NetworkingGuidelines..

Information & Guidelines

on

Networking in Schools

Version 1.0

Issued by

National Centre for Technology in Education (NCTE)

Date: Dec’ 1st 2003

NCTE Guidelines for Schools Networking 1

1.0 Introduction

These guidelines should be read in the context of the letter of 8 th December 2003, from the Department of Education and Science, (DES) and in association with the NCTE Advice and Planning Pack issued to schools in 2002.

An extract from the DES letter of Dec 8 th reads as follows: “There are several practical advantages to having a school network, including shared access to files, software and other resources, centralised administration systems and shared access to the internet, printers, scanners and other devices. Accordingly, it is recommended that school authorities should give priority, where relevant, to achieving improved levels of networking of computers within the school and that grants should be primarily used towards this goal. For more information on networking, please consult with the ICT Advisor in your area or refer to the networking section of the NCTE website at www.ncte.ie/networking ”

The guidelines are not meant to be a complete guide to all aspects of networking but rather as a support to schools in planning the next stage of the local network in their school.

Other related objectives of this document are: to assist schools in understanding the benefits of networking to help schools place in context the current stage of the development of their local school network to provide standard networking ‘models’ and best practice to schools which will assist schools in

the next stage of planning their network.

This document includes information under the following main headings: Networking Models – Towards a networked school Example network configurations Costs of Networking Cabling Guidelines and recommendations: Basics of school Networking Types of Networks Advantages of Networking Some relevant terms.

Having reviewed the document schools requiring further advice should consult with their regional ICT Advisor whose contact details may be found on the NCTE website at: http://www.ncte.ie/ICTTraining/AdvisorNetwork/

During 2004, and in addition to this document further information/resources relating to networking will be added to the NCTE website at http://www.ncte.ie/networkingFor latest NCTE information schools are advised to consult this section of the website when they are undertaking an upgrade of their local school network.

Note: School Administration Network and General school networkThis document focuses primarily on the general school network rather than the specific requirements of th administration network within a school. The two areas are of course related and there are opportunities to apply a more integrated approach such as combining internet access, setting up different workgroups, or virtual local area networks etc. This area is not covered in the document and will be covered either as an update or in a separate Guideline in 2004.


http://www.ncte.ie/networking

http://www.ncte.ie/ICTTraining/AdvisorNetwork/

http://www.ncte.ie/networking

1.1. Networking Models: Towards a Networked School This model (fig 1) shows a simplified diagram of a networked school indicating the various types of networking models used. These include computer rooms, networked classrooms, and networked specialist rooms for specific subjects. Mobile networked solutions are shown in the Resource room, the General Purpose room and in Building 2. Note: To improve readability, only the network points are shown here, rather than cabling itself.

Main School Building

Fig 1: Representation of a Whole School Network Model

NCTE Guidelines for Schools Networking

Technology RoomPost

Primary

Science Labs Post

Primary

Principals Office

School Admin Office

Standard

Classroom

s

Computer roomwith 15-30 computers

General Purpose Room

ICTServer &

Equipment Room

Store Room

Standard Classroom

Standard Classroom

Standard Classroom

Standard Classroom

Standard Classroom

Standard Classroom

Standard Classroom

Standard Classroom

Specialist RoomPost

Primary

Building 2Temporary Pre-Fab- Wireless Network

Building 3

Staff Room

Wireless link to Building 2

Specialist RoomPost

Primary

Resource Room

4

Fig 2: Typical Network Model for a Primary or Special school.Figure 2 shows a network model for a Primary or Special school. This includes connectivity to all classrooms to a local area network (LAN). The network connects to a File and Print Server. Internet access is handled via a modem or router, while Web Caching and Proxy service are all handled via a dedicated server.

Fig 3: Typical Network Model for a Post Primary school.

Figure 3 shows a model for a Post Primary school. This includes connectivity to all classrooms back to a central network. The network connects to a File and Print Server. Internet access is handled via a modem or router, while Web Caching and Proxy service are all handled via a dedicated server.


1st Class# of computers

Senior Infants # of computers

Junior Infants # of computers

2nd Class# of computers

6th Class# of computers



3rd Class# of computers

Resource room# of computers

School ‘Local AreaNetwork’ (LAN)

Principal/Office Staffroom# of computers

File & Print Server

Cache, Proxy, Server

Modem or Router / Firewall

Access to:Internet content & learning resources, Scoilnet etcEmail communication

Principal/Office # of computers

Staff room # of computers

computer room # of computers

specialist room# of computers

standard classroom# of computers

resource room# of computers

technology lab# of computers

science lab# of computers

Library# of computers


File & Print Server

Cache/Proxy, Server

Modem or Router / Firewall


5

Fig 4: Server Functionality Model

Server Functionality (Fig 4)The network connects to a file and print server. The ‘file server’ stores common files, while the ‘print server’ manages the different requests for printing. A multimedia or CD server is used to store and distribute Multimedia - sound, video, text learning applications. Internet access is handled via a modem or router, while while Web Caching and Proxy service are all handled via a dedicated server.

Example network configurations:

Models for Networking First let’s review some simple models where no networking exits and where computers are used in standalone or ad-hoc mode. The following represent some simple models representing classrooms.

Model 1a: One computer in a classroom with its own private printer. It is recommended that schools with computers in this situation would network the classrooms in question as shown. Networking will more effectively make use of commonly shared resources such as file servers and school printers, internet, email etc. When a mobile PC or PC with projector is require in a room the network points are already present.In this scenario, there could be a single LAN-connected point for the teacher and an additional LAN connection to allow for a portable switch. Model 1a

Fig 5a: From single PC to networked LAN Points


File & Print Server

Cache/Proxy, Server

Modem or Router/Firewall


Multimedia or CD Server

Printer

Scanner

To Network

Main Servers & Internet Access

6

Model 1b: This scenario is similar to Model 1a, but where other equipment such as printers, scanners are used in ad-hoc and inefficient configuration. It is recommended that schools with computers in this situation would network the relevant classrooms. Networking will more effectively make use of commonly shared resources such as scanners, printers, internet, email etc. In this scenario there may be a single LAN-connected point for the teacher and some LAN connection points in the room to allow students access to the school LAN. The connection points may be situated as required around the room depending on the specific purpose that the room is used for.

Model 1b:

Fig 5b: Networking other commonly used equipment

Networked Computer RoomModel 1c: A non networked computer room or resource area with an ad-hoc and inefficient use of printers, scanners etc. A networked computer room is essential so that all PCs can access common resources such as file servers, printers, the internet, email etc. This scenario represents a school computer room which can be timetabled for classes, and with each computer networked to the LAN. There may be a single LAN-connected presentation point for the teacher and LAN-connected computers throughout the classroom for pupils. Traditionally, ICT in Irish secondary schools has been concentrated in dedicated computer rooms, which is attractive as an entire class can receive hands-on computer use. Primary schools usually have more varied deployment.

Model 1c:

Fig 5c: Networked computer lab.


Media Bays (Ref Fig 6a)Mobile Media bays, or data suites are clusters of about four desktop computers, and often including a scanner and printer which can be moved (usually on a trolley) to particular areas or classroom in the school as required. Though self-sufficient in terms of peripherals, once they are moved to a networked classroom they can be plugged in to the local school network and thus avail of the use of common resources such as file servers, internet access etc. They can be used by teachers or pupils either individually or in small groups and could accommodate both task-oriented activities and self-directed learning.On of the advantages of Media Bays is the flexibility they facilitate, allowing resources to be moved quickly to classrooms or other school areas as required. If the Media bay includes a small hub or switch connected as shown, it requires only one network connection to connect all elements to the network.

Fig 6a: Movable or mobile Media Bays with one network connection

Laptop and Data Projector (Ref Fig 6b)A combination of laptop and data-projector is a highly effective teaching solution model where a teacher wants to provide the whole class with visual or multimedia content. It can be used in conjunction with an existing LAN point in the room for best effect. By connecting to the network the whole class can access content from the internet etc.

Fig 6b: Movable or mobile Laptop PC with Digital Projector

Wireless LAN (Ref Fig 6c)A Wireless LAN solution has the capability to connect multiple computers to the school LAN without providing direct LAN connections between the computers and the network. No LAN cabling is required for the classroom; instead all computers are radio linked to the LAN. Wireless LAN technology is relatively new and generally more expensive and more limited than standard cabled LANs. Wireless LAN data rates are typically slower than CAT5e LAN cabling. There is the potential, however, to save on cabling a particular school area by using the wireless option.


Wireless connections allow a region to be connected to a network by radiowaves, which link a wireless card in the computer to a wireless access point. One should remember that the access point itself must be connected by cable to the local school network for the solution to work.

Advantages Flexibility of setting up networks - a network could be quickly set up, this may be especially

appropriate in a situation where the network needs may change in the future, and where the cabling investment might be lost if further building changes were required.

Wireless networking means that large common areas such as school canteens or libraries can be easily connected to the network.

Disadvantages Wireless networking may prove more expensive if wiring large numbers of computers which are

close together, as is the case in a computer room. Generally in this case it is best to cable the computer room rather that use a wireless network.

Wireless access point data rates of 11Mbps are considerably less at present than their cabled equivalent and thus is unsuitable for high data volumes such as multimedia access by large numbers of machines, however newer 54Mb/sec data rates are available which can better support multimedia.

Manufacturers stated ranges of 100 - 300 metres do not work satisfactorily in practice expecially where walls exist between the points in question. Ranges of less than 18 metres are not uncommon. Data rates drop off as distance increases. Concrete or block walls will also affect whether wireless will operate effectively in a particular school environment. Where older thicker walls are in place, this makes it more difficult if not impossible to deploy wireless networking.

There are security implications of using a wireless network, such that it may be possible for a external party to access the school network using certain equipment. If the nature of the data is sensitive and not to be viewed by external parties then the school should seek advice from in terms of the solution to be deployed, especially if the data if either sensitive or important.

While it is unlikely that wireless will replace data cables in the near future they do provide a flexibility that can be harnessed creatively.

Fig 6c: Wireless LAN (WLAN)


1.2. Costs of Networking:The costs of networking a school or a section of a school can be better understood by reviewing the items that contribute to the costs. Indicitive prices are outlined in Tables 2 -6 as a guideline, though these will vary. Professionally installed structured cabling to CAT5e standard is assumed, as anything of a lesser standard will generally cause problems, or have to be upgraded as schools needs change. Every school building is different with some local or particular requirements, so the table gives approximate costs for a single building situation. The outlined costs do not include the costs of PCs, Servers, Software etc. VAT applies at 21% for equipment and at 13.5% for services. Installation is a service and as such should have the appropriate VAT rate included.

Networking ComponentPrice

(ExVAT)Comment

Cabling (to Min CAT5e standard)

Cabling per network point €100-160Includes CAT5e cable, Installation, Patch leads, Device leads, trunking, Patch panels, Testing and Certification (includes cable and service)

Wall Cabinet €20015U (ie 18 inches high) Wall Cabinet is used to house/protect cables/patch panels

Standard Networking (ie Wired networks)

Standard Network card €20-50Installed in each PC to allow connection to the network

Wireless Networking (11 or 54Mb/sec) NCTE recommend using the newer 54Mb/sec version

Wireless PC Card €50-100Installed in each PC to allow connection to a Wireless network

Wireless Access Point (or Basestation) or Wireless Router

€350-600A Wireless Access Point communicates with Wireless PCs

Switches/Hubs

Switch (24 port) €250-500Switches rather than Hubs are recommended for connecting PCs

Hub (8 port) €40Hubs are older technology which are not generally recommended in the main local area network

Table 1: Network Components typical pricing for a school single building

Example 1: Large Post Primary School with 800 pupils want to add a new computer room with 30 networked computers, ie 30 networked points.

Networking a computer room with 30 points

QtyUnit Cost

Totals (ex

VAT)Cabling per network point 30 €150 €4,500Wall Cabinet 1 €240 €240Standard Network card (one per PC) 30 €35 €1,050Switch (24 port) 2 €400 €800Totals €6,590

Table 2: Networking a new computer room with 30 networked computers


Model Pricing to network one classroom/office with 2 network points.This table gives an indication as to what it would cost to network just one classroom. The model is provided so that schools can use it as a base

Network 2 Classrooms (with 2 network points per classroom)

QtyUnit Cost

Totals (ex

VAT)Cabling per network point 4 €160 €640Wall Cabinet 1 €240 €240Standard Network card (one per PC) 2 €25 €50Switch (24 port) 1 €400 €400Totals €1,330

Table 3: Networking one room with 2 network points

Example 2: Large Primary School with 350 pupils want to network an additional 12 classrooms with 2 networking points per classroom.

Network 12 Classrooms (with 2 points network points per classroom)

QtyUnit Cost

Totals (ex

VAT)Cabling per network point 24 €160 €3,840

Wall Cabinet 1 €240 €240Standard Network card (one per PC) 24 €25 €600

Switch (24 port) 1 €400 €400Totals €5,080

Table 4: Networking 12 rooms with 2 network points each

Example 3: Large Post Primary School with 800 pupils want to add a wireless network of 24 PCs to the science lab.

Add a Wireless Network of 24 PCs to the Science Lab

QtyUnit Cost

Totals (ex

VAT)

Cabling per network point (for Wireless Access Points)

3 €150 €450

Wall Cabinet 1 €240 €240Wireless PC Card 24 €75 €1,800

Wireless Access Point 3 €500 €1,500

Switch (24 port) 1 €400 €400Totals €4,390

Table 5: Networking a Lab with 24 wireless accessible points3 wireless Access points are used in this example to increase the bandwidth per access point, however 2 or even 1 wireless access point could be used but with the limitation of reduced bandwidth of 11Mbps for the whole lab.


Cabling Guidelines and recommendations:Cabling Recommendations:Structured cabling to be used throughout. All network points to be terminated on patch panels A minimum of CAT5e to be used, Cabling to CAT6 to be used for all new installations All cabling to be fully tested and a formal certification signoff to be obtained from the supplier. Cabling to be carried out only by qualified personnel.

Number of Networking Points required: (ref DES Building Unit Guidelines)This section details the approved provision of points for the various rooms and areas in a school and the approved density. All teaching and habitable rooms should be networked. Each of these rooms should have two networked points at appropriate areas. In specialist rooms other I.T. points are to be provided as indicated and these shall be networked through a local switch or to the MDF or IDF which ever is the most economical.

Table 2 below gives recommended number of network points to be included for various room/spaces. These recommendations may change so please do consult the NCTE website to check the number of recommended network before finalising your network, or expansion.

Local Area Network (LAN) Points.TPNP = Teacher Position Network Point. SPNP = Student Position Network Point.NP = Network point in non-teaching Spaces.

Type of Room/Space. Network Points.

General Classroom 1 TPNP + 4 SPNP (distributed around room)Computer Room 1 TPNP + 30 SPNP

2 student printer NPScience Laboratory Preparation Area 1 TPNP + 6 SPNP Lab.

1 NP Prep. Area.Learning Support Room 1 TPNP + 6 SPNPLanguage Room 1 TPNP + 4 SPNPMultimedia Learning Laboratory 1 TPNP + 30 SPNP +

2 student printer NP.Physics Laboratory Preparation Area 1 TPNP + 6 SPNP Lab.

1 NP Prep. Area.Art/Craft Room & Store 1 TPNP + 6 SPNPHome Economics 1 TPNP + 4 SPNPWord Processing/Keyboarding Skills Room

1 TPNP + 30 SPNP +2 printer NP

Business Studies/Commerce 1 TPNP + 4 SPNPTechnical Graphics /Cad 1 TPNP + 6 SPNPConstruction Studies/Wood Technology Room

1 TPNP + 6 SPNP

Technology Room. 1 TPNP + 6 SPNPWood/Technology Machining & Prep area 1 NPEngineering/Metal Technology Room 1 TPNP + 6 SPNPLibrary & Ancillary Stores 100 m2 1 TPNP + 8 SPNPLibrary & Ancillary Stores 136 m2 1 TPNP + 11 SPNPPrincipal’s Office. 2 NPDeputy Principal’s Office. 2 NPGeneral Office. 30 m2 3 NP + 1 printer NP.General Office. 20 m2 2 NP + 1 printer NPStaff Room 2 NP 200 – 499 Pupils

4 NP 500 + PupilsMeeting Room 2 NPP.E.Hall / PE Balcony 1 NP in each


Music/Drama Area 1 TPNP + 4 SPNPGuidance Suite: (1 classroom +1 office)

1 TPNP + 4 SPNP1 NP office

Social Studies Room 1 TPNP + 4 SPNPHome School Community Liaison. (Classroom + office)

1 TPNP + 4 SPNP1 NP office

Religion Room, Meditation Area Chaplain’s Office

1 TPNP1 NP office

Table 6: Local Area Network (LAN) Points

1.3. Basics of Networking A computer network consists of a collection of computers, printers and other equipment that is connected together so that they can communicate with each other (see Advice Sheet 17 on the ICT Planning for schools pack). Fig 1 gives an example of a network in a school comprising of a local area network or LAN connecting computers with each other, the internet, and various servers.

Fig 7: Representation of Network in a school.

Broadly speaking, there are two types of network configuration, peer-to-peer networks and client/server networks.

Peer-to-peer networks are more commonly implemented where less then ten computers are involved and where strict security is not necessary. All computers have the same status, hence the term 'peer', and they communicate with each other on an equal footing. Files, such as word processing or spreadsheet documents, can be shared across the network and all the computers on the network can share devices, such as printers or scanners, which are connected to any one computer.



Modem or Router


Cache, Proxy, Filtering, FirewallServer

Userscomputers

Other users, computers

File and Print Server CD or Multimedia ServersPrinters , Scanners etc

13

Fig 8: Peer to Peer Networking

Client/server networks are more suitable for larger networks. A central computer, or 'server', acts as the storage location for files and applications shared on the network. Usually the server is a higher than average performance computer. The server also controls the network access of the other computers which are referred to as the 'client' computers. Typically, teachers and students in a school will use the client computers for their work and only the network administrator (usually a designated staff member) will have access rights to the server.

Fig 9: Client - Server Networking


Peer to PeerNetwork

File Server

Other equipment

14

Table 7 provides a summary comparison between Peer-to-Peer and Client/Server Networks.

Peer-to-Peer Networks vs Client/Server NetworksPeer-to-Peer Networks Client/Server Networks· Easy to set up · More difficult to set up· Less expensive to install · More expensive to install

· Can be implemented on a wide range of operating systems

· A variety of operating systems can be supported on the client computers, but the server needs to run an operating system that supports networking

· More time consuming to maintain the software being used (as computers must be managed individually)

· Less time consuming to maintain the software being used (as most of the maintenance is managed from the server)

· Very low levels of security supported or none at all. These can be very cumbersome to set up, depending on the operating system being used

· High levels of security are supported, all of which are controlled from the server. Such measures prevent the deletion of essential system files or the changing of settings

· Ideal for networks with less than 10 computers

· No limit to the number of computers that can be supported by the network

· Does not require a server · Requires a server running a server operating system

· Demands a moderate level of skill to administer the network

· Demands that the network administrator has a high level of IT skills with a good working knowledge of a server operating system

Table 7: Peer-to-Peer Networks vs Client/Server Networks

Components of a NetworkA computer network comprises the following components:

A minimum of at least 2 computers Cables that connect the computers to each other, although wireless communication is becoming

more common (see Advice Sheet 20 for more information) A network interface device on each computer (this is called a network interface card or NIC) A ‘Switch’ used to switch the data from one point to another. Hubs are outdated and are little

used for new installations. Network operating system software

Structured CablingThe two most popular types of structured network cabling are twisted-pair (also known as 10BaseT) and thin coax (also known as 10Base2). 10BaseT cabling looks like ordinary telephone wire, except that it has 8 wires inside instead of 4. Thin coax looks like the copper coaxial cabling that's often used to connect a Video Recorder to a TV.

10BaseT CablingWhen 10BaseT cabling is used, a strand of cabling is inserted between each computer and a hub. If you have 5 computers, you'll need 5 cables. Each cable cannot exceed 325 feet in length. Because the cables from all of the PCs converge at a common point, a 10BaseT network forms a star configuration. Fig 10a shows a Cat5e cable, with a standard connector, known as an RJ-45 connector.Fig 10b shows a standard Cat5e Wall Outlet socket which the cables are connected to.Fig 10c shows a standard Cat5e Patch Panel Wall Outlet socket which is used to terminate the cables from various points in the school bank to a central point.Fig 10d shows a wall mounted cabinet used to house and protect patch panel cables and connectors.


Fig 10a: Cat5e Cable and a close up of RJ-45 connector

Fig 10b: Cat5e Wall Outlets

Fig 10c: Cat5e Patch Panel

Fig 10d: Wall Mounted Cabinet

10BaseT cabling is available in different grades or categories. Some grades, or "cats", are required for Fast Ethernet networks, while others are perfectly acceptable for standard 10Mbps networks--and less expensive, too. All new networks use a minimum of standard unshielded twisted-pair (UTP) Category 5e 10BaseT cabling because it offers a performance advantage over lower grades.

Network Interface Card (NIC)A NIC (pronounced 'nick') is also known as a network card. It connects the computer to the cabling, which in turn links all of the computers on the network together. Each computer on a network must have a network card. Most modern network cards are 10/100 NICs and can operate at either 10Mbps or 100Mbps.Only NICs supporting a minimum of 100Mbps should be used in new installations schools. Computers with a wireless connection to a network also use a network card (see Advice Sheet 20 for more information on wireless networking).


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Fig 11: Network Interface Cards (NICs)

Hub and SwitchA hub is a device used to connect a PC to the network. The function of a hub is to direct information around the network, facilitating communication between all connected devices. However in new installations switches should be used instead of hubs as they are more effective and provide better performance. A switch, which is often termed a 'smart hub'. Switches and hubs are technologies or ‘boxes’ to which computers, printers, and other networking devices are connected. Switches are the more recent technology and the accepted way of building today's networks. With switching, each connection gets "dedicated bandwidth" and can operate at full speed. In contrast, a hub shares bandwidth across multiple connections such that activity from one PC or server can slow down the effective speed of other connections on the hub.

Now more affordable than ever, Dual-speed 10/100 autosensing switches are recommended for all school networks. Schools may want to consider upgrading any hub based networks with switches to improve network performance – ie speed of data on the network.

Fig 12a: An 8 port Hub

Fig 12b: 2 Examples of 24 port Switches

Wireless NetworksThe term 'wireless network' refers to two or more computers communicating using standard network rules or protocols, but without the use of cabling to connect the computers together. Instead, the computers use wireless radio signals to send information from one to the other. A wireless local area network (WLAN) consists of two key components: an access point (also called a base station) and a wireless card. Information can be transmitted between these two components as long as they are fairly close together (up to 100 metres indoors or 350 metres outdoors).


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Fig 13a: Wireless Access point or Wireless Basestation

Suppliers would need to visit the schools and conduct a site survey. This will determine the number of base stations you need and the best place(s) to locate them. A site survey will also enable each supplier to provide you with a detailed quote. It is important to contact a number of different suppliers as prices, equipment and opinions may vary. When the term 'wireless network' is used today, it usually refers to a wireless local area network or WLAN. A WLAN can be installed as the sole network in a school or building. However, it can also be used to extend an existing wired network to areas where wiring would be too difficult or too expensive to implement, or to areas located away from the main network or main building. Wireless networks can be configured to provide the same network functionality as wired networks, ranging from simple peer-to-peer configurations to large-scale networks accommodating hundreds of users.

Fig 13b: Desktop PC Wireless LAN card Fig 13c: Laptop PC Wireless LAN card

What are the advantages and disadvantages of a Wireless LAN?Wireless LANs have advantages and disadvantages when compared with wired LANs. A wireless LAN will make it simple to add or move workstations, and to install access points to provide connectivity in areas where it is difficult to lay cable. Temporary or semi-permanent buildings that are in range of an access point can be wirelessly connected to a LAN to give these buildings connectivity. Where computer labs are used in schools, the computers (laptops) could be put on a mobile cart and wheeled from classroom to classroom, providing they are in range of access points. Wired network points would be needed for each of the access points.

A WLAN has some specific advantages: It is easier to add or move workstations It is easier to provide connectivity in areas where it is difficult to lay cable Installation can be fast and easy and can eliminate the need to pull cable through walls and

ceilings Access to the network can be from anywhere in the school within range of an access point Portable or semi-permanent buildings can be connected using a wireless LAN While the initial investment required for wireless LAN hardware can be similar to the cost of

wired LAN hardware, installation expenses can be significantly lower Where a school is located on more than one site (such as on two sides of a road), it is possible with

directional antennae, to avoid digging trenches under roads to connect the sites In historic buildings where traditional cabling would compromise the façade, a wireless LAN can

avoid drilling holes in walls Long-term cost benefits can be found in dynamic environments requiring frequent moves and

changes They allows the possibility of individual pupil allocation of wireless devices that move around the

school with the pupil.

WLANs also have some disadvantages:

As the number of computers using the network increases, the data transfer rate to each computer will decrease accordingly


As standards change, it may be necessary to replace wireless cards and/or access points Lower wireless bandwidth means some applications such as video streaming will be more

effective on a wired LAN Security is more difficult to guarantee, and requires configuration Devices will only operate at a limited distance from an access point, with the distance determined

by the standard used and buildings and other obstacles between the access point and the user A wired LAN is most likely to be required to provide a backbone to the wireless LAN; a wireless

LAN should be a supplement to a wired LAN and not a complete solution Long-term cost benefits are harder to achieve in static environments that require few moves and

changes It is easier to make a wired network ‘future proof’ for high data transfer.

Wireless Network ComponentsThere are certain parallels between the equipment used to build a WLAN and that used in a traditional wired LAN. Both networks require network interface cards or network adapter cards. A wireless LAN PC card, which contains an in-built antenna, is used to connect notebook computers to a wireless network. Usually, this is inserted into the relevant slot in the side of the notebook, but some may be internal to the notebook. Desktop computers can also connect to a wireless network if a wireless network card is inserted into one of its internal PCI slots. In a wireless network, an 'access point' has a similar function to the hub in wired networks. It broadcasts and receives signals to and from the surrounding computers via their adapter card. It is also the point where a wireless network can be connected into an existing wired network.The most obvious difference between wireless and wired networks, however, is that the latter uses some form of cable to connect computers together. A wireless network does not need cable to form a physical connection between computers.

Benefits and Educational UsesThe installation of cables is time consuming and expensive. The advantages of not doing so are apparent:

the amount of work required and the time taken to complete it are significantly reduced the network is accessible in places where wiring would have been difficult or impossible with no cables linking computers together, cable-related faults and network downtime are

minimised Where a wireless network is in place, teachers or students can have continuous access to the

network, even as they move with their equipment from class to class. The space over which a wireless network operates is not planar but spherical. Therefore, in a

multi-level school, network access could be available in rooms above or below the access point, without the need for additional infrastructure.

In a location within a school where network access is required occasionally, desktop computers fitted with wireless network cards can be placed on trolleys and moved from location to location. They can also be located in areas where group work is taking place. As they are connected to the network, documents and files can be shared, and access to the Internet is available, enhancing group project work.

As the range of the wireless network extends outside the building, students and teachers can use wireless devices to gather and record data outside, e.g., as part of a science experiment or individual performance data as part of a PE class.

Technical and Purchasing ConsiderationsNetwork interface cards for wireless networks are more expensive than their wired counterparts. The cost of the access points has also to be considered. Wireless networks work at 11Mbps, whereas wired networks normally work at100Mbps (Fast Ethernet). This data transmission rate is dependant on the number of users, the distance from the access point and the fabric of the building (metal structures in walls may have an impact). A wireless network will be noticeably slow when a group of users are transferring large files. This should be considered if multimedia applications are to be delivered over the network to a significant number of users.


As the range of the network may extend beyond the walls of the building, it can be accessed from outside. Consideration should be given to what security features the equipment provides to ensure that only valid users have access to the network and that data is protected.

1.4. Advantages of Networking schools

Speed. Networks provide a very rapid method for sharing and transferring files. Without a network, files are shared by copying them to floppy disks, then carrying or sending the disks from one computer to another. This method of transferring files in this manner is very time-consuming.

Cost. The network version of most software programs are available at considerable savings when compared to buying individually licensed copies. Besides monetary savings, sharing a program on a network allows for easier upgrading of the program. The changes have to be done only once, on the file server, instead of on all the individual workstations.

Centralized Software Management. One of the greatest benefits of installing a network at a school is the fact that all of the software can be loaded on one computer (the file server). This eliminates that need to spend time and energy installing updates and tracking files on independent computers throughout the building.

Resource Sharing. Sharing resources is another area in which a network exceeds stand-alone computers. Most schools cannot afford enough laser printers, fax machines, modems, scanners, and CD-ROM players for each computer. However, if these or similar peripherals are added to a network, they can be shared by many users.

Flexible Access. School networks allow students to access their files from computers throughout the school. Students can begin an assignment in their classroom, save part of it on a public access area of the network, then go to the media center after school to finish their work. Students can also work cooperatively through the network.

Security. Files and programs on a network can be designated as "copy inhibit," so that you do not have to worry about illegal copying of programs. Also, passwords can be established for specific directories to restrict access to authorized users.

Main challenges to be addressed relating to NetworkingCosts Although a network will generally save money over time, the initial costs can be substantial, and the installation will require the services of a technician or other experienced IT person.

Requires Administrative Time. Proper maintenance of a network requires considerable time and expertise. Many schools have installed a network, only to find that they did not budget for the necessary administrative support.

Server Failure Although a server is no more susceptible to failure than any other computer, when the files server "goes down," the entire network may come to a halt. When this happens, the entire school may lose access to necessary programs and files. As such all important files should be backed up so that it the server does fail that the data is recoverable. Digital Audio tape (DAT) or tape backup are the most commonly used options.


2.1. Some Relevant Terms

LAN Local Area NetworkEthernet Ethernet is a standard for transferring data over networks.USB Universal Serial BusModem A simple device used to access the internet Router A more technically advanced device used to access the internet Mbps Megabits per second (1,000,000 bits per second)Kbps Kilobits per second (1,000 bits per second)MDF Main Distribution Frame IDF Intermediate Distribution FrameBroadband Refers to a higher speed always on internet connectionNarrowband Refers to speeds of up to 128kbpsDial up Refers to having to dial up the internet every time one goes online. Always On Refers to the nature of broadband, being ‘always on’ means a dial up is not required.Download speed The speed at which data is delivered to a school modem from the internet Upload speed The speed at which data is sent to the internet from a school modem.ISP Internet Service Provider ISDN Integrated Services Digital Network (64kbps single channel or 128kbps dual channel)PSTN Public Switched Telephone Network (refers to an ordinary telephone line)ADSL Asymmetric Digital Subscriber Loop

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