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Basic Concepts in Wireless LAN

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Dr Shashikant Athawale
Dr Shashikant Athawale

This document summarizes the history and key standards of wireless internet communication. It discusses the major milestones including the original 802.11 standard from 1997 and subsequent amendments that increased bandwidth and functionality. It describes the technologies used by each standard such as DSSS and OFDM. The document also discusses wireless LAN applications and challenges, as well as the Wireless Application Protocol (WAP) which aimed to make internet content accessible on mobile phones.

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Shashikant V. Athawale Assistant Professor Department of Computer Engineering, AISSMS COE ,Pune
 Wireless Standard  Wireless LAN And Technology  Wireless Application Protocol
 There have been 5 major milestones in wireless internet communication. ◦ 802.11 – Released in 1997, the original wireless protocol ◦ 802.11a – Released in late 1999 ◦ 802.11b – Released in late 1999 ◦ 802.11g – Released in mid 2003 ◦ 802.11n – Released in 2009
 The ORIGINAL wireless protocol. ◦ Security implemented via WEP  Wired Equivalent Privacy (Legacy)  Provided Bandwidth ◦ 1 or 2 Mbit/s due to use of CSMA/CA  Relatively Unpopular  Low interoperability due to loose specifications  Used DSSS  Considered Legacy and no longer used
 One of two amendments to the original 802.11 specification released simultaneously  Provided up to 54 Mbit/s bandwidth  Uses OFDM ◦ Orthogonal Frequency-Division Multiplexing  Transmits a signal over several sub signals for higher efficiency
 Second of two amendments released in 1999  Provided up to 11 Mbit/s bandwidth  Uses DSSS ◦ Direct-Sequence Spread Spectrum  Transmits a signal over several sub signals for higher efficiency
 Pretty much the most common wireless network in use today.  Operates on 2.4Ghz band  Provides up 54Mbit/s bandwidth ◦ 108Mbit/s with special implementations  Uses OFDM for modulation  Adopted quickly after release for cheap and high bandwidth
 Newest member of the 802.11 family.  Has rated 600Mbit/s bandwidth  Introduces MIMO ◦ Multiple-Input Multiple-Output  OFDM Modulation ◦ Uses higher frequencies for increased number of carrier waves
 A wireless LAN uses wireless transmission medium  Used to have high prices, low data rates, occupational safety concerns, and licensing requirements  Problems have been addressed  Popularity of wireless LANs has grown rapidly.
 Saves installation of LAN cabling  Eases relocation and other modifications to network structure  However, increasing reliance on twisted pair cabling for LANs ◦ Most older buildings already wired with Cat 3 cable ◦ Newer buildings are prewired with Cat 5  Wireless LAN to replace wired LANs has not happened  In some environments, role for the wireless LAN ◦ Buildings with large open areas  Manufacturing plants, stock exchange trading floors, warehouses  Historical buildings  Small offices where wired LANs not economical  May also have wired LAN ◦ Servers and stationary workstations
Basic Concepts in Wireless LAN
Basic Concepts in Wireless LAN
Basic Concepts in Wireless LAN
 Peer-to-peer network  Set up temporarily to meet some immediate need  E.g. group of employees, each with laptop or palmtop, in business or classroom meeting  Network for duration of meeting
Basic Concepts in Wireless LAN
 Same as any LAN: High capacity, short distances, full connectivity, broadcast capability.  Throughput: efficient use wireless medium  Number of nodes:Hundreds of nodes across multiple cells  Connection to backbone LAN: Use control modules to connect to both types of LANs  Service area: 100 to 300 m  Low power consumption:Need long battery life on mobile stations  Transmission robustness and security:Interference prone and easily eavesdropped  Collocated network operation:Two or more wireless LANs in same area  License-free operation  Handoff/roaming: Move from one cell to another  Dynamic configuration: Addition, deletion, and relocation of end systems without disruption to users
 Infrared (IR) LANs: Individual cell of IR LAN limited to single room ◦ IR light does not penetrate opaque walls  Spread spectrum LANs: Mostly operate in ISM (industrial, scientific, and medical) bands ◦ No Federal Communications Commission (FCC) licensing is required in USA  Narrowband microwave: Microwave frequencies but not use spread spectrum ◦ Some require FCC licensing
 An open, global specification that empowers mobile users with wireless devices to easily access and interact with internet information and services instantly.  The wireless industry came up with the idea of WAP. The point of this standard was to show internet contents on wireless clients, like mobile phones.
 WAP is an application communication protocol  WAP is used to access services and information  WAP is inherited from Internet standards  WAP is for handheld devices such as mobile phones  WAP is a protocol designed for micro browsers  WAP enables the creating of web applications for mobile devices.  WAP uses the mark-up language WML (not HTML) WML is defined as an XML 1.0 application
 To enable easy, fast delivery of relevant information and services to mobile users.  Type of devices that use WAP  Handheld digital wireless devices such as mobile phones, pagers, two-way radios, smart phones and communicators -- from low- end to high-end.  WAP works with most Wireless networks such as: CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, TETRA, DECT, DataTAC, Mobitex.
 Leverage existing standards whenever possible  Define a layered, scalable and extensible architecture  Support as many wireless networks as possible  Optimize for narrow-band bearers with high latency  Optimize for efficient use of device resources  Provide support for secure applications and communication
 WWW programming model is optimized and extended to match characteristics of the wireless environment  Utilizes proxy technology to connect between the wireless domain and WWW
Basic Concepts in Wireless LAN
Basic Concepts in Wireless LAN
 WAP Device - Is used to access WAP applications and content. It might be a PDA, handheld computer.  WAP Client - Entity that receives content from Internet via a WAP Gateway. This is usually the WAP Browser.  WAP Content/Origin/Application Server - Element in the network where the information or web/WAP applications resides.
Web Server Wireless Network WAP Proxy HTML Filter WTA Server WAP Client WML WML HTML
Other Services And Applications Transport Layer (WDP) Security Layer (WTLS) Transaction Layer (WTP) Session Layer (WSP) Application Layer (WAE) GSM CDMA PHS IS-136 CDPD PDC-P FLEX Etc…
 General-purpose application environment based on a combination of WWW and mobile telephony technologies.  It defines the user interface on the phone. It contains WML and WTA (Wireless Telephony Application).  Primary objective – interoperable environment.  WAE includes a micro-browser (Client software designed to overcome challenges of mobile handheld devices that enables wireless access to services such as Internet information in combination with a suitable network) server environment which provides ◦ WML ◦ WML script ◦ WTA ◦ Content formats
• WAP provides a markup language and a transport protocol that open the possibilities of the wireless environment and give players from all levels of the industry the opportunity to access an untapped market that is still in its infancy. • The bearer-independent nature of WAP has proved to be a long- awaited breath of fresh air for an industry riddled with multiple proprietary standards that have suffocated the advent of a new wave of mobile-Internet communications. WAP is an enabling technology that, through gateway infrastructure deployed in mobile operator's network, will bridge the gap between the mobile world and the Internet, bringing sophisticated solutions to mobile users, independent of the bearer and network. • Backed by 75 percent of the companies behind the world's mobile telephone market and the huge development potential of WAP, the future for WAP looks bright.
 http://en.wikipedia.org/wiki/IEEE_802.11  http://www.cisco.com/en/US/prod/collateral/wireless/ps 5678/ps6973/ps8382/prod_white_paper0900aecd806b8 ce7_ns767_Networking_Solutions_White_Paper.html  www.palopt.com.au/wap
 Books ◦ Mobile communications: Jochen Schiller, Addison Wesley 2000 ◦ Understanding WAP:  Official Website (specifications) ◦ www.wapforum.org  Technical/Developer Info and tools ◦ www.palopt.com.au/wap ◦ www.wap.net  Major players ◦ www.nokia.com/wap ◦ www.ericsson.se/wap ◦ phone.com  OpenSource effort ◦ www.wapgateway.org (Kannel WAP gateway project)
THANK YOU…!!!

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Basic Concepts in Wireless LAN

  • 1. Shashikant V. Athawale Assistant Professor Department of Computer Engineering, AISSMS COE ,Pune
  • 2.  Wireless Standard  Wireless LAN And Technology  Wireless Application Protocol
  • 3.  There have been 5 major milestones in wireless internet communication. ◦ 802.11 – Released in 1997, the original wireless protocol ◦ 802.11a – Released in late 1999 ◦ 802.11b – Released in late 1999 ◦ 802.11g – Released in mid 2003 ◦ 802.11n – Released in 2009
  • 4.  The ORIGINAL wireless protocol. ◦ Security implemented via WEP  Wired Equivalent Privacy (Legacy)  Provided Bandwidth ◦ 1 or 2 Mbit/s due to use of CSMA/CA  Relatively Unpopular  Low interoperability due to loose specifications  Used DSSS  Considered Legacy and no longer used
  • 5.  One of two amendments to the original 802.11 specification released simultaneously  Provided up to 54 Mbit/s bandwidth  Uses OFDM ◦ Orthogonal Frequency-Division Multiplexing  Transmits a signal over several sub signals for higher efficiency
  • 6.  Second of two amendments released in 1999  Provided up to 11 Mbit/s bandwidth  Uses DSSS ◦ Direct-Sequence Spread Spectrum  Transmits a signal over several sub signals for higher efficiency
  • 7.  Pretty much the most common wireless network in use today.  Operates on 2.4Ghz band  Provides up 54Mbit/s bandwidth ◦ 108Mbit/s with special implementations  Uses OFDM for modulation  Adopted quickly after release for cheap and high bandwidth
  • 8.  Newest member of the 802.11 family.  Has rated 600Mbit/s bandwidth  Introduces MIMO ◦ Multiple-Input Multiple-Output  OFDM Modulation ◦ Uses higher frequencies for increased number of carrier waves
  • 9.  A wireless LAN uses wireless transmission medium  Used to have high prices, low data rates, occupational safety concerns, and licensing requirements  Problems have been addressed  Popularity of wireless LANs has grown rapidly.
  • 10.  Saves installation of LAN cabling  Eases relocation and other modifications to network structure  However, increasing reliance on twisted pair cabling for LANs ◦ Most older buildings already wired with Cat 3 cable ◦ Newer buildings are prewired with Cat 5  Wireless LAN to replace wired LANs has not happened  In some environments, role for the wireless LAN ◦ Buildings with large open areas  Manufacturing plants, stock exchange trading floors, warehouses  Historical buildings  Small offices where wired LANs not economical  May also have wired LAN ◦ Servers and stationary workstations
  • 14.  Peer-to-peer network  Set up temporarily to meet some immediate need  E.g. group of employees, each with laptop or palmtop, in business or classroom meeting  Network for duration of meeting
  • 16.  Same as any LAN: High capacity, short distances, full connectivity, broadcast capability.  Throughput: efficient use wireless medium  Number of nodes:Hundreds of nodes across multiple cells  Connection to backbone LAN: Use control modules to connect to both types of LANs  Service area: 100 to 300 m  Low power consumption:Need long battery life on mobile stations  Transmission robustness and security:Interference prone and easily eavesdropped  Collocated network operation:Two or more wireless LANs in same area  License-free operation  Handoff/roaming: Move from one cell to another  Dynamic configuration: Addition, deletion, and relocation of end systems without disruption to users
  • 17.  Infrared (IR) LANs: Individual cell of IR LAN limited to single room ◦ IR light does not penetrate opaque walls  Spread spectrum LANs: Mostly operate in ISM (industrial, scientific, and medical) bands ◦ No Federal Communications Commission (FCC) licensing is required in USA  Narrowband microwave: Microwave frequencies but not use spread spectrum ◦ Some require FCC licensing
  • 18.  An open, global specification that empowers mobile users with wireless devices to easily access and interact with internet information and services instantly.  The wireless industry came up with the idea of WAP. The point of this standard was to show internet contents on wireless clients, like mobile phones.
  • 19.  WAP is an application communication protocol  WAP is used to access services and information  WAP is inherited from Internet standards  WAP is for handheld devices such as mobile phones  WAP is a protocol designed for micro browsers  WAP enables the creating of web applications for mobile devices.  WAP uses the mark-up language WML (not HTML) WML is defined as an XML 1.0 application
  • 20.  To enable easy, fast delivery of relevant information and services to mobile users.  Type of devices that use WAP  Handheld digital wireless devices such as mobile phones, pagers, two-way radios, smart phones and communicators -- from low- end to high-end.  WAP works with most Wireless networks such as: CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, TETRA, DECT, DataTAC, Mobitex.
  • 21.  Leverage existing standards whenever possible  Define a layered, scalable and extensible architecture  Support as many wireless networks as possible  Optimize for narrow-band bearers with high latency  Optimize for efficient use of device resources  Provide support for secure applications and communication
  • 22.  WWW programming model is optimized and extended to match characteristics of the wireless environment  Utilizes proxy technology to connect between the wireless domain and WWW
  • 25.  WAP Device - Is used to access WAP applications and content. It might be a PDA, handheld computer.  WAP Client - Entity that receives content from Internet via a WAP Gateway. This is usually the WAP Browser.  WAP Content/Origin/Application Server - Element in the network where the information or web/WAP applications resides.
  • 27. Other Services And Applications Transport Layer (WDP) Security Layer (WTLS) Transaction Layer (WTP) Session Layer (WSP) Application Layer (WAE) GSM CDMA PHS IS-136 CDPD PDC-P FLEX Etc…
  • 28.  General-purpose application environment based on a combination of WWW and mobile telephony technologies.  It defines the user interface on the phone. It contains WML and WTA (Wireless Telephony Application).  Primary objective – interoperable environment.  WAE includes a micro-browser (Client software designed to overcome challenges of mobile handheld devices that enables wireless access to services such as Internet information in combination with a suitable network) server environment which provides ◦ WML ◦ WML script ◦ WTA ◦ Content formats
  • 29. • WAP provides a markup language and a transport protocol that open the possibilities of the wireless environment and give players from all levels of the industry the opportunity to access an untapped market that is still in its infancy. • The bearer-independent nature of WAP has proved to be a long- awaited breath of fresh air for an industry riddled with multiple proprietary standards that have suffocated the advent of a new wave of mobile-Internet communications. WAP is an enabling technology that, through gateway infrastructure deployed in mobile operator's network, will bridge the gap between the mobile world and the Internet, bringing sophisticated solutions to mobile users, independent of the bearer and network. • Backed by 75 percent of the companies behind the world's mobile telephone market and the huge development potential of WAP, the future for WAP looks bright.
  • 31.  Books ◦ Mobile communications: Jochen Schiller, Addison Wesley 2000 ◦ Understanding WAP:  Official Website (specifications) ◦ www.wapforum.org  Technical/Developer Info and tools ◦ www.palopt.com.au/wap ◦ www.wap.net  Major players ◦ www.nokia.com/wap ◦ www.ericsson.se/wap ◦ phone.com  OpenSource effort ◦ www.wapgateway.org (Kannel WAP gateway project)