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Saturday, November 8, 1997 Published at 12:54 GMT



Sci/Tech

New satellites to revolutionise communications

The new satellites will allow people to make phone calls from the remotest parts of the world

An historic breakthrough in telecommunications comes one step closer on Saturday November 8. Five more satellites, which will eventually form part of a "constellation" of 66 above the world, are to be launched from Vandenburg Air Force base in California.

This new satellite network is designed to allow people in the most remote corners of the planet to talk to each other using only a pocket sized mobile phone.

Weather permitting, the satellites will be carried into orbit by a Boeing Delta II rocket blasting off at exactly 17:34 PST (01:34 on Sunday GMT).

Satellites were formerly considered too closely linked to national security to be owned by anyone other than national governments. But in 1992 the mobile satellite services industry was allocated part of the broadcast spectrum.

The network will also allow other types of information to be transmitted, such as faxes or pager numbers. It is also designed to be complementary to landline and mobile (or cellular) phone networks.

Telecommunications revolution

This latest development is mainly aimed at business professionals, but is also being marketed as useful to travellers, people who live in rural or undeveloped areas, and disaster relief teams.

The satellites have been designed and built by Motorola, for Iridium LLC, a consortium of telecommunications a companies. Iridium LLC is on course to be the first company with a network of communications satellites. It will be called the "Iridium constellation".

The new technology will not be cheap to use. Iridium phones will retail for around $3000 (£1,800) and calls are likely to cost around $3 (£1.80) a minute.

The advantages the new networks will offer over current satellite calling options:

  • greater convenience - currently callers have to carry around a lap-top sized unit to send or receive calls.
  • Integration with current mobile phone networks
  • Better quality sound

Competition

The level of competition in the billion dollar business of global communications is fierce. A host of satellite services are due to get airborne over the next five years. Iridium are currently leading the race after sending their first satellites into orbit in May. So far 34 satellites have been launched from California, China and Kazakhstan and they hope to have 44 in orbit by the end of the year.

Putting all 66 into space will cost around $3.5 billion (Over £2 billion) and up to $5 billion (£3 billion) in total to set up the entire service infrastructure.

Iridium's closest competition comes from Globalstar, another consortium of companies working on setting up a network of 48 satellites. They too hope to be up and running by the end of 1998. Their estimated set up costs are expected to be around $2.5 billion (£1.5 billion). Globalstar are likely to be offering cheaper call rates of around $1.25 (75p) per minute.

Sabine Hage, Manager of Corporate Communications for Iridium at Motorola said she was "confident they were two to three years ahead of Globalstar". Ms Hage also said that with less satellites, their competitors will not have the complete global coverage Iridium boasts.

Unlike the geostationary satellites which are inter-governmental satellite systems, mobile satellite services are mostly funded by private investors.

It is not clear whether there is a large enough market to cover the massive costs required to set up the networks. Some estimates place the number of customers the networks will attract in the next decade as between 8 to 16 million worldwide. This number could only support roughly two main companies. In addition, with the continual improvement of current services, the amount of time that someone will be out of reach of the terrestrial networks is already fairly limited.

How does it work?

Satellite communications are nothing new - they have been around since the 1960s.

The idea of communications satellites was first put forward by physicist and prolific science fiction writer Arthur C Clarke over 50 years ago. Best known as the author of '2001: A Space Odyssey' Mr Clarke's theory was that if a radio repeater or satellite was placed in orbit around the earth, there could be communication between two fixed points on the planet which do not have a direct line of sight.

These became known as geostationary earth orbit (GEO) satellites, because they have a rotational period identical to the earth's and therefore appear to be motionless in the sky.

Airships, aeroplanes and trucks have relied on these geostationary satellites to provide mobile satellite communications for years. The new mobile satellite services rely on newer low earth orbit (LEO) satellites.

Unlike GEO satellites, which have an altitude of 22,300 miles above the earth, the LEO satellites are only around 400 miles up. This lower altitude, in tandem with other technological advances, makes it possible for people to communicate across the globe with a pocket sized mobile phone.

Because these LEO satellites are so much closer, a network of them is needed to provide the same coverage that one geostationary satellite would offer. They promise to offer better quality sound with no 'echo effect'. However, old GEO satellites will still be better suited to wide band transmissions such as television,

Two leading companies

Iridium LLC: will consist of 66 interconnected satellites, with six extra as backup, orbiting about 420 miles above the earth. The constellation is expected to become fully functional on September 23, 1998. The network will be the only one where the satellites link to each other as well as ground stations and individual phones. This means that satellites can pass on calls between each other before they drift out of range. Calls can also go straight to a satellite and the then be beamed down directly to another Iridium phone.

Globalstar: will consist of 48 satellites. It expects to have them all in position by the end of 1998. These satellites are 'pipe bent repeaters' which means they are not networked with each other, but that they send signals down to a ground station that then feeds into land lines.










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