The Computer Revolution/Networks/Wi-Fi
This alliance has been created in 1999 to try to create one world wide acceptable standard for high speed networking. So far there is about 250 members and it is growing every day. W-Fi is meant to be used with any network that is 802.11.
These Wi-Fi products are tested and approved by the Wi-Fi trademark. It means that any of the devices that are certified by Wi-Fi are capable to work with each other. Even if the two products are made by different manufacturers. The organization is helping other developers with information on acceptable standards for today’s world network. Some of the well known current members are Nintendo, HP, US robotics, BenQ, Alpine, Lexmark, Sharp, AT&T, and many more.
Wi-Fi Hotspots are establishments that offer access to the Internet via a wireless LAN network. These places allow you to access the Internet on your portable device; sometimes you will be prompted with an online agreement before using the Wi-Fi. The Wi-Fi is usually used within the facility since the range is limited; once you leave the facility you lose the Wi-Fi connection.
Many public places today offer these Wi-Fi Hotspots such as: coffee shops, restaurants, waiting rooms, libraries, and many more public places. Establishments are starting to offer Wi-Fi Hotspots more-and-more. Though it is not meant to be a primary source of Internet; it is great to use when you stop somewhere for a short time.
Piggybacking on Wi-Fi access points is the practice of establishing an internet connection by using somebody other than your own Wi-Fi connection with out the direct consent of the other party. It is very controversial and laws vary depending on where it is being done. There are many motives for people wanting to “piggyback” off a connection. The motives vary but the main reason is the cost of internet for some people is too much. Although no harm is meant by most individuals who perform this act, others use “piggyback” to perform illegal activities such as identity theft, child pornography, and illegal downloads. http://www.nytimes.com/2006/03/05/technology/05wireless.html?pagewanted=all 
Personal Wi-Fi Hotspots
Most of the newest phones on the market today have internet access. When you set up service, you pay not only for your telephone plan, but also a data plan as well. This data plan allows you to use your phone to surf the web, send emails, watch videos on Netflix, and most any other web based task you can think of. But what if you are going on vacation? Of course you bring your phone and your laptop. Now assume that you don’t have a data plan for your laptop (why would you after all). Instead of surfing the net on your nice big 15” laptop screen, you are stuck watching your tiny phone screen. Wouldn’t it be great if there was a way to share your data plan between the two devices? Well there is. Most mobile carriers (e.g. AT&T and Verizon) offer the capability to use a Personal Mobile Hotspot. You basically turn your phone into a WiFi access point so that you can connect your laptop, or iPad, or any WiFi capable gadget to the internet. You can also purchase a special gadget to provide the hotspot (e.g. Verizon’s MiFi device) instead of using your phone. Of course the carriers will normally charge extra for this feature, but the incremental cost is usually less than setting up a new data plan for each device.
Wi-Fi SD Cards
A convenient new technology that has become available recently is the Wi-Fi SD card. An example is the brand Eye-Fi. Eye-Fi SD cards were the first memory card to automatically upload videos and photos using Wi-Fi. The Wi-Fi SD card not only works with your camera and stores media, but the built-in Wi-Fi lets you instantly send photos to your computer, smartphone, or other device. There is also the security of knowing your photos are safe on your home computer/online. The cards are useful in the case of personal pictures being lost through theft, damage to the card/camera, or losing the camera.
Reference: Morely, Deborah; Parker, Charles. Understanding Computers Today and Tomorrow. Course Technology, 2011, Page 282.
How Wi-Fi works
Wi-Fi uses two types of frequency carrier: a single direct-sequence area distributed spectrum radio carrier and a multi-carrier OFDM (Orthogonal Frequency Division Multiplexing) radio technology. "There are two common ways to put information in a radio wave, and you've likely run into them yourself. They are called A.M. and F.M. just like the two choices you've always known are on a radio. To understand these two ways of sending information it is important to know that radio waves, by themselves, have very regular patterns. Generally they keep the same amplitude or frequency all the time. (Amplitude is the "height" of the radio wave, frequency is how close the waves are to each other.)" [Forbus, K. and Gentner, D. 1997]. http://www.qrg.northwestern.edu/projects/vss/docs/Communications/1-how-is-data-put-on-radio-waves.html  http://upload.wikimedia.org/wikipedia/en/8/81/Wi-Fi_logo.png 
The speed of a Wi-Fi connection depends on many different factors. First, it can become slower if there are a lot of solid objects between the computer being used and the access point. Also, the amount of interferences can play a role in making the connection slower. For instance, baby monitors, microwaves, and other devices that operate on the same frequency can affect it. Finally, the type of hardware used may affect the connection. Wi-Fi connections are typically between 100 and 300 feet indoor and 300-900 feet outdoors. Distance can be extended using devices designed for that purpose such as antennas.
How to Protect Yourself When Using Wi-Fi
While using Wi-Fi hot spots may be convenient, you must always think about protecting your computer. Wi-Fi is less secured than a wired network. A suggestion to keep your hard drive safe is to turn off file sharing when using a Wi-Fi hotspot so no one has access to any personal information. Another idea is to turn off automatically connecting to a Wi-Fi spot on your computer, so you can choose what networks you want to join. A user should also look and see what Wi-Fi network the computer is connected to. By doing this, this ensures they are on a secured Wi-Fi and not a Wi-Fi spot that someone set up to hack into your computer.
- Morley, Deborah, Charles S. Parker, and Charles S. Parker. Understanding Computers: Today and Tomorrow. 13th ed. Boston, MA: Course Technology, Cengage Learning, 2011. Print.
- MARRIOTT MICHEL, 2006-03-05.Hey Neighbor, Stop Piggybacking on My Wireless, The New York Times. Retrieved 2012-10-10.
WiMAX is similar to Wi-Fi, but instead WiMax is designed for a longer wireless network connection. WiMax is able to cover a certain location but coverage can extend up to six miles, it has the ability to cover a broader geographical range. The areas covered by Wi-Fi are known as Hotspots, while WiMax covered areas are called Hotzones. WiMax can provide coverage for an entire city by using WiMax towers. WiMaz utilizes radio frequencies like Wi-Fi to avoid interference. There is also a mobile version of WiMax, called Mobile WiMax. Mobile WiMax enables cellphone or portable computer users to stay connected through a wireless broadband network.
Reference: Morley, Debrah, and Charles S. Parker. Understanding Computers: Today and Tomorrow. 13th Edition. Course Technology, Cengage Learning, 2011. Print.
WiFi and Smartphones
When using your phone while it is connected to a WiFi network your mobile data plan does not get deducted. It is not possible to write the specific details for all phones, since all of them are slightly different, but here are some directions on how to connect to a WiFi network on your smartphone:
• Go to the Applications menu
• Click on the icon for Setup WiFi
• Click Next
• Your Blackberry will scan for networks. When the list of available networks appears click on the network you would like to connect to
• Scroll down and click Connect
• When you have successfully connected click Next and then Finish
• You can now use the web browser and access the Internet
iPhone or iPad
• Open up your "Settings" icon
• click on the Wi-Fi tab
• Turn on Wi-Fi
• Your iPhone will scan for networks. Choose which network you would like to connect to
• You can now use the web browser and access the Internet