IPWireless is revamping its Time Division-CDMA to allow for one-way multicast transmissions, effectively turning its high-power 3G data infrastructure into a mobile TV broadcast network. IPWireless also announced a $10 million investment from Sprint, which is currently testing its TD-CDMA broadband technology in Virginia.

The technology, called TDtv, eliminates the uplink in the 3G architecture, using the downlink signal's entire capacity to broadcast multiple video and audio channels--similar to a standard television broadcast network. Under such a set-up a carrier could stream 50 100 kb/s video channels in a small screen format, IPWireless officials said.

IPWireless is targeting the reconfigured architecture at European carriers with unpaired UMTS licenses allocated for TD-CDMA. Most carriers have not yet used the spectrum, which most often consists of a single 5 MHz license, choosing instead to launch 3G in wideband CDMA bands where spectrum is more plentiful and the technology more accessible. IP Wireless has had some success in encouraging carriers to trial its TD-CDMA technology in the unpaired bands, but with the new multicast infrastructure many more carriers can build a business case around TD-CDMA, said Jon Hambidge, IPWireless vice president of marketing.

"We've been talking to a lot of European operators, and they see mobile TV as the next big opportunity," Hambidge said. Despite numerous trials of digital video broadcast-handheld (DVB-H) networks in Europe, many carriers are unconvinced of its merits, Hambidge said. Since DVB-H runs over a separate network, carriers would have to either partner with a broadcast provider or build up their own networks, while with TD-CDMA they could use their current UMTS footprints. In addition, carriers have invested billions in buying 3G spectrum, over which they are trying to deploy new high-bandwidth applications, Hambidge said.

"They are saying 'let's keep the next big app on 3G instead of going out and partnering or buying new spectrum," Hambidge said. "The last thing Vodafone wants to tell Wall Street is we spent $6 billion on spectrum, but we're not using it for the next big thing in mobile."

With only 5 MHz available on most TD-CDMA licenses, carriers cannot deploy wideband CDMA over the spectrum. While many operators are exploring the possibility of using IPWireless' and other time division duplexing technologies over the spectrum, they are presented with the problem of running two separate 3G networks, using separate technologies. So carriers have been looking to deploy different types of services over the TD spectrum, just as Sprint is looking to deploy alternate services over its 2.5 GHz spectrum in the U.S.

Hambidge said that one of TDtv's biggest selling points will be its cost. By taking out the uplink--and all of the associated infrastructure used to maintain a return signal from the handset--the cost of a TD-CDMA basestation would be cut down by as much as 70%. Chipset receivers added to phones would add about $10 to a cost of the handset, he said.

Several European operators are planning to trial the technology in Europe, according to IPWireless, but so far the only announced carrier is an Asian one. IPMobile in Japan plans a trial of the infrastructure in the 2010 MHz band.

On the funding side, IP Wireless announced a $10 million investment from Sprint, which is added to the $4 million Nextel invested in the company before Sprint acquired it this summer. Nextel began a trial of IPWireless's TD-CDMA technology (for broadband data services) in July in the Washington, D.C. area. IPWireless has now raised more than $200 million.