Abstract: A mobile station (14) carrier-senses the radio wave receiving levels sent from a plurality of base stations (12) and informs a master station (10) of the result via a base station (12) which has jurisdiction over that mobile station (14). The master station (10) determines the next base station (12) with which a mobile station (14) should execute communication according to the carrier sense results of a plurality of base stations (12) from each mobile station (14). Consequently, the master station (10) learns with which base station (12) each of the mobile stations (14) can execute communication and the master station (10) determines the next base station (12) to have jurisdiction over a mobile station (14) so that there is no disparity between the numbers of mobile stations (14) over which each base station (12) has jurisdiction.

Abstract: Through a technique such as a carrier sense system or the like, a mobile station (14) identifies a base station (12) (requested base station) by which the mobile station is to be controlled. In response to polling from a key station (10), the base station informs the key station (10) of the requested base station. When the key station (10) performs the polling to know that a receiving base station which obtained the response is different from the requested base station, the next polling will be made through both the base stations (12). If the key station receives the response from the requested base station, the key station switches the base station controlled by itself from one to another.

Abstract: A tripod type constant velocity universal joint comprises a driven part having an axis of rotation; a driving part having an axis of rotation; a spider member, integral with one of the parts, having three roller supporting rods extended radially from the concentrated portion thereof with an angle of 120 degrees formed therebetween; three roller elements respectively rotatably supported on the roller supporting rods and slidable along the axial directions of the roller supporting rods; and a pot member, integral with the other of the parts, defining three pairs of roller raceways. The longitudinal axis of each pair of roller raceways symmetrically approaches along straight lines a rotational axis of the pot member on both sides of the roller raceways in their longitudinal direction.

Abstract: An external member for a tripod joint including a cup shaped spider holding portion for holding a spider formed with trunions and a stem portion formed with splines for power transmission coupled to the bottom of the spider holding portion and wherein the bottom of the spider holding portion is made imperforate and at least the spider holding portion or the stem holding portion is formed with an annular ridge and the spider holding portion and the stem portion are integrally friction-welded together at the annular ridge.