The above description is only embodiments of the present disclosure and is not intended to limit the patent scope of the present disclosure. Any equivalent structures or equivalent process transformations made based on the description and the accompanying drawings of the present disclosure or any direct or indirect application in other related technical fields are all included in the patent protection scope of the present disclosure.

In the several embodiments provided in the present application, it should be understood that the devices and methods disclosed can be implemented in other ways. The device embodiments described above are merely exemplary, for example, the classification of the elements is merely a classification of logic functions, and in practice implementations, there are other classification ways. For example, some of the elements or components may be combined or integrated into another system, or some features may be omitted or unexecuted. Moreover, coupling or direct coupling or communication connection between the components illustrated or discussed herein may be indirect coupling or communication connection of devices or elements by some interfaces or may be electrical connection, mechanical connection or the other forms of connection.

The elements described as separate components may be or may be not physically separated, and the components illustrated as elements may be or may be not physical elements, i.e., they may be located at one place or distributed in a plurality of network elements. Moreover, some of or all the elements may be selected according to actual demands to implement the purpose of the embodiments of the present disclosure.