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November 1, 1999
Technology Design Options for School Projects
By Jeffrey A. Lupinacci
When a school district seeks to address the technology needs of its staff, faculty, and students, many systems must be investigated, including voice, data, video, paging, and security. Each system has many types of products that have been designed to meet a specific situation. As the old adage says, "There is more that one way to skin a cat." Each district will have unique needs and processes, so it is essential to find the right mix of equipment and services.
Districts sometimes decide to hire a consulting engineering service. What are the advantages? See "Why Use a Consulting Engineering Service?" to understand what some districts see as benefits.
Unfortunately, outside vendors often sell customers the products the vendors have on their shelves, not the products that best meet their customers' needs. The best way to protect your limited funding is to understand the options available to you. What follows are some of the technology needs and common solutions that face school districts today. A basic understanding of the systems allows you to select the right size and type of products for your individual operation.
VOICE SYSTEMS
The best options for voice systems, of course, depend on how a school and district want to handle their calls. A single operator, for example, screens all calls; other systems allow direct phone access to different individuals.
Interbuilding communications can affect the choice for voice equipment. Some districts cross the boundary that is covered by the local telephone provider's central office. This means that different pieces of equipment for the same telephone company service the various buildings in a district, often resulting in toll calls between buildings.
The variables for each school or district must be evaluated before a selection is made. The right solution may include mixing different components in order to meet all of the district's needs.
Option 1: Centrex Service
Centrex service uses individual lines from the local telephone company. Each line may be digital or analog. Centrex telephones provide many station features that allow users to process calls. Optional services are available, such as voice mail and hunt groups, but these have additional monthly costs. This option has the lowest up-front costs, but the highest recurring costs.
Option 2: Key Telephone System
A key telephone system provides more station features than the Centrex service for station user call processing. Optional services may include voice mail, direct inward dial (DID) service, hunt groups, multiple line appearances, and easy in-house communications, but each has an additional cost up front. Each line may be digital or analog. The number of lines from the local telephone company would be less than a Centrex environment because users share lines between specific stations. This option will result in moderate up-front costs, but lower recurring costs.
Option 3: Private Branch Exchange (PBX) Telephone System
A PBX telephone system provides the most station features available for station user call processing. Additional services may include private voice networking between buildings, voice mail, DID service, hunt groups, multiple line appearances, easy in-house communications, and automatic least-cost call routing; again, each may have an additional up-front cost. Each line may be digital or analog. The PBX system offers the most flexibility in modifying and customizing system performance based on users' needs. The number of lines from the local telephone company would be less than a Centrex environment because users share lines throughout an entire system. This option will have higher up-front costs, but reduced recurring costs and the greatest degree of control available.
DATA SYSTEMS
Data communications systems can vary based on the types of applications used by a school and district. Most districts provide services for administrative personnel, faculty members, and students.
The administrative network carries information on budgets, finances, payroll, contracts, schedules, grades, attendance, maintenance, correspondence, Internet access, and so forth.
Similarly, the faculty network carries information about grades, attendance, lesson plans, schedules, tests, test results, correspondence, research, Internet access, and so on.
The student network carries information on extracurricular activities, schedules, assignments, correspondence, research, Internet access, and so on. This network may often be used by users other than students and be accessed from outside the school-for example, from a public library. This network is the most vulnerable to data and system corruption.
Many issues must be reviewed when deciding from between or among options. Who will maintain and support the users? What are the users' skill levels, age levels, and computer literacy levels? What is the district's strategic plan for technology? The lines among these options quickly blur, and a variable mix of technologies frequently results.
Option 1: Stand-Alone Workstations
Stand-alone workstations allow only access to one person at a time. They have the lowest up-front costs but limit the information that can be accessed.
Option 2: Local Area Network (LAN)
A LAN will allow all the users in a building to access common information and applications. Many types of LANs are available, depending on the equipment and application programs users need to access. Some of the most common LANs use 10Base-T (Ethernet), 100Base-TX (Fast Ethernet), 1000Base-T (Gigabit Ethernet), Token Ring, FDDI (Fiber Distributed Data Interface) and ATM (Asynchronous Transfer Mode). These may run on copper cables or fiber-optic cables, depending on the distances involved. By definition, a LAN is local to a building or campus. This type of data-networking system has a moderate cost, but it expands the abilities of each user to access more than the limited amount of information available on a single PC.
Option 3: Enterprise Network
An enterprise network is a LAN that exceeds can reach other campuses within the organization or other services around the world. Accessing these other places and services can be done through equipment such as routers, switches, bridges, gateways, and modems. The communications paths may include private networks, virtual private networks (VPNs), public switch telephone networks (PSTNs), and satellites.
VIDEO SYSTEMS
Video systems are like data systems: They quickly become a mix based on user needs. Multimedia has infiltrated the education field in many ways, including community antenna television (CATV), satellite stations, VCR and DVD recordings, PC presentation programs as curricula, and so on.
Option 1: Traditional Video Use
Traditionally, a moving cart with VCR and monitor has been pushed from room to room as needed. CATV feeds are often placed in a limited number of rooms by the local cable-TV company for free. This is an inexpensive option, but it does require resource scheduling and legwork.
Option 2: In-House CATV System
An in-house CATV system allows for many channels to be sent to each room. The head-end equipment for this video network may include video sources such as DVD or VCRs. The system may have the ability to broadcast user-originated video presentations. Individual locations are equipped with TV monitors and wall-mount brackets. They may also have VCRs or scan converters. This design has a moderate up-front cost, but it is highly flexible and simple to use.
Option 3: Media-Retrieval System
A media-retrieval system uses an in-house CATV system to transmit video signals, and it has many additional features. This system allows on-demand selection and control of various video sources from the classroom. The TV monitor location has an interface unit that communications with a controller at the head end. The user can start, stop, review, and search through a video recording. Scheduling on-demand playback of recordings is also possible. This system is the most complicated and expensive for up-front costs, but it offers great flexibility, giving the user control over a centralized, shared resource.
Option 4: Multimedia System
In large-group instruction (LGI) or auditoriums, LCD projectors often are installed and integrated with the remote sound system that serves that room. This can provide a front-end control system that is integrated with the lighting controls, projection screen controls, and all sound and video sources.
CABLING SYSTEMS
Based on the options chosen for voice, data, and video systems, the cabling system should support them and allow for growth and the addition of new applications are expected in the future. A well-designed cabling system should be flexible enough to allow reconfiguration as required.
Voice Cabling
At a minimum, the cable used for voice applications should be Category 3 unshielded twisted pair (UTP) cable. This is based on standard industry practice. More often, all rooms are cabled for a minimum of one voice connection to allow the instructor to communicate privately with other faculty members, administrators, or parents.
Data Cabling
Cable used for data applications can be selected from a great number of options. It should allow for the greatest flexibility and bandwidth for all anticipated applications and beyond. A minimum of Category 5 UTP cable should be installed in accordance with standard industry practice. Other options may include fiber-optic cable, shielded twisted pair (STP) cable, and Enhanced Category 5 cable. Rooms should be cabled for at least the instructor and more often for a computer work center in the room. Computer labs are also densely cabled for the increased number of connections that are expected in that environment. Other areas that should be considered for data communications cabling, even if not expected for use now, would be conference rooms, auditoriums, gymnasiums, and the cafeteria. These types of connections become critical during course registration, presentations, large-group instruction, sports reporting, and so on.
Sound Systems
Sound systems vary in their ability from addressing everyone in the building through a public-address (PA) system to addressing individuals through an intercommunications system. The system also may incorporate clocking and sound signals, sound sources such as CDs, cassette tapes, and radios. If a voice system is used in the building, the system is usually interfaced at minimum for an "all page," or it can be configured to allow two-way communications with an individual room or zone with a DTMF telephone touch pad. Systems may be monaural or stereo.
Option 1: Clocking and Single-Zone Paging
The system can be used to synchronize all of the clocks in a facility and provide period tone signaling through all speakers. A single point of announcement can send voice pages to all speakers. Sound sources may be included to broadcast to all speakers.
Option 2: Clocking and Two-Way Zoned Paging
The system also can be used to synchronize all the clocks in a facility and provide period tone signaling through all speakers. A single point of announcement can produce voice pages to all speakers, or a single room or zone can be accessed individually for two-way conversation. Sound sources may be included to broadcast to all speakers.
Option 3: Clocking and Two-Way Zoned Paging with Telephone System Interface
The system can be used to synchronize all the clocks in a facility and provide period tone signaling through all speakers. This system allows users to make announcements from any location to all speakers or to access a single room or zone for a two-way telephone conversation. Sound sources may be included to broadcast to all speakers.
Option 4: Remote Sound System
A remote sound system allows the broadcasting of sound from or for a presentation or recorded source. The system can be stereo or monaural. The system may be interfaced with the main sound system to broadcast emergency messages or to share the presentation with other areas of the building. Sound sources are usually included for broadcast to all speakers in a specific area.
SECURITY SYSTEMS
Security is more that an electronic system. It encompasses procedures and equipment that will protect people and property. The amount of security that is desirable is based on the value of the items being protected, the purpose of the space, the number of people who enter this space, and their reasons for doing so.
Option 1: Intrusion
A security system can be installed that will notify a central site in the event that a door is opened, a window is broken, a person has entered, a fire is burning, and so on. This type of system must be specifically designed with the building's physical properties in mind. The up-front cost is reasonable, and the recurring costs of monitoring are quite low.
Option 2: Access Control
This system can incorporate all of the features listed above, as well as to restrict or limit authorized building occupants from specific areas during specific times. This system can act as a time clock for people, and it can reduce losses from district personnel. This system requires the issuance of access cards that are programmed into a computer to allow or disallow access to individual cardholders. This system can be augmented with keypads or biometric authentication devices. Both up-front and recurring costs for such a system are moderate. Monitoring and some supplies and maintenance of the system are required.
Option 3: Surveillance System
A surveillance system consists of cameras and gear that allow one to view areas that have historical problems with safety or loss such as computer rooms, entrances, public corridors, and loading docks. The images from the closed circuit television (CCTV) system can be recorded but provide the best protection if they are monitored live. The cost depends on the number of areas that are to be protected and the viewing and recording quality required. This system can quickly become expensive.
SUMMARY
All of the systems that are described above are just tools to be used to get the desired results. Do not expect that an electronic system will solve all problems or be the panacea that will make people more effective. In many cases, the least expensive system will adequately meet your current expectations.
Getting the right mix of products for a specific environment and set of issues is the reason for hiring a consulting engineer. If you do hire such a consultant, then be sure to provide all of the information you can about your current and future building plans, applications, existing equipment, existing processes, preferences, and so forth. The ultimate responsibility for all technological systems rests with the customer, so comment early and frequently about the designs. Trust that the consulting engineer is working to meet your needs.
E-Mail: Jeffrey Lupinacci
RCDD/ LAN Specialist,
Senior Telecom Designer
Brinjac, Kambic & Associates, Inc.
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