A router is a switching box programmed to send data where it needs to go. Large routers connect networks over the Internet. Small routers connect computers and other devices on a home or office network, also called a Local Area Network (LAN). You can recognize a router because the back is occupied by a bank of perhaps four to eight jacks for plugging in Ethernet cables, while the front sports an array of blinking or steady light emitting diodes (LEDs), indicating the status of data traffic.

A Wi-Fi router lets you send data wirelessly so that you don’t have to connect Ethernet cables between every device on your network.

Wired Congestion: In typical wired networks, the Internet feeds a router, which in turn feeds an entire LAN network comprised of routers, switchers, servers, workstations, printers, fax machines, etc. All too often ethernet-tethered networks become a tangled web of wires.
One or more antennae attached to a router indicates that the device is Wi-Fi capable, but some Wi-Fi routers don’t let on what they are because they embed their antenna. For wired use, a Wi-Fi router still has the array of Ethernet jacks (called RJ-45s, which are wider versions of the RJ-11 snap-in ports on phones), but you don’t necessarily have to use them since the Wi-Fi router also contains a transceiver for transmitting and receiving data. Hence, if you want to buy “Wi-Fi” for your home or office, what you’re really asking for is a router with a built-in radio.

Not entirely. One of the router’s RJ-45 ports is usually dedicated for attaching a wire to your cable or DSL modem. The port may have a different color or be labeled WAN for Wide Area Network―the ramp to the Internet, the considerably wider network than your LAN, and arguably, the most vital link on your router. Also, you’ll need to plug in the power supply.

If your laptop, notebook or netbook was manufactured in the last few years, it will almost always be Wi-Fi capable, so you won’t necessarily have to attach an Ethernet cable between it and the router. A desktop computer is more likely to ship without Wi-Fi ability, so you’d either need to run an Ethernet cable between it and the router or purchase a Wi-Fi adapter for the computer.

As for the iPod touch, iPad, or other Internet-savvy portable you have on hand, it almost always lacks an Ethernet jack and will depend on the wireless connectivity of your router.
The conventional answer is about 300 feet, but the range varies greatly based on whether you’re talking a large open area versus the signal having to penetrate or get around walls and floors and the type of construction in place. The manufacturer’s claimed distance also varies by model.

The good news is that because Wi-Fi uses a radio signal (2.4 or 5 Gigahertz), it doesn’t require the line-of-sight necessity of an infrared remote. And more robust protocols than those available a few years ago have increased the range, reliability and speed of wireless data transmission.
The most popular, leading-edge standard is called 802.11n. It’s the type of Wi-Fi embedded in all the latest portable computers and other new devices. If your router is N-compatible, but one or more legacy computers or devices you own incorporate the older 802.11g or even older 802.11b standard, not to worry. N-type routers are downwardly compatible. (Some N routers also support 802.11a, a less popular protocol originally intended to succeed 802.11g especially for high-def video applications. “N” stole its thunder.)
A bit of background: Because of the higher bit rates supported by N, you can transmit high-definition video, for instance, from a computer or the Internet to a media receiver or an embedded Wi-Fi receiver in a Blu-ray Disc player or HDTV set. The other wireless protocols mentioned above would choke on this type of application, causing the picture to freeze up. You’d be reaching for an Ethernet cable in no time. On the other hand, if all you care about is transmitting photos, Web pages or music, you can get by with an 802.11b router. For standard-definition video, you would want at least 802.11g.

The trade-off: While N-Type Routers are backwards-compatible, there is a trade off on performance when pairing an N-type router with legacy versions.
If you send or receive high-definition video (originating from your camcorder or streamed from the Internet), and you do it wirelessly, you’ll be frustrated by anything less than an 802.11n (or 802.11a) router. Also, if you want to extend the range of your Wi-Fi network, upgrading may help.
An 802.11n router may incorporate a radio technology called MIMO (for “multiple input multiple output”) that uses multiple antennas for both transmitting and receiving to improve communication performance. The most advanced 802.11n routers are also dual band, transmitting simultaneously at 2.4 and 5 Gigahertz. This is a way of avoiding the crowded 2.4GHz frequency used by older Wi-Fi networks, some cordless phones, baby monitors and microwave ovens.

MIMO is an acronym of the phrase Multiple-Input Multiple-Output. MIMO creates a channel matrix that operates at speeds 4-5x faster than 3G.
Though there are exceptions, generally you own the router but rent the modem from your broadband service provider such as a cable TV operator or phone company. The router is dedicated to distributing data between your computers, network attached storage devices, network printers, home theater devices, media players, Wi-Fi appliances, smart phones and personal digital assistants. The modem is dedicated to connecting the router to the Internet. Though this duality typically means separate pieces of equipment, there are a number of hybrids that combine Wi-Fi connectivity with a built-in DSL or cellular data network modem.

With the rise of wireless Internet access through advanced cellular phone networks, some specialized routers let you create an instant hot spot for use by several of your Wi-Fi devices no matter where you happen to be, providing you can pick up the wireless broadband service to which you subscribe. People who own recreational vehicles, attend tailgate parties or go camping could bring along a notebook computer and iPod touch and share a ramp to the Internet in their ad hoc hot spot.

Cellular routers typically get their broadband connection using the same types of modems you’d slide into the PCMCIA slot of a notebook computer or plug into a USB port. An important difference between them is which type of interface they accommodate. While some 3G routers only accept USB-type modems, others accept both types.
Some routers may contain a USB port for connecting a hard drive or a printer. Traditionally, you’d connect a network-capable peripheral to one of the router’s RJ-45 ports in order to make storage or printing available to everyone on your network. By putting a USB port on the router and configuring software, you’ll be able to put wider-available USB peripherals to use on the entire network rather than on just one computer.
Some routers offer longer-range performance by boosting the signal to the highest allowed by federal regulations.
The newest routers also offer exponentially faster speed over its wired connections. While the typical Ethernet link provides transfer speeds of up to 100 megabits per second, the newest routers increase speeds up to 1000 Mbit/s. It’s called Gigabit Ethernet
Through firmware in the router accessed by your computer. Unlike Ethernet cables that imprison bits and stay in place behind walls and doors that lock, Wi-Fi doesn’t respect boundaries. Your neighbor can piggyback your unprotected Internet connection; a passer-by can park in front of your home and gain access without physically entering. What to do?
A router protects you because it can be equipped with password, authentication and encryption features to monitor data packets entering your network. Routers can have firewalls to prevent unwanted entry. In fact, one reason not to regularly connect a computer directly to a cable modem is that you forfeit the router’s firewall, which is important if you don’t have a software firewall installed on your computer.

Look for a router that implements the latest in security technology. That’s Wi-Fi Protected Access 2 (WPA2). A Wi-Fi network using WPA2 is both secure and private. You can control who connects to your network, even providing guest access. With encryption, transmissions across the network cannot be read by others.
The Takeaway