New victory in the US

One question that did arouse interest in the US, however, was future digital mobile telephony – as long as it did not involve European solutions. On the other hand ERA’s position as one of the three leading suppliers was a reality. In 1988, therefore, ERA was invited together with two competitors, AT&T and Motorola, to propose a digital “multiplex standard” for the US, based either on TDMA or FDMA.

Jöran Hoff, now head of commercial development at ERA, made sure that seminars for the mobile industry in the US were told that TDMA was the technology that digital radio signals should be based on: “I remember one occasion at Dallas in particular as I was presenting the technological arguments to an audience of several hundred and a professor stood up, pointed at me and shouted: ‘He’s lying’”.

In the late autumn of 1988, it was time for the three competitors to prove their points. They were asked to install a pilot system in Los Angeles and then had to show that it worked and argue for it.

 Uddenfeldt marshaled ERA’s troops. “There was some fighting but we had developed a sound knowledge of TDMA. For three weeks we received operators at our test installation and described the possibilities the system offered.”

The tests turned out to support ERA completely. “Our competitors were unlucky,” says Hoff. In a nutshell, their FDMA system had problems while ERA’s TDMA system worked exactly as promised.


Uddenfeldt recalls: “There was a vigorous public debate about this, of a kind that you never see in Europe. The decisive session took place in a ballroom and was attended by at least 500 people. You had to be able to argue your case, respond effectively at the right times and look like a winner. We had two major American companies opposing us. I am still amazed that we won. But we were so committed.”

The American decision therefore was that ERA’s TDMA solution would be the standard technology for digital mobile telephony. Everyone had assumed that FDMA would win, and one side-effect was that ERA’s competitors had to fire a whole horde of FDMA experts they had recently taken on.

“One thing that certainly contributed to our success was that the TDMA solution made it possible to upgrade existing analog AMPS networks to TDMA networks without having to scrap all the old technology or build new base stations,” Uddenfeldt says.

To begin with, the American digital technology was known as D-AMPS, to indicate that in fact it involved an upgrade of the analog system. It was to be five years before the digital system actually began to operate in the US, in 1993, and then with the somewhat confusing name of TDMA.

One explanation for ERA’s victory, according to Sven-Olof Öhrvik, can be found in the research into digital radio technology going on at the time in Swedish universities: “The knowledge we had acquired there was critical for the tests in Los Angeles.”

Author: Svenolof Karlsson & Anders Lugn

Rick Clawson from Bell South visiting ERA

Rick Clawson from Bell South visiting ERA



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