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 number of cycles (up and down) that happen in one time unit (a second).  Wave Speed is equal to the Frequency multiplied by the Wavelength.  In symbols: v = f * λ  Pay attention to the units.

7.  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

8.  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

9.  802.11i  Improved data encryption on 802.11a/b/n  802.11r  Increases speed of hand-off between access points

10.  Bluetooth  WiMAX  RFID  NFC

11.  What is Bluetooth  Piconet  Uses ISM Band  Up to eight (8) devices  Three power classes  Class 1 – 20dBm - ~100m  Class 2 – 4dBm - ~10m  Class 3 – 0dBm - ~ 1m

12.  Discovery  Inquiry procedure  Paging procedure  Piconet  Paring  Passkey

13.  Worldwide Interoperability for Microwave Access  IEEE 802.16e  Under development IEEE 802.20  Not a single protocol design.  Serves many different types of topologies.  Many different frequencies  Many different power levels  Uses OFDM modulation

14.  WiMAX  BWA  NLOS  Last mile

15.  Radio Frequency Identification  Three types of RFID systems  Active  Semi-active  Passive  Three frequency bands  LF (low frequency) – 125/134 kHz  HF (high frequency) – 13.65 MHz  UHF (ultra high frequency) 860-960 MHz & 2.4GHz

16.  RFID tag (a transponder)  RFID reader (a transceiver)

19.  Tracking inventory  Easy Pay  Checking ID Cards  Tracking animals  Wrist bands to track people (hospitals, etc.)  What else can you think of??

20.  RFID  Backscatter  Slotted Aloha

21.  Near Field Communications  Used for many new purposes such as  Apple Pay  Pay by cellphone  Security devices such as watches  Many other under development

22.  Why do we want to secure a wireless network?  How do we secure a wireless network?  Change passwords  Change SSID  Change passcode  Turn off broadcast  Use MAC filtering  Use RADIUS  Use third party encryption software

23.  Two ways to authenticate clients  Open  Shared-key  Encryption technologies  WEP  WPA  WPA2