|
Schools
Online
About the Author Footnotes List of Figures
The Internet, that global network of computer networks, is increasingly important in educational circles. The main reasons people want to use the Internet in 2001 is the same as the early days: to communicate with other people, to have access to information resources, and to have access to other computer resources that are unavailable locally. The Internet is now in almost every country in the world, and the number of users and individual computers connected to this global network of networks is increasing rapidly though very unevenly. Most of the growth has been in the industrialized nations and in urban areas. According to NUA surveys in Ireland, 400 million people were connected to the Internet at the end of 2000. That is about 7% of the world's population. It ranges from about 0.6% of the population in the Middle East, 0.8% in Africa to 41% in North America. The variations can be explained by differences in wealth, culture, infrastructure, attitudes toward technology, government regulations, and amount of training and exposure to new technologies in schools and universities as well as the media. Even if teachers and students have not used it, many have heard about it on television or from the newspaper or other people.
This guide will provide you with a basic explanation of the range of services available for a school that needs an Internet connection. This information may be useful for another kind of organization or small business. The guide will help you decide on the kinds of activities that can be undertaken in the classroom, library, or technology center, depending on the connection available at your school The infrastructure of the Internet is changing. There are new technologies being developed every month, as well as improvements on existing ones. This can make it difficult to decide how to spend your money, how to choose a service, and when to abandon an old technology in favor of a newer one. This guide will discuss some of the current options for connectivity and mention some of the future technologies that are promised. However, the technology marketplace is very volatile, and some of these may never be an option for your school, while new ones may appear with little warning.
As you begin reading this guide, you may know
little about Internet connectivity, but after you have begun your investigation
and made a choice, you will have experience that is important to share
with other colleagues in education as well as people in your town or
region. One of the strengths of the Internet is the willingness of people
to spread their particular knowledge and experience to others following
later. We hope this general guide will be a starting point and not a
final product. Let us know how we can improve the guide by writing to
guide@schoolsonline.org
It is important to remember that not all of these connectivity options will be available for your school. Prices will vary from country to country and between urban and rural areas. How can you determine which ones are options in your country? There are several types of people and organizations to consult: the technical staff in the ministry of education, or in your school district. The Internet Society¹ has many local chapters in dozens of countries. Among the members are volunteers who may be able to advise you about local conditions.
What do you want do with the Internet? The type of connection you have determines what you
can do on the Internet. The connections will vary by speed and by cost.
Low cost connections make it easy for schools to include Internet access
for students and teachers, whereas high costs make budgeting more difficult.
In many documents and in many meetings, writers and network users will
talk about the speed of their connection and say, All of these are terms used to describe in a kind of shorthand, the type of connection. This guide will help you understand the different options. The speed of the network connection is measured in bits per second. The term, bandwidth, is used to express the speed of a connection. Other terms are "capacity" and "throughput." Many years ago, the connections were only 300 bits per second, then 1200, 2400, and with improvements to equipment technology the speed of the modem (the equipment used to convert a telephone signal to a data signal) climbed to approximately 56,000 bits per second. Modems are usually included in most new computers, and you can buy external modems that will connect to different machines and can be transported more easily than the complete computer. Faster parts of the network run at speeds equivalent to 1,544,000 bits per second (T-1 connection), 2,048,000 bits per second (E1) and much higher. Experimental networks are running over one billion bits per second, but these are rarely available to schools at this time. Generally, faster network connections allow
you to use more services and to have more computers hooked into the
network. Your school can be more productive and allow more students
to make use of the networked resources. Some computer literature and
sales material from companies make it seem like a slow connection is
not a useful one, but that is not true. In the 1980's the whole Internet
was running on a connection no faster than what the average consumer
has on her home computer in the United States, and hundreds of scientists
and researchers were able to make huge advances even with these slow
connections. You can do quite a bit with a slow connection. What follows
is an arbitrary division of connection speeds and what sorts of operations
can be performed with each bandwidth.
Slow connections: up to 9600 bits per second. These can be used for electronic mail including mailing lists, sending and receiving small files, database searches, chat, and browsing the World Wide Web if the pages are not complex or full of graphics. If you have a slow connection, you can use electronic mail to retrieve World Wide Web documents. A guide is located here: http://www.bellanet.org/email.html. Slow connections are adequate for a single machine, not a network of computers. Average connection: up to 56 kilobits per second. Many home users in urban areas of the United States and Europe are connected at this speed. It allows most users to use the World Wide Web, listen to audio files, chat, make telephone calls, exchange electronic mail with files attached, and download medium-sized programs from remote sites. Sometimes small networks share a single modem for the connection to the Internet.
Very fast: up
to 2,500 kilobits per second. Some schools in the United States are
connected at T1 speeds. This allows large numbers of users to perform
complex operations without any degradation of services. However, new
applications like Napster (one of the popular programs to share multimegabyte
MP3 format music files) make intense use of network resources and can
slow down even very fast connections if several people are using it
at once. Several universities have banned the use of Napster on their
networks.
The Internet is a network comprised of thousands of other networks all over the world. Millions of computers are sharing resources: information, file servers, and the network itself. These networks use common standards or protocols to allow different brands of machines and operating systems to communicate easily with each other. IBM, Apple, Microsoft, Sun, Linux, and numerous others operating systems use the TCP/IP protocols when connecting to the Internet. Figure 1. Connecting to the Internet How you are connected will determine what kind
of service you will experience. The fastest part of the Internet is
called the backbone. Actually, there are many backbones, or trunk lines
that carry huge amounts of traffic between continents or across the
United States or Europe or within your country. Most networks in developing
countries have a direct connection by land, sea, or satellite to a backbone
of the Internet in the United States or Europe. There are many projects
to encourage regional cooperation and to encourage local connections
in addition to the ones to Europe and the United States. However, at
present, much of the traffic flows in and out of Europe and North America,
but other areas are growing quickly, as improvements to the network
are made, and as more users begin using the Internet in those areas.
A school in a rural area of an African country may connect to the telephone network in a regional town, and all messages or traffic are passed to the capital city. From there the message will be sent to a point in the United States or Europe and on to its final destination. Any traffic must travel this path with many hops before a destination is reached. In some cases, a message to a country adjacent to yours will have to travel to your capital, then to the U.S., then to Europe, and back to the other country until it reaches the addressee. In other words, the network does not always follow the shortest distance geographically. The fastest route in a network may not be a straight line. Some parts of the network have more traffic than others, and this can greatly affect the kind of service you have. The value of the Internet is the accessibility of the users, the information, and the computing resources, but it is also the source of congestion. Imagine that you had a private road running from your town or village to the capital. You would be able to travel faster because nobody else was using the road. However, on a public road, there are other cars, trucks, and maybe animals and pedestrians sharing the same resource. Your traveling time will be much slower. With a direct 56 kb Internet connection to the Internet Service Provider (ISP) in the capital, your service will be faster than if you and other subscribers all have 56 kb connections to a local ISP who has only one direct 56 kb connection to a larger ISP in the capital. Usually, as the traffic flows from the edge of the network to the center, the connections increase in speed, but this is not a rule. Some parts may be faster at the edge than further along the path. How can this happen? An ISP in a small town may sell very fast connections
in the town but the connection between the town and the Internet backbone
may only be a fraction of that speed. As a result, the subscribers won't
really benefit from the fast connection they purchased, unless most
of their traffic is local. There are usually public network diagrams
available that show the kinds of connections in different areas of your
country.
Networks have grown at very different rates. This is a legacy of language, the way the telephone company operated in the past, which companies have invested in your country, the laws that allow certain technologies and ban others, and the current business climate for entrepreneurs. It may be related to politics. Generally, rural areas do not get the same resources and improvements that the capital and other large cities do. For each country there are different histories and different costs. For this reason, it is impossible to give costs for services that will be described in this booklet. Unfortunately, the countries that most need
improved telecommunications networks have some of the highest charges
for individuals or organizations to connect to the Internet, but with
projects such as Schools Online this may change. It is important for
regulatory agencies in a country to allow a range of new technologies,
partly because it will benefit schools and other public institutions
in civil society as much as it will benefit business or government.
A group of non-profit telecommunications workers have written a manifesto
calling on their governments to have favorable rates for new telecommunications
technologies used in schools, libraries, and telecenters. For more information
see the Manifesto of Papallacta (Ecuador): http://www.tele-centros.org/english/manifiesto/manif_en.html
In the following section we will discuss the ways to connect to the Internet. There are four main divisions of service: telephone network, satellite, land-based wireless systems, and cable television networks. Because of cost considerations we will not discuss fiber optic, microwave, or optical networks. Many systems are hybrids of one or more of these technologies. That is, there may be a telephone line that reaches a connection point in the town, and then a wireless network distributes the signal to other users, or a connection uses satellites or microwave to connect a remote area to the fiber optic network. Many telephone networks are complex combinations of fiber, copper telephone wire, satellite, cellular, and microwave services. Services that use the telephone network Dialup telephone lines and modems: While the
word "dialup" refers to the older phone sets with rotary dials,
this is still the most common method for people around the world to
connect to the Internet. The computer stores information in digital
form, and the phone network moves information (like your voice) in analog
form. The modem is a device built into your computer or externally connected
to it that converts the digital signals to analog and vice-versa. The
speed is measured in bits per second. Modems now can move data at 57,600
bps, but older ones may go as slowly as 300 bps. Some modems can send
and receive faxes. Because the quality of phone lines vary, it is important
to have a good modem that will not disconnect when it encounters line
noise in poor quality lines. At the other end of the line the ISP has
numerous modems and phone lines for all the customers. If there are
not enough modems for the number of subscribers, you may encounter busy
signals when trying to connect. Another problem in many countries is
the poor condition of the phone line. When a modem encounters noise
it will drop its speed, and many places never see speeds over 14,400
bps, even when using new modems. It should be protected against electrical
surges and grounded against bad weather (lightening). There are many
options for a school that uses modems and the telephone network.
Cellular networks: A few schools that have no other option than cellular phones to connect to the Internet, but the speed of the connection is very slow, and the cost is high. This option should only be considered where no other exists. In the next few years a new kind of cellular service will be offered in some countries. Japan is planning to start in 2001, but the cost of expansion is very high. The so-called 3G or third generation cellular service will provide high speed (144 kbps to 2 megabits per second) connections to mobile phone users. This may be a solution for schools in some countries where the cellular service is spreading more quickly than the older telephone network. However, at present this network offers few practical choices for schools needing a connection. One phone line: If the there is only one phone line, it can be shared between the telephone, fax machine, and modem hooked to the computer. However, you will need to schedule the use of the modem during the school day, in order to cause less disruption to others who need to use the phone and fax. Costs for connecting via the phone line vary by location, country, and Internet provider. Some schools can afford to be online a short time each day, and others are charged a flat rate (one sum for as much time online the whole month) and will use it continuously.
Separate phone line for the Internet: When the school connects to the Internet Service Provider over a second telephone line not used for voice or fax, it can have one computer and one modem, or several computers can share one modem. Extra devices and software such as Wingate http://wingate.deerfield.com or Webetc http://www.webetc.com/ allow a small local area network of computers to share one modem. Depending on the uses of the Internet, performance will vary. If you are mainly sending and receiving email, you can have more computers sharing one modem, than if they are receiving web pages and doing file transfers. Multiple phone lines for the Internet: If the cost of phone lines is reasonable, a school may have multiple lines for multiple modems, thus allowing each connected computer to have its own line. Another solution is called modem teaming which connects two modems and two lines into a virtual single line with a maximum speed of 110 kbps. Many ISPs do not allow this, but it is used in places where other high speed options are not available. Dedicated leased phone line: This is also called a dedicated circuit. The simplest configuration could between your school and the phone company or Internet Service Provider office. The cost is high because you are paying for reliability and you are not sharing the line with any other party. When the school is closed, the line is not used even though you are paying for it. Dedicated lines need special equipment. At each end of the line a CSU/DSU must be installed. CSU means Channel Service Unit; DSU means Digital Service Unit. These replace the modems used in dialup connections. Speeds vary from 56,000 bits per second (56 kb) to T1 (1.56 million bits per second).
Integrated Services Digital Network (ISDN): It has been very popular in Europe and Japan. However, newer technologies are replacing this as a way to obtain a fast connection to the Internet. Because of the investment by the phone companies in the past, ISDN may be offered as a choice long after it is not competitive with these new technologies. ISDN allows transmission of voice and data over the same line at speeds of 128 kbps for the service known as BRI or Basic Rate Interface. In many countries you pay by the minute, so your monthly bill can vary greatly. Frame Relay: It is a protocol used by telephone companies on their digital lines as well as a type of service offered. Developed in 1988, it is a more efficient way of moving data at high speeds because it cuts out some processes in the network that detect errors. This allows for a more efficient and faster service. Frame relay is a good way to interconnect Local Area Networks instead of leasing many private lines on the regular phone network. It is much faster than using a modem and a dialup connection to the Internet. A telecommunications company might propose to link up a region of schools using frame relay. If this is proposed for your school, find out how the costs compare with leasing private lines. It should be cheaper. Each school would be guaranteed a certain speed for a fixed monthly price which varies according to the company and rates set in each country. The speeds can be anywhere from 56,000 bps up to 1.5 million bps. In many cases a customer will opt for what is called "fractional T1" meaning some percentage of a connection that runs at about 1.5 million bps. However, some businesses use frame relay to interconnect offices in different countries. The service is offered in more than one hundred countries around the world.
Figure
4. Frame Relay Figure 5. Digital Subscriber Line Satellite: Satellites have been used for connecting remote areas of the planet for many years. Recently, technological breakthroughs by several companies have brought the price down to the point where more schools can afford a connection to the Internet .
There are two new consumer services of interest being sold in North America. Later they may be offered elsewhere. DirecPC, also available outside of North America, is a hybrid system that uses a small satellite dish (less than one meter) and satellite modem to receive Internet data at up to 400 kbps, and each subscriber needs a phone line to send information and web page requests to the Internet. The download speed in other countries may be slower. Users pay according to the amount of data per month, once they exceed a limit. This system is being upgraded in the United States so that no phone line will be needed. DirecWay will have the same download speed, and the return speed will be 128 kbps. Of course, as more people use the system, the speeds will slow down during busy times. This system works with Windows machines and there will be an option to connect local area networks. A competing service called Starband in the United States offers similar services with speeds. Heavy tropical rain can make the signal fade away temporarily. Most enterprise systems for schools, businesses, and other organizations use VSAT: Very Small Aperture Terminal is a term applied to satellite systems that have been used for many years in remote areas of the world. VSATs vary in price and capability. The dishes are usually larger than than the new consumer systems mentioned in the previous paragraph, and the expense of purchasing installing them can be very high. The diagram below shows a typical VSAT configuration: a small (one meter or more) dish and router at your school which is connected to the Internet through the satellite to the host gateway in another country which uses a large dish (5-6 meters) and is near the backbone, a very high speed part of the Internet . Each company will have slightly different equipment that is not interchangeable.
Satellite companies have very different ways of calculating the cost and type of service they will provide. Some may guarantee a certain bandwidth, a fixed amount of data per month, while others may only allow a few machines to use the connection at a given price. Others may charge by time of day. This makes purchasing decisions very difficult for someone without experience, but satellites will be the only way many parts of the world can connect to the Internet for many years to come. Figure 6. VSAT Satellite Connection Wireless Internet Connections: While satellites do not use wires, most wireless Internet systems use radios and small antennas to move signals along the earth's surface, rather than to and from a satellite. The frequencies vary but they are different from those used for AM/FM radio or television signals. Some of the unlicensed radio frequencies are also used by cordless telephones and other consumer devices. There may be some interference that will affect an Internet connection. For very remote areas HF radio may be an option. It works using very slow connections and requires HF radio modems at each end of the connection, a license, and an operator for each session. This has been operating in some African countries where no other options are available for remote locations, but the cost is high. Additionally, it is sold as a service for cruise ships and yachts (SeaMail, CruiseEmail, SailMail) all over the world.
Figure
7. Point-to-Point Wireless Connection Chart 1. Internet Connection Speed Comparison
Once you have made a decision about an Internet connection,
you may have to sign a contract. Usually, a company will lower the price
for a longer contract. For instance, if you agree to pay at the beginning
or sign for two years of service, some of the equipment may be discounted
or even free. If you pay on a month-to-month basis, your initial costs
may be higher, but you will also be able to change service providers
if one proves to be better than the original. With new technologies
being developed or offered in other countries, you may wish to switch
from one kind to another. If you have signed a long term contract, this
may be difficult. However, determining what the future telecommunications
options are, is very difficult and time consuming. Local advertising
may be placed to assess the potential of the market and not actually
offer new services when you need them. For that reason, you need a network
of other sources for advice. Once you have an Internet connection, that
becomes easier, Remember, share the knowledge you have gathered. Other
schools want to get connected, and they will need advice just as you
did.
Steve Cisler's background is in libraries where he
worked for 14 years before going to Apple Computer, Inc. in 1988. As
a member of Apple's Advanced Technology Group he directed the Apple Steve has lectured extensively in many countries on
the promise and the cultural challenges of the Steve has written for American Libraries, Library
Journal, Online, Database, Wired, First Monday, He can be reached at cisler@pobox.com
1: Internet Society, 11150 Sunset Hills Road, Suite 100, Reston, VA 20190-5321 USA. TEL: +1 703 326 9880. http://www.isoc.org
Figure
1. Connecting to the Internet Figure 5. Digital Subscriber Line Figure 6. VSAT Satellite Connection Figure
7. Point-to-Point Wireless Connection |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||