A method of initiating a service with an access point name (APN) of a wireless communication system for a mobile device in the wireless communication system is disclosed. The mobile device has a plurality of connections with the APN. The method comprises disconnecting at least one first connection of the plurality of connections from the APN, wherein the mobile device keeps at least one second connection of the plurality of connections connected; and initiating the service with the APN, after disconnecting the at least one first connection from the APN; wherein the APN is congested or overloaded.