1. Wireless Technologies
Networking for Home and Small Businesses – Chapter 7

2. Wireless Technologies
The use of electromagnetic waves to carry information.
We call them “radio waves”
Common wireless technologies
Infrared
Radio Frequency
Electromagnetic
Spectrum

3. Infrared Technology Line of sight transmission
Unable to penetrate through walls
Used by:
remote controls
wireless mouse and keyboard

4. Radio Frequency (RF) Technology
Signal able to transmit through walls
RF bands set aside for wireless devices, including cordless phones and computer peripherals
900 MHz – used by cell phones
2.4 GHz
Bluetooth technology
low speed, short range
can communicate with many devices at once
5 GHz
Wireless LAN
transmit at a higher level = greater distance
conform to standards
Activity on page over RF and IR Signals

5. Benefits of Wireless Mobility Scalability Flexibility Cost
can be added to a network easily
Flexibility
anytime, anywhere connectivity
Easy to add additional devices to the network
Cost
easy & inexpensive to install
reduced installation time

6. Limitations/Risks of Wireless
Uses unlicensed regions of the RF spectrum
used by many different devices
Interference
cordless phones
microwaves
Security
easy access to the network
encryption/authentication helps with security issues

7. Wireless Technologies
WLAN
Wireless LAN
uses RF standards
conform to standards
connects through Wireless AP
Copy chart from page over the wireless technologies

8. Wireless Technologies
WWAN
Wireless WAN
coverage over large areas
cell phone network
Activity on page over types of wireless

9. IEEE Wireless Standards
Copy chart from page
Define wireless device communication
– wireless standards
group of all standards = Wi-Fi Wireless Fidelity

10. vs Bluetooth
wireless technology is able to transmit further distances than Bluetooth technology because of its higher power output.

11. Components of a WLAN Wireless client Access point (AP)
any host that can participate in a wireless network
Access point (AP)
control access between wired and wireless networks

12. Access Point Antennas Directional antenna Omni-directional antenna
increases output signal strength (gain)
receives the wireless signal
higher gain = increased distance
Directional antenna
concentrates signal in one direction
allows for greater distances
Omni-directional antenna
emits signal equally in all directions
used by most Access Points

13. Configuring a Wireless Access Point
Modes
Specific to a device
Mixed Mode – supports multiple types of hosts b,802.11g,802.11n
decreases performance – supports more devices
SSID(Service Set Identifier)
used to identify which WLAN the device belongs to
all devices that participate must use the same SSID
SSID broadcast to everyone
allows for easy detection (Turn Off)
Wireless Channel
auto locate
finds the least congested channel
Activity on over setting up SSID
Activity on over wireless channel

14. Wireless Bridge & WI-FI
Wireless Bridge connects two networks with a wireless link
The WI-FI logo indicates that the device is interoperable(will work with) with other devices of the same standard that also display the Wi-Fi logo.

15. Wireless Configuration Screen
SSID Broadcast allows the presence of the access point to be known to nearby clients

16. Configuring a Wireless Client
Client configuration must match that of the Access Point
Clients can be called STA
Windows XP
wireless client software
included as part of the operating system
can control most configurations
Using stand-alone software
supplied with the wireless NIC
includes enhanced functions
Once software is installed, check connectivity

17. Wireless Security
No physical connection needed, wireless is easy to access
Attacker can “tune into” your network just like tuning into a radio station
Easy access if all settings are set to default, so . . .
Turn off SSID broadcast so the hacker or user must know the SSID to access the network

18. Security – Authentication
Controls who connects to the network
Permitted based on set of credentials
Helps to verify the “trustworthiness” of the device
usernames
passwords
Occurs before client is connected to WLAN

19. Security - Open Authentication
Can be called EAP or Open Authentication
On by default (most common method used by AP’s)
No authentication is required
Should only be used on public wireless networks
Schools
Internet Café

20. PSK (Pre-Shared Keys) Authentication
Both AP and client must have the same secret key or word to work together
Here’s how it works:
AP sends random string of bytes to client
Client accepts it, encrypts it, and sends it back to AP
AP receives encrypted string, decrypts it
if decrypted string = original string  client is added

21. Activity on 7.3.4.3 over wireless security
Encryption
Process of encoding wireless data so that intercepted wireless data cannot be read if intercepted.
WEP (Wired Equivalency Protocol)
advanced security feature
Key Lengths of WEP
64 bit
128 bit
Activity on over wireless security

22. Traffic Filtering
Controls the type of traffic allowed to enter a wireless network
Able to block traffic based on:
IP Address

23. Ad Hoc Wireless
Ad Hoc Wireless is created by connecting wireless clients in a peer-to-peer network

24. Securing the AP

25. Planning the WLAN Determine the type of wireless standard
Determine layout
look at existing infrastructure
Size of the building - # of solid interior walls – microwave ovens or other devices that could interfere with wireless should be documented
Installation/Security
Total Cost of Ownership (TCO)
Site Survey
signal strength
possible interference
Backup/Updating Devices
MAC Address
Port Numbers