A Hard Look at Wireless Networks

Wireless networks have captured the attention and imagination of our increasingly mobile society. The public is learning just how easy it is to get connected—whether in the workplace, on campus, or at home—without ever touching a network cable. Libraries for their part have been quick to keep up. Across the country, librarians are beginning to provide their customers with wireless connectivity, wireless-ready laptops for borrowing, or new programs and services based on this technology.

As excited as librarians may be about the ability to provide wireless access within their buildings, it is mobile access to the Internet that remains the star attraction. The ability to surf the web and grab e-mail while out and about can be considered the killer application that drives Wireless Fidelity (Wi-Fi). An increasing number of providers that offer fee-based services are creating wireless hot spots in locations frequented by on-the-go computer users—airports, hotels, and coffee shops. We can expect wireless Internet services to become increasingly widespread in the next few years. We can also expect users to be reaching their library—and their online reference service—from a variety of wireless devices.

Despite wireless technology's many advances, it cannot replace wired networks. For one thing, wireless networks have serious security risks. Without adequate protection, a wireless LAN can provide a free on-ramp to the Internet or the means for hackers to invade an organization's network. Speed, while acceptable for many functions, can be slow compared with what most users expect from typical LANs. Nevertheless, wireless technology, when properly planned, belongs in libraries. Our public increasingly expects wireless access, and the technology can provide us with solutions and new opportunities. Even more importantly, wireless networks are part of the evolving development of Internet technology, and librarians need to remain active participants in that experimentation.

Computers on standard networks communicate with each other by sending and receiving packets of information over cables. Electrical signals over copper wires or pulses of light over glass strands have proven to be highly effective media for transmitting large amounts of data at extremely fast speeds. Wireless networks, however, transmit data using radio waves over the air.

The IEEE standard 802.11b specifies the deep technical details of the current standard for wireless networking. In very broad terms, it defines a radio frequency network that transmits at a frequency of 2.4 GHz. The frequency delivers 11megabits per second with a range of about 300 feet. The next generation of wireless networks, 802.11a, is expected to be available around mid-2002; it offers 54 mb/sec. But since it operates on a different frequency, 5 GHz, existing wireless LANs will be completely incompatible.

Setting up a wireless network is easy and inexpensive. An access point attaches to an existing network, typically connecting directly to a 10 or 100 mb/sec Ethernet jack, creating a "hot spot" for wireless connectivity. A computer equipped with a wireless network card can access the network, provided it is properly configured and close enough—a maximum of 300 feet, but it varies considerably. Access points start at about $175, and wireless network cards are available for $80 or less.

Technically, the access point performs multiple tasks. It works as a transmitter and receiver, as an Ethernet hub, and as a router. In most cases, connecting to a wireless network is transparent for the end user. Technical details such as negotiating an IP address happen automatically through a built-in service called DHCP (dynamic host configuration protocol). Each access point will have a service set identifier (SSID) that users will need to know to gain access. It is almost too easy.

In a well-endowed Wi-Fi academic environment, students enjoy the ability to roam their campus with their laptop computers—from the dorm, to the classroom, and even to the coffee shop across the street—all without losing access to the Internet. If the academic or corporate campus provides wireless access to its students and faculty, then the library or information center mustn't be left out. It is important for libraries to be well integrated into the network infrastructure of its larger organization, be it wired or wireless. While the demand for Wi-Fi in public libraries may be less, the growth of this technology will increase demand here also.

In addition to providing yet another hot spot of public wireless Internet access, libraries are considering other innovative uses of this technology. Wireless networks can be used to extend library services. Most libraries offer desktop computers for access to the library's catalog and other resources. Libraries frequently experience periods of peak use that exceed the number of workstations available. Expanding public workstations usually means ordering computers, procuring furniture, planning space, and installing power outlets and network cabling. Laptops with wireless connectivity can be a more creative way to supplement public workstations. While the laptop computers themselves cost more than comparably powered desktop computers, they require little else. Laptops can be loaned, allowing them to be used in a more comfortable setting than the crowded elbow-to-elbow area typical of public workstations.

Wi-Fi is also being used in public libraries to create mobile computer labs for training and outreach activities. Labs include a group of laptops, each equipped with wireless cards, that can be easily transported along with an access point. The equipment could be set up in community centers, schools, or remote meeting rooms.

Library staff can use wireless networks for remote circulation and inventory tasks. Wireless laptops equipped with barcode readers can be used to scan books in the stacks as part of an inventory project or for help in weeding collections.

One of the major pitfalls of Wi-Fi lies in the security arena—it is often said that the technology was designed for ease of use and interoperability first, with security an afterthought. A basic trade-off exists between making it easy for users to take advantage of Wi-Fi hot spots and preventing unauthorized users from breaking in. On one level, you need to know the SSID to gain entry to an access point. But in libraries, the SSID is often left at its default setting, meaning that just about anyone knowledgeable in Wi-Fi equipment can easily gain access. Even if it has been changed, the SSID is broadcast as part of the beacon signal of an access point and can be easily discovered.

The primary security architecture of Wi-Fi depends on Wired Equivalency Privacy (WEP). If WEP is disabled, users can gain access if they know the SSID of the access point. But if WEP is enabled, the communication stream of a wireless-connected device can theoretically be considered just as secure as that on a wired network.

WEP uses a security key to identify authorized users and encrypts their network traffic that travels over the airwaves. With WEP enabled, the security key must be installed in authorized users' computers in advance for them to be able to connect. But many implementers of Wi-Fi do not employ WEP; this allows anyone with a Wi-Fi-enabled device to roam into their hot spots unimpeded. A major weakness of WEP involves its use of a static security key. In its simplest implementation, the same key is used for all users of an access point. Once cracked, the compromised key can be continually recycled to gain unauthorized access. A more advanced release, called Dynamic WEP, generates a new key with each session, providing an additional level of security.

An increasing number of individuals are taking advantage of leaky wireless networks—ones where the usable and unsecured Wi-Fi signals extend beyond their intended audience. Tools abound for breaking into an organization's wireless network. A directional antenna, costing about $60, taps into the signals of an access point from beyond its intended range—such as a library's parking lot. For institutions that haven't implemented any security features, that's all that is needed. Once connected, exposed network services and vulnerabilities can be exploited. Breaking into wireless LANs has grown into a hackers' sport, often called "war driving."

Although security for Wi-Fi continues to improve, these networks should be treated with utmost care. Wireless networks should be carefully and distinctly separated from the library's business network. VLANS or firewalls can be employed to ensure that even if someone gains unauthorized access, he/she will not get more than a free ride onto the Internet.

Advertisements for Wi-Fi tout its speed as being 100 times faster than dial-up. It is also at least 100 times slower than typical wired LAN speeds. Today, most wired users connect at 100 mb/sec. With a shared media Ethernet hub, that 100 mb/sec is shared among the users of the hub. But increasingly, wired LANs are built out of Ethernet switches that give each user 100 mb/sec of dedicated bandwidth. Remember that Wi-Fi operates at 11 mb/sec, with that bandwidth being shared by all users of the access point. Gigabit (1024 mb/sec) offers power users and high-performance servers even faster access. A 10 GB/sec Ethernet is right around the corner. Even the next generation of Wi-Fi will offer only 54 mb/sec—still just half as fast as the typical wired connection.

Wireless certainly doesn't suit all needs and may not compare favorably to what's possible in the wired world. But many users are clearly willing to exchange a little speed for the convenience of mobility. After all, it wasn't that long ago that 10 mb/sec was the desktop standard.

Wi-Fi offers the greatest attraction to those computer users who are constantly on the go. Wireless network cards tend to be installed in laptop computers rather than on desktop systems, since laptops are inherently mobile devices. You can also add wireless connectivity to PDAs and other hand-held computing devices.

Wireless access is rapidly expanding beyond the workplace, campus, and library. An increasing number of providers offer fee-based services allowing wireless Internet access. Boingo Wireless (www.boingo.com), for example, offers hot spots in hundreds of locations in the United States, primarily in hotels. VoiceStream provides wireless access to 500 Starbucks coffee shops. Access to these services is through subscription fees ranging from about $45–$95 a month. Wireless Internet services are expected to become increasingly widespread in the next few years, even though providers have so far generally experienced a rough start.

You don't have to be an Internet provider to establish a public wireless Internet service. Like a grass-roots movement, some users have taken to providing community wireless networks, sharing one residential high-speed Internet among neighbors by positioning the wireless access point so that its signal goes beyond the walls of the immediate home or apartment. Most of the ISPs of high-speed Internet frown upon, or even explicitly ban, sharing Internet access in this way. So far, few aggressively pursue such use since it's difficult to detect, but it's unlikely that such tolerance will endure indefinitely. Librarians are wise to watch both the evolving wireless user and the expanding access to wireless Internet service; both contribute to users' expectations of libraries.

Wi-Fi offers a high level of convenience, but it is easy to overstate its benefits and lose perspective, dismissing the wired alternatives. Wireless technology is often touted as making it possible to construct new buildings with no wiring at all. This is misguided. While Wi-Fi may well be used to extend an existing LAN's wired infrastructure to mobile users, it cannot replace wired infrastructure.

As a relatively low-bandwidth technology, Wi-Fi does not meet the needs of high-performance computing applications. Those who need to transfer large volumes of data on the network will be frustrated by the performance capabilities of wireless LANs. There is no reasonable circumstance where a network server should connect to a network through Wi-Fi. Both security and performance considerations demand a wired connection for all network servers.

Like any new technology, it is important to get past the hype and focus on its appropriate applications. In balance, wired networks will always have significantly faster capabilities, making Wi-Fi appropriate for those situations where moderate transmission speeds will suffice. Wireless networks flourish for mobile computer uses. The ability to stay connected as a user roams with a laptop from office to office to conference room to airport is compelling, even if it means working at lower speeds. In some cases the installation of physical cabling may be especially problematic. Concerns for historic preservation of a building, for example, may mean that Wi-Fi can be employed when network cabling cannot be affordably installed.

The wired world of copper and fiber-based networks will continue to be the basic fabric of networks for the predictable future, but Wi-Fi is a rapidly growing niche. Wireless technologies will undoubtedly continue to grow in popularity, increase performance capabilities, and harden walls of security. Mobile computer users will become a larger proportion of any library's clientele. Libraries will find it necessary to extend their commitment to wireless networking. It is important, however, to move forward with balance and perspective. With the caveats described, wireless networking is a technology that libraries can use effectively.