HONG KONG — When top tech minds sat down to set the global standards underpinning today’s cellphone networks, China was left largely on the sidelines. Companies in the West owned much of the crucial technology, and they prospered.

Now, as the world prepares for a new generation of mobile internet that could let you download a feature-length movie in mere seconds, a Chinese company is determined to lead, putting it at the center of an international fight over the technology’s future.

Huawei, the giant maker of telecommunications equipment, has been pouring money into research on 5G, or fifth-generation, wireless networks and patenting key technologies. It has hired experts from foreign rivals and pushed them to guide international groups that are deciding the technical standards for tomorrow’s wireless gear.

But the company has also been a top concern of Washington officials. It was effectively shut out of the United States after a 2012 congressional report said Beijing could use Huawei’s equipment to spy on Americans. And this week, a United States Treasury official flagged Huawei’s 5G push as the American government investigates the proposed takeover of Qualcomm, a San Diego-based chip maker, by Broadcom, a rival based in Singapore.