The present invention relates to a communication node arrangement (1, 1') comprising at least two antenna units (2, 3, 4, 5; 6, 7). Each antenna unit (2, 3, 4, 5; 6, 7) comprises at least one signal port (8, 9, 10, 11; 12, 13) and at least one antenna element (14, 15, 16, 17; 18, 19, 20; 21, 22, 23, 24; 25, 26, 27, 28), where each signal port is connected to at least one corresponding antenna element (14, 15, 16, 17; 18, 19, 20; 21, 22, 23, 24; 25, 26, 27, 28). Each antenna unit (2, 3, 4, 5; 6, 7) comprises at least one sensor unit (29, 30, 31, 32; 33, 34) arranged to sense its orientation relative a predetermined reference extension (35, 36). The communication node arrangement (1, 1') comprises at least one control unit (63, 74) and is arranged to feed a respective test signal into each of at least two different signal ports (8, 9, 10, 11; 12, 13). For each such test signal, the communication node arrangement (1, 1') is arranged to receive the test signal via at least one other signal port. The communication node arrangement (1, 1') being arranged to determine relative positions of said antenna units (2, 3, 4, 5; 6, 7) based on the received test signals, and to determine relative orientations of said antenna units (2, 3, 4, 5; 6, 7) based on data received from the sensor units (29, 30, 31, 32; 33, 34).