Mainland mobile phone card network providers have negotiated with Hong Kong CSL network providers, so when you arrive in Hong Kong, you will switch to CSL network, and you cannot switch to other networks.

Introduction to csl:

Hong Kong Mobile Communications Limited ("CSL") is not only a mobile phone company, but also actively changes the face of Hong Kong's telecommunications industry, providing innovative voice and data services through world-leading technology. Established in 1983, CSL is the largest mobile communication network provider in Hong Kong, leading the most competitive telecom market in the world.

CSL is the first mobile communication company in Hong Kong to adopt a clear market segmentation strategy, providing customers with mobile communication services that meet their needs through leading technology.

As a leader in the mobile communication market, CSL provides innovative and caring services to different customers through different brands: 1O 1O, One2Free and New World Transmission Network. On 20 10, CSL launched the world's first LTE/DC-HSPA+ network, a new generation of mobile broadband network, which greatly improved the network capacity and speed.

In March 2009, CSL launched the NextG TG network, which won many international awards. NextG is a world-class all-IPHSPA+ commercial mobile broadband network, which not only provides a download speed as high as 2 1Mbps, but also has the widest coverage in Hong Kong.

CSL also provides full prepaid stored value card service for local and overseas customers. CSL is a major roaming service network provider in Hong Kong, with more than 530 roaming service network providers providing international multimedia access services covering the whole world. CSL is a subsidiary of TelstraCorporationLimited, a major telecommunications and information company in Australia.