The Specs Explained
Several major types of network technology compete for your investment in dollars and hours. They fall into two major categories: those for networks that use wires and those for networks that don't.
The ranks of wired networks include the granddaddy of networking technology: reliable old ethernet. Such connections create the fastest, most secure, and cheapest (at least for components alone) network. But installing the technology requires running special cables, which can be expensive--and an eyesore-producing hassle.
Power-line networks don't require running any new wires, because they piggy-back on the electrical wires already installed in your home or office. But they don't afford users the mobility of wireless--and with three different fast but incompatible power-line technologies on the market (Digital Home Standard, HD PLC, and HomePlug AV), you must take care to buy compatible products.
With wireless networks, the vast majority of buyers will choose equipment based on draft 2 of the fast 802.11n standard. Routers come in a wide range of features and prices, as we saw in our most recent review of draft-n routers. Key differentiators include gigabit ethernet support, the number of transmitting and receiving antennas, and frequency band support (most support 2.4 GHz; you'll pay more for 2.4 GHz and 5 GHz support together).
Important: Tested Speed
All networks are fast enough for sharing Internet access and printers. But if you want to transfer large amounts of data--for example, to back up to a networked hard drive or file server--you should consider one of the faster wired or wireless technologies. Draft-n and pre-n Wi-Fi networks can move data at speeds of 30 to 50 mbps, or even faster at close range, but speed declines dramatically as the distance between the networked device and the router increases, especially if obstacles such as walls and ceilings intervene.
The newest power-line devices can transfer data at speeds comparable to those of the swiftest Wi-Fi networks, and they maintain those speeds even at distance. In our tests conducted when these power-line products first appeared, straight file transfers were fastest--about 42 mbps--with a Netgear product based on DS2 technology, approaching ethernet's tested real-world speed of 52 mbps. But HomePlug AV proved significantly better at streaming high-def video, especially on a circuit with another electrical device plugged in. Newer power-line products are due later this year, and we'll report on any changes in test results; but since the basic standards haven't changed, we don't anticipate dramatic differences.
Somewhat Important: Rated Speed
The rated speed is the theoretical maximum speed of the network under ideal conditions. While rated speeds might be useful in comparing the relative performance capabilities of different network technologies, tested speeds are much better indicators of what kind of real-world performance to expect from your network.
Ethernet is the most secure networking method. Because older homes or apartments may share power circuits, it's possible (though unlikely) that someone else on the same circuit could sneak onto your HomePlug network, especially if you don't change the default settings of your equipment. For HomePlug AV, newer products are expected to make adjusting the settings easier, by eliminating the need to do so via desktop software.
Wi-Fi networks are the most vulnerable to intruders because no physical connection is required to access them. Also, the basic WEP encryption in all Wi-Fi devices has been shown to be fairly easy to penetrate. However, if all of your network equipment can support the more recent and more effective WPA or WPA2 security, your Wi-Fi network will probably be reasonably secure.
Somewhat Important: Cost per Network Adapter
At $10 to $40, ethernet adapters are generally cheaper than those for Wi-Fi ($10 to $50 for 802.11b, $20 to $90 for 802.11g, and $70 to $100 for pre-n and draft-n) and HomePlug ($60 to $100). But an ethernet network also requires that you run Category 5 cables to all networked devices. If your home or small office doesn't already have Cat5 wiring, you will also have to factor in the cost of installing such wiring, which may be significant.
Somewhat Important: Cost per Router/Access Point or Bridge
Routers direct traffic between networks--for example, between devices on your home network and the Internet. Simple home network routers typically have a wide-area network port that connects to a cable or DSL modem, and an ethernet switch with several local-area network ports into which you plug ethernet cables connected to PCs, printers, or other networkable devices. You can buy one of these basic routers for $30 to $70.
Wi-Fi routers include a built-in wireless access point through which Wi-Fi devices connect to the LAN. You can buy a 802.11n router now for as little as $40 (for a two-antenna router without gigabit ethernet support), or spend as much as $180 to $200 for a dual-band router. No vendors offer routers for the newer power-line technologies; to set up a power-line network, you simply plug a power-line adapter into an available LAN port on a standard router. You can, in fact, use a single Wi-Fi router with an ethernet switch to support Wi-Fi, ethernet, and power-line-connected devices.
Somewhat Important: Multimedia Optimization Features
While many people initially install a home network in order to share Internet access, printers, and files, the up-and-coming application for such networks is the ability to stream media. A growing number of new set-top boxes, digital video recorders, and living-room PCs have built-in networking support so that you can access their content on other networked devices--for example, to view a show recorded on your living-room DVR on the HDTV in your bedroom. But to do this, your network needs more than just sufficient bandwidth to support the media stream; it also needs technology that can prioritize the packets to ensure smooth playback.
There's actually a Wi-Fi standard for this, known as 802.11e. However, not all Wi-Fi devices support it--and Wi-Fi gets particularly problematic for media playback if you live in a crowded urban environment with lots of nearby Wi-Fi networks. If multimedia playback is important to you, you should investigate a network technology's support for this feature and consider using a wired network technology if possible.