COMPARISON OF SHORT RANGE WIRELESS NETWORKS (PAN’ s) zigbee, Bluetooth

1. COMPARISON OF SHORT RANGE WIRELESS
NETWORKS (PAN’ s)

2. OBJECTIVE
Explain two major used PANs
ZigBee Bluetooth
 Similarities between them
 Differences between them

3. ZigBee-Introduction
• ZigBee based on IEEE 802.15.4 standard
• Specifically for control and sensor networks
• For a low data rate WPAN
• Also provides low power consumption
• Low complexity
• Data rate limited to 250 kbps in global 2.4 GHz ISM band
• 20 kbps in 868 MHz band used in Europe
• 40 kbps in 915 MHz band used in North America and Australia
• Remote monitoring and control for sensory network applications
• Created by an organization known as ZigBee Alliance

4. ZigBee-How it works?
 Uses digital radios
 A typical ZigBee network consists of several types of devices
 A network coordinator is a device that sets up the network
 Manages-information about each node-information transmitted or
received
Router (FFD)
Devices that interact
with physical world
(FFD)
Network coordinator
(FFD)
 Other Full Function Devices (FFD's) may be found in the
network(coordinators ,routers ,other devices)
 Several topologies are supported by ZigBee, including star, mesh, and
cluster tree

5. ZigBee-How it Operates?
Zeegbee operates in two major modes
Beacon mode Non-beacon mode
 Fully coordinated mode  Less coordinated mode
 All devices know when to coordinate with  Any device can communicate with the
one another coordinator at will
 Network coordinator will periodically "wake-  This operation can cause different devices
up“ to send out a beacon within the network to interfere
 Beacon subsequently wakes up each device  Coordinator must always be awake to
 The device returns to sleep, as will the listen for signals
network coordinator, once its job is complete  ZigBee obtains its overall low power
consumption

6. ZigBee-What does it do?
 Designed for wireless controls and
sensors
 Could be built into anything around
your home or office
 Devices can interact without wires and
you can control them all
 It goes well beyond single-purpose
wireless devices
 Such as garage door openers and "The
Clapper" that turns light on and off
 It allows wireless two-way
communications
 It travels across greater distances and
handles many sensors that can be
linked to perform different tasks

8. Bluetooth Introduction
 Bluetooth can streamline the process
 A Bluetooth connection is wireless and automatic, and it has a
number of interesting features that can simplify our daily lives
 When any two devices need to talk to each other, they have to
agree on a number of points
 The first point of agreement is physical
 How much data will be sent at a time?
 How will they speak to each other?
 This means developing a set of commands and responses known
as a protocol
 Bluetooth offers a solution to the problem

9. Bluetooth-How it creates connection?
 Removing the need for user intervention and keeping
transmission power extremely low to save battery power
 Bluetooth is essentially a networking standard that works at
two levels:
 It provides agreement at the physical level -- Bluetooth is a
radio-frequency standard
 It provides agreement at the protocol level
 Products have to agree on when bits are sent?
 How many will be sent at a time?
 How the parties in a conversation can be sure that the message
received is the same as the message sent?

10. Bluetooth-Piconets
 Bluetooth can be either half-duplex or full-duplex
 Bluetooth can send data at more than 64 kilobits per second
(Kbps) in a full-duplex link
 If a particular use calls for a half-duplex link -- Bluetooth can
transmit up to 721 Kbps in one direction, with 57.6 Kbps in the
other. If the use calls for the same speed in both directions,
Bluetooth can establish a link with 432.6-Kbps capacity in each
direction

11. Bluetooth-Advantages
 It is wireless, inexpensive and automatic
 Infrared communications are fairly reliable and don't
cost very much to build into a device

12. Bluetooth-Advantages
 You can make sure a message goes only to the intended recipient
 The older Bluetooth 1.0 standard has a maximum transfer speed
of 1 megabit per second (Mbps)
 Bluetooth 2.0 can manage up to 3 Mbps
 Bluetooth 2.0 is backward-compatible with 1.0 devices

13. Bluetooth-How it operates?
 Transmits data via low-power radio waves
 Frequency of 2.45 gigahertz (ISM Band)
 Garage-door openers an dthe newest generation of cordless
phones all make use of frequencies in the ISM band
 Avoid interfering by sending out very weak signals of about 1
mill watt
 By comparison, the most powerful cell phones can transmit a
signal of 3 watts
 The low power limits the range of a Bluetooth device to about
10 meters (32 feet)
 Even with the low power, Bluetooth doesn't require line of sight
between communicating devices
 Bluetooth can connect up to eight devices simultaneously

14. Bluetooth-How it operates?
 Bluetooth uses a technique called spread-spectrum frequency
hopping (FHSS)
 A device will use 79 individual, randomly chosen frequencies
within a designated range, changing from one to another on a
regular basis
 Transmitters change frequencies 1,600 times every second
 Meaning that more devices can make full use of a limited slice of
the radio spectrum
 It’s unlikely that two transmitters will be on the same frequency
at the same time
 It also minimizes the risk that portable phones will disrupt
Bluetooth devices, since any interference on a particular
frequency will last only a tiny fraction of a second

15. Bluetooth-How it operates?
 When Bluetooth capable devices come within range of one
another
 An electronic conversation takes place to determine data sharing
or controlling
 The user doesn't have to press a button or give a command -- the
electronic conversation happens automatically
 Once the conversation has occurred, the devices -- whether
they're part of a computer system or a stereo -- form a network
 Bluetooth systems create a personal-area network (PAN), or
piconet
 Once a piconet is established, the members randomly hop
frequencies in unison so they stay in touch with one another

16. Bluetooth-Security
 The automatic nature-a huge benefit in
terms of time and effort, is also a
benefit to hackers
 Bluetooth users can establish "trusted
devices“-without asking permission
 Service-level security and device-level
security work together
 Security methods include authorization
and identification procedures
 A user can also simply switch his
Bluetooth mode to "non-discoverable“
 Cell-phone virus writers have taken
advantage of Bluetooth's automated
connection process
 Bluebugging
 Bluejacking
 Car Whisperer

17. VS
ZIGBEE BLUETOOTH
• ZigBee is focused on control • Focused on connectivity
and automation between laptops, PDA’s
• Low power consumption • High power consumption
• Works with small packet • Works with large packet
devices devices
• Designed to respond • Takes much longer -
quickly detrimental to the
• Goal to put couple of application
batteries in the devices and • Frequent battery
forget about them for recharging
months to years

18. Comparison-ZigBee vs Bluetooth
 Zigbee
 Remote sensing & control
 Bluetooth
 Machine to machine

19. Comparison-ZigBee vs Bluetooth

20. Thank You