Until just over a year ago, Gong Kangshun spent much of his life trekking over the mountains around his remote village in south-west China. It isn't easy to make a living in Xiuxi, a tiny settlement of 58 families deep in Aba county, Sichuan. Gong grows crops on a small plot and sells rare fungi found on the steep slopes nearby. Many young people, including his brother, leave to find work in the factories and shops of China's east.
But a single purchase has shortened his working hours and sent his income soaring – by helping him to find buyers for his fungi. It has even improved his relationships with family and friends. "I'd panic without my mobile phone," the 35-year-old admits.
Across China, tens of millions have similar tales to tell. Many had never enjoyed phone access until recently. Now, for as little as £20, they can buy a handset, slot in a pre-paid sim card, start calling – and change their lives.
Most, like Gong, can thank one firm: China Mobile. With more than 70% of the domestic market it has 518 million subscribers; more than any other mobile carrier on the planet.
It is the world's largest phone operator by market value and the largest Chinese company listed overseas. Its work on 4G technology and its interest in foreign acquisitions suggest its international profile may soon grow.
Already the company's influence is rippling out across the world, almost unnoticed. The rapid spread of mobiles facilitated by the company's high-speed network roll-out, is both a product of China's aggressive development and a contributor to it – accelerating the pace of life and business, shrinking distances.
Some activists are enthusiastic about the potential for mobiles and the internet to expand the flow of information in a country with heavy censorship. They point to cases where camera phones have captured and shared images of unrest or official abuse.
The authorities certainly seem to be aware of the potential – Chinese social networking sites are strictly controlled and overseas services such as YouTube are blocked. In restive Xinjiang text messaging was turned off after vicious ethnic violence. The authorities also use mobiles for everything from political education to monitoring individuals.
The social and political effects of new technology are rarely straightforward, but for most people, mobiles are simply a part of their life. Whether a highly-paid Shanghai executive, or an independent farmer-cum-trader such as Gong, no one can afford to be without a phone – or a signal. China Mobile's 500,000 base stations now cover 98% of the population. You can call home from city subway trains, distant fields, or the peak of Mount Everest.
"If you have a requirement, we will have coverage," pledged the firm's chairman and chief executive Wang Jianzhou, who has more than three decades of experience in the sector.
"When we started this business we thought very few people would usemobile phones – only the rich," he said. Now he is dissatisfied with a penetration rate of 57%. "I think every adult should have at least one mobile … they are an extension of human ears, eyes and mouths."
Before the network reached Xiuxi, in late 2008, Gong used the phone perhaps twice a month. Each time he would walk for an hour to the nearest landline to call traders interested in buying the valuable "caterpillar" and "sheep stomach" fungi used in Chinese medicine.
"Now, on a busy day, I might make 20 calls," he said. "I can contact buyers in Chengdu and Shanghai. I can do business sitting at home and buyers can reach me, too."
His income has risen 50%, to 20,000 yuan (£1,820). And instead of walking seven hours a day to find the fungi collectors, he can call and ask them to deliver.
In his spare time, he chats to his younger brother, a chef in Zhejiang province who comes home at most once a year. Villagers hear a lot more news from the outside world these days – even Gong's 14-year-old son has his own phone. In 1997, there were just 10 million mobile users in China; by 2005, China Mobile had 240 million. Since then it has more than doubled.
The government pushes all carriers to serve the poorest. But since taking charge at China Mobile in 2004, Wang has shown sceptics that focusing on rural areas is a viable business strategy.
"Many analysts and investment bankers told me: never go to rural areas because they are low revenue. You will not make a profit," Wang said, in an interview at his spacious but low-key office in the company's headquarters on Beijing's Financial Street.
"I didn't believe that … with fixed lines, providing rural services is very, very difficult and expensive. [We have] low average revenue per user – but also low costs."
With a penetration rate of just 37%, there is plenty of room for growth among China's 700 million rural population. And there is plenty of demand. In Yangcun county, close to Beijing, Chen Fengmei anxiously scrolls through her latest text message: advice from officials on how the day's weather will affect her tomato crop. Another villager, Li Chunyu, checks the latest market prices for his pigs, no longer needing to trust middlemen or to give them a cut of his profits. "I never need to go anywhere. I can stay on the farm and find out everything," he said.
