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Wednesday, November 28, 2012

IEEE 802 Wireless Standards:


The IEEE 802 Standard comprises a family of networking standards that cover the physical layer specifications of technologies from Ethernet to wireless. IEEE 802 is subdivided into 22 parts that cover the physical and data-link layers of networking. 

 All the 802.11 specifications use the Ethernet protocol and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) for path sharing. The original modulation used in 802.11 was phase-shift keying (PSK). However, other schemes, such as complementary code keying (CCK), are used in some of the newer specifications. The newer modulation methods provide higher data speed and reduced vulnerability to interference.
802
Overview
Basics of physical and logical networking concepts.
802.1
Bridging
LAN/MAN bridging and management. Covers management and the lower sub-layers of OSI Layer 2, including MAC-based bridging (Media Access Control), virtual LANs and port-based access control.
802.2
Logical Link
Commonly referred to as the LLC or Logical Link Control specification. The LLC is the top sub-layer in the data-link layer, OSI Layer 2. Interfaces with the network Layer 3.
"Grandaddy" of the 802 specifications. Provides asynchronous networking using "carrier sense, multiple access with collision detect" (CSMA/CD) over coax, twisted-pair copper, and fiber media. Current speeds range from 10 Mbps to 10 Gbps.
802.4
Token Bus
Disbanded
802.5
The original token-passing standard for twisted-pair, shielded copper cables. Supports copper and fiber cabling from 4 Mbps to 100 Mbps. Often called "IBM Token-Ring."
802.6
Distributed queue dual bus (DQDB)
"Superseded **Revision of 802.1D-1990 edition (ISO/IEC 10038). 802.1D incorporates P802.1p and P802.12e. It also incorporates and supersedes published standards 802.1j and 802.6k. Superseded by 802.1D-2004." 
802.7
Broadband LAN Practices
Withdrawn Standard. Withdrawn Date: Feb 07, 2003. No longer endorsed by the IEEE. 
802.8
Fiber Optic Practices
Withdrawn PAR. Standards project no longer endorsed by the IEEE.
802.9
Integrated Services LAN
Withdrawn PAR. Standards project no longer endorsed by the IEEE. 
802.10
Interoperable LAN security
Superseded **Contains: IEEE Std 802.10b-1992. 
Wireless LAN Media Access Control and Physical Layer specification. 802.11a,b,g,etc. are amendments to the original 802.11 standard. Products that implement 802.11 standards must pass tests and are referred to as "Wi-Fi certified."

·         Specifies a PHY that operates in the 5 GHz U-NII band in the US - initially 5.15-5.35 AND 5.725-5.85 - since expanded to additional frequencies
·         Uses Orthogonal Frequency-Division Multiplexing
·         Enhanced data speed to 54 Mbps
·         Ratified after 802.11b

·         Enhancement to 802.11 that added higher data rate modes to the DSSS (Direct Sequence Spread Spectrum) already defined in the original 802.11 standard
·         Boosted data speed to 11 Mbps
·         22 MHz Bandwidth yields 3 non-overlaping channels in the frequency range of 2.400 GHz to 2.4835 GHz
·         Beacons at 1 Mbps, falls back to 5.5, 2, or 1 Mbps from 11 Mbps max.

·         Enhancement to 802.11a and 802.11b that allows for global roaming
·         Particulars can be set at Media Access Control (MAC) layer

·         Enhancement to 802.11 that includes quality of service (QoS) features
·         Facilitates prioritization of data, voice, and video transmissions

·         Extends the maximum data rate of WLAN devices that operate in the 2.4 GHz band, in a fashion that permits interoperation with 802.11b devices
·         Uses OFDM Modulation (Orthogonal FDM)
·         Operates at up to 54 megabits per second (Mbps), with fall-back speeds that include the "b" speeds

·         Enhancement to 802.11a that resolves interference issues
·         Dynamic frequency selection (DFS)
·         Transmit power control (TPC)

·         Enhancement to 802.11 that offers additional security for WLAN applications
·         Defines more robust encryption, authentication, and key exchange, as well as options for key caching and pre-authentication

·         Japanese regulatory extensions to 802.11a specification
·         Frequency range 4.9 GHz to 5.0 GHz

·         Radio resource measurements for networksusing 802.11 family specifications

·         Maintenance of 802.11 family specifications
·         Corrections and amendments to existing documentation

·         Higher-speed standards -- under development
·         Several competing and non-compatible technologies; often called "pre-n"
·         Top speeds claimed of 108, 240, and 350+ MHz
·         Competing proposals come from the groups, EWC, TGn Sync, and WWiSE and are all variations based on MIMO (multiple input, multiple output)
802.11x

·         Mis-used "generic" term for 802.11 family specifications
802.12
Demand Priority
Increases Ethernet data rate to 100 Mbps by controlling media utilization.
802.13
Not used
Not used
802.14
Cable modems
Withdrawn PAR. Standards project no longer endorsed by the IEEE.
Wireless Personal Area Networks
Communications specification that was approved in early 2002 by the IEEE for wireless personal area networks (WPANs).
802.15.1
Short range (10m) wireless technology for cordless mouse, keyboard, and hands-free headset at 2.4 GHz.
802.15.3a
UWB
Short range, high-bandwidth "ultra wideband" link
802.15.4
Short range wireless sensor networks
802.15.5
·         Extension of network coverage without increasing the transmit power or the receiver sensitivity
·         Enhanced reliability via route redundancy
·         Easier network configuration - Better device battery life
Wireless Metropolitan Area Networks
This family of standards covers Fixed and Mobile Broadband Wireless Access methods used to create Wireless Metropolitan Area Networks (WMANs.) Connects Base Stations to the Internet using OFDM in unlicensed (900 MHz, 2.4, 5.8 GHz) or licensed (700 MHz, 2.5 – 3.6 GHz) frequency bands. Products that implement 802.16 standards can undergoWiMAX certification testing.
802.17
802.18
Radio Regulatory TAG
802.19
Coexistence
802.20
Mobile Broadband Wireless Access
802.21
Media Independent Handoff
802.22
Wireless Regional Area Network



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