1. Prof. Alfred J Bird, Ph.D., NBCT http://www.cs.umb.edu/~abird abird@cs.umb.edu Office – Science 3rd floor – S-03-130 Office Hours – Monday and Thursday 3:00PM to 4:00PM

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

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

4.  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.

6.  Speed of light in a vacuum 3x10 8 m/s or 1.86X10 5 mi/s  WBZ – 1030kHz  λ = v/f : 300000000m/s ÷ 1030000hz ≈ 300m  λ = v/f : 300Mm/s ÷ 1.03Mhz ≈ 300m  WBZ – 99.5MHz  λ = v/f : 300000000m/s ÷ 99500000hz ≈ 3m  λ = v/f : 300Mm/s ÷ 99.5Mhz ≈ 3m  Cell Phones – 980MHz  λ = v/f : 300000000m/s ÷ 980000000hz ≈ 0.3m  λ = v/f : 300Mm/s ÷ 980Mhz ≈ 0.3m  ISM – 2.4GHz  λ = v/f : 300000000m/s ÷ 2400000000hz ≈ 0.125m  λ = v/f : 300Mm/s ÷ 2.4Ghz ≈ 0.125m

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

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

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

12.  Defines:  Physical layer  Media access control layer  Media access control management protocols and services  802.11a/b/g/n

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

14.  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

17.  DSSS  FHSS  OFDM  Infrared

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

21.  802.11a  Data rates up to 54Mbps  Operating range up to 75 feet  Uses 5Ghz band  Uses OFDM modulation  802.11b  Data rates up to 11Mbps  Operating range of 100-150 feet  Uses ISM (2.4Ghz) band  Uses DSSS modulation

22.  802.11g  Data rates up to 54Mbps  Operating rages up to 150 feet  Uses ISM (2.4Ghz) band  Uses DSSS or OFDM modulation  802.11n  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

23.  802.11i  Improved data encryption on 802.11a/b/n  802.11r  Increases speed of hand-off between access points

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