The quake has damaged more than 3,000 China Mobile base stations in Sichuan province. Other operators are facing similar difficulties not helped by a higher-than-usual volume of calls.

Fixed-line operator China Telecom says its staff is monitoring and controlling the number of phone calls to and from the quake-hit region. They're keeping the lines clear to ensure telecommunications for disaster relief.

China Mobile says call volumes in Sichuan Province are six to seven times what they normally are. More than a fifth of the cell phone network in the region is overloaded. And less than half the calls being made in Chengdu, the capital of the province, are getting through.

Zheng Xiaoming, Manager Network Department, China Mobile, said, "The main reason is that too many people are calling at the same time. Customers can wait for a couple of seconds if they cannot get through. We also suggest customers use text messages instead."

China Mobile has assigned emergency communications vehicles to the quake-hit regions and taken various measures to relieve the pressure on the mobile network.

Zheng Xiaoming said, "Three transmission facilities were affected by the main earthquake. But we had them fixed at around 5 a.m. this morning."

China Mobile says things are running more smoothly in southern Gansu Province, as well as Chongqing, where network congestion was severe.

Meanwhile, the networks of China's other mobile operator, China Unicom, were also affected.

Cell phone service was cut in Wenchuan County, where the epicenter of the quake was located. China Unicom says it has sent technicians and a vehicle equipped with satellite telecommunication facilities to the area.

(CCTV May 13, 2008)