Yesterday, Apple has launched Apple Pay in China, entering a mobile payment market with about 360 million users and fierce competition.But it was off to a sour start as many smartphone users encountered problems signing up for Apple Pay."It kept telling me the phone 'cannot connect to Apple Pay' or the verification for the card is not available when I was linking a bankcard," said Duan Ge, a 31-year-old employee of a film production company.Duan said he managed to link his debit card after about 30 minutes of trying, but later when he tried to register another credit card, he said he “couldn’t even open the app."Apple spokesman Cong Jie said the problem was due to too many people trying to sign up and that by the second day it wouldn’t be an issue.It was indeed a sour start for Apple, which enters a market that is dominated by two of China’s Internet emperors, Alibaba and Tencent.But Apple doesn’t come to the market without ammunition.It has partnered up with UnionPay, which itself has been brooding about the dominance of Alibaba and Tencent in mobile payment, as well as 15 major lenders, including the nation’s largest, the Industrial and Commerce Bank of China.And for now, sixteen businesses in China, including 7-Eleven, McDonald's and Carrefour will accept Apple Pay.The payment service can also be used to buy movie tickets, book airplane tickets and food delivery via mobile phone apps.Some mobile payment experts also argue that Apple Pay is a safer payment option than an Internet-based system because it uses something called a near-field communication to exchange data with banks.