Wireless Systems Remove Boundaries to Learning
Administrators enter a conference room, turn on their laptop computers and achieve high-speed connectivity to the district network. Teachers sit down in the cafeteria with their notebooks and instantly update class schedules, grades and attendance records in a centralized database. Students take hand-held devices outside of the classroom, collect scientific data and share their findings in real-time with peers via the Internet.
Sound like a vision for the 21st century? Actually, all these scenarios can take place today thanks to recent advances in mobile computing and wireless technology. Already, wireless local area networks (WLANs) have extended, or replaced, traditional LANs in hundreds of educational sites, and many more IT managers are carefully examining the benefits of wireless solutions.
In particular, this article will survey some leading WLAN products and share several case studies from schools and universities across the United States. Readers are encouraged to contact the companies listed in the directory and local systems integrators for help with product selection and implementation.
"Unplugged" Communications
First, here's a little background on wireless LANs. Traditional LANs link personal computers to one another -- and to file servers, printers and other equipment -- using cables or optical fibers. To connect to the LAN, one must literally plug into a wall or floor LAN outlet. A WLAN, on the other hand, employs microwave, spread-spectrum radio or infrared technologies to transmit data within or between buildings.
Access points create circular ìcellsî of wireless coverage, with the range depending on the strength of the signal and the physical characteristics of the environment (walls, partitions, etc.). Anyone with a portable computer (equipped with a compatible PC Card adapter) can move freely between overlapping cells and seamlessly maintain their network connection.
Although the initial investment for WLAN hardware might be higher, long-term cost savings can be realized because technicians never need to pull wire through walls or ceilings to expand the network. Following are some examples of how educators have successfully implemented wireless solutions.
LA District Links 13 Schools
The Bonita School District in Los Angeles began experimenting with wireless technology in 1996, when a taskforce searched for alternatives to running cable through buildings, many of which are over 40 years old. The district previously relied on 56 Kbps leased lines, each costing $30,000 a year. In October, representatives from BreezeCOM set up a WLAN that transmits data at up to 3 Mbps.
Specifically, Bonitaís 13 schools are linked through BreezeNET WB-10D wireless bridges, AP-10D access points, SA-10D station adapters and antennas. One leased T-1 line in the district office serves as the gateway to the Internet. BreezeCOMís products operate in the license-free 2.4 GHz ISM (industrial, scientific and medical) band, enabling co-existence with other wireless systems in the same geographic area.
"We recently showed the system to the taskforce, and everyone was excited about its potential; they loved what they saw," says Sally Walby, Bonita's coordinator for state and federal programs. In fact, members have discussed extending the network beyond the schools to two local senior centers and some community offices.
WLAN Configuration at Bonita School District in Los Angeles County, Ca (Courtesy BreezeCOM)
A Bridge to the Internet
When two public school districts in central Illinois wanted classroom access to the Internet, they applied for a grant from the National Center for Supercomputing Applications (NSCA) at the nearby University of Illinois at Champaign-Urbana. The grant paid for the installation of directional antennas on a radio tower belonging to WILL, the university's Internet Service Provider. AIRLAN/Bridges from Solectek were placed at one high school in each district.
The AIRLAN/Bridges are coupled with Cisco 4500 routers, allowing middle and elementary schools to connect through a twisted-pair FDDI backbone. Last summer, many teachers attended training classes, where they learned how to use the Internet to develop curriculum. "The connection to the Internet would not have been possible without Solectekís wireless bridges," notes Del Ryan, principal of Mahomet-Seymour Junior High School.
Smaller institutions in rural parts of the country have also found wireless networking to be cost-effective. At Neodesha High School in southeastern Kansas, students access the Internet and CD-ROM indexes from "mobile labs," comprised of rolling cabinets with Macintosh PowerBooks. Starfish II wireless access points from Digital Ocean are located throughout the hallways to provide complete campus coverage.
Thirty teachers at Neodesha can share the mobile labs, a difficult task with fixed terminals. According to one teacher, students in foreign language classes have downloaded materials from the Web and even participated in chat sessions with kids overseas. He says the school selected equipment from Digital Ocean because the firm offers generous educational discounts and specializes in the Macintosh platform.
University Conducts Research
Wireless LANs are also gaining popularity in higher education, where faculty members often count on fast, reliable access to the network. Carnegie Mellon University (CMU) in Pittsburgh, Penn., received a $500,000 grant from the National Science Foundation (NSF) to create an experimental high-speed wireless network to serve the campus and support research in the field. The program, known as the Wireless Initiative, aims to overcome the restraints inherent in mobile computing environments and advance the capability of interactive video.
After testing a variety of products, CMU's Information Networking Institute staff chose the WaveLAN system from AT&T (now Lucent Technologies). In the first phase, staff connected some 200 IBM PC and Macintosh workstations via WavePOINT access points to Andrew, the central distributed network.
Lucent Technologies' WaveLAN
The WLAN at Carnegie Mellon currently functions at 2 Mbps, but that may change soon. Scientists at a Lucent's Bell Labs facility in the Netherlands recently patented a new technology they call Direct Sequence/Pulse Position Modulation (DS/PPM), which promises robust wireless transmission rates of up to 10 Mbps. DS/PPM complies with the spectrum spreading rules defined by the IEEE 802.11 standard for the 2.4 GHz band.
Impact of IEEE Standard
Industry executives predict that IEEE 802.11, ratified in June, will drive down prices for WLANs and improve performance on mixed networks. The Medium Access Control (MAC) protocol works seamlessly with Ethernet, making wired and wireless nodes logically indistinguishable. "The standard will have a significant impact on the wireless marketplace by making it easier to extend enterprise LANs to the growing number of mobile computer users," says Roger Murphy, president and CEO of Aironet, a leading manufacturer of WLAN products.
The passage of the 802.11 standard d'es not mean that all WLAN systems will be identical, however. In fact, some companies are introducing devices that operate in the Unlicensed National Information Infrastructure (U-NII) band, which ranges from 5.15 to 5.85 GHz. Apple Computer has long lobbied the FCC to open up greater bandwidth for "community networks." RadioLAN, founded four years ago, already has adapted its product line to support the 5 GHz range.
Computer Vendors Take Note
Recognizing the potential for widespread WLANs, computer companies have continued to enhance their machines for the emerging wireless world. Apple, Fujitsu, Hitachi, IBM, Sun Microsystems, Toshiba and other hardware and software vendors have agreed upon the Mobile Network Computer Reference Specification (MNCRS), a set of guidelines on how mobile devices should ìtalk toî networks.
Some firms have forged partnerships to deliver wireless network computers (NCs). Proxim and Wyse Technology, for example, collaborated to produce the Winterm 2930, a hand-held Windows terminal that incorporates WLAN technology. All applications and data are stored on a local server, accessible on the go from any location covered by Proxim's RangeLAN2 system.
Apple, meanwhile, weighs in with the eMate 300, a Newton pen-based device priced under $800. The eMate ships with word processing, drawing, spreadsheet and calculator applications, and many third-party vendors have developed software appropriate for the classroom. A built-in infrared port lets students "beam" their homework to the teacher's computer within 3.3 feet.
A Comprehensive Solution
NetSchools, a Silicon Valley startup, has fully embraced the wireless paradigm by offering a comprehensive solution for K-12 that includes hardware, software and ongoing training. At the heart of the package is the StudyPro notebook PC, designed to withstand the wear and tear anticipated in everyday school use. The firm provides a notebook for every student, pre-loaded with Microsoft Works and Internet tools; the units communicate to a WLAN via infrared access points in the corners of each room.
The NetSchools Solution also calls for a dedicated server featuring a collection of curriculum software chosen by the school. An Academic Information System (AIS) lets teachers or students monitor their performance anytime. Besides extensive pre-install training, the firm provides a full year of hands-on instructional and technical support.
"For over a decade, educators have looked forward to the day when every student would have their own computer, connected to the world," says Thomas W. Greaves, president and CEO of NetSchools. Costing around $1,600 per student, the NetSchools Solution will be rolled out in select school districts this fall.
Expect to hear even more about wireless computing in the future. Government efforts (and funds) promoting universal access to the Internet should spur demand for WLAN equipment. The Yankee Group, a market research firm, predicts the market for WLANs will expand sixfold to roughly $1 billion by the year 2000.