Techniques: Options

If it's mobility you're after, a wireless network could set you free

Curious about what technologies are on the horizon? Here's a preview, so you'll be able to make wiser buying decisions today.

Wireless local area network (WLAN).

Wireless LANs do the same things that wired LANs do--enable users to send and receive E-mail and share files and equipment like printers and scanners, among other things--without the cables. That means that users can roam 500 feet or more away from their network's server indoors and 1,000 feet or more away outdoors and still stay connected.

Until recently, low transmission speeds made WLANs impractical. Today, however, WLAN speeds of 1.6Mb are common, and some vendors even offer WLANs that run at 10Mb or more--the speed at which wired LANs run. (As a comparison, consider that a standard modem speed is 56Kb. The common WLAN speed of 1.6Mb is almost 30 times faster than that.) WLANs can operate on their own or in conjunction with a wired LAN.

Like cellular phones, WLANs communicate using radio waves, instead of the fiber-optic or coaxial wires that connect standard LAN components. They commonly use wideband radio frequencies and technology derived from secure military communications systems. Typical WLAN configurations require two kinds of hardware--a transceiver (which is called an access point) and wireless-network-interface cards (also known as adapters). The access point, housed in a small box, connects directly to a computer server or to a wired network via a hub (a rectangular unit with multiple ports that links together all the computers of a wired LAN). The access point transmits the data between the server or the wired network and users' wirelessly connected computers and any other networked device (for instance, printers or external storage devices). The adapters--one of which typically sits inside the computer or is connected to the computer (or other device) to be networked--make the data available for use.

A third kind of hardware, an extension point, looks like an access point but does not attach to the server or the wired network. Instead, it stands on its own and wirelessly communicates with access points to extend the physical range of the WLAN. Because extension points reduce the integrity of the data, there's a limit to how many you can add to your WLAN to extend its range.

If you don't have a conventional client/server LAN (that is, a network with one dedicated server and several computers connected to it), it's simple to set up a peer-to-peer WLAN (one with no dedicated server and two or more computers). Some vendors offer access points that connect to the parallel port of each computer, enabling the machines to be networked peer to peer.

Are you planning to relocate your office soon? Does sharing facilities with other businesses preclude a wired LAN? Do the job requirements of your employees make mobility necessary?

If you answered yes to any of the above questions, a WLAN may be right for you.

A wired network is an investment in the physical infrastructure of your business location. In older buildings, the cost of cabling can be exorbitant. And because you can't take your cabling with you, a move to new quarters means leaving your investment behind. Wireless technology can go wherever you go.

Companies with wired LANs in place can add a WLAN to their existing network. But if you have yet to network your computers and your current location is temporary, consider making a WLAN your network core. Do consultants or other employees work in your facilities on an intermittent basis? It's efficient and cost-effective to set up such workers with computers that are movable and connected wirelessly to your network, no matter what kind of network you have.

Some businesses need the mobile advantage of a WLAN. For example, warehouse workers, who are always on the move, can be much more productive if they have continuous access to their company's network. Likewise, health-care providers who need uninterrupted and instant access to medical records would have no trouble keeping patient records up-to-date. And if you've ever tried to set up computers for a group training session that required access to a wired network, you know that a wireless configuration would make everyone's life a lot easier.

The price of WLANs varies depending on how many adapters and access points you need. Components cost somewhat more than the adapters and hubs for wired LANs, but wireless networking can still be economically more attractive than a wired solution. The cost of labor and cabling materials is substantial, and you avoid the expense of user downtime during construction phases when you set up a WLAN.