We live in an information-driven society. Human activities and institutions increasingly depend on reliable telecommunications and information technology (IT) systems and networks. Many schools and universities are faced with a need to incorporate new IT systems that did not even exist when the schools originally were designed. Accommodating these new technologies demands careful planning for technology infrastructure upgrades as part of any renovation, expansion or new construction program.
Whenever an institution embarks on a construction project, it is an opportune time to take a look at the technology infrastructure and evaluate what can be incorporated cost-effectively into the program. The planning team will need to deal with four key issues:
Evaluate, forecast and prioritize future telecommunications and IT needs.
Determine the nature and capacity of the physical infrastructure, including supporting electrical and environmental systems, that will be needed to support current and future IT system operations.
Evaluate network alternatives, including wired vs. wireless networks.
Plan the space required to build a cost-effective, flexible infrastructure to meet future needs.
Administrators do not need to be IT professionals in order to make sound decisions — ideally, in-house and independent IT professionals will be part of the planning team — but they do need a fundamental understanding of the issues and terminology.
There are many ways to connect a school to the Internet, the school district's central office and other external information resources. In many people's minds, optical fiber is a “must-have,” but this is not necessarily so. Satellite or terrestrial wireless radio, a digital subscriber line (DSL) or an integrated services digital network (ISDN) can be used when fiber is not available and is cost-prohibitive to install.
It can be argued that fiber has advantages over wireless, DSL and ISDN services including speed, capacity and reliability, and it is wise to plan for its eventual installation. However, it is not the only effective solution in the school environment. A planning team should consider all of the options and identify the most cost-effective approach for a school's specific and most immediate needs.
Networking and convergence
Once the information has been delivered to a building, it needs to be distributed to end users. Traditionally, standalone systems have been employed for educational and administrative applications. If there were a small data network, it probably served only the administrative offices. Now the trend is to integrate educational and administrative systems into a single data network throughout the facility to enable data sharing.
Just as individual data applications are starting to converge into a single network, technologies that we once thought of as separate entities also are converging. The best examples are the mergers of voice, data and audiovisual technologies. Separate AV networks and systems seldom are built anymore, and telephone and data applications often are being integrated into common networks as well. Separate PBX-based telephone systems are still reasonably common, but telephone services will be integrated into the data network in the future.
Most future voice, data, video and audiovisual services will be integrated and delivered over the same network within school districts and throughout individual schools. It is prudent to plan for this integration by physically consolidating PBX, data and audiovisual common equipment in the same equipment rooms and designing network infrastructure robust enough to support this migration.
There are three basic types of networks for delivering information: point-to-point, circuit-switched and packet-switched. A point-to-point network is simply a permanent, hard-wired arrangement connecting two or more locations. These networks are costly, inefficient and inflexible, and are rarely installed today. Circuit-switched networks are a telephone legacy, but can be used for data and video transmission. They provide a temporary point-to-point connection between two or more points.
A certain bandwidth is occupied while that circuit is open, even if no voice or data is being exchanged, and the bandwidth is not available for use by any other data. While more efficient and cost-effective than point-to-point networks, circuit-switched networks still are considered expensive and outmoded.
In contrast, a packet-switched or “connectionless” network has no physical or real-time connections among its end points. This type of network takes all forms of information, whether it is a picture, sound, mathematical formula, data or e-mail; breaks that data into small “packets;” adds a destination address; efficiently moves the packets around the network using whatever path is available; and reassembles them at the destination into the original format. This all happens in fractions of a second and appears to the user to be instantaneous.
The Internet backbone is an example of a packet-switched network. It is becoming the standard for all data and converged data, voice and video networks. Any new network infrastructure should be designed to support current and future packet-switched technologies.
There are several levels of network geographic coverage, each serving a different purpose. The school's infrastructure should accommodate a wide area network (WAN), which links the school with distant resources including the Internet; a metropolitan area network (MAN), which links resources or sites within a school district or community, that is, covering only those sites within its own area of interest; and a local area network (LAN), which links users and resources within the school building or campus. Traditionally, there were multiple, separate data LANs. Increasingly, schools are integrating these into a single LAN.
Personal area networks (PAN) link devices within a very small radius of a central device, such as connecting a PC with its peripherals in a classroom, or musical instruments and headphones in a music practice room. This is accomplished by using either a universal serial BUS (a multi-port device with the same kind of connectors) or wireless technology. This is not an essential form of network coverage today, but schools may want to consider it in the future.
Network physical media
There are several options in network physical media, that is, the hardwired connections within the school building or campus.
Category 5E cable, the current performance standard of unshielded, twisted-pair (UTP) copper cable, has been in use in higher-education facilities for some time; increasingly it is being considered for K-12 facilities. Although Category 5E cable is somewhat more costly than lower-performance cables, it should be considered for school installations for three reasons: it offers high performance; it can be adapted electronically to carry all types of information including voice, data and video distribution; and today's applications are being developed to the Category 5E standard. Alternatives like Category 6 UTP and fiber promise even higher performance than Category 5E, but their extra cost and complexity rarely are justified in a K-12 environment. In a small school with just a few servers, data can be distributed to every location within the school on Category 5E cable. However, Category 5E cable can be used only where the server or nearest switch is less than 90 meters (295 feet) from the destination.
A large building requires a number of intermediate distribution facilities (IDF) housing packet switches. If the maximum Category 5E cabling distance is exceeded, optical fiber may be used to get that data from a server to an IDF; from there, Category 5E cable can be used to reach each location.
A common misconception is that wireless technology will replace the entire wired infrastructure; instead, it is evolving as a supplement to that infrastructure. Today's LAN wireless technology really does only one thing — it replaces the piece of wire between the computer and the wall. The entire wired network infrastructure behind the wall is still necessary. Wireless simply allows the user to unplug from the wall and have more mobility. It also allows several users to share the same wireless connection, but at the cost of having to share the same limited bandwidth.
Thus, in the classroom, wireless technology allows a group of students to work together in peer-to-peer mode, sharing files and data among a number of computers. It also can work in a traditional client-server mode, allowing students, teachers and administrators to get on the LAN with their laptops.
When space planning for renovation or expansion, plan for equipment spaces to house and maintain file servers, which are the heart of today's networks, and the legacy PBX and audiovisual systems that eventually will integrate into the data network. These Server-PBX rooms require adequate security and 24-hour climate control, although today's servers are not as sensitive to heat and humidity as the old mainframes. Also consider floor loading and fire protection.
Because of the cost benefit, it rarely is recommended that schools install an uninterruptible power system (UPS) or a generator to back up their networks. It may be appropriate to provide enough backup to allow the server to go through its standard shut-down procedure in the event of a power outage, and this can be provided cost-effectively. Several backup phone lines can be provided for emergency communications.
Schools also need space for a small room or steel cabinet to house the service entrance facility. By code, this facility must be isolated from the interior of the school building because of the types of materials comprising outdoor fiber and cable. From the service entrance facility, service is routed to the Server-PBX room using the appropriate indoor cable or fiber.
Plan for adequate network spaces and pathways to route cables from the Server-PBX room to individual network devices. Network pathways can be as simple as a space in an accessible ceiling or a dedicated set of conduits or cable trays. Multi-floor school buildings also require a riser pathway comprising one or more 4-inch sleeves between floors. The key planning considerations are that the pathways provide capacity for additional service in the future — that they are filled to no more than 40 percent of their available capacity — and that they remain accessible for maintenance and future upgrades.
An appropriate use for wireless technology is where a school can't afford to wire for every possible device that may come on line in the future. For example, a classroom may have a single computer terminal or smart board with a single connection to the network. One day the school receives a grant for 12 more computers in that classroom, but there still is only one connection.
To prepare for such an event, the school can be “wired for wireless.” An extra network cable is installed at the ceiling to accept a wireless access point (WAP) — a relatively inexpensive radio transmitter box — in the future. The WAP wirelessly connects a number of computer devices in the room to the LAN.
Building in flexibility
Throughout the planning process, try to build in as much flexibility as possible. First, comply with current telecommunications cabling and infrastructure size, performance and capacity standards; installation of Category 5E or 6 cables and the 40 percent capacity standard for cable trays are just two of these standards. If the school follows these standards, it will get the most for its dollar because future network devices are being designed to work on the standard network infrastructure. (At the same time, avoid an agreement with any vendor that proposes building an infrastructure for its proprietary network and devices.) True, the institution will spend a little more today, but it will gain capacity, performance and flexibility in the future. It's not quite futureproofing, but it's a good start.
Consider alternate uses of space in anticipation of future expansion. Even if the school cannot afford a network today, allocate a suitable space for a future server room and its cooling system. For the time being, perhaps, the space will function as a storeroom or small meeting or prep room. Also allow for network spaces and pathways. If a ductbank is being installed to bring in copper telephone-based services, plan to add an empty subduct or pipe in which to run optical fiber in the future.
Laying the groundwork for a fast, efficient information technology system is not as complicated as it first seems. The most important thing is simple and straightforward: if there is only a dollar to spend, spend it on the infrastructure. Once the school is on a solid foundation, it can run an application to solve virtually any problem and meet virtually any educational or administrative need.
There are several levels of network geographic coverage, each serving a different purpose. They include:
The Wide Area Network links the school with distant resources, including the Internet.
The Metropolitan Area Network links resources or sites within a school district or community, that is, covering only those sites within its own area of interest.
The Local Area Network links users and resources within the school building or campus.
The Personal Area Network links devices within a very small radius of a central device, such as connecting a PC with its peripherals in a classroom, or musical instruments and headphones in a music practice room.
Bjornsen is principal with Cerami & Associates, a New York City-based IT, audiovisual and acoustics consulting firm.