BEIJING—Twenty million of China’s 123 million mobile-phone users regularly use short message service (SMS) to send each other text messages. China Mobile, the country’s biggest operator, predicted that 10 billion messages will be sent this year.
Sending an SMS is four times cheaper than a one-minute phone call in China.
One problem holding back the use of SMS is that messages cannot be exchanged between users of the networks of the two mobile carriers, China Mobile and China Unicom.
