NXP Semiconductors has teamed with China's T3G Technology Co. Ltd to validate automatic handover of multimode TD-SCDMA and GSM/GPRS/EDGE calls, which the companies say will boost mass adoption of handsets in the fast-growing China mobile market.

The bi-directional on-the-fly automatic handover between TD-SCDMA and GSM networks was achieved with T3G's reference design platform in multiple networks built by major infrastructure vendors in China including Datang Mobile, ZTE and TD-Tech.

T3G is a joint venture between NXP Semiconductors, Datang Mobile, Samsung Electronics and Motorola.

The reference platform and handset is based around an NXP Nexperia cellular system solution, the T3G 7208. This uses NXP's EDGE platform and the design meets the major Chinese operators' plans to upgrade their 2G network to EDGE to offer fallback of data services.

NXP says that by keeping the same baseband, 2G chipset and application software interfaces for both standards, the reference design enables handset manufactures to maximize their R&D investment in both TD-SCDMA and W-CDMA.

TD-SCDMA networks are being rolled out by China Mobile and other China operators in 10 cities including six 2008 Olympics host-cities. The handover will be crucial to the operation of the network not only to ensure TD-SCDMA 3G services to interested audiences at these Olympic host cities, but also to allow the continued use of existing 2.5G network infrastructure.

"With the realization of TD-SCDMA and GSM/GPRS/EDGE automatic handover feature, thus ensuring great backward compatibility with 2.5G networks, the most challenging technological hurdle facing the TD-SCDMA handsets at the initial commercial stage has been cleared," commented T3G CTO Daijun Zhang. "The addition of the TD-SCDMA/GSM/GPRS/EDGE automatic handover feature to the T3G reference design platform will give our handset maker customers an advantage in creating a rich variety of competitive TD-SCDMA mobile handsets that meet the demands of the China market."