You Can Call Home Easier Than E.T. Did

WITHIN the next decade, you should be able to pull out a portable phone and use it anywhere in the world. It won't matter whether you're driving in Mt. Lebanon, Pa., or climbing Mt. Everest, in Tibet. You'll always be in touch.

Of course, some of this is already possible. Cellular telephones already link up big cities and suburbs. By the year 2000, they'll be even more pervasive. But these networks won't reach the Sahara or the Australian outback. Worse, a cellular phone from the United States doesn't work in Europe because the systems use different standards.

One telecommunications industry thinks it has the answer for a worldwide hand-held phone: Satellites.

``It's kind of an international office-in-the-pocket concept,'' says Durrell Hillis, vice president and general manager of Motorola's satellite communications division. ``Now you can put a phone in your pocket and anywhere you go in the world, you have communications along with paging and facsimile.''

``The whole future of the business is in the hand-held,'' adds Ron Mario, president of Comsat Mobile Communications.

These two companies are at opposite ends of a commercial push to build the ultimate hand-held phone. The technological challenge is how to build such a system. Should the companies expand the current satellite system? Or start from scratch?

Motorola is starting from scratch. Its system, called Iridium, calls for 66 satellites orbiting the earth in a line around the North and South Poles. The cost: $3.5 billion. Availability: up and running by 1998, Motorola promises.

Comsat, based here in Bethesda, Md., is taking the most conservative route. It plans to expand an existing system called Inmarsat.

Inmarsat is an international consortium that provides telephone links to ocean-bound ships. Comsat is the US signatory to the consortium, its largest shareholder, and the only Inmarsat member covering the oceans around the work with its own facilities. By revamping the system, Comsat says it can create a worldwide portable telephone network for land users as well. ``This is all evolutionary,'' Mr. Mario says.

Other companies are also vying to establish satellite-based portable phones. Qualcomm and Loral have joined forces to build a 48-satellite network. TRW wants to launch a 12-satellite system in 1997, although it would not cover the world. American Mobile Satellite Communications plans next year to launch a satellite service covering North America.

These networks would probably complement rather than compete with ground-based mobile systems.

Mario sees his system attracting the professional traveler who needs to be in constant touch and cellular users who either live or travel to areas outside the range of cellular networks. Iridium and Inmarsat would use dual-use phones, capable of using either terrestrial networks, such as cellular, or satellites when the former aren't available.

``You're always going to have a need to fill the gaps,'' Mr. Hillis of Motorola says. Even in the United States, an estimated 25 million people won't be covered by cellular service in the year 2000.

Comsat's and Motorola's systems are poles apart in terms of technology. Iridium will use low-earth-orbiting satellites, about 460 miles above the surface of the earth. Inmarsat hasn't decided whether to use a geostationary system (23,300 miles up) or a mid-earth orbit (about 12,000 miles up). It has already rejected the low-earth-orbit as too cumbersome - and too expensive.

``It's a complicated network,'' Mario says of Iridium. For every $1 billion a company spends to build its system, it will have to charge users $1 a minute for using it. ``To me, the magic number is $2 billion.... Low-earth [satellites] didn't make sense, because you couldn't do it for that price.''

The higher the orbit, the fewer satellites needed. With a geostationary system, Mario envisions a system that could cover virtually the entire globe with three or four satellites. That's much less expensive than the 66-satellite Iridium. A mid-earth orbit would require 12 to 15 satellites that would be 2-1/2 to three times as expensive as the geostationary system, he says.

The problem with the higher orbits is that the signal is weaker. That means the hand-held phone has to be bigger to receive and transmit signals. The first-generation Inmarsat phone came in two suitcases, each weighing about 50 pounds. The current system requires a single 24- to 30-pound suitcase. The next generation will weigh about 10 pounds. But to attract a big customer base, Mario estimates the portable unit can be no more than two to three pounds. That's an improvement, mobile phone analysts say, but still bulky for today's traveling business people.

``You have to wonder if they really want to be in touch'' enough to carry around that much weight, says Paris Burstyn, vice president of telecommunications research at Business Research Group. ``There are some areas where people do need to be in touch where a 2-1/2-pound phone is not a problem. For a niche like that, the Inmarsat ... makes sense.''

That niche may be limited, he says, to researchers in remote areas or villages in the third world where one stationary unit could serve thousands of people.

Iridium's advantage is the weight of its phone. A satellite less than 500 miles above the earth could work with a telephone no bigger than Motorola's vest-pocket Microtac, weighing less than a pound, Hillis says.

That fits in with the business customer's needs for portability, but, because it's a more expensive system, it will cost more to use. Hillis estimates the cost will be about $3 a minute.

These cost estimates for Iridium and Comsat don't include local and long-distance fees over regular land lines. For example, a call from an Iridium phone in Paris to an office phone in Phoenix might mean that the satellite signal comes down to the nearest land-based gateway, say, in Los Angeles and then is transmitted over land lines to Phoenix. Thus, the cost of the call would be $3 for Iridium plus a long-distance charge from Los Angeles to Phoenix.

Will business people really carry expensive dual-use phones to always stay in touch?

``I'm not convinced,'' says Ira Brodsky, president of Datacomm Research Company, a consulting and market research firm in Wilmette, Ill. ``The real hard-core market for this thing will be in the tens of thousands. And if it's that, they're in trouble.''

He too sees possible applications for developing nations, such as solar-powered phone booths in remote locations. By broadening its market to land users, Inmarsat is expanding its market, he says. ``Iridium is much riskier.''

Mr. Burstyn is blunter: ``I don't think it's going to be Inmarsat or Iridium'' providing global portable service. He sees the major countries working out a system where cellular phones in country are usable on any cellular network.

Motorola is challenging the right of Comsat and Inmarsat to participate in the market, since this telephone system falls outside of the international consortium's original charter to provide maritime service. Comsat points out that Motorola originally asked Comsat to become a customer or joint-venture partner in Iridium.

``If they want to compete in the land area, then they should compete on an equal basis,'' Hillis says. ``Inmarsat pays no taxes.... It does give them a clear income advantage.''

``Poor, small $20 billion Motorola is afraid of $200 million Comsat?'' Mario counters. ``This is a company that took on the Japanese and won. They're afraid to take us on?... All we want is the ability to compete.''