Wireless Network Adapters
Each computer you wish to connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes also called NICs, short for Network Interface Cards. Wireless adapters for desktop computers are often small PCI cards or sometimes card-like USB adapters. Wireless adapters for notebook computers resemble a thick credit card (see Page 1 sidebar for illustration). Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebook or handheld computers.Wireless network adapters contain a radio transmitter and receiver (transceiver). Wireless transceivers send and receive messages, translating, formatting, and generally organizing the flow of information between the computer and the network. Determining how many wireless network adapters you need to buy is the first critical step in building your home network. Check the technical specifications of your computers if you're unsure whether they contain built-in wireless adapter chips.
Wireless Access Points
A wireless access point serves as the central WLAN communication station. In fact, they are sometimes called "base stations." Access points are thin, lightweight boxes with a series of LED lights on the face (see Page 1 sidebar for illustration).Access points join a wireless LAN to a pre-existing wired Ethernet network. Home networkers typically install an access point when they already own a broadband router and want to add wireless computers to their current setup. You must use either an access point or a wireless router (described below) to implement "hybrid" wired/wireless home networking. Otherwise, you probably don't need an access point.
Many access point products are available on the market; see the following supplementary article for some good examples:
Wireless Routers
A wireless router is a wireless access point with several other useful functions added. Like wired broadband routers, wireless routers also support Internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points (see Page 1 sidebar for illustration).A key benefit of both wireless routers and access points is scalability. Their strong built-in transceivers are designed to spread a wireless signal throughout the home. A home WLAN with a router or access point can better reach corner rooms and backyards, for example, than one without. Likewise, home wireless networks with a router or access point support many more computers than those without one. As we'll explain in more detail later, if your wireless LAN design includes a router or access point, you must run all network adapters in so-called infrastructure mode; otherwise they must run in ad-hoc mode.
Wireless routers are a good choice for those building their first home network. See the following article for good examples of wireless router products for home networks:
Wireless Antennas
Wireless network adapters, access points, and routers all utilize an antenna to assist in receiving signals on the WLAN. Some wireless antennas, like those on adapters, are internal to the unit. Other antennas, like those on many access points, are externally visible. The normal antennas shipped with wireless products provide sufficient reception in most cases, but you can also usually install an optional, add-on antenna to improve reception. You generally won't know whether you'll need this piece of equipment until after you finish your basic network setup.Wireless Signal Boosters
Some manufacturers of wireless access points and routers also sell a small piece of equipment called a signal booster. Installed together with a wireless access point or router, a signal booster serves to increase the strength of the base station transmitter. It's possible to use signal boosters and add-on antennas together, to improve both wireless network transmission and reception simultaneously.Both antennas and signal boosters can be a useful addition to some home networks after the basics are in place. They can bring out-of-range computers back into range of the WLAN, and they can also improve network performance in some cases.
