A wireless communication system for a moving vehicle having a plurality of carriages, said wireless communication system comprising: a plurality of routers, each router being arranged in a separate carriage and each router being configured to: receive and transmit wireless data communication to and from a stationary communication server outside said moving vehicle through at least one exterior mobile network via at least one external antenna, wherein said at least one exterior mobile network provides at least one data link; receive and transmit data packets to and from at least one client onboard the moving vehicle; 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; at least one controller configured to evaluate a set of performance parameters of said at least one data link between each router and said at least one exterior mobile network and to assign data streams to said at least one data link, through said onboard router network, at least partly based on said evaluated set of performance parameters, characterized in that each router comprises a plurality of modems (8a-n) for communication with said at least one exterior mobile network, wherein each modem (8a-n) is accessible by each router of the plurality of routers through said onboard router network, wherein for each router at least one of said modems (8a-n) is configured to be connected to at least two of said external antennas in order to enable MIMO, multiple input multiple output, communication wherein the at least two external antennas are arranged close to the fore and aft end of the carriage, respectively. a plurality of routers, each router being arranged in a separate carriage and each router being configured to: receive and transmit wireless data communication to and from a stationary communication server outside said moving vehicle through at least one exterior mobile network via at least one external antenna, wherein said at least one exterior mobile network provides at least one data link; receive and transmit data packets to and from at least one client onboard the moving vehicle; 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; receive and transmit wireless data communication to and from a stationary communication server outside said moving vehicle through at least one exterior mobile network via at least one external antenna, wherein said at least one exterior mobile network provides at least one data link; receive and transmit data packets to and from at least one client onboard the moving vehicle; 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; at least one controller configured to evaluate a set of performance parameters of said at least one data link between each router and said at least one exterior mobile network and to assign data streams to said at least one data link, through said onboard router network, at least partly based on said evaluated set of performance parameters, characterized in that each router comprises a plurality of modems (8a-n) for communication with said at least one exterior mobile network, wherein each modem (8a-n) is accessible by each router of the plurality of routers through said onboard router network, wherein for each router at least one of said modems (8a-n) is configured to be connected to at least two of said external antennas in order to enable MIMO, multiple input multiple output, communication wherein the at least two external antennas are arranged close to the fore and aft end of the carriage, respectively.