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zigbee, Bluetooth

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  2. 2. OBJECTIVEExplain two major used PANs ZigBee Bluetooth  Similarities between them  Differences between them
  3. 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. 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 interactwith physical world (FFD) Network coordinator (FFD) Other Full Function Devices (FFDs) may be found in the network(coordinators ,routers ,other devices) Several topologies are supported by ZigBee, including star, mesh, and cluster tree
  5. 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. 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
  7. 7. 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
  8. 8. 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?
  9. 9. 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
  10. 10. Bluetooth-Advantages It is wireless, inexpensive and automatic Infrared communications are fairly reliable and dont cost very much to build into a device
  11. 11. 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
  12. 12. 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 doesnt require line of sight between communicating devices Bluetooth can connect up to eight devices simultaneously
  13. 13. 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
  14. 14. 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 doesnt have to press a button or give a command -- the electronic conversation happens automatically Once the conversation has occurred, the devices -- whether theyre 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
  15. 15. 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 Bluetooths automated connection process Bluebugging Bluejacking Car Whisperer
  16. 16. 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
  17. 17. Comparison-ZigBee vs Bluetooth Zigbee  Remote sensing & control Bluetooth  Machine to machine
  18. 18. Comparison-ZigBee vs Bluetooth
  19. 19. Thank You