Method and system for providing service channel for vehicular environment, method and system for switching service channel, and computer readable medium

A method for switching service channels of vehicular environment is provided, configured for performing communications between a user unit and a service provider unit according to a switch ratio of a service channel and a control channel in a multi-channel switching wireless communication environment, including: in response to a message indicating that the service provider unit uses an access mode of an extended service channel, querying whether information corresponding to the switch ratio was stored in service information of the user unit or not in the user unit according to geographical information provided from the service provider unit; and setting the access mode of the extended service channel which the user unit enters thereinto when information corresponding to the switch ratio was stored in the service information of the user unit in the querying step.