Created by Amit Pindoria
almost 8 years ago
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3 Phyiscal (PHY) layer specfications for 802.11
802.11 radios PHY that can transmit in channels subdivided from the entire 2.4 GHz
Radios, which are permitted to transmit on 1 MHz subcarriers in the 2.4
1 Mbps and 2 Mbps data rates were part of the ______ 802.11 standard
802.11b is also known as
Uses CCK (Complementary Code Keying)
Data rates of 1, 2, 5.5, and 11 Mbps
Uses 3 different 100 MHz unlicensed frequency
Data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbps
Technology called Extended Rate Physical (ERP)
Two mandatory PHYs are:
ERP-OFDM and ERP-DSSS/CCK
Two optional PHYs are:
ERP-PBCC and DSSS-OFDM
Country code information is delivered in beacons and probe responses
Defines mechanisms for dynamic frequency selection (DFS) and transmit power control (TPC)
5.150 GHz–5.250 GHz
5.250 GHz–5.350 GHz
5.47 GHz–5.725 GHz
5.725 GHz–5.825 GHz
Major security enhancements in Wireless Standard
Data privacy using RC-4 ciphers
Data privacy using AES encryption
Defines the entire method for authentication, generating encryption keys for clients and APs
Japanese 4.9 GHz and 5 GHz bands
Wireless Standard for QoS
Contention-based method determining who gets to transmit on the wireless medium next
Access point briefly takes control of the medium and polls the clients
Has 2 access mechanisms to provide QoS
- extension to DCF
- provide for the “prioritization of frames” based on upper-layer protocols
- Extension of PCF
- Gives the access point the ability to provide for “prioritization of stations.”
- Like PCF never adopted by WLAN vendors
WMM
Fast basic service set transition (FT)
Radio Resource Management (RRM)
802.11k:
802.11h defined this for 5GHz frequency
802.11k:
These client statistics are reported back to the AP for RRM
Noise floor information and Channel load information is reported back to the access point
Learn details about other access points that the client might want to roam to from the access point or the WLAN Controller
Robust management frames
Designed to prevent DOS attacks against management frames
Broadcast and multicast frames are protected using the Broadcast/Multicast Integrity Protocol (BIP)
Known as Wireless Access in Vehicular Environments (WAVE)
Allows client stations to bypass the access point and communicate with direct frame exchanges
Wi-Fi Alliance’s Hotspot 2.0 specification and its Passpoint certification
This standard and certification is designed to provide seamless roaming for wireless devices between your Wi-Fi network and other partner networks, similar to how cellular telephone networks provide roaming
Provides for an exchange of information that can potentially ease the configuration of client stations wirelessly from a central point of management
Standardizing mesh networking using the IEEE 802.11 MAC/PHY layers
QoS enhancements to the 802.11 Media Access Control (MAC) for robust audio and video streaming for both consumer and enterprise applications
Very High Throughput (VHT) at 60Ghz at up to 7 Gbps
256-QAM modulation
Null data packet (NDP)
Use of wireless in the newly opened TV white space (TVWS) frequencies between 54 MHz and 790 MHz