It should be noted that the above embodiments only exemplify division of the functional modules. In actual applications, said functions can be implemented by different functional modules as needed. The internal structure of the device can be divided into different functional modules so as to implement all or part of the functions described above. In addition, the function of one of the above modules can be implemented by multiple modules, and the functions of the multiple modules can also be implemented by one integrated module.

Finally, it should be further noted that the relation terms such as first and second herein are only used for distinguishing one entity or operation from another entity or operation, and are only used for identifying different entities or operations, not necessarily requiring or implying presence of any such actual relation or order between these entities or operations. Moreover, the term “comprise”, “include” or any other variants intends to cover nonexclusive inclusion, thereby enabling a process, a method, an article or a terminal device comprising a series of elements to not only comprise those element but also comprise other elements not explicitly listed, or further comprise elements inherent for the process, the method, the article or the terminal device. In the case of no more limitations, the element defined by the wording “comprising a . . . ” does not exclude presence of another same element in the process, the method, the article or the terminal device comprising said element.