A vehicle communication system includes a mobile server unit configured to be operably deployed onboard a first vehicle of a vehicle system. The mobile server unit includes an antenna, a transceiver, and a controller. The controller is configured to control the transceiver to establish a wireless onboard private long term evolution (LTE) network with plural mobile client units that are located on other vehicles of the vehicle system, for wireless communications between the vehicles of the vehicle system, while the vehicle system is moving. The mobile server unit may be configured to establish the private LTE network in coordination with other mobile server units that are onboard other vehicles in the vehicle system, such that a selected one of the mobile server units is designated as a master server unit for overall control of the private LTE network, and the other mobile server units are designated as subordinates.