BUCHAREST, Romania-Throughout the 1990s, NMT analog wireless systems became somewhat obsolete, particularly with the advent of GSM technology. Digital GSM systems, which offer users services such as short message service, caller ID, group calls and data transmissions, are widespread throughout Europe and have outperformed NMT networks in terms of user numbers and profitability.
NMT operators have been forced to transition their analog networks to digital systems or close the NMT networks altogether.
The NMT Memorandum of Understanding established several solutions to help NMT operators survive. GSM 450 MHz was encouraged by vendors Nokia Corp. and L.M. Ericsson, and the CDMA 450 MHz solution was backed by Samsung and Qualcomm Inc. A third solution involved a hybrid technology using GSM’s baseband and signaling and a digital Terrestrial Trunked Radio solution known as D-NMT (Digital NMT) and proposed by Swedish company Radio Design AB.
Most operators and manufacturers embraced the first two solutions, but the third option did not have sufficient backing to move forward.
GSM 450 MHz technology has the advantages of GSM’s widespread adoption in Europe, allowing roaming among different networks and a full range of feature-rich services and capabilities that are already available in the 900 MHz, 1800 MHz and 1900 MHz bands.
In April 2000, Alan Hadden, president of the Global Mobile Suppliers Association, proposed that operators of NMT 450 MHz analog mobile services could take a major step toward the early migration to digital services using GSM 400 MHz technology through a joint activity program.
“GSM 400 is fully standardized as the newest member of the global GSM digital cellular system and is the preferred digital technology of the majority of NMT operators throughout Europe and Asia now considering digitalization of their operations,” said Hadden.
GSM networks offer fast time to market and strong price performance due to open standards, multivendor supply and economies of scale derived from its position as the most popular cellular system in the global mobile market. Automatic international roaming delivers global availability and valuable revenues.
According to GSM 400 MHz proponents, the characteristics of the 400 MHz frequency band offer better coverage for voice and data services than competing technologies and ensure nationwide digital coverage at minimum cost.
The war between GSM 400 MHz and CDMA 450 MHz technologies was fueled with this declaration.
The CDMA Development Group met in September 1999 and announced its support for the NMT operators’ transition to digital CDMA technology.
“CDMA allows operators to meet 3G requirements in as little as 1.25 megahertz and up to 4.5 megahertz,” said Ted Hoffman, secretary of the CDG and vice president of technology development at Bell Atlantic Mobile. “Given that the technology has completed the first phase of 3G standardization, we are confident that CDMA offers NMT 450 operators the best technical solution for the new millennium.”
The first phase of cdma2000, also known as 1xRTT, was approved for publication by the Telecommunications Industry Association subcommittee TR45.5 in July 1999, achieving the final milestone in the standardization process for the international 3G standard.
“When considering capacity needs, CDMA is a smart choice for carriers that have an opportunity to evaluate and choose a digital wireless technology,” said Craig Farrill, past-president of the CDG and former chief technology officer of Vodafone AirTouch. Farrill is now managing director and chief technology officer at inOvate Communications Group.
From these meetings, some NMT operators decided try the CDMA technology to determine how it could be used in Europe’s sea of GSM networks. Eastern European operators that tested CDMA technology included Westel Radiotelephone from Hungary and Telemobil in Romania. Before the trials, the only CDMA carriers in the region operated wireless local loop systems or were small operators, such as in the country of Moldova, with just a couple of thousand customers on their networks.
Westel 450 from Hungary began the first CDMA mobile network trials last fall, cooperating with Lucent and Qualcomm Inc. The first phase of the trial provided coverage throughout Budapest, with up to 100 phones active on the system. The trial focused on radio-frequency optimization and maximizing network coverage within the city.
During the second phase, Westel tested the features and services of the CDMA technology, including packet data and mobile Internet. At that time, officials were optimistic in their comments about the technology.
After the successful tests in the Hungarian capital, Westel said it would not use the CDMA solution for its digitalization of its NMT network, but did not say what technology it would adopt in the future. Westel officially announced in February that due to changes in the company strategy, it would not play an active role in the Digital Interest Group in the future.
“This decision in no way was made based upon the technical performance of the CDMA 450 trial system,” said Gabor Vlaszaty, technical manager of the company.
The other operator planning to introduce CDMA technology in Eastern Europe is the Romania’s Telemobil, due to recent changes in the company’s shareholdings.
Doug Grapevine, chief technical officer of the company, said, “Telemobil is migrating to 3G 1x cdma2000 technology with Qualcomm being a principal shareholder in the parent company. Lucent is a strategic partner and will be providing the infrastructure equipment for the CDMA 450 network.”
It seems Telemobil will be the first 450 MHz operator in the world to launch a CDMA network in the 450 MHz band, although company officials could not offer a firm launch date.
Grapevine said there are several reasons why an analog operator would choose CDMA technology. First, there is no GSM infrastructure or handsets currently available for the 400 MHz band, capacity is 10 times more in CDMA networks than in GSM networks, and the voice quality is superior to wireline networks. Also, 1x data speeds could be at 144 kilobits per second (kbps) from the beginning without sacrificing capacity for voice.
Despite the technology specifics, one issue remains. Telemobil currently has a 10-year license for an analog NMT service, which will expire in two years. The company doesn’t have another license for digital communications service, although Grapevine said in three months, the carrier would have a decision about a license.
The only CDMA system in Romania is a WLL network operated by Romtelecom and the Ministry of Communications and Information Technology has not stated whether it will grant a digital cellular CDMA 450 license in the future. Therefore, there is uncertainty about how Telemobil will receive a CDMA 450 MHz network license. Nonetheless, by the end of the year, CDMA 450 MHz test handsets are expected on the streets of the Bucharest.
