There were few frequencies available for mobile telephony in Europe at the end of the 1970s: existing radio technology imposed an upper limit of about 1 GHz; the frequencies below the NMT band of 450 MHz had all long been occupied; the 470–890 MHz band was in general use for television broadcasts. All that was left, therefore, was 900 MHz and above.
This worried the Nordic NMT engineers and in 1979 they launched a joint initiative. They proposed to WARC (the World Administrative Radio Conference) that the 900 MHz band should be reserved for future terrestrial mobile communications. WARC accepted the proposal but without specifying any of the details. Was the band to be used for public or private systems? Was the system to be digital or analog?
Haug recalls: “We were happy about the WARC decision but we knew that it would not hold up for long. The frequency band was attractive for many others, so there really was no time to be lost before we started to use it.”
The Nordic countries also raised the frequency issue at the 1980 CEPT (the European Post and Telecommunications Conference) the following year, with representatives from industry authorities in 26 countries.
CEPT was an informal organization (“more or less like a residents’ association but with a secretariat that kept track of documents as best it could,” Haug writes); from 1959 onwards, it had taken care of standardization issues because it was felt that the ITU standardization bodies CCITT and CCIR worked far too slowly.
The 1980 CEPT made an important decision: two 25 MHz sub-bands in the 900 MHz band were earmarked for use for mobile telephony in Europe.
MOBILE CHAOS IN EUROPE
Once the rest of the world learned about NMT, there were two different reactions. One was to acquire the system, the other to construct one’s own. The problem with the latter was that the resulting system would not be compatible with NMT or with any system developed by anyone else – unless countries cooperated. Outside Scandinavia, such cooperation was rare.
Philippe Dupuis, later to lead the French in European cooperation on mobile telephony, describes how in 1981 France realized that it had fallen well behind in this area. Shortly after the NMT premiere, he and a French delegation visited Televerket and L.M. Ericsson. He described how the French had begun preparations for an NMT system in the 900 MHz band. Haug mentioned Nordic plans to go up to the same frequency in the future, but digitally. Indeed, the Nordic countries had already done some preliminary work.
Dupuis was so surprised that he repeated his question to make sure he had understood correctly. “Do you mean a completely digital system that could function for instance in TDMA?” Haug confirmed this.
Author: Svenolof Karlsson & Anders Lugn