The invention relates to a method and apparatus. In the method a determining a first position of a user of a mobile node is determined at a first time instant. A second position of the user of the mobile node is determined at a second time instant. A time difference is determined between the first time instant and the second time instant. A walking speed of the user is determined using the time difference, the first position and the second position. A third position of the user of the mobile node is determined. A walking time required for the user to reach at least one elevator is determined from the third position based on the walking speed of the user. An elevator call and the walking time are transmitted to an elevator call control node.