A wireless communication system for a moving vehicle, said wireless communication system comprising: a plurality of routers, each router being configured to receive and transmit wireless data communication to and from a stationary communication server outside the moving vehicle through at least one exterior mobile network via at least one antenna; receive and transmit data packets to and from at least one client onboard the moving vehicle; and communicate with every other router in said moving vehicle in order to receive and transmit data packets to and from said every other router, thereby forming an onboard router network. Each router is arranged to receive a media access control address (MAC address) from any client connecting to the onboard router network, and wherein each router is provided with a set of MAC address representations, representing MAC addresses to accept or to ignore, and wherein each router is arranged to analyze said received MAC address and compare it to its set of MAC address representations, and to determine, based on said analysis whether to accept or ignore said client. Hereby, a very efficient and scalable client balancing is obtained, which also provides redundancy.