A valve has a piezo actuator, a valve element, a valve body and a valve seat. The multi-channel mixer uses a nonlinear optical material exhibiting an effective nonlinearity deff whose spatial distribution is defined by a quasi-phase-matching grating, e. The user can quickly complete intended setting without redundant procedures. The dummy cell controller performs a program operation for each of the adjacent dummy cells within the memory cell array and a program verify operation of the adjacent dummy cells, and performs a program verify operation for remaining dummy cells, which are not adjacent dummy cells, and then a program operation for the remaining dummy cells requiring programming. In the present application, a base station can learn a rank of a channel loss extent of a first UE, so as to perform data transmission according to the rank, thereby improving the quality of communications between the base station and the first UE. The five phases of the logic include Registration, Stack Determination, Callback Notification, Callback Processing and Diagnostic Data Packaging.