Introduction to Wireless Networking

Module-01Wireless Standards, Organizations and Applications

Jerry BernardiniCommunity College of Rhode Island

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Presentation Reference Material

• CWNA Certified Wireless Network Administration Official Study Guide, Fourth Edition, Tom Carpenter, Joel Barrett Chapter-1

• CWNA Exam Requirements• IP-Addressing Notes

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Abbreviated Wireless Network History ??dates

• 1830: Professor Joseph Henry transmitted the first practical electrical signal.

• 1880: Maxwell’s Equations• 1905: Marconi• 1920: Radio Receivers• 1935: Television• 1941: Radar• 1958: Satellite• 1970: ALOHAnet• 1990: Internet• 1998: WLAN

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Why Study Wireless Networks? A Partial List

• Cordless phones• Wireless Voice over IP phones• Wireless print servers• Wireless access points, routers, and bridges• Radio Frequency Identification devices• Wireless presentation gateways• Wireless conferencing systems• Laptop computers, PDAs, and other mobile wireless client• device

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Wireless Industry Guided by Three Categories of Organizations

• Regulation- Boundaries of Operation– Federal Communications Commission (FCC)– European Telecommunications Standards Institute (ETSI)

• Power limits and Frequencies

• Standardization- How systems work together– Institute of Electrical and Electronics Engineers (IEEE)

• 802.11 a, b, g, n

• Compatibility – Tests for interoperability– Wi-Fi Alliance

• If you buy Wi-Fi certified gear it work with other Wi-Fi gear

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FCC - Federal Communications Commission

• Regulatory Bodies – City, State, Country• FCC- Born in 1934 to regulate radio, television, cable,

satellite and wire communications• FCC regulates

– Radio frequencies– Output power levels– Indoor and Outdoor usage

• Every country has regulatory bodies

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FCC Wireless Bands• 1985:Industry, Scientific and Medical Industrial

License-Free Bands – ISM Bands– 900 MHz band, (900 to 928 MHz range)– 2.4 GHz band, (2.4 to 2.483 GHz range)– 5 GHz band, (5.725 to 5.850 GHz range)

• 1997: Unlicensed National Information Infrastructure U-NII bands– 5.15 to 5.25 GHz– 5.25 to 5.35 GHz– 5.725 to 5.825 GHz

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FCC Unlicensed Bands

Advantages Disadvantages•No licenses required•No Fees•No Permits•Comply with rules and build anything

•Everyone can use the bands•Interference between users•Bandwidth Contention•First-come-first –serve•Interference from late-comers

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FCC Regulates Frequencies

• Frequencies are grouped into bands– Wireless LAN bands include: (Hz = Hertz)

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Frequency Band Total Bandwidth License-Free Band

2400–2500 MHz 100 MHz ISM

5.15–5.25 GHz 100 MHz U-NII

5.25–5.35 GHz 100 MHz U-NII

5.470–5.725 GHz 255 MHz U-NII

5.725–5.825 GHz 100 MHz U-NII

FCC Power Output Limits-U-NI Bands

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Band Power Output Limits Area Usage

U-NII 5.15–5.25 GHz 40 mW Restricted to indoor operations

U-NII 5.25–5.35 GHz 200 mW Indoor/outdoor

U-NII 5.470–5.725 GHz 200 mW Indoor/outdoor

U-NII 5.725–5.825 GHz 800 mW Higher output power assumes outdoor operations

mw = 1/1000 watt

Non-USA Standard Organizations

• OfCom-Office of Communication –United Kingdom• MIC- Ministry of Internal Affairs and

Communications-Japan• ARIB-Association of Radio and Businesses – Japan• ACMA-Australian Communications and Media

Authority

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International Telecommunications Union Radiocommunications Sector (ITU-R)

• 1947: United Nations creates ITU-R to:– Promote cooperation and technical development

• ITU-R maintains a database of frequencies with five administrative regions– Region A: The Americas– Region B: Western Europe– Region C: Eastern Europe– Region D: Africa– Region E: Asia and Australia

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Institute of Electrical and Electronics Engineers - IEEE (Eye-triple-E)

• World’s leading non-profit professional organization for the advancement of technology

• Mission – – promote “the engineering process of creating, developing, integrating,

sharing, and applying knowledge about electronics and information technologies and sciences for the benefit of humanity and the profession.”

• 350,000 individual members in 150 countries.• Nearly 900 active standards with 700 under

development.

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IEEE Wireless Standards

• IEEE 802 project is the most important with multiple working groups– IEEE 802.3 (Ethernet)– IEEE 802.11 Wireless LAN (WLAN)– IEEE 802.16 WiMAX– IEEE 802.16 Mobile Broadband

• Most of this course will deal with IEEE 802.11

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IEEE 802.11 Standards

• 1997: First 802.11 ratified• Three ways of implementing a physical

communications layer (PHY)– Frequency-hopping spread spectrum (FHSS)– Direct-sequence spread spectrum (DSSS)– Infrared communications (not implemented extensively)

• All operate at 1Mbps and 2Mbps• To be covered in depth is subsequence lessons

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IEEE 802.11 Amendments (details text pp.13-14)

• IEEE 802.11a – OFDM, 5 GHz U-NII, 54 Mbps• IEEE 802.11b – DSSS, 2.4 Mhz ISM band, 11 Mbps• IEEE 802.11c – Bridging operation• IEEE 802.11d – regularity specifications• IEEE 802.11e – Quality of Service (QoS)• IEEE 802.11F- access point re-association• IEEE 802.11g – DSSS/OFDM, 2.4 Mhz, 54 Mbps• IEEE 802.11h – Dynamic frequency, power control• IEEE 802.11i – important security enhancements

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IEEE 802.11 Amendments (details text pp.14-15)

• IEEE 802.11j – 4.9-5 Mhz band in Japan• IEEE 802.11k – channel management above 5 Mhz• IEEE 802.11n –Important 100 Mbps plus WLAN• IEEE 802.11p –Intelligent Transportation Systems• IEEE 802.11r – Roaming amendment• IEEE 802.11s – Extended Mesh network interoperate• IEEE 802.11T – measurement and test conditions• IEEE 802.11u – handoffs between WiMax and WLAN• IEEE 802.11v – device management• IEEE 802.11w – improved management frames04/18/23 Wireless Networking J. Bernardini 17

More IEEE Standards

• IEEE 802.1X – port-based authentication for security• IEEE 802.3-2005 Clause 33 – defines power over

Ethernet (PoE)• IEEE 802.1D – bridging priority• IEEE 802.1Q – priority tagging and VLAN FOR QoS

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IETF – International Engineering Task Force

• Primarily a volunteer organization• The most important standards organization for the

Internet operation• Operates on the basis of the Request-For-Comment

(RFC)– IETF issues an RFC in a technical issue– After a period of time all responses to the RFC are gather and voted on

• WLAN RFC 3748, RFC 2865 are important for wireless– RFC 3748 - WLAN security– RFC 2865 -security and the use of RADIUS server

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Wi-Fi Alliance

• Certification organization for testing and interoperability

• Ensures that devices are compatible with IEE standards

• Before October 2002 know as the Wireless Ethernet Compatibility Alliance (WECA)

• Most commercial products will have a Wi-Fi logo

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Spread Spectrum Technology Uses

• Spread spectrum is a technique of transmitting radio signals over multiple frequencies – The common method of transmitting WLAN signals– Spread Spectrum will be explained in depth in chapter-3

• Spread spectrum is used by – Wireless LANs (WLANs)– Wireless PANs (WPANs)– Wireless MANs (WMANs)

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Use Examples Range Speeds

WLAN /Backhaul IEEE 802.11 375 ft/ miles > 2Mbps

WPAN Bluetooth 1-3 meters .723 – 3 Mbps

WMAN/ Backhaul WiMax and EDGE 10 km ~ 40 Mbps

WWAN / backhaul AT&T microwave variable ~75-135 kbps

Wireless LANs (WLANs)

• The major application of IEEE 802.11• WLANs provide mobility and unwired fixed

connectivity• Three primarily roles of WLANs

– Access role– Distribution role– Core role

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Wireless PANs (WPAN)

• Wireless Personal Area Networks• 10 meter radius connectivity• Primarily Bluetooth Applications

– headsets– mouse– PDA

• Uses 2.4 GHz ISM band which can interfere with 802.11 WLAN

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Wireless MANs (WMAN)

• Wireless Metropolitan Area Network• Uses both Point-to-Point and Point-to-Multipoint• WiMAX and IEEE802.16• Leased networks covering multiple miles• Provide QoS mechanisms

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Wireless WANs (WWANs)

• Expansion of WAN technology– DSL– ISDN– Cable

• WWANs connect LANs to backbone • Uses both Point-to-Point and Point-to-Multipoint• WWANs provide multi-channel communications

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Last-Mile Delivery

• Last mile is the connection between the ISP and the end user– Example: home and telephone central office– Example: Office and Cable provider hub

• Last mile comes from the old telephone network design; – max of 18000 ft to central office

• Last mile can be expensive• Wireless Internet Service Provider (WISP)• WISP use WiMAX (IEEE 802.16)

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Major Wireless Applications

• SOHO – Small Office / Home Office– Less than 25 computers– Router connections

• Mobile Office Network– Similar the SOHO but mobile– Mobile IP usage

• Educational/Classroom Use• Hotspots• Warehousing and Manufacturing• Health Care

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Wireless Hotspots

• Hotspots often use Wi-Fi• Free and wide open• Free and secure• Subscription based• Pay-as-you-go• Mixed

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