Prof. Alfred J Bird, Ph.D., NBCT Office – Science 3rd floor – S Office Hours – Monday and Thursday 3:00PM to 4:00PM

 Seven Levels  7 – Application  6 – Presentation  5 – Session  4 – Transport  3 – Network  2 – Data Link  1 - Physical

 4 – Applications  3 – Transport  2 – Internet  1 – Network Interface

 Wavelength – the distance between two similar points on the wave.  Frequency – The time it takes for a wave to complete one complete cycle of the wave.  Wave Speed is equal to the Frequency multiplied by the Wavelength.  In symbols: v = f * λ  Pay attention to the units.

 Speed of light in a vacuum 3x10 8 m/s or 1.86X10 5 mi/s  WBZ – 1030kHz  λ = v/f : m/s ÷ hz ≈ 300m  λ = v/f : 300Mm/s ÷ 1.03Mhz ≈ 300m  WBZ – 99.5MHz  λ = v/f : m/s ÷ hz ≈ 3m  λ = v/f : 300Mm/s ÷ 99.5Mhz ≈ 3m  Cell Phones – 980MHz  λ = v/f : m/s ÷ hz ≈ 0.3m  λ = v/f : 300Mm/s ÷ 980Mhz ≈ 0.3m  ISM – 2.4GHz  λ = v/f : m/s ÷ hz ≈ 0.125m  λ = v/f : 300Mm/s ÷ 2.4Ghz ≈ 0.125m

 Twisted Pair – Copper  Fiber Optical Cabling  Wireless Networking

 Extremely wide system bandwidth  Immunity to electrostatic interference  Elimination of crosstalk  Lower signal attenuation  Lower costs  Safety  Corrosion  Security

 A cost-effective networking media for use in areas that are difficult and/or too costly to wire  User mobility in the workplace

 Defines:  Physical layer  Media access control layer  Media access control management protocols and services  a/b/g/n

 WLAN  Access point  Transceiver  Roaming  Hand-off

 BSS – also called an ad-hoc network  Zero or one access point(s)  No central control of the network  ESS  More than one access points  Central control of the network  CSMA-CA

 DSSS  FHSS  OFDM  Infrared

 Random  Pseudorandom  Hoping Sequence  ISM  MIMO  Space Division Multiplexing

 a  Data rates up to 54Mbps  Operating range up to 75 feet  Uses 5Ghz band  Uses OFDM modulation  b  Data rates up to 11Mbps  Operating range of feet  Uses ISM (2.4Ghz) band  Uses DSSS modulation

 g  Data rates up to 54Mbps  Operating rages up to 150 feet  Uses ISM (2.4Ghz) band  Uses DSSS or OFDM modulation  n  Data rates of 200Mbps or higher  Operating range up to 150 feet  Uses both ISM (2.4Ghz) and 5Ghz bands  Uses DSSS and/or OFDM modulation

 i  Improved data encryption on a/b/n  r  Increases speed of hand-off between access points

 SSID  Passcode  Site Survey  Association  Point to Point  Point to Multi-Point  Site Survey