Network type: Wireless networks lack messy cord tangle, and they are especially convenient for notebook users who don't want to be confined to one physical location. Most laptops now come with built-in Wi-Fi adapters that at the very least support 802.11b and g. Some have 802.11a support, and a growing number of newer portables support draft 2 of 802.11n, at least on the 2.4-GHz band. (A few laptops now have integrated mobile broadband wireless adapters, which let you connect to the Internet via a cellular broadband network.)
Range limitations, however, can make a wireless network impractical in spaces that are very large, occupy several floors, or contain lots of obstructions such as doors and walls. Plus, wireless networks have inherent security drawbacks; see the security section below for more.
If any of these issues pose a problem to you, several wired choices are available. Ethernet remains the fastest, cheapest, and most secure networking technology, but you must connect all network components using Category 5 cable--and installing Cat5 cable can be a challenge.
Depending on the layout of your house or apartment, home users who want a wired network may be better off with a power-line network that lets you connect your PCs and peripherals using existing electrical circuitry. Power-line adapters typically connect to ethernet ports in PCs and other networkable devices on one end, and to standard wall outlets on the other end. You also need to plug a power-line adapter into an available ethernet port on your router (and a wall outlet).
Which power-line network technology should you get? All of the newer high-speed technologies (HomePlug AV, DS2's Digital Home Standard, and Panasonic's HD PLC) transfer files quickly and support streaming standard-definition video. But in our tests in late 2006, adapters based on the HomePlug AV specification were best able to transmit high-definition video content, even with interference from another electrical device.
What if you want to network a mix of devices--for example, laptops that support wireless and media centers that could benefit from a wired hookup? Creating a hybrid network isn't that difficult. You could, for instance, buy an 802.11n router to connect wirelessly with the notebook, and plug power-line adapters into the router and your media center to enjoy a smoother streaming-media experience.
Speed and range: If you plan to use your network primarily for sharing broadband Internet access, the speed limitations of your networking technology won't matter much: Even poky 802.11b significantly exceeds the top speed (1 to 6 mbps) of residential DSL or cable service in most regions. But if you intend to stream multimedia or move large files between PCs and other networked devices, you'll appreciate the difference between a fast network and a slow one.
Today's 10/100-mbps ethernet networks are the fastest in widespread use, but gigabit ethernet is becoming more common. Power-line products based on HomePlug AV, Digital Home Standard, or HD PLC technology aren't quite as fast as 10/100 ethernet, but they are reliable and generally maintain better speed over a much wider range than wireless networks can support.
The fastest current wireless products are based on draft 2 of the upcoming 802.11n standard--be sure to look for Wi-Fi Alliance interoperability certification. Prices for draft-2 gear have come way down in the last year or so, and though some 802.11b and g products are still available, we recommend spending a little more for 802.11n technology. For the fastest and best coverage, seek out 802.11n products with three receiving and three transmitting antennas; they will cost more than models with two antennas, but will perform better.
If money is tight, and speed and range aren't huge concerns (in a small studio, for example), you might go for some older 802.11g products at fire-sale prices. Lagging considerably behind are 802.11b Wi-Fi (11 mbps maximum) and HomePlug 1.0 (14 mbps maximum) products; remember, for any of these devices, you should expect real-world throughput of less than half the theoretical maximum speeds. Most vendors aren't even making products based on these early-stage technologies anymore.
It's also important to note that speed on wireless networks deteriorates rapidly as distance from the access point increases or as obstacles such as doors, walls, metal objects, and ceilings intervene. Though many Wi-Fi vendors claim a range of up to 300 feet, you shouldn't count on a range of more than about 100 to 125 feet for 802.11b or g Wi-Fi in a typical office, and somewhat less in a home, depending on the layout (and the potential obstacles) in the environment. The range for pre-n and draft-n networks should be significantly greater.
For tips on improving your wireless network's range, read "Give Your Wi-Fi Network Wider Range, More Speed."
Wireless range extenders, which improve the strength of a wireless access point's signal and increase the distance from which you can connect to a wireless network, may help. Extenders cost approximately $60 and up, and they appear to your wireless adapter as a separate network. Be sure, however, that an extender is compatible with your Wi-Fi flavor.
Security: Because would-be intruders don't have to plug in to a physical port for direct access to a wireless network (as they do with a wired network), such networks are generally vulnerable to attack. Designers intended the encryption algorithm built into the 802.11x spec, called Wired Equivalent Privacy (WEP), to provide the same level of protection as the physical barrier in a wired network. Unfortunately, encryption experts have shown that WEP is vulnerable to attack.
Fortunately, most Wi-Fi products introduced in the last couple of years support an improved encryption scheme called Wi-Fi Protected Access, or WPA, and 802.11n products all support the even more stringent (but more efficient, since it's hardware-based) IEEE 802.11i standard known informally as WPA2. However, a Wi-Fi network's security is only as strong as the weakest scheme that all of the networked devices support, so if you are using older products that support only WEP, all components on the network will be vulnerable to attacks that circumvent WEP.
If you're stuck with equipment that supports only WEP security, you can improve your odds by purchasing network adapters that support 128-bit encryption (versus the 40-bit encryption possible with basic wireless cards). But if security is vital, take additional precautions, such as using a virtual private network (VPN) and/or a sturdy firewall, whether your network is wired or not. Also, consider upgrading to faster and newer gear that does support WPA2.
Hardware support: Not all types of network components are available for each network technology. For example, if you want to share a single broadband Internet account over a wireless network, you can find several Wi-Fi routers that combine the components you need--basically an access point for the wireless connections and a router to manage network traffic. (Most wireless routers also provide a few wired-ethernet ports, as well.)
Wi-Fi client gear can be trickier to find for the format you want. Locating PC Card adapters for laptops in all Wi-Fi flavors used to be easy; but with so many notebooks now shipping with built-in Wi-Fi, some manufacturers are skipping the cards in favor of USB adapters. Some vendors also offer PCI Wi-Fi adapters for desktops.
Firewall features: If you use a router or gateway to connect your network to the Internet, it will typically have a built-in firewall to ward off intruders. But the configurability of such firewalls varies widely. Some make it easy for authorized applications to connect directly to a designated PC on your network, which is useful for certain videoconferencing and messaging applications, not to mention online games. If you have a static IP address, some gateways will even help you set up a Web server. Others offer parental controls, allowing you to block access to Web sites by URL or even by certain keywords. In addition to turning on your router's hardware firewall, it's a good idea to install a software firewall, which can protect you from Trojan horses and other PC malware.