Magazine article Information Today

The Benefits of Wireless Technologies: Their Applications Offer Many Advantages to Libraries and Patrons Alike. (the Systems Librarian)

Magazine article Information Today

The Benefits of Wireless Technologies: Their Applications Offer Many Advantages to Libraries and Patrons Alike. (the Systems Librarian)

Article excerpt

An increasing number of libraries are implementing--or are at least planning to implement--wireless technologies. This month I'll present a brief overview of how wireless technologies work, the equipment and standards that underlie wireless networks, and how it all compares to the wired alternatives. I'll also explore some of the applications that are especially well-suited for the wireless world and talk about some library-specific uses.

Wireless Basics

A wireless network operates just like a traditional LAN, except without the wires. Instead it uses signals transmitted over radio frequencies to enable computers to communicate with one another. To get started, you need to install what's called an access point, which will serve as a network hub for a group of wireless devices. An access point can support a finite number of mobile computers. The exact number depends on the model, but most support eight to 16. The access point connects to your organization's physical network (typically through a 10-or 100-Mbps Ethernet connection), and should be positioned to serve the widest area. Users who roam too far from the access point or find themselves behind dense walls will lose their connectivity. (For example, we've found that our bookstacks fairly effectively block wireless communication.) Through the use of multiple, well-positioned access points, a building can deliver wireless connectivity throughout.

To start with, a user's computer needs to be equipped with a wireless network card. This performs the same function as an Ethernet adapter, except that it has an antenna instead of a wire jack. Wireless cards are available for desktop computers, laptops, and PDAs. If there's an access point in sufficiently close proximity, a computer with a wireless network card will establish a network connection that's almost invisible to the user. Most wireless LANs use DHCP (Dynamic Host Configuration Protocol) to manage details such as assigning an IP address with no pre-configuration by a network administrator or with no user intervention.

Fortunately, wireless components have become quite affordable. Low-end access points cost $200-$500, with more industrial-strength units priced somewhat higher. Wireless network cards for PCs and laptops are typically about $100.

While wireless LANs work well for mobile computer users with light to moderate data-transfer needs, some network users with more bandwidth-hungry applications will find the level of available bandwidth inadequate. I can think of no circumstance in which it makes sense to connect a server to a network using a wireless rather than a wired connection.

The Current Standard: 802.11b

Standards ensure that wireless networks comprising components from several different vendors will work properly. Theoretically, cards manufactured by one company will work with an access point from another. The current standard for wireless networks is known as 802.1 lb. This standard is in the same family as Ethernet, which is generally known by the designation 802.3.

Equipment that follows 802.11b is capable of a theoretical data throughput rate of 11 Mbps. This level of bandwidth is quite respectable, given that many wired networks continue to operate at 10 Mbps. However, the actual usable bandwidth averages about half the theoretical capability.

The previous generation of wireless networks operated at 2 to 3 Mbps. Not surprisingly, they didn't become popular until the introduction of 802.11b. The emerging 802.11a standard, which is expected to find more common use within the next 1 to 2 years, will deliver data at 54 Mbps.

Still a Niche Product

Despite the steadily increasing speed of wireless technology, wired networks will always outperform it by long strides. Today, 100-Mbps Ethernet cards prevail in most business LANs, with Gigabit Ethernet (1,024 Mbps) finding common use as network backbones and for connecting high-performance servers. …

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