Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for switching a secondary cell to a primary cell. A user equipment (UE) monitors a first radio condition of the UE for beams of a primary cell and a second radio condition for beams of one or more secondary cells configured for the UE in carrier aggregation. The UE transmits a request to configure a candidate beam of at least one candidate secondary cell as a new primary cell in response to the first radio condition not satisfying a first threshold and the second radio condition for the at least one candidate secondary cell satisfying a second threshold. A base station determines to reconfigure at least one secondary cell as the new primary cell. The base station and the UE perform a handover of the UE to the new primary cell.

Abstract: In a six-degree-of-freedom precision positioning system, magnetic force and fluid buoyancy are used to levitate a platform, and the non-contact magnetic force between electromagnets and magnets forms a main driving force for the platform. Therefore, no friction is present in the system and no lubricating mechanism is needed for the system. Moreover, in the system, electric current is converted by electromagnets and magnets into a magnetic driving force without using any transmission gears. Therefore, the backlash phenomenon that is not easily controllable in the conventional servo positioning systems is avoided. The system has simplified structure without the need of complicated fabrication, and utilizes the properties of fluid to achieve low power consumption, high precision positioning, and fast response.

Abstract: In a six-degree-of-freedom precision positioning system, magnetic force and fluid buoyancy are used to levitate a platform, and the non-contact magnetic force between electromagnets and magnets forms a main driving force for the platform. Therefore, no friction is present in the system and no lubricating mechanism is needed for the system. Moreover, in the system, electric current is converted by electromagnets and magnets into a magnetic driving force without using any transmission gears. Therefore, the backlash phenomenon that is not easily controllable in the conventional servo positioning systems is avoided. The system has simplified structure without the need of complicated fabrication, and utilizes the properties of fluid to achieve low power consumption, high precision positioning, and fast response.