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 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.
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
Bluetooth WiMAX RFID NFC
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
Discovery Inquiry procedure Paging procedure Piconet Paring Passkey
Worldwide Interoperability for Microwave Access IEEE e Under development IEEE Not a single protocol design. Serves many different types of topologies. Many different frequencies Many different power levels Uses OFDM modulation
WiMAX BWA NLOS Last mile
Radio Frequency Identification Three types of RFID systems Active Semi-active Passive Three frequency bands LF (low frequency) – 125/134 kHz HF (high frequency) – MHz UHF (ultra high frequency) MHz & 2.4GHz
RFID tag (a transponder) RFID reader (a transceiver)
Tracking inventory Easy Pay Checking ID Cards Tracking animals Wrist bands to track people (hospitals, etc.) What else can you think of??
RFID Backscatter Slotted Aloha
Near Field Communications Used for many new purposes such as Apple Pay Pay by cellphone Security devices such as watches Many other under development
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
Two ways to authenticate clients Open Shared-key Encryption technologies WEP WPA WPA2