham
-
radio
-
and
-
mesh
-
networks.html>
Mesh Networking
Mesh networks consist of three types of nodes:
Coordinator
Router
End Devices
What does a Coordinator do? Why?
Search for open wireless channel
Establish “PAN ID”
Wait for queries from new nodes
End devices, when not in use, shut down
to conserve power. They have no routing
responsibilities.
Image Source:<
http://i.cmpnet.com/rfdesignline/2009/03/FIGURE_01_TI.jpg>
Mixed Star and Mesh Topology
8
Mesh Networking
•
Advantages of Mesh Networking:
Allows devices to communicate to multiple other devices
in the network.
Multiple paths to destination
–
greater flexibility against
interference.
Allows overall network to grow to larger physical sizes than
possible with point
-
to
-
point networks.
•
Mesh Characteristics:
Self
-
forming
–
ZigBee
devices can establish
communication pathways when new devices appear.
Self
-
healing
–
If a node is removed from the network
(either intentionally or not) the remaining network will
look to establish alternate routes of communication.
9
Is it safe?
•
High
-
level Wireless security
:
•
IEEE 802.15.4 standard AES
128
-
bit
encryption elements.
•
ZigBee
-
specific Mesh security
–
Uses a system of security keys
(
Link
,
Master
,
Network
) to maintain
security against:
Unauthorized network access
Packet integrity damage
Packet snooping (internal and external)
Image Source:
<http://www.jennic.com/elearning/zigbee/files/graphics/key_lock.jpg>
10
Xbee
Introduction
•
XBee
–
16 models, 3 wireless protocols.
ZigBee
,
DigiMesh
, and IEEE
802.15.4
•
XBee
for the demo
–
Xbee
802.15.4 S1
•
Uses protocol 802.15.4
•
No mesh network
-
Point to point, point to multipoint
•
No underlying infrastructure.
•
Basis for
Zigbee
11
RX
RX
T
X
T
X
RX
RX
T
X
T
X
UART
–
Serial Communication
Transparent Serial Communication
Xbee
Demo
Are you using
XBee’s
for your project? Pay
attention
•
X
-
CTU software
•
Set Baud Rate
•
Set Destination Address
–
high and low
12
Demo Code For The
Arduino
Boards
Master Slave
Demo Notes
•
Xbee
–
non standard pin size.
•
Uart
interface. Uses
tx
-
rx
.
•
To Program
Xbee
use
a
FTDI
-
Uart
to
usb
.
•
Xbees
uses 3.3 volts
14
But wait, there’s more!
EECS 498 Lab
http://
www.eecs.umich.edu/courses/eecs498
-
brehob/Labs/498Lab1.pdf
ZigBee
Alliance
www.zigbee.org
http://
www.zigbee.org/Standards/ZigBeeHomeAutomation/FAQ.aspx
http://docs.zigbee.org/zigbee
-
docs/dcn/06
-
4482.pdf
Wikipedia
http
://
en.wikipedia.org/wiki/Zigbee
http
://
en.wikipedia.org/wiki/Mesh_networking
http
://
en.wikipedia.org/wiki/AODV
Libelium
http
://www.libelium.com/security_802.15.4_zigbee
/
Digi
http://www.digi.com/learningcenter/video/player?id=zigbee
-
part
-
i
-
mesh
-
networking
-
basics
Digikey
http://www.digikey.com/us/en/techzone/wireless/resources/articles/comparing
-
low
-
power
-
wireless.html
15
Questions?
16
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