China Unicom, one of the nation's three leading mobile operators, started trials of its high-speed, third-generation (3G) network yesterday.

3G lets users enjoy faster wireless data downloads, make video calls and watch TV programs via mobile phones.

The trial network covers 55 cities and would expand to 284 cities by the end of September, said company president Chang Xiaobing.

He said regular service would start at the end of the year.

China Unicom is the last operator after China Mobile and China Telecom to start trial operation for a 3G service.

However, experts warn that the new service may not give a boost to the telecommunications market due to its high cost.

"Developing killer applications (such as the text messaging in the 2G era) is critical to spur the 3G business," said Chen Jinqiao, deputy chief engineer from China Academy of Telecommunication Research. “People are still used to and satisfied with the dominant voice and text messaging service available in the 2G era,” he added.

"This is the only way the 3G business can really take off," said Chen, predicting it will take at least five years for 3G to be widely popular in China.

According to an online survey by sina.com.cn, the largest Internet portal in China, only 1.9 percent of 363,000 respondents said they "have an idea of what 3G really is".

And although 59 percent of respondents said they would "ultimately become a 3G subscriber" in the future, nearly half said the pricing offered by the three telecom carriers was "too high".

According to the survey, in addition to the price and the need to get a new handset, 17.5 percent of respondents said the limited 3G application was the third biggest reason why they wouldn't rush to get a 3G phone.

The ministry expected the three operators to invest 170 billion yuan ($25 billion) in 3G network construction this year.

Despite the fanfare of 3G entering the market, some analysts said it would not give much boost to China's telecom carriers.