Chapter 10. How Home Networks Work

In today's world, where many households have more than one computer, home networks have become commonplace. Home networks are primarily used to allow multiple computers to share a broadband Internet connection, but also allow those computers to share a printer and exchange files among each other.

The most common networks you'll find at home are wireless networks based on the 802.11 family of protocols called Wi-Fi. (For more details about how Wi-Fi works, see Chapter 9 "How Wireless Connections and WiFi Work.")

Wireless networks, although they got their start in the business world, are now more commonly used at home than at work. There are several reasons for that; a big one has to do with cost. Corporations are located in office buildings that are already wiredthe buildings have Ethernet cables strung throughout that connect computers to the network, so building an entirely new wireless network is a very expensive proposition.

By way of contrast, homes don't have Ethernet cables strung throughout the walls. Therefore, to network computers in several roomsin a study, a home office, and several children's bedrooms, for exampleone would have to snake cables throughout the walls, and that costs a significant amount of time and money. With a wireless network, you don't need to spend that time and money.

The other reason that wireless networks have become popular at home is that the simple ones used in homes are very easy to set up, and have become quite inexpensive, in some cases costing less than a hundred dollars for an entire network. To build a wireless network at home, you can buy a network kit with all the required pieces, or you can buy the pieces individually. You'll need a wireless router that connects all the computers to one another and to the Internet. And you'll need to buy wireless network cards for each computer you want to connect to the network. The computers all connect to the wireless router, and the router routes all the traffic among the computers and between the computers and the Internet.

The main reason why people install wireless networks is to share a high-speed Internet connection, such as a cable modem or a DSL modem. But they can use the network for other things as well, notably sharing devices such as printers, sending files back and forth between computers, or playing computer games over the network against other family members. And wireless home networks can also be used to wirelessly stream music and videos to televisions and stereos.

Although today, mainly computers at home are networked wirelessly, in the future other kinds of devices and appliances will be connected to one another as well, such as small, inexpensive email devices that only send and receive email, and even traditional home appliances such as refrigerators, microwave ovens, and alarm clocks. Not only will they connect to one another, they'll connect to the Internet as well.

Connecting these kinds of devices and appliances will make life more convenientyou'll be able to use your refrigerator to automatically generate shopping lists, for example, and send orders directly to grocery stores. And you'll have an alarm clock that can change the time it awakens you based on traffic reports it garners from the Internet. These kinds of devices aren't mere fantasythey are already being sold or tested. Initially, many will require wires to connect to each other and the Internet, but soon they'll connect wirelessly as well, and some already do.