1 Nurul Sarkar, AUT Session 3 - Learning Outcomes By the end of this session you will be able to: u...
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Transcript of 1 Nurul Sarkar, AUT Session 3 - Learning Outcomes By the end of this session you will be able to: u...
1Nurul Sarkar, AUT
Session 3 - Learning Outcomes
By the end of this session you will be able to: Compare and contrast the following wireless
networking technologies:– Microwave, satellite, radio and infrared.
Discuss relative advantages and disadvantages of wireless LANs over wired LANs.
Explain how the cellular technology works. Describe the potential applications of wireless
LAN and Bluetooth technology.
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Topics
Microwave Satellite Radio Infrared Cellular technology Wireless LAN Bluetooth technology
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References
WebLan-Designer: http://elena.aut.ac.nz/homepages/weblandesigner
Textbook Ch. 6 – Telecommunication Technologies for E-Business.
Lough, D. L. et al. “A short tutorial on Wireless LANs and IEEE802.11” http://www.computer.org/students/looking/sum…/ieee802.html
Blankenbeckler, D. “An In troduction to Bluetooth” http://www.wirelessdevnet.com/channels/blue../bluetooth.htm
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Key terms Microwave Satellite Radio Infrared Line-of-sight Geosynchronous transponder Earth station Wireless LAN
Cellular networks CDMA2000 GSM GPRS Bluetooth Mobile JetStream Gigahertz Terahertz
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Wireless and mobile computing technologies
Communications can be– Terrestrial Microwave
– Satellite Microwave
– Infrared
– Cellular
– Radio
– Wireless LANs and WANs.
Devices include– laptop, palmtop, pocket computer, PDA (personal
digital assistant), cell-phones, and other hand-held devices.
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Terrestrial Microwave
An example of directional wireless transmission. A parabolic dish antenna is usually directed
toward a receiving antenna in a line-of-sight configuration.
Characteristics» Frequency range: 2 - 40 GHz» Bandwidth: 7-220 MHz, Data rate: 1Mbps -
10Gbps Applications
» Long haul telecommunications (both voice and TV)» short point to point links (TV or data)» data link between LANs.
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Satellite Microwave
Geo-synchronous earth orbit (GEO)» 36,000km above the earth surface. 3 satellites can be
used to cover the whole world.
Medium earth orbit (MEO)» within 6000 miles from Earth. More than 10 satellites to
cover the planet.
Low earth orbit (LEO)» within 1000 miles from Earth. Few hundred satellites to
cover the planet. Iridium, Teledisc, Globalstar.
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Infrared technology
Requires transceivers Transceivers must be line-of-sight Frequency range: 300GHz – 200THz Data rate: 1-16Mbps Applications:
» LANs where no cabling required
» short distance communication (within a room)
» remote control (TV/Video)
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Broadcast radio Generally omnidirectional
» does not require a disk-shaped antenna Frequency range
» 3kHz to 300GHz» Data rate: 1-10Mbps» covers AM, FM, VHF and part of UHF band
Applications» Radio broadcasting (AM, FM, short waves)» data networks» Cellular networks
Main source of impairment» multipath interference caused by reflection
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Wireless communication networks
Wide area networks– Uses media from a telephone company
» Cellular systems, Satellite systems, Pagers
Local area networks– Network within ones property
» Wireless LANs
Personal area networks– Up to 10 meter coverage
» Bluetooth technology
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Target Applications Metro/Geographical area Ubiquitous public connectivity with virtual private
networks
2G/3G Technology Characteristics Licensed Wireless Spectrum Multi-cell coverage for metropolitan/wide area
mobility Modest to high power output (200-1000mw) 2G: 28-56Kbps 3G: 144Kbps-2Mbps
3G3G
UMTSUMTS
CDMA 1XCDMA 1X
GPRSGPRS
3G3G
UMTSUMTS
CDMA 1XCDMA 1X
GPRSGPRS
TDMATDMA
CDMACDMA
GSMGSM
CDPDCDPD
Wireless wide area networks
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Cellular technology
1G: Analog technology – eg. AMP (Advanced mobile phone system)
2G: Digital narrowband technology – GSM, CDMA 3G: Digital wideband technology – CDMA2000, W-CDMA
Cell
Mobile telephone switching office
Optical fibre
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Wireless WAN technologies Nextel
– One transmitter covering a large area. 2-way radio dispatch service. Used by Taxis and public safety people.
Paging– One directional, point-to-point, character/ numerical based
(display caller telephone number).– Cheaper and simpler than cellular phone service
I-Mode– Packet based wireless phone service. Offered by NTT DoCoMo in
Japan. Audio and video over hand held devices.
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Target Applications: Building or Campus Enterprise / premises advanced application voice &
data network extension.
IEEE 802.11 wireless LAN: Unlicensed wireless spectrum Multi-cell coverage for workplace mobility &
roaming. Low to modest power output (30-100mw) 2-11Mbps today 22-54Mbps in 12-24 months
CT2CT2
UPCSUPCS
DECTDECT
PHSPHS
802.11802.11
802.11b802.11b
802.11a802.11a
HiperLAN2HiperLAN2
802.11802.11
802.11b802.11b
802.11a802.11a
HiperLAN2HiperLAN2
Wireless LAN Technologies
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Overview of wireless LAN
Supports mobility Medium
– Radio frequencies (including microwave). Applications
– Retail shops, Hospitals, Airports, Warehouses Standards
– IEEE 802.11b (up to 11 Mbps)– IEEE 802.11a/g (up to 54 Mbps)
Configurations– Ad hoc network (Peer-to-peer)– Infrastructure network.
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IEEE 802.11 Configurations
Ad hoc Network
Wired Backbone Network
Access point
Infrastructure Network
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Example of wireless LAN connectivity
Wireless laptops connecting to a backbone wired LAN through a network access point that can support 50 clients over 500 feet.
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Wireless LAN growth
Rapid growth since IEEE 802.11b standard agreed by the industry in 1998.
Gartner Dataquest Study - Sept 2002– Shipments of WLAN equipment will grow 73 percent in
2002 to 15.5 million units
– Mobile Computer shipments with WLAN
» 2000 9%
» 2003 50%
» 2007 90%
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Overview of Bluetooth technology
Short-range (up to 10 m) radio technology Connect home and office based systems in a
network. Connect PCs, printers, telephones, stereos, TVs.
Modest performance (721 Kbps) Low power - well suited to handheld
applications. Support for both voice and data. Packet switching technology.
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M-commerce (1)
Transactions and non-transaction functions over wireless networks.
Growth due to:– Newer and smaller technologies– More mobile populations– Deregulation of telecommunication markets– Less costly infrastructure than wired alternative
Slower to grow in US than Europe and Asia