Zigbeex

klapdorothypondMobile - Wireless

Nov 23, 2013 (3 years and 11 months ago)

76 views

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