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Wireless Fundamentals Chapter 6 Introducing Wireless Regulation Bodies, Standards, and Certifications
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Objectives Describe the IEEE Describe the Wi-Fi Alliance
Describe country code regulatory bodies such as the FCC and ETSI Describe the family of protocols Describe the original protocol Describe the b protocol Describe the g protocol Describe how b and g interact Describe the a protocol Describe the n protocol Describe the main components of the n protocol
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IEEE Wireless Standards
The IEEE The IEEE develops communication standards in electrical and computer sciences, engineering, and related disciplines. There are more than 1300 protocols. The committee analyzes the applications and environments in which wireless networks are used and develops standards for them. The family has more than 26 sub protocols.
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The Wi-Fi Alliance The Wi-Fi Alliance
Wi-Fi Alliance certifies interoperability between products WLAN products. The Wi-Fi Alliance was created to solve the compatibility issue Products include a, b, g, n draft v2.0, dual-band products, and security testing. The organization provides assurance to customers of migration and integration options. Cisco is a founding member of Wi-Fi Alliance. Certified products can be found at
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Regulatory Bodies Each country or region defines its rules about the use of the RF space, including the following rules: Which frequencies are allowed (spectrums and channels) Which transmit powers are possible (transmitters and antennae gain and EIRP) How a wave can be sent in each frequency (modulation and encoding techniques)
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Wireless Spectrum The 2.4-GHz ISM band ranges from 2.4 to GHz ( GHz in Japan). In this range 11 channels are allowed in the United State, 13 in Europe, and 14 in Japan. The 5-GHz ISM band ranges from to GHz. The 5-GHz ISM band overlaps with the Unlicensed National Information Infrastructure (UNII) bands: – UNII-1 ranges from 5.15 to 5.25 GHz (4 channels). – UNII-2 ranges from 5.25 to 5.35 GHz (4 channels). – UNII-2 extended ranges from to GHz (up to 11 channels). – UNII-3 ranges from GHz to GHz (4 channels).
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Wireless Spectrum
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The IEEE 802.11 Family of Protocols
Some IEEE Standard Activities 802.11a — 5GHz, 54 Mb/s; ratified in 1999 802.11b — 2.4 GHz, 11 Mb/s; ratified in 1999 802.11d — World Mode; ratified in 2001 802.11e — QoS; ratified in 2005 802.11g — 2.4GHz, 54 Mb/s; ratified in 2003 802.11h — DFS and TPC mechanisms; ratified in 2004 802.11i — Authentication and security; ratified in 2004 802.11k — Radio resource measurement enhancements (under development) 802.11n — Higher throughput improvements using MIMO antennas (under development) 802.11t — WPP; test methods and metrics recommendation (under 802.11w — Protected management frames (under development)
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The 802.11 Standards for Channels and Speeds
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The Original Protocol became a standard in July 1997, the first standard for wireless. Two RF technologies were defined: FHSS and DSSS. The standard allows 1 Mb/s and 2 Mb/s. It defined specifications for Layer 1 and Layer 2, and basic security is defined in the 2.4-GHz ISM band. Three nonoverlapping channels is the most common deployment.
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The 802.11b Protocol 11 Mb/s, 2.4 GHz, DSSS
Ratified as standard in September 1999 11 U.S. channels 13 ETSI channels 14 Japanese channels Power levels: – 36 dBm Effective Isotropic Radiated Power (EIRP); FCC – 20 dBm EIRP; ETSI Approved for use nearly worldwide Not recommended for new deployments
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802.11b Speed Coverage Two different encodings: - Barker 11 - CCK
Two different modulations: - DBPSK - DQPSK Four different speeds: - 1 Mb/s (Barker + DBPSK) - 2 Mb/s (Barker + DQPSK) - 5.5 Mb/s (CCK-16 + DQPSK) - 11 Mb/s (CCK DQPSK)
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The g Protocol Standard for higher-rate extension in the 2.4-GHz ISM spectrum Speed up to 54 Mb/s OFDM added to DSSS Backward-compatible with b
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802.11b/g Cell Speeds 802.11g speeds: – 54 Mb/s, 48 Mb/s
– Include b data rates Client looks for the best speed
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802.11b/g Encoding and Modulations
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802.11b and 802.11g Coexistence 802.11b presence triggers
protection mode: - RTS/CTS - “CTS to self” protection “Non-ERP present” wave spreads throughout the network. Throughput can drop from 22 Mb/s to 8 Mb/s.
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The 802.11 a Protocol Ratified as standard in September 1999
54 Mb/s 5 GHz (OFDM) 23 U.S. channels - Dynamic Frequency Control (DFS)* - Transmitter Power Control (TPC)* 19 ETSI channels (many countries) - DFS - TPC *Required by July 20th, 2007
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802.11a Speeds Same speeds as 802.11g No 802.11b interoperability
Higher frequency, which implies lower range but also less scattering
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Comparing the Technologies 802.11a Data Rates
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802.11n: State of the Protocol
IEEE is developing n standard features and attributes. Wi-Fi Alliance is using n Draft 2.0 in an interim baseline. Goal is for software upgrades to meet standard compliance and minimize hardware upgrades.
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Summary The IEEE defines the 802.11 family of protocols.
The Wi-Fi Alliance ensures the interoperability of wireless devices. The local or regional regulatory bodies define what is allowed in which spectrum. The family has more than 26 protocols. The original protocol defined 1- and 2-Mb/s speeds with FHSS and DSSS. 802.11b increased the speed to 11 Mb/s. 802.11g increased the speed to 54 Mb/s, but still in the ISM band. 802.11b devices degrade the performances of g cells. 802.11a uses the same modulation and speed as g, but inthe 5-GHz band. 802.11n tries to increase speed and throughput in the ISM and UNII bands.
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