Infrastructure requirements for schools.
In general, K-12 education did not keep up with the computer and Internet revolution. Two reports by the U.S. Department of Education, National Center for Education Statistics ("Advanced Telecommunications in U.S. Public Elementary and Secondary Schools," NCES 95-854, and "Survey on Advanced Telecommunications in U.S. Public Schools", NCES FRSS 64, 1997) indicate that Internet access to public schools increased from 35% in 1994 to 78% in 1997. However, the 1997 report also indicated that only 27% of instructional rooms actually had access to the Internet.
The need for educated staff with computer technology background became evident as businesses and government upgraded their computer and network systems and required knowledgeable personnel to staff the offices. Additionally, the growth of the Internet and the World Wide Web (WWW) has provided a mechanism for accessing information on various topics and from various sources that could help in the education of students in the classroom. Educators intend to use these resources to address the following requirements:
* Expose students, early in their education, to computer technology in general.
* Provide continent and up to date information to students by accessing data through the Internet and WWW.
* Develop curricula based on access to the Internet and computer applications in general.
* Use computers and the Internet as tools to facilitate teaching and increase interest within the classrooms.
Schools need to have an infrastructure to support these objectives.
As in any project, schools should begin by developing a campus or even district wide plan for their computer infrastructure. Without this initial planning, schools may find -- as did business and government -- that their initial investments and efforts either will fall short of the objectives or will turn out to be a case of throwing money at a problem and not addressing the issue. Without trying to address all project management requirements, the following areas need to be addressed early in the project:
* Project management and administration Schools should have someone to take the lead in planning and following through in the infrastructure development. In many cases, lack of central management will lead to disparate efforts being established within the district that may or may not ultimately meet the school's requirements.
* Determine the school's unique requirements Each school may have different requirements based on local support, funding, or student and teacher requirements. Even a quick review of the requirements may be beneficial in planning the actual infrastructure implementation. User requirements should be paramount in deciding the technology to be used.
* Strategic Plan Schools should develop a strategic plan that will address the long-term goals of the area. The plan should have a clear mission and address the goals and objectives of the school. The plan must have buy-in from the user community and school and community leadership. Once developed, the school and administrators should have a blueprint of the direction the infrastructure should be headed.
* Standardization The school needs to standardize on certain products, technology, or other requirements in order to facilitate the implementation, training, and long term support of the infrastructure. Standardization can address questions such as whether the Macintosh or PC platform is best for the school, or address the server software to be used throughout the campus (Novell or Windows NT).
By instituting an agreed upon framework, the school can monitor its progress in meeting its commonly set goals.
Infrastructure: Wiring the Campus
The basis for the school network is the wiring and cabling infrastructure. Most trouble calls in new network implementations can be traced back to problems with the LAN cabling. This is usually due to the use of low grade wire, poor workmanship, or improper cabling techniques (using two pairs of a four pair cable for voice and two for data). Most of these problems can be eliminated by proper cabling procedures and standards.
Accepted standards for cabling have been published by the American National Standards Institute (ANSI). These publications include the ANSI EIA/TIA 568 and ANSI EIA/TIA 570 standards. The ANSI standards specify minimum wire and fiber specifications to be used for voice and data cabling and include proper techniques for their installation (including distance limitations, wiring room requirements, patch cords, outlets, etc.). Additional ANSI standards describe building requirements for installing raceways for cabling and proper testing of the installations. The use of these standards should be requested when procuring services for cabling installation.
The wiring infrastructure can be divided into three general areas:
* Inter-building backbone cabling,
* Intra-building vertical and horizontal backbone cabling, and
* Distribution to the classroom.
Inter-building cabling requirements vary by school and campus environments. In general, it is recommended that fiber cable be used for most inter-building requirements. Cases for wireless technologies can be made, but are usually site dependent. Fiber comes in several sizes (measured by diameter) and types (multi-mode and single mode). The most common fiber used is 62.5-micron multi-mode fiber, but single mode fiber is used often when distance is an issue.
Intra-building backbone cabling involves all vertical cabling (floor to floor cabling) and horizontal cabling between wiring closets. In planning the wiring infrastructure, the location of the wiring closets is key in properly cabling the building. The use of janitorial closets and other non-secure or environmentally unsound locations may be convenient, but may cause future problems (cable corrosion, tampering, accidental disconnects, etc.).
The backbone intra-building cabling will include a mixture of fiber cable and Category 5 wiring, depending on the individual school requirements. The purpose, of the backbone cabling is to centralize hub equipment in closets and to centralize the horizontal cabling (cabling to the classrooms or workstations) from the classrooms. The backbone cabling should also be planned to allow for network segmentation (dividing users by access needs, divisions, etc.). Segmentation will also alleviate network congestion. Future growth potential and network bandwidth requirements are also a consideration.
The distribution cable from the wiring closet to the workstation, or horizontal cabling, is the last critical link. Due to predicted bandwidth requirements of the future (100 MBPS to the workstation), the common thought was to run fiber to the workstation. It was also widely perceived that if fiber were installed all the way to the workstation, it would be the last time a building would need to be cabled. However, technology enhancements have increased performance and the bandwidth able to be used on Category 5 unshielded twisted pair (UTP) wire. Due to cost constraints and the improved technology on network support equipment, Category 5 UTP is now the standard cabling to the workstation.
Other considerations in horizontal cabling include the number of runs from a wiring closet to a classroom. It is not necessary to have one to one cable to workstation ratio when cabling classrooms. Depending on the need, a single UTP cable can be used to hub multiple workstations in a classroom. It is recommended that more than one cable be run for future use. Additionally, each classroom will have different requirements and, depending on use, may require a one to one cable to workstation arrangement.
Finally, the wiring infrastructure should also consider the electrical power requirements of the building. Basic power needs can be overlooked and can cause circuits to be overloaded. Classroom electrical power may need to be re-cabled in order to address the computer station requirements.
Network Hub Equipment
The network infrastructure includes the hub wiring equipment and servers supporting the networked computers. Ethernet or Token-Ring local area network (LAN) architectures are determined by the wiring hub and network interface cars installed on the computers. It is recommended that schools conform to one of these architectures. Industry continues to standardize on these two architectures and support of other LAN architectures is diminishing. The horizontal cabling connects the workstation to the hub equipment, completing the network loop.
LANs are segmented for traffic distribution and bandwidth considerations. Segmentation is accomplished through the connections to the wiring hubs and is competed either by intelligent software or simple wiring arrangements to the hubs. A typical Ethernet segment may support up to 30 devices, but the amount of devices on a segment varies with the user environment.
There are varied amounts of wiring hub products with ranges on cost and performance -- usually with equipment functionality, performance and manageability improving with costs. Schools should standardize on wiring hubs. Qualities to consider include:
* Central network management and SNMP support (Simple Network Management Protocol -- the TCP/IP management standard),
* Virtual LAN capabilities (assigning of users to LAN segments based on management software, as opposed to actual hard wiring on the hubs),
* Modular growth for expansion purposes, and
* Enhanced features such as switching and routing functionality.
Network servers and the network operating system are the final piece of the internal school infrastructure puzzle. Servers are the brains of the operation and are the means to administer users, manage network configurations and trouble shoot problems in the network. The network servers administer internal and external applications. Among the different server functions, schools will need to address the following areas:
* A network operating system (NOS) to operate the network: NOSs include Novell and Windows NT. User preference and local expertise will help determine the most appropriate platforms for the network.
* Internet mail and domain name system (DNS) server: These functions address, store and forward functions of incoming and outgoing Internet mail and identify the site's Internet mail suffix (example: firstname.lastname@example.org) and translate the IP addresses on the Internet to the proper mail address and vice-versa.
* Web server: The Web server establishes the sites' presence on the WWW. This function can be on the same server as the DNS/mail server or reside on separate servers.
* Departmental servers: Departmental or division servers are usually set up to distinguish an administration server from the educational or student servers. Each server requires a separate NOS. The need for separate departmental servers is an internal school preference or requirement.
Again, schools should standardize on the NOS and server platform for their system, thus simplifying network administration and support.
The local infrastructure needs to integrate into the Internet in order to complete the information access and content requirements. A link to an Internet Service Provider (ISP) is accomplished through telecommunication services provided by the local telephone company. Local ISP services and telephone company limitations determine the type of bandwidth available to the schools.
Typical Internet connections are completed by connecting the LAN to a router. The router serves to translate LAN protocols to the Internet protocol TCP/IP and provides the IP address tables needed to communicate to the Internet. The router is connected to the wiring hub like other LAN devices. Interfacing the router to data communication equipment (DCE) completes the connection to the telecommunication circuit. The DCE varies with the circuit connection, but includes modems (analog circuits), DSU/CSU (for dedicated digital circuits -- T1, Fractional T1 and 56K lines), and NT1 devices (for ISDN lines). The ISP costs and telecommunication costs are both monthly charges that need to be included in the school's budget.
Administration and Support
Finally, no school infrastructure is complete without addressing the ongoing support of the network infrastructure. Besides equipment maintenance and software licensing costs, schools need to support the network and the users by budgeting for staff to maintain the network and train and support the user community. Additional management equipment, such as network analyzers and isolate traffic bottlenecks on the network. Many schools are considering outsourcing these functions instead of competing with private industry for staff.
The network infrastructure described above explains the complexity of the problem that school are addressing. Schools still need to address the workstations and workstation software, network applications such as internal mail and schedulers, and content applications for the students and educators.
Additionally, in order for the infrastructure to fulfill the original goals in the school's strategic plan, the instructors must be trained in using these tools in the classroom, curricula must be developed for the students, and useful content accessed to present to the students. All these components need to be addressed in the original planning for the school infrastructure, in order to ensure a successful implementation.
Eddie Esquivel currently works as a telecommunications specialists for the Department of Information Resources with the State of Texas.
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|Title Annotation:||Technology Tutorial; plan for developing a computer network system for kindergarten through 12th grade education|
|Publication:||T H E Journal (Technological Horizons In Education)|
|Date:||Jun 1, 1998|
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