SHANGHAI, Nov. 3 -- Shanghai has built the country's first outdoor testing facility for fourth generation mobile phone technology, which could eventually enable cell phone users to watch high-definition TV, browse the Internet and hold video conferences using their mobile handsets, city officials said yesterday.

The facility, which received central government approval on Wednesday, is a key part of China' efforts to develop fourth generation (4G) wireless technology, they said.

"The facility is a crucial step towards completion of a national 4G wireless network for cell phone users," said Nie Chunni of the Shanghai Science and Technology Commission.

Work on 4G technology started five years ago and the country aims to create a nationwide network for 4G cell phone users, she said.

The outdoor testing facility consists of a vehicle-mounted receiver and several signal stations in Changning District.

Engineers use the facility to test transmissions between the stations and the vehicle while it is running on elevated roads around the city.

The city government also plans to build a pilot 4G wireless network on Chongming Island in 2007 or 2008, Nie said.

Officials can't say when China expects to have a nationwide 4G network up and running, as the country has yet to build a full network for third generation cell phones.

The 4G wireless technology is expected to provide data transfer rates of up to 100 megabits a second - about 100 times faster than current networks and 50 times faster than a 3G network.

Such fast speed is essential to support constant picture, video and voice data transfer to people on the move, experts said. The system is designed to support phones moving at up to 300 kilometers an hour, so they can be used on trains, cars an other vehicles.

So far, the city government has invested about 60 million yuan (US$7.5 million) to build the outdoor testing facility and the central government has invested around 200 million yuan in developing 4G technology, commission officials said.

"The 4G technology will enable people to check e-mails and download films and music through mobile phones anytime and anywhere," said You Xiaohu, head of the Shanghai Wireless Communication Research Center.

The International Telecommunication Union plans to launch a new radio frequency for 4G technology by the end of 2007, previous reports revealed.

China has become the world's biggest mobile communication market.

By August, it had more than 430 million cell phone users and the number has been growing by 5.5 million users a month since late last year.