A data transmission system for transmitting and receiving data comprising a first communication system configured to transmit and receive, data over a first network and a second communication system configured to transmit and receive data over a second network. The second network has a more contiguous physical coverage than the first network. The system further includes a proxy unit configured to select a routing of user data from a user device through either the first communication system or the second communication system. The proxy unit being configured to select the routing based on a user condition. The user condition may be based on a user preference, a detection of a type of user session (e.g., an SSL session), and/or a travel path of the user. A communication system is selected that provides the best network coverage, including continuity, based on the user condition.