Europe's T-Mobile gave IP Wireless' Time Division-CDMA technology a huge stamp of validation this week, announcing it would deploy a nationwide broadband network in the Czech Republic using the nascent wireless technology.

T-Mobile operates a 4.4 million subscriber GSM/GPRS in the Czech Republic, but until today had not announced its 3G strategy for the eastern European nation with one of the lowest levels of broadband population on the continent. Using IP Wireless base stations, data cards and subscriber modems, T-Mobile will build out TD-CDMA networks, starting in Prague this year and expanding to 85 cities in the country in 2006, using 1.9 GHz UMTS spectrum earmarked by regulators for single-channel 3G, as well as in paired bands of 872 MHz analog spectrum.

"A lot of people have been waiting to see when a Tier I operator would go into the TD-CDMA space," said Jon Hambidge, vice president of marketing for IP Wireless. "This announcement is big because it's with one of the top five carriers in the world."

While IP Wireless has been trialing its TD-CDMA technology with Orange, all of the vendor's commercial deployments have been with smaller regional carriers and non-traditional wireless providers. T-Mobile represents the first commitment of a major wireless carrier to the technology.

TD-CDMA is part of the UMTS standard, and all of the UMTS licenses issued in Europe contained spectrum for both Wideband CDMA and TD-CDMA. Carriers, however, first launched services in the paired bands for W-CDMA, which uses frequency division duplexing (FDD) dividing the uplink and downlink of the transmission between separate frequency bands. TD-CDMA uses Time Division Duplexing technology, which transmits and receives on the same channel at different periods. The paired FDD spectrum was more plentiful and W-CDMA was further along in development and backed by all of the major vendors, so it was the logical choice for initial 3G launches. Most carriers have let the TDD channels go unused.

T-Mobile, however, isn't just using IP Wireless' technology to fill its empty UMTS channels, it's also using an FDD variation of TD-CDMA to launch services over former analog channels in the 872 MHz bands. The spectrum has much greater propagation characteristics than the 3G spectrum, making it ideal for deployment in less dense markets. While T-Mobile plans to target the mobility market in Prague in larger cities with the 1.9 GHz solution, it plans to use the 872 MHz spectrum as a fixed-mobile substitution service in non-urban areas.

The TDD-FDD hybrid essentially uses an uplink and downlink on separate channels, but uses the TDD modulation scheme over the individual channels. Hambidge said the technology uses the same baseband chip as its standard TDD solution, and requires only minor infrastructure tweaking to implement.