A communication system supports communication between an end node (101) of a vehicle (103) and a remote correspondent node (105) via a fixed network (107) which comprises a plurality of wireless access points (109) with a directional antenna arrangement for mm wave radio communication using directional beams. A vehicle (103) comprises wireless modems (111, 113, 701, 703) employing electronically steerable beamforming directional antennas for establishing mm wave radio communication links to the access points (109). At least one first access point (109) is arranged to transmit multipath environment data for an area supported by the access point to the wireless modems (111, 113, 701, 703). A controller (1101) of the vehicle is arranged to set a diversity property for transmissions of data from the wireless modems to the wireless access points in response to the multipath environment data.