Ready to Pull the Plug?

The advantages of a local area network (LAN) are obvious: Users can share software applications and data—in short, they can stay in touch. Equally obvious are its disadvantages: Each computer—even an otherwise portable laptop—must be tethered by cable to a port in the wall. Unplug and you’re offline and out of touch.

THE SPEED ISSUE

In the past, speed was not wireless’ strong suit, so potential users will want to know: Is a WLAN fast enough for our needs? A typical wired LAN transmits data at between 10 and 100 megabits per second (Mbps). The old wireless LANs (based on the 802.11 technical standard for wireless transmission) crept along at no more than 2 Mbps, which is why most users rejected WLANs unless they had no other choice. Now a new standard (802.11b) is able to move data at more than an order of magnitude faster—a speed that makes it nearly as fast as the lower end of the standard LAN transmission rate, and thus a practical choice for most business environments.

Compared with LAN hardware, WLAN equipment is relatively expensive (we’ll break down costs later in this article). However, when you factor in WLANs’ many savings—which we’ll also outline—the entire setup works out to be less expensive. Here’s why: The biggest single expense of a traditional LAN is the cost of installing it. Wires or cables have to be snaked under floors and through ceilings and walls, and ports must be installed for each computer hook-up. When an office is reconfigured, new cable usually has to be added and new ports installed so users can plug in. Those costs typically amount to several times the cost of the LAN equipment itself.

With a wireless system, however, you avoid all those structural installation costs because there’s no need to run wires or cable to each port—transmission is through the air. Since floors, ceilings and walls are transparent to radio waves, the signals go right through them. And since WLAN software is mostly plug-and-play capable, much of it loads onto the computer network automatically, requiring little customization.

In addition, because WLANs don’t need structural installation, moving the computer setup to a new office space is as simple as packing up the equipment, then unpacking it in the new location and plugging it into the electric wall socket. No walls or floors to open up, no cables, wires or ports to install. Even upgrades or office expansions are relatively easy because there is no need to replace or move anything structurally.

From a productivity point of view, WLANs are especially attractive. If the computer users in the office all work on laptops—recommended in a wireless office—they can stay connected no matter where in the area they tote their computers (or PDAs or handhelds). All the computers need are wireless network interface cards (NICs). That gives them full access to the files on the network, printers and the Internet. A WLAN with sufficient, properly positioned access points can provide wireless connectivity over an entire building or even over an office complex.

WORKING TOGETHER

When used in an audit or consulting engagement, WLANs really shine. For example, the auditors can take their laptops with them and

Share disk storage on the senior auditor’s laptop, making many hard-copy workpapers unnecessary.

Access special application software designed for networks or collaborative workgroup projects, making the engagement more efficient.

Link to a client’s system more easily, enabling the use of client resources, including disk access for file downloads and fast Internet access.

When used in conferences, meetings and training programs, a wireless system makes it easier to display multimedia presentations, technical documents, training exercises and other materials directly on the participants’ computers. A wireless setup could replace expensive multimedia projectors, which cost a minimum of about $4,000 each.

The bottom line: The cost of installing a WLAN varies considerably. Much depends on the organization’s current computer equipment, the wireless hardware selected, the vendor, the physical proximity of the computers, the number of staff members who access the system and whether and how much professional assistance is needed to get the system up and running.

Proper positioning of access points is critical to achieve optimal communications; fortunately, several vendors bundle system survey tools to determine the best positions with their equipment. In general, equipment designed for enterprise-wide wireless networking is more expensive because the equipment and bundled software are more sophisticated than that designed for small office use. However, prices have been dropping recently.

CALCULATE COSTS

The following provides a minimum and maximum cost estimate of the equipment that is needed for a WLAN in a typical office:

Generally, every staff person who must move about the office with his or her computer should have a laptop that can accommodate a wireless NIC. A good quality laptop costs between $2,000 and $3,500.

Every laptop needs a wireless NIC, which costs between $100 and $300.

Every desktop to be connected to the WLAN will require adapters (a PCI or ISA) and a wireless NIC, which costs between $160 and $400. At least one desktop unit should act as a file and print server.

Wireless LAN signals have a transmission range of 80 to 1,500 feet, depending on the type of equipment, the data exchange rate and the obstacles that the signals must pass through. Access points also vary by the maximum number of simultaneous users, ranging from 15 to 60 users per access point depending on the type of equipment.

For optimal positioning of access points, it’s probably wise to engage a consultant to conduct signal testing. In general, you’ll probably need an access point for every 2,000 square feet of floor space. Access points cost between $200 and $1,500.

You should also add between $200 and $1,000 for a firewall or cable/DSL router.

These estimates don’t include training staff members, obtaining professional assistance in installation, special-purpose network software to increase staff productivity, fees charged by the Internet provider, network administration and maintenance.

Although security problems exist with any type of network, WLANs are slightly more risky than traditional LANs. The new 802.11b standard includes built-in security, providing some defense against unauthorized interception and access; however, there still are weaknesses. To upgrade security, some developers have implemented proprietary solutions; unfortunately, these features may make it impossible to interchange equipment from different manufacturers, limiting your LAN design options. But, as a practical matter, most users probably should not worry about security unless they feel that their size or type of business make them high-risk targets.

Should you consider unplugging and going to a WLAN? That depends on many factors. If you must upgrade your conventional wired LAN, and that work involves new wires or cables, you may want to unplug because in the long run it will probably save you money.

One thing you can be assured of is that wireless technology is the wave of the future—or at least the immediate future. While the hardware today is a bit pricey, costs are falling and will continue to do so for some time to come, and speed and reliability will improve apace. Since WLAN installations do not require structural work, it may be cheaper to unplug now and upgrade over time as WLAN hardware improves rather than make a huge investment in new cables and wires.
 
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