A knuckle-swivel is used with well drilling equipment for protecting helical wound line 62, which may be wire rope, cable andor strand, against torsional forces and also providing for angular displacement of sinker bars or other tools during wireline strip over operations to minimize interference with rig equipment when pulling pipe or tools 64 from a well head. The base station receives a plurality of first uplink transmission requests of a plurality of first wireless devices of a first group and a plurality of second uplink transmission requests of a plurality of second wireless devices of a second group in a first time interval, and approves one of the second uplink transmission requests. The first half primary and secondary windings are overlaid with a ferrite layer.