Zigbeex

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