CWNA

• transmitting radio signals by rapidly switching a carrier among frequency channels using a pseudorandom
• sequence known to both the transmitter and the receiver

data rate of 1 and 2 Mbps

• Data signal at the sending station is combined with a higher data rate bit sequence, or chipping code, that divides the user data according to a spreading ratio.
• data rate of 1 and 2 Mbps

transmits multiple signals simultaneously over a single transmission path, such a cable or wireless system

• signal travels within its own unique frequency range (carrier), which is modulated by the data (text,
• voice, video, etc)

data rate of 6, 9, 12, 18, 24, 36, and 54 Mbps

the 802.11b 5.5 and 11 mbps speeds

• physical layer specification defined for clause 19 radios.
• operates at 2.4 ghz ism band

data rates of 6 - 54Mbps

1 and 2 Mbps.

1- of 6, 9, 12, 18, 24, 36, 48, and 54 Mbps, but only 6, 12, and 24 Mbps are mandatory)

number of bits/ second the physical layer carries during a single frame transmission

measurement of the amout of user data that successfully transverses the network over a period of time

. DSSS, FHSS, HR-DSSS, and ERP

5 GHz UNII bands

2.4 ghz ISM band

• b only
• g only
• b/g mixed
• support different spread spectrum technologies and have different aggregae throughput reults

802.11h admendment, regulate power levels in .11a erc and fcc mandate radio at 5Ghz,

RSN (Robust Security Network). 802.11i makes use of the Advanced Encryption Standard (AES) block cipher, whereas WEP and WPA

• Defines Quality of Service (QoS) mode of operation
• Defines enhanced medium access methods
• Uses Hybrid Coordination Function (HCF

• Adaptive configuration support
• Standardization of Mesh Networking
• Uses the MAC and PHY layers of 802.11
• Specifies the DS be Wired

• Multiplexing (HT-OFDM)
• Uses MIMO
• Uses Channel Bonding
• Works in both 2.4 GHz and 5 GHz bands

• 802.11 that support Intelligent
• Transportation Systems (ITS)
• Also known as Wireless Access in Vehicular
• Environments (WAVE)
• Can reach speeds up to 124 MPH/200KPH at 3281
• feet/1000 Meters
• Will possibly be licensed in the 5.9 GHz band
• but supports 5 GHz bands

• Uses Protected Management Frames
• Forces mutual authentication prior to deauthentication and disassociation
• Reduces simple denial of service attacks

• •900 MHz
• •2.4 GHz
• •5.8 GHz

signals transmitted using higher power, and very little bandwidth

• uses more bandwidth for transmission and less
• power

OFDM uses Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) modulation for lower data rates

•QAM (Quadrarture Amplitude Modulation) is a hybrid of phase and amplitude modulation

amout of time that the FHSS system transmits on a specific frequency befor it switches to the next frequency in the hop set

the amount of time it takes for the transmitter to change from one frequency to another

dely between the reception of the main signal and the reflected signal

• Not being used by 802.11 devices
• Legacy wireless networking

• 1 Mbps
• modulation for lower data rates

• at 2, 5.5 and 11 Mbps
• modulation for lower data rates

• 4 bits of data with 8 chips (5.5 Mbps) and
• can encode 8 bits of data with 8 chips (11 Mbps)

• Let the code to be transmitted is 10
• •11111111111 00000000000 XOR
• 10110111000 10110111000
• 01001000111 10110111000

is a hybrid of phase and amplitude modulation

16-QAM and 64-QAM is used for higher data rates

26 MHz wide

•Includes 902 MHz to 928 MHz

•Legacy wireless networking

• •Partially allocated for Global System Mobile
• Communications (GSM Cellular) in parts of the world

•Used by cell phones

•Not being used by 802.11 devices

• 83.5 MHz Wide
• Covers 2.4 GHz to 2.4835 GHz
• USA has 11 channels, each of 22MHz wide
• Channels 1,6 and 11 are most widely used because they don’t overlap
• Used by 802.11, 802.11b, g and n IEEE standards
• 2.4 GHz ranges uses DSSS modulation
• Also widely used by non-networking devices (microwaves, baby monitors, etc.)
• Devices transmitting on Adjacent Overlapping Channels cause Interference for each other.
• Channels 1, 6 and 11 are
• Adjacent Non-Overlapping Channels.
• That is why they are used so often in
• co-location of 802.11 devices

• 150 MHz Wide
• Includes 5.725 GHz to 5.875 GHz
• Divided into channels, each 20 MHz wide
• Total of 23 non-overlapping channels
• Used by many non-networking devices
• Should not be confused with UNII-3 Bands
• 5.81 ISM band is 50 MHz larger than UNII-3
• Used by 802.11a standard and the new 802.11n draft Uses OFDM
• Data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbps are defined

Contains Three 5 GHz Bands

• Defined as Lower, Middle, and Upper UNII
• Bands (aka UNII 1, UNII 2, and UNII 3)

• In the United States, The FCC opened more
• channels for UNII 2. Now UNII 2 Extended
• offers 11 more channels for use, with some restrictions.

• Has 4 Channels
• Includes 5.15 GHz to 5.25 GHz
• Typically Used Indoors
• Allowed a Maximum IR of 50 mW by
• the FCC
• Most Vendors Limit the IR to 40 mW
• Prior to 2004 UNII 1 Devices Were Required to
• use Fixed Antennae
• After 2004, Detachable Antennae may be used
• Within Regulatory Body Guidelines

• Has 4 Channels
• Includes 5.25 GHz to 5.35 GHz
• IEEE Maximum 200 mW IR
• FCC Maximum 250 mW IR
• Power limits may vary by country

• Has 11 Channels
• FCC added 255 MHz of Spectrum to within 5.47
• GHz to 5.725 GHz
• Maximum Allowed IR Strength 250 mW
• IEEE Maximum IR Strength 200 mW
• Requires Dynamic Frequency Selection (DFS)
• Requires Transmit Power Control (TPC)

• Has 4 Channels
• Includes 5.725 GHz to 5.825 GHz
• FCC maximum power 1000 mW
• IEEE maximum power 800 mW
• Shares starting frequency with the 5.8 GHz
• ISM Band
• UNII 3 is 100 MHz wide while the 5.8 GHz ISM
• Band is 150 mW wide