| Better go look out your window. There could be someone lurking in her car outside your home connecting to your wireless network right now. Tip  | Wi-Fi is usually used with a laptop, but if you have a desktop computer, you can add Wi-Fi to it by buying a Wireless adapter card. The adapter card, which contains an antenna and Wi-Fi circuitry , fits into an open slot (called a PCI slot) in the rear of the PC. This is useful if the computer is located in a different room from the Wi-Fi router because it saves running a cable. |
I am not kidding. It happens every day. In fact, it could have been me. I've been at curbside in my car numerous times waiting for someone and checked my email on my laptop by connecting to someone's open wireless network. I didn't do anything bad. But I could figure out what brand of wireless router they had, what settings it had, and what computers were on the network. It would have even been possible to print a note on their printer"Andy was here. Thanks for the toner." I didn't, but I could have. To understand how strangers can access your computer just by parking outside your house, it's important to understand what a wireless home network is. Tip | | If you have a Wi-Fi router in your home, you probably already know it. But if you're not sure, here's how to check. Locate the modem that connects to your high-speed service. If it connects directly to your computer with a cable, you don't have Wi-Fi network. If the modem connects to a small box with one or two pencil- sized antennas, that small box is likely a Wi-Fi router. |
Let's first look at the basics. A home network is a way to connect computers and other devices together so they can share stuff such as files, access to the Internet, and printers. Businesses have been networking for a long time, but the technology has recently become available so you can do this at home very cheaply. This is achieved by attaching wires from each computercalled CAT-5 cablesto a little box called a home network router (see Figure 6.1) or connecting them wirelessly across radio waves. The router, in turn , is connected to a high-speed Internet modem, which connects to the Internet. Figure 6.1. At the heart of a home network is a router. It's a junction box that connects computers together so they can share files. It also gives them access to the Internet and resources such as a printer. 
A printer can also be attached to this set-up so any computer on the network can print to it. And computers on this network can send or get files from each other.  | There is one thing a wired connection is better at: speed. Although the fastest flavor of Wi-Fi moves data at potentially 54Mbps, wired networks can be much faster. A wired connection, called Ethernet, comes in three speeds. It started at a pokey 10Mbps, but these days the 100Mbps version is most common. And now 1000Mbps, or Gigabit Ethernet, is available. |
To make wireless work, you need a router that has Wi-Fi or Wireless Fidelity capability and a computer with a wireless network adapter. Most home network routers these days come with Wi-Fi built in. Since Wi-Fi is turned on by default in these routers, any computer that has a Wi-Fi adapter can connect wirelessly to the router within a range of about 300 feet. This is useful at home because it means you can sit by the pool with your laptop and order urgent groceries, such as margarita mix, using the Web. The bad part is you can also get email wirelessly from your egomaniacal boss who can chastise you about your expense report that includes a receipt for margarita mix. What's with the Wi-Fi Alphabet? If you listen to Wi-Fi geeks chat, you'll sometimes hear some weird terms when they refer to different types of Wi-Fi technology: "Oh yeah, my Wi-Fi network uses eight-oh-two-dot-eleven-gee!" If you want to play along with this wiener, here's the magic decoder ring for that conversation. There are three types of Wi-Fi: 802.11b, 802.11a, and 802.11g, plus one new one on the way: -
802.11b This is the slowest version of Wi-Fi with a maximum speed of 11Mbps (and a real-world speed of 24Mbps). It's the oldest Wi-Fi technology around. It works in the 2.4GHz radio spectrumthe same part of the radio dial that your cordless phone, baby monitor, garage door opener , and microwave work in. It has a range of up to 300 feet. -
802.11a This is the fastest version of Wi-Fi with a maximum speed of 54Mbps (with an actual speed of 2030Mbps or so). It's the second oldest. It works in the 5GHz part of the radio spectrum where some new cordless phones work. It tends to have a reduced range of 150 feet, instead of 300 feet. -
802.11g This is the latest version of Wi-Fi. It's 802.11b on growth hormones . It works at a theoretical 54Mbps (or real world 2030Mbps), but it also works in the 2.4GHz radio spectrum. And it works with old 802.11b gear. It also has a range of up to 300 feet. -
802.11n This is super-fast and super-new Wi-Fi that's supposed to work at more than 100Mbps. It's also supposed to have super-far range. The smart people thinking about it are still arguing about what rules it should follow, but by the time you read this, they might have kissed and made up and be on their way to agreeing to what kind of snacks to stock the break room with. |
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