Emerging Technology:  Networking

 LANS in the Schools

 Additional Information





    Networking has been made available to the general population and is fast becoming a necessity for schools, businesses and homes.  Technology is  developing faster and easier systems that outdistance those of only a year ago, which offer more ease of use for all systems and users.  I have looked through a variety of types of kits being offered at present, and discuss them in the following paragraphs.
 

    Small businesses benefit by being able to share frequently accessed files, databases and documents, while in the home, having a network can mean requiring only one printer, or one modem and phone line to access the Internet.  Children particularly enjoy games that include multiplayer options, and with this technology, they can compete against each other from opposite ends of the house.   In larger applications, educational districts with numerous computers are now better able to take advantage of wireless networking systems.
 

    Among the types of small system networking kits, LAN connection kits can be used for small-office/home-office (SOHO) users.  Home use ethernet kits are capable of connecting two desktop PCs and a printer.  Wireless networking kits employ radio waves, AC current, and telephone lines.  These products typically contain enough hardware to connect two PCs, and allow for additional PCs and peripherals as your system grows.  However, in large systems, such as in schools, internet companies are vying for types of hook-ups, from ethernet to wireless applications.   An article from http://www.solectek.com/tech-center/wp-school.html states:

Educators at
            all levels, from grade school through high school, recognize
            the tremendous potential of the Internet to enhance both the
            content and process of education. It has taken the
            development in two key areas of technology to make this
            new movement possible.

                 1) The extension of the Internet over the past two
                 years has made communication and information
                 that used to be available only to a few, available
                 to most Americans.

                 2) In the schools themselves, computer
                 equipment that used to be found only in
                 computer labs has been moving onto the
                 desktops in other classrooms in all disciplines.
                 Those computers are now being networked,
                 both within schools and between schools.

            However, there is still much work to be done. According to a
            recent survey conducted by the U.S. Department of
            Education, 50% of the nation's public schools have at least
            one computer with Internet access, but more than 90% of
            instructional classrooms are not yet connected. Funding and
            inadequate wiring were the most frequently cited barriers to
            acquiring on-line access.

            While the content and culture of the Internet has been getting
            most of the attention, it is really changes in the infrastructure
            that will bring the Internet to students. Physically, the Internet
            is a vast array of interconnected networks, estimated at
            60,000 in July, 1995. These networks are comprised of
            many millions of computers, connected via phone lines,
            satellite links, fiber-optic cable, etc. .

            Around the nation schools are making or planning to make
            an Internet connection. It is a time of both excitement and
            trepidation for the people deciding what to buy for their
            school districts.

            Although organizations like the National Science Foundation
            have provided some technology grants to schools, getting
            schools on-line has been mostly a local or state initiative.
            That will be changing. The Telecommunications Reform Act
            of 1996 states that, "schools and classrooms... should have
            access to advanced telecommunications and information
            services." The act establishes the National Education
            Technology Funding Corporation (NETFC) which will offer
            financial and other assistance to schools, libraries, and
            other non-profit educational organizations. Schools and
            libraries are now entitled to discounts on services. This is
            the first major change in the nation's basic communications
            law since 1934, and it should increase the deployment of
            Internet and other information services in schools across the
            nation.





    Networking desktop PCs and laptops allows for sharing files, printers, Internet access, and expensive peripherals, such as a removable cartridge or tape backup drives.  In LAN home and small business kits a PC is designated to host the device.  That means for printers, the PC host must be turned on in order to send a job to the printer unless a print server is added onto the system.  The additional software required to share an Internet connection, out of the box comes with the kits from Kingston Technology and Linksys on the ethernet side, and Intelogis, Proxim, and WebGear for non-ethernet.

    In making a choice, Fast Ethernet is more expensive per computer but allows for greater bandwidth, which means you get a wider pipe for data to pass through.  However there are often compatibility problems with other network devices.  Fast Ethernet is the better choice if you're shuttling large graphics, audio, or video files.  Plain Ethernet is good for sharing printers, files, and a 56-Kbps dial-up connection, which is all most homes require.  LAN kits have print and file sharing services built right in, eliminating the need for third party networking software.  The trouble with ethernet is the wires.  If you are connecting several PCs in the same room or in adjoining rooms you can connect by wires, but for separate parts of the house or small business, an electrician is almost a necessity.  The cost of setting up internet facilities through cable was shown in a school where wiring charges seemed prohibitive.  Yet alternatives may prove as costly. http://choices.cs.uiuc.edu/schools/db-roosevelt.html  Systems that use radio waves, electrical power, and telephone lines to transmit data are possibly better choices, for the simple matter of electrical work and extensive cables.  http://www.electronic-school.com/0197f1.html

    Other Ethernet alternatives such as the Intelogis PassPort Plug-In Network and the Tut HomeRun Adapter use power lines and phone lines for LAN.  The PassPort connects the unit to your PC's parallel port and you then plug the adapter unit into a wall outlet.  The HomeRun uses technology similar to DSL (digital subscriber line) to send a data signal on your existing phone wiring. The non-ethernet products also have difficulty in compatibility and use.  There are problems with unified radio frequency networking standards, however newer models of wireless networking kits are presently working out the "bugs."

   Products from Proxim, RadioLAN, and WebGear use microwave frequency radio wave technology to transmit data, also called radio frequency (RF). Though wireless LANs have been a mainstay in some industries for years, high price tags have kept the products out of the SOHO marketplace.  Although Proxim and WebGear are good for homes, RadioLAN is geared more for business or school use and supplies an ethernet performance.  As technology continues to grow in these areas, cost will decrease, allowing high-tech solutions to these problems.
 

LANS in the Schools

http://www.tcet.unt.edu/wlan.htm



     As school districts struggle with how to interconnect local area networks (LANs) that they have in operation at various campuses to form a wide area network (WAN), one viable solution that is not well known is the use of wireless technology. Wireless network bridges, using spread spectrum radio waves or microwaves, can be used to
connect LANs that are separated by as much as 25 miles. Many of the less powerful
bridges, however, may be limited to a range of 2-5 miles.

     These wireless links can provide data transfer rates from less than 1 Mbps to more than 10 Mbps. As one might expect, the greater the link distance capability, and the higher the data transfer rate, the more expensive is the equipment. For example, a pair of bridges operating at a radio frequency of 900 MHz may cost $6000, provide a link distance of 1.0-2.0 miles, and transfer data at 1 Mbps.

     A 2.4 Ghz bridge might cost approximately $5000, provide a reliable link over a
 distance of 3-6 miles, and transfer data at 2 Mbps.

     A microwave link at 31 Ghz may provide a connection over 7-10 miles at 10Mbps (full duplex) for a cost of less than $30000 for the equipment.

     One really attractive feature of wireless connections, and their major advantage, is that  there is a one-time cost for the equipment and installation. There are no recurring, on-going monthly costs! Thus, when compared to connection options that have continuing monthly fees associated, the wireless solution quickly pays for itself.

     The potential drawbacks to a wireless solution include environmental factors. The
terrain may eliminate wireless as an option. Intervening hills and tall buildings or trees  can block the radio frequency (RF) signals. Wireless RF technology is referred to as "line-of-sight". This means that the antennas on the wireless bridge units must be able to "see" each other; there must be no obstacles in the way to block or reflect the transmitted signals.

     Severe weather, such as torrential rains, can adversely affect signal transmission and temporarily down the link. Similarly, the link might be susceptible to other radio
frequency interference. Dense fog could possibly be a problem for microwave links.

     The bottom line: wireless connectivity must be seriously considered if the terrain allows its use. Some reports indicate that microwave links can be more reliable than leased data lines. Below are links to other information concerning wireless computer
networking. The first link is to a site which reports on a National Science Foundation
project designed to demonstrate the usefulness of wireless networking technology in
education.
 
 

Additional Information
For reviews and information on choices including cost and the newest wireless
technology, research the pages below:
http://computershopper.zdnet.com/texis/cssearch/list.html?psearch_term=wireless&searchcat=C0000000
http://www.pcworld.com/top400/article/0,1361,11600,00.html
http://www.zdnet.com/sr/stories/news/0,4538,379552,00.html
http://computers.cnet.com/hardware/0-122333-410-716727.html