Unit 2_Presentation_BE_wireless_computer_Scienece.pdf

Unit 2_Presentation_BE_wireless_computer_Scienece.pdf

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  Unit II: Wirelessindoor and outdoor networks Prof. Snehal Nichale Prof Prachi waghmare Prof M.K Pote E&TC Dept, CCEW Pune
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  Unit II: Wirelessindoor and outdoor networks • WLAN, • WiFi, • Bluetooth, • Zigbee, • Ultra Wideband communication, • Infrared, • UHF narrowband, • WiMax, • Limitation of indoor networks
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  Disclaimer This presentation isonly for educational purpose and non commercial usage. This presentation is meant for Final Year B.Tech students of Cummins College of Engineering for Women, Pune only. The students should not share it outside the college and should not use it for any activity other than education References - • T. Rappaport, “Wireless Communications - Principles and Practice”, Prentice Hall, (2ndEdition) , (2011). • Vijay Garg, “Wireless Communications and networking”, Elsevier, (1st Edition), (2007). • NPTEL course on Wireless Networks • Few diagrams from the internet
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  Introduction • Wireless networksare networks that use radio waves to connect devices, without the necessity of using cables of any kind. • Devices commonly used for wireless networking include portable computers, desktop computers, hand-held computers, personal digital assistants (PDAs), cellular phones, pen-based computers, and pagers etc. • Wireless networks allow remote devices to connect without difficulty, independently these devices are a few feet or several KM away. • No need to break through walls to pass cables or install connectors. • This has made the use of this technology very popular, spreading rapidly • There are many different technologies that differ in the transmission frequency used, speed and range of their transmissions. • Necessary steps should be taken to ensure the privacy of data transmitted over wireless networks
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  Wireless technologies • Wirelessnetworks can be classified into four specific groups according to the area of application and the signal range 1. Wireless Personal-Area Networks (WPAN), 2. Wireless Local-Area Networks (WLANs), 3. Wireless Metropolitan-Area Networks (WMAN), 4. Wireless Wide-Area Networks (WWANs)
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  Wireless networks canbe also divided into two broad segments: short range and long-range
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  Short-range wireless Networks •Confined to a limited area. • This applies to local area networks (LANs), such as corporate buildings, school campuses, manufacturing plants or homes, as well as to personal area networks (PANs) where portable computers within close proximity to one another need to communicate. • These networks typically operate over unlicensed spectrum reserved for industrial, scientific and medical (ISM) usage. • The available frequencies differ from country to country. • The most common frequency bands are at 2.4 GHz and at 5 GHz, which are available across most of the globe. • The availability of these frequencies allows users to operate wireless networks without obtaining a license, and without charge. As a license is not required for use, this has facilitated the expansion of such networks.
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  Long-range Wireless networks •Connectivity is typically provided by companies that sell the wireless connectivity as a service. • These networks span large areas such as a metropolitan area (WMAN), a state or province, or an entire country. • The goal of long-range networks is to provide wireless coverage globally. • The most common long-range network is wireless wide area network (WWAN). • When true global coverage is required, satellite networks are also available.
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  Wireless Personal-Area Networks(WPAN) • WPAN based on IEEE 802.15 • permit communication in a very short range, of about 10 meters. • Little or no infrastructure or direct connectivity to the world outside the link. • This allows small, power efficient, inexpensive solutions to be implemented for a wide range of devices such as a smartphone and a PDA. • low power demands and a low bit rate. • Such kind of networks relay on technologies such as Bluetooth, IrDA, ZigBee or UWB.
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  • From anapplication point of view, • Bluetooth - cordless mouse, keyboard, and hands- free headset, • IrDA - point-to-point links between two devices for simple data transfers and file synchronization, • ZigBee - reliable wirelessly networked monitoring and control networks • UWB (Ultra Wide band) is oriented to high- bandwidth multimedia links.
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  Bluetooth • Bluetooth correspondsto the IEEE 802.15.1 standard. • Originally Bluetooth was designed for low power consumption, short range and omni-directional (point to multipoint) communications, and cheap devices, to be used as a cable replacement, linking devices through an ad hoc connection of radio waves • This technology operates for three different classes of devices: Class 1, class 2 and class 3 where the range is about 100 meters, 10 meters and 1 meter respectively. • Using the 2.4 GHz band, two devices within the coverage range of each other can share up to 720 Kbps of capacity or transfer rate. • A Bluetooth network is also called a piconet, and is composed of up to 8 active devices in a master-slave relationship
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  • A Bluetooth devicemay participate in several pico-nets at the same time, thus allowing for the possibility that information could flow beyond the coverage area of the single pico-net. A device in a scatter-net could be a slave in several pico-nets, but master in only one of them.
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  IrDA The InfraredData Association (IrDA) • IrDA specifies a complete set of infrared communications standards. • IrDA is a low-power, low-cost, unidirectional (point to point), narrow angle (< 30º) cone, ad hoc data transmission standard to operate over a distance of up to 1 meter • At speeds of 9600 bps to 4 Mbps (currently), 16 Mbps (under development). • Devices that use IrDA are notebooks, PDAs, printers and cameras.
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  ZigBee • ZigBee isbased on the IEEE 802.15.4 standard • Developed as an open global standard to address the unique needs of easy implementation, high reliability, low-cost, low- power and low-data rate wireless device networks. • ZigBee operates the unlicensed bands including 2.4 GHz, 900 MHz and 868 MHz at a maximum transfer rate of 250 Kbps, enough to satisfy sensor and automation needs using wireless. • ZigBee also serves for creating larger wireless networks not demanding high data throughput. • Two different device types can participate in a ZigBee network- Full function devices (FFD) and reduced-function devices (RFD)
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  • FFDs canoperate in three modes serving as a WPAN coordinator, coordinator or device. • RFD is only intended for applications that are extremely simple, such as a light switch. • ZigBee supports three different topologies: star, mesh, and cluster tree
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  Sr. No. Bluetooth Zigbee 1 Frequencyrange supported in Bluetooth vary from 2.4GHz - 2.483GHz. While the frequency range supported in Zigbee mostly 2.4 GHz worldwide. 2 There are 79 RF channels in Bluetooth. There are 16 RF channels in zigbee. 3. It uses GFSK modulation technique. Whereas it also uses BPSK and QPSK modulation techniques like UWB. 4. There is maximum of 8 cell nodes in Bluetooth. While there is more than 65,000 cell nodes in ZigBee. 5. Built using the point-to-point master- slave approach in which there is one master and up to seven slaves form a piconet, which leads to forming a scatter net which is a linking of two or more piconets. Networked in a variety of generic, including a star, mesh topologies. A cluster can be created by connecting different Zigbee-based network topologies. Zigbee Coordinator, Zigbee Router, and Zigbee Endpoint nodes make up any Zigbee
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  Sr. No. Bluetooth Zigbee 7. Bluetoothrequires low bandwidth. While zigbee also requires low bandwidth but greater than Bluetooth’s bandwidth most of time. 8. The radio signal range of Bluetooth is 10m While the radio signal range of zigbee is 10-100m. 9. Bluetooth was developed under IEEE 802.15.1 Whereas it was developed under IEEE 802.15.4 10. Bluetooth batteries may be recharged. Although ZigBee batteries cannot be recharged, they last longer. 11. Blue tooth uses high data rates and a lot of power on large packet devices. Zigbee employs low data rates and little power on small packet devices.
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  Sr. No. Bluetooth Zigbee 12. Bluetooth employsthe Frequency Hopping Spread Spectrum. In frequency hopping, the carrier signal is made to fluctuate in frequency. Zigbee employs the Direct Spread Spectrum technique. In direct spread spectrum; the original signal is mixed and recovered from a pseudo random code at transmitter and receiver. 13. A network speed of up to 250 Mbps. A network speed of up to 1 Mbps. 14. The time it takes to join a network using Bluetooth is about 3 seconds. The time it takes to join a network using Zigbee is about 30 milliseconds. 15. Bluetooth’s protocol stack is 250K bytes in size. Zigbee’s protocol stack is 28K bytes in size. 16. Computer peripherals like wireless keyboards, mice, headsets, and other peripherals are the main use cases for Bluetooth-based applications. Additionally, several wireless remote controls and gesture-controlled devices communicate data via Bluetooth. Systems built on the Zigbee protocol are intended for wireless sensor networking, and they are more popular with compact and energy-efficient gadgets. Zigbee- based networking is used in a variety of applications, including SCADA system sensors, medical devices, and television remote controls.