Learning Resources
Lesson
Wireless LANs are also referred to as WiFi (Wireless Fidelity) networks. WiFi is a standard that specifies how the devices must work. The original standard was 802.11a. Widely available, 802.11b has a bandwidth of 11Mbps, similar to 10baseT Ethernet. 802.11g has a bandwidth of 54Mbps, about half of fast Ethernet (100baseTx). 802.11g at 108 Mbps is also available.
WiFi radio transmission is typically at 2.4 GHz (2.4 Gigahertz or 2400 million cycles per second). This is the same as a microwave oven and many wireless phones. WiFi does have a number of channels to choose from, which can reduce interference form other devices. A few operate at 5.0 GHz. The information below outlines things that are different from, or in addition to, a wired network.
- Wireless Router (and switch). A wireless router/switch does exactly the same things as a wired device. The only difference is the addition of a radio transmitter/receiver. The wireless part, often referred to as a WAP (Wireless Access Point), is only used for the LAN. The device still has a 10Mbps ethernet connection to the internet. Most of them also have a four port switch as in the regular device above. The WAP allows connection to the LAN by devices that have compatible wireless cards. The unit below has a four port switch, with ethernet to three computers and a hub. The hub serves one additional computer and a print server. The wireless is used for a laptop and other devices.
Figure Router/Switch with 802.11g WiFi. Note the activity lights and the two antennas.
- Wireless LAN Card. Cards are available for laptop computers, desktop computers, and handheld computers like Palm and PocketPC. WiFi print servers and other devices are also available.
Figure 802.11g WiFi Card for Laptop Computer
Figure 802.11g WiFi Card in Computer. The Antenna portion extends outside the computer
For Additional Information
For additional information on WiFi, check these sites
- How Stuff Works, How Wireless Networking Works
- How Stuff Works, How Wireless Internet Works
Activity
Please complete all activities
- Conduct research to identify the range of devices that may be connected to a WiFi network
- Compile a profile that includes device name, maker, function, network standard (for example, 802.11a), cost, and whether it is a stand alone device or if it requires a computer
- Create an entry in your course portfolio
- Publish to you course portfolio web
Test Yourself
There is no self test for this lesson.