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| <nettime> hegener on internet unwired |
From: mh@nrc.nl (Michiel Hegener)
[posted on nettime with the permission of the author. g.]
Internet Unwired
By Michiel Hegener, Journalist.
Appeared in the Sept.-Oct. issue of 'OnTheInternet', the
magazine of the Internet Society.
See also: http://www.iicd.org/articles/articles.htm
Just two or three years after the Internet really took
off, it is already commonplace to say that the world is
being swept by a telecommunications revolution; so we
shan't say it. It is a valid question, though, to ask
what is meant by the world in this particular case,
because hundreds of millions of people in less
well-to-do parts of it have never heard of
datacommunications, let alone what it could do for them.
Something to worry about? Very much so.
Information and communication technology (ICT or IT)-the
Internet in particular-has a huge potential to sweep
away poverty and ignorance, which is a far more
interesting application than sweeping the world as such
or keeping shareholders happy. This article is not about
proving that ICT can serve as a powerful engine for
economic growth in underdeveloped regions-thousands of
examples can be found on the World Wide Web-but it may
be worth noting that that idea is now getting widely
accepted.
Last June in Toronto, at the world conference called
Global Knowledge '97, cohosted by the World Bank and the
government of Canada, United Nations secretary-general
Kofi Annan said, "What is so thrilling about our time is
that the privilege of information is now an instant and
globally accessible privilege. It is our duty and
responsibility to see that gift bestowed on all the
world's people, so that all may live lives of knowledge
and understanding." Among the 1,500 attendees listening
to those words were many representatives of the very
countries where the biggest gains can be made. Several
of the donor countries, too, are becoming keenly aware
that ICT is not a luxury but a necessity [1].
Leading the pack, the World Bank has really embraced the
idea that the way to basic prosperity and justice for
all is paved partly with ICT. That doesn't necessarily
mean a fiber-optic cable running under the pavement;
satellites overhead might do just as well-in some
respects even better and, above all, quicker. Although
only a very small part of our planet has been wired so
far, every place on earth has Internet access via
satellite: a PC, a dish antenna and some equipment in
between are all that's needed to hook up straight to an
Internet backbone, even if you live in a tiny village in
the middle of Mali or Myanmar. However, for the
individual end user or even for a small business, the
price of a very-small-aperture terminal (VSAT) and the
tariff per kilobyte sent or received are quite
prohibitive, certainly in the poorer regions of the
world.
Additionally, in many countries, licenses for the use of
wireless communications are hard to get, if they can be
gotten at all. In spite of that, a VSAT is a viable
solution for larger companies and organizations as well
as for Internet service providers in developing
countries. For instance, about a dozen African ISPs now
have their own dedicated satellite links, including a 3-
or 4-meter dish antenna on their premises [2]. The dish
is trained or a geostationary-earth-orbit satellite
(GEO) at 35,786 kilometers (22,187 miles) above the
equator, which relays the signals to and from a ground
station somewhere in the West that is directly linked to
an Internet backbone. The big disadvantage of such a
line in the sky of fixed throughput-usually a few
hundred kilobits per second-is the waste of bandwidth
that occurs at night and the shortage of it during peak
hours.
The good news amid all of the limitations is that
satellite service providers and satellite builders-often
closely linked, by the way-are becoming very keen on
reaching end users directly, and new technologies enable
them to do so in an affordable way. They realize that
there is a huge demand for high-speed Internet
connections and that only satellites can deliver them
quickly to the unwired parts of the world. Where good
telephone lines or even ISDN is readily available, the
new satellite services have a lot to offer as well: high
speed means we are talking hundreds of kilobits per
second uplink, and downlinks of a few megabits.
Future users of these direct-to-home interactive
satellite broadband services owe a debt to the present
users of direct-to-home satellite television, a
phenomenon that has given tremendous impetus to the
entire satellite industry. One of the spin-offs is a
huge amount of research into new technologies; another
is enough money for the initial, or even the entire,
funding of the new, interactive broadband services.
Beware: a few years from now you will need to spend only
$1,000-$2,000 on equipment to get your own high-speed
Internet link. Transmission costs may drop to about a
cent per megabyte. And there will be a whole range of
dedicated satellite systems to choose from: more than a
dozen if all the plans proposed so far become reality.
Starting about the year 2000, every square meter of our
planet will be showered with connectivity. No strings
attached. Or are there?
Before taking a closer look at some of the plans, let's
investigate certain basics that apply to them all. There
are several ways to get the prices down in order to
reach the end user. As no one will be interested in
paying thousands of dollars a month for a 64- or
256-kilobit leased channel 24 hours a day, access to the
satellite has to be demand assigned. If you want to send
out just a short e-mail message, a few kilobits during
less than a second is all you need. When you want to
search the Web for a while, a 64-kilobit channel would
be more suitable. And online viewing of a piece of video
might require more than a megabit. When mowing the lawn
or hiking in the Adirondacks, most users would select
zero bits a second, but they would certainly choose a
standby downlink option-if the system offered one-so any
incoming e-mail would go straight to them and not to
their ISP first. In all cases, you will pay as you go,
like you are now doing with your electricity. Apart from
such demand-assigned, multiple-access techniques,
frequency reuse is another way to bring down the cost of
the links, because radiospectrum is scarce and
expensive.
Most of the present 250-odd civilian geostationary
telecommunications satellites have dish antennae that
cover half a continent or more. Now, for broadcasting
that's fine: casting a signal out over a broad area is
precisely what you want. But if a satellite sends out a
signal to just one VSAT, the frequency used is for some
time unavailable to others within the entire footprint,
like half or the whole of Latin America. With today's
level of VSAT use that is tenable, but it isn't when you
want to send many, many different high-bandwidth signals
to many, many users at the same time-for instance, when
every Tom, Dick, and Harry is surfing the Web. Therefore
the new, interactive broadband satellite systems will
sport many small antenna beams with slightly overlapping
footprints of a few hundred kilometers across, together
covering very large areas. One and the same frequency
can then be used in various spot beams at the same time,
provided they don't overlap.
The problem here is that you need complex onboard
switching techniques between the beams. In spite of
frequency reuse techniques like this one, the new,
interactive satellite services still need astonishing
amounts of radiospectrum-so much that almost all are
forced to use the very high frequencies of the Ka-band:
between 20 and 30 gigahertz-the spectrum equivalent of
the American West in the 19th century. "Go Ka-band,
young man," a senior satellite engineer might say these
days.
Dangers lurking behind the hardly charted hills all have
to do with difficult technology, which is of course why
the seniors didn't go there themselves. Also, at 30
gigahertz the length of one wave cycle is just 1
millimeter, which makes the whole wave-carrying the Web
page you just requested-very vulnerable to raindrops,
like a mouse running over a field littered with rat-size
rocks. The meteorological hazards can be negotiated to
an extent by the Internet transfer control protocol, but
when it starts raining real hard, as happens often in
tropical regions, you are bound to suffer a complete
outage. One possibility is a temporary boosting of the
transmission power in the spot beam, which covers bad
weather-another advantage of multiple spot beams. For
the uplink, though, that doesn't help. A stronger
transmitter and a bigger antenna do, but then of course
the hardware price will be boosted as well. So, one of
the biggest challenges for those who have joined the
race is to develop really affordable user kits-VSATs
essentially.
A lot of the money for a present-day VSAT is spent on a
strong transmitter. It has to be, because geostationary
satellites are so far away: lower than 35,786 kilometers
they orbit the Earth in less than the 23 hours and 56
minutes the Earth needs to turn on its axis and they'd
therefore no longer be geostationary. The huge advantage
of these fixed satellite positions is of course that you
can use dish antennae that are just as fixed-to your
roof, for instance. One advantage of the Ka-band is that
to get the same results, smaller and therefore cheaper
dishes than for lower frequencies can be used.
Equipping the satellite with more-sensitive receiving
facilities also contributes to a cheaper kit for the end
user. A much more dramatic move is to lower the
satellites: to reach a satellite 800 kilometers above
you requires about 1/2000 of the power needed to get the
signal to the geostationary arc. At 800 kilometers, a
satellite orbits earth in less than 2 hours, so instead
of dish antennae you need omnidirectional ones which
wastes a lot of transmission power. There are other
complexities as well-and other advantages. Phased-array
antennae-though technologically still in their
infancy-will offer an alternative before too long.
The best-known low-earth-orbit (LEO) broadband satellite
system is Teledesic, of the Teledesic Corporation,
founded by Bill Gates and Craig McCaw as long ago as
1990. Indeed, there are very few others, as most players
intend to use GEOs. Teledesic was publicly announced in
March 1994. Although the looks and the design of the
satellites still needed some attention, their sheer
number-840-was immediately alive and kicking, blazing a
broad trail of awe through the telecommunications world
and impressing would-be end users around the globe.
Those users may have been a little disappointed when it
was announced last April that the fleet size would be
trimmed down to just 288 satellites plus 36 on orbit
spares, while their orbit altitude went up from 785 to
more than 1,300 kilometers. The change followed shortly
after the announcement that aircraft manufacturer Boeing
had been selected as the main contractor for building
the fleet. Both Teledesic and Boeing are based in the
Seattle conurbation, as indeed is Microsoft, whose
chairman provided part of the seed capital-some tens of
millions of dollars. Representatives of Microsoft and
Teledesic insist there is no formal link between the two
companies. And though $9 billion will be needed to get
Teledesic up and running, Gates and McCaw have promised
not to pay that amount out of their own deep pockets. As
Teledesic president Russell Daggatt says quite
significantly, "On the investment side, Bill and Craig
will eventually get diluted down to insignificance."
The high number of satellites is needed to make sure
that no matter where you are, you always have at least
one at more than 40 degrees above the horizon. The
reason has a lot to do with the system's availability
during adverse weather conditions: the signals have to
struggle through only a rather thin slice of the
atmosphere if the satellite is more or less above the
earth station-your antenna and transceiver, that is. The
use of phased-array antennae on the satellites as well
as on the ground is another way to boost Teledesic's
capacity. Phased array essentially means you can direct
the signal by means of electronic steering, without
moving parts and instantaneously. So, when online, the
parabolic, mushroom-shaped antenna on your roof will
always follow one of the satellites as they move across
the sky. The satellite, in the meantime, will train its
multiple phased-array spot beams on fixed grid cells on
the surface, including the one from which you are
operating. As soon as another satellite gets closer to
you, the signal will be handed over automatically. By
using intersatellite links, Teledesic needs in theory
only a few large gateway earth stations to interface
with terrestrial networks, including Internet backbones.
For regulatory and economic reasons, however, there will
be close cooperation with local service providers-a
policy that will translate into at least one gateway in
each country that allows the use of Teledesic.
GEO service providers rely on a lot of proven
technology, but Teledesic has chosen not to follow the
beaten track. As Daggatt puts it, "Ten years ago LEOs
were impossible. Today it's a challenge. Ten years from
now, no big deal."
A good overview of the coming Ka-band systems in the
March 1997 issue of Via Satellite reported that
Teledesic was under "ongoing criticism from its
competition regarding the system's feasibility," which
is surprising, because you'd expect any infeasibilities
to be a source of relief and delight to the other
contenders. However, scarcity of available spectrum, of
which Teledesic needs quite a slice-1 gigahertz-lends
the criticism some justification. If Teledesic flops,
the world will have suffered a waste of spectrum, which
will also be the case, of course, if any other fleet
flops. Some almost certainly will: that is one of the
near certainties in this whole endeavor. There are just
too many plans.
Part of the Teledesic technology still hasn't been
sorted out, but the same is true, to a lesser degree,
for the GEO systems. All Ka-band systems still need a
lot of research and engineering if they want to be
really affordable, which is what they all want. In the
meantime, a LEO network has at least two big advantages
over GEOs. One is far more even coverage of the globe,
especially when the satellites follow near-polar orbits,
as is the case with Teledesic. You then get an orbital
pattern that resembles the dividing lines between the
parts of a peeled orange while the rotation of the Earth
is doing the rest. Although this model brings most
connectivity to the polar regions and has the lowest
satellite density around the equator (see orange), it is
utterly egalitarian otherwise. Most important, it
doesn't favor prosperous areas-a characteristic that
should please all who agree with the sentiment, quoted
earlier, of Kofi Annan.
Each Teledesic cell-whether on Manhattan or in the depth
of the Amazon basin-has a diameter of 80 kilometers and
a capacity of 64 Mbps in each direction. It should be
added that cells can and sometimes will be shut off. "We
certainly would not allow service in a territory where
the government doesn't allow it," says Daggatt. That
must be bad news for the inhabitants of Tibet, Eastern
Timor, and Southern Sudan, to mention a few areas where
the population isn't as loyal as the central authorities
would like. Worse news even: it looks as if all other
systems intend to behave just as obediently. Given the
great expectations that the Internet has raised for the
cause of freedom and democracy-buzzwords at Global
Knowledge '97 really-it is a pity to see how the whims
of all sorts of undemocratic regimes will be nicely
catered to by tomorrow's Internet satellite operators.
In fairness, it should also be said that their
cooperation is rooted in both the noble wish not to
bypass local telecom operators without official consent
and the sound marketing policy needed to be successful
at all. As Ron Maehl, president of CyberStar, the GEO
system of Loral Space and Communications, puts it, "We
will comply with all the local policies. We are not
trying to make a political statement, but we are
providing a communications service." For some readers
belonging to resistance and rebel movements, this dark
cloud has a silver lining: whereas LEO systems can very
precisely locate a certain user-by measuring Doppler
effects-a GEO system knows only in which spot beam the
user is sitting. In the case of CyberStar those beams
are about 200 kilometers across, whereas the beams of
the GEO system of Hughes Communications, called
Spaceway, will measure 650 kilometers on the ground. A
beam that covers a part of, say, northern Kenya, may
well spill across the border, where it can be used by
the Sudan People's Liberation Army if the army pays its
bills on time-or has them paid by associates in the
West, which is a more likely scenario.
All players in this field like to stress how beneficial
their services will be for developing countries, even
though their public relations material is usually a bit
thin on detail. But in fact only the providers of LEO
systems will reach the entire globe-not so much because
they are saints, but because that is inherent in LEOs.
On the other hand, the multiple spot beams of Ka-band
GEOs won't reach every corner of the earth. When asked,
both Ron Maehl of CyberStar and Edward Fitzpatrick, vice
president of Spaceway, said they would go for the most
promising markets first. As Fitzpatrick said, "We will
put the capacity where the market is-where it is needed
most. The first satellite will be launched in the latter
part of 1999. We are focused on North America and Asia.
Those will probably be followed not much later by Europe
and Latin America. We haven't made a hard decision on
that point, but that is the current prespective. The
whole U.S. will be covered; Europe too; but in Africa
and Latin America it will be more selective rather than
ubiquitous." (For elaboration of the geography of
satellite communications, see "Internet, Satellites, and
Economic Development" in the Sept./Oct. 1996 issue of
OnTheInternet).
A second big advantage of LEOs stems from their
proximity to the Earth compared with that of GEOs. When
you are online via a GEO and browsing the Web by
clicking your mouse, the signal will have to travel
about 80,000 kilometers to get to the Web page itself,
plus another 80,000 to bring back the result. Given the
speed of radio signals-300,000 Kilometers per
second-that means you will have to wait half a second
after each click to see a change on your monitor-not
disastrous, but not very handy either. The same delay
may result in disaster, though, when you're in a pinball
competition with someone who is online via LEO or cable.
Furthermore, the half-second delay is not conducive to
smooth videoconferencing or voice
conversations-certainly not to smooth interruptions. The
defendants of GEO systems maintain that this constitutes
about all of the damage the delay of their satellites
will cause; the LEO people will of course say there is a
lot more to it than that. Whatever the case, all of this
matters a great deal. No one wants to bet on the wrong
horse. The stakes can be high-for instance, for
organizations, companies, or ISPs in developing
countries that consider buying a VSAT in order to
replace a leased line and get broader Internet access.
What to do if they gather that GEOs are no good for
high-speed Internet? Wait till 2002, when, hopefully,
Teledesic becomes available? Or is the geostationary
delay nothing compared to delaying their plans? Who will
tell them the truth?
In order to make an attempt to see who is right, we'll
have to descend into a muddy mix of propagation delays
and default TCP buffer sizes. While keeping your breath,
keep thinking of the bottom line: whatever the
arguments, consumers will eventually decide for
themselves what they like best. And maybe you should
also keep your ISOC membership card ready, because this
is an issue the society ought to keep an eye on. In
essence, it is simple: after a certain number of bytes,
TCP wants acknowledgment that they arrived well-and will
retransmit damaged packets if necessary. If there is a
geostationary satellite between two routers, it takes
just over a quarter of a second before the load of bytes
arrives on earth again. A similar amount of time passes
before confirmation reaches the sender, which will then
proceed by sending a new load. Hence, the top
per-secondspeed of a TCP/IP link via GEO is about 1.65
(1:0.6) times the number of bytes sent at a time. The
maximum size of this buffer is 65,536 bytes, which means
that TCP/IP can reach a top speed of about 865 kilobits
per second over a GEO. That much is certain. It is also
a fact, though apparently a bit less preordained, that a
buffer size of 8 kilobytes is usually used-for instance,
in Windows 95 and Windows NT. That reduces the top speed
to 106 kilobits per second: quite attractive today, but
probably not tomorrow. According to a white paper about
latency-another word for the round trip delay-which can
be found at Teledesic's Web site, "Using a small buffer
wasn't just an oversight. Small buffers can improve
performance in many common circumstances, such as when
one computer serves many users simultaneously (e.g., a
popular Web server)." So, is Spaceway creating false
hopes by announcing that its system will offer a
384-kilobit TCP/IP uplink? Or is CyberStar, which offers
similar speeds? Says Maehl, "We can send at 600 kilobits
per second and still be consistent with the TCP/IP
protocol." Fitzpatrick is equally adamant: "There are
some challenges, and they are easily overcome. TCP/IP
can be dealt with effectively." And so is John
Stevenson, manageer of transmission engineering at
Intelsat, which owns the world's largest fleet of GEOs:
"The differences between satellite and terrestrial are
very minor, and they certainly shouldn't be allowed to
turn away people to have no Internet access other than
by satellite. They are led to believe that GEOs don't
work. It is quite the opposite. They work quite well,
and in one hop you get to the Internet backbone."
Intelsat-an international consortium with 141 member
countries-prides itself in having carried lots of
Internet traffic since the very beginning, when the
Internet was still ARPANET. Almost all Internet traffic
to and from Africa, for instance, goes via Intelsat: via
proprietary VSATs or via lines leased from the local PTT
that lead to an Intelsat gateway earth station. Only
Djibouti, North Africa, and South Africa have cable
links to the rest of the world. The Internet takes up an
ever more central place in the Intelsat business plan,
whereas Stevenson and other engineers devote a lot of
research to the pros and cons of TCP/IP via GEO. One of
the best outcomes of this appears to be the pairing of
TCP/IP and frame-relay-based multiplexing. According to
Stevenson, frame relay is highly complementary to
TCP/IP. High speeds can be achieved by taking some
special measures. The high speed is achieved by taking
some special measures. Increasing the buffer size can be
one. But when sending your story about life in Rio all
the way to the ISP of your aunt Maud in Liverpool, some
other routers using 8-kilobyte buffers stand in the way.
A better trick is the use of an overlay protocol , which
kind of fools TCP by saying all the time that no packets
were damaged, while keeping stock of the ones that were.
All retransmissions can then be done at the end of the
session.
Both methods reduce the transparancy of the GEO link to
the rest of the Internet, but to what extent? And who is
paying what price for the speeding-up maneuvers? Daggatt
says, "The whole point of the Internet is moving away
from application-specific networks and proprietary
networks in favor of open, public networks-where even
private networks will be virtual private networks
operating over the public networks-with common
protocols, that is, TCP/IP." Stevenson says, "We are
definitely interested in collaborating with people to
improve the situation. We don't think it is ideal, but
today you can do an awful lot of Internet-based
application via GEO with the protocols as they stand.
There will be a lot of pressure from users to have
TCP/IP with a larger default buffer size. There is
nothing preordained in this." But according to Daggatt
something is: "The GEO guys say, 'You can modify the
protocol.' But if you modify the protocol, the party at
the other end has to modify it, too. The whole world has
to change. And if you optimize it for a high
latency-network, for GEO, it is suboptimal for the
ground."
At least two advantages of GEOs over LEOs deserve
mention. GEOs may be a lot more expensive than LEOs, but
in theory you need only three of them to cover the
globe, instead of 60-300 as with LEOs. Note that the
equation should include infrastructure on the ground.
Either a LEO network is very expensive because you need
intersatellite links or, not having them, a lot of
funding is needed for many gateway earth stations to
interface with terrestrial networks because LEOs are
short-sighted.
All in all, Teledesic is about two or three times as
costly as the average GEO system. Even though all
parties are shooting for a hardware price of
$1000-$2000, those parties all are cagey-maybe
ignorant-about transmission costs. If the GEOs will be
cheapest, as you'd expect, that will be something to
reckon with. How much are we willing to pay for low
latency? That may well be the question. Not for Daggatt,
who expects, "We figure our end-user cost will be about
one-quarter that of the GEOs. So, the better performance
of a low-latency LEO link does not require a cost
premium-just the opposite." We'll see. If he's right,
the people behind the GEO systems would be damn foolish
if they didn't immediately cancel all their plans.
The second advantage of GEOs is that they are good at
casting data out over entire continents because they're
so high up. As Fitzpatrick sees it, "The whole Internet
experience will evolve very dramatically in the next few
years. The multimedia machines people have in their
homes will be able to store huge amounts on the hard
drive: 20 gigabytes in 2000." In other words, magazines,
statistics, schoolbooks, pizza recipies, encyclopedias,
weather forecasts, and travel warnings can all be
digitized and sent to millions of end users at once and
at very high speeds. All of that and more will reach
your dish antenna. Courtesy of a preselection option and
hard thinking on your part, your receiver will ignore
everything except a few magazines about pet rodents, the
proceedings of the Perry Como Appreciation Society, and
pizza recipies containing oregano. In addition, the user
can order specific long files, which should arrive a
split second later at high speed. In developed and
well-wired regions, these data-casting techniques will
even take up a predominant place in the broadband
satellite systems. As Maehl sees it, "In developing
countries, the satellites will go much closer in the
network to the end user. You may have more people with
dishes that actually do two-way communication. There it
will be a primary means of communication, as opposed to
a bandwidth enhancer."
The GEO/LEO debate apparently still needs some time to
draw to a conclusion, though everybody seems ready to
agree that both have at least some inherent advantages.
Such seemed to be the state of affairs when on June
17-presto-Motorola announced Celestri, a $12.9-billion
plan for 63 LEOs at an altitude of some 1,500
kilometers, fully integrated with a smaller fleet of
GEOs. If that weren't enough, a day later an alliance
was announced between SkyBridge, the $3.5-billion 64-LEO
constellation of the French company Alcatel, and the
$1.6-billion CyberStar GEO system-even though it wasn't
immediately clear whether the name of the new venture
was going to be CyberStar/SkyBridge or SkyStar or
CyberBridge. Says Maehl, "Right now we are not planning
any GEO/LEO links because we don't see a product that is
more efficiently created by having them. The LEOs won't
have links either. It is typically a last-mile system:
high-speed, two-way communications for end users and get
them into the network."
With so many participants in the race to interactive
broadband satellite services, this is not the place to
describe all their differences or-an even bigger
subject-what they have in common. The overview in has
already been mentioned; but don't forget to remove page
58, because AT&T's bid, VoiceSpan, has recently been
withdrawn. Also, most plans have a good Web site;see the
hyperlink version of this article.
One thing to bear in mind is that almost all important
players in the satellite world are aware of the
exploding global demand for high-bandwidth Internet
connections and of their ability to meet at least some
of that demand. Various satellite TV providers, for
instance, have serious plans. One is the
Luxembourg-based Soci=E8t=E8 Europ=E8enne des Satellites,
otherwise known as ASTRA, which has chosen the typical
scenario of data casting first and becoming interactive
a couple of years later. In the first phase, you still
need your terrestrial Internet link to order the long
files, which should reach your PC fast and cheap an
instant later via an ASTRA satellite and your dish
antenna. While copycats are crowding the rooftops, the
credit for thinking up that model of triple Internet
connections-low-speed symmetrical terrestrial access
plus a high-speed satellite downlink for long files-goes
to Hughes Network Systems, which introduced its 400 Kbps
Internet downlink system DirecPC a few years ago in the
United States and this year in Europe.
Intelsat is also seeking ways to reach the end user. In
fact, what makes the likes of Teledesic, Spaceway,
CyberStar, and Astrolink-the $3.75-billion GEO plan of
satellite builder Lockheed Martin-so special can be done
by others as well-to an extent at least-and quicker if
they have their assets in place, like 24 satellites in
the case of Intelsat. After all, no end user is really
interested in the difference between LEO or GEO, between
Ka-band and other bands, between satellite and cable.
What end users are interested in is simply performance,
hardware retail prices, transmission costs, and, first
and foremost, whether a system is available or not.
Footnotes / References
[1] Some countries which have already given a more or
less prominent place to ICT in their program for
development cooperation are: Canada, Great Britain,
Netherlands, United States, Sweden and Switzerland.
[Back]
[2] Here are some examples of African ISP's which hook
up to the Internet backbone via satellite: Ghana and
Uganda.
[Back]
Last modified: 28 August, 1997.
(C) Michiel Hegener
P.O. Box 11586
2502 AN The Hague
The Netherlands
information@iicd.org
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# collaborative text filtering and cultural politics of the nets
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