critical path through the code is taken for the transmission failure immediately before the mode down it is composed of 10 statements other cases are much shorter in setting the algorithm it is necessary to set only the parameter a t which slightly affects accuracy of the mode up test the present invention may be implemented as computer readable codes on a computer readable medium the computer readable mediums include all types of recoding devices for data storage that can be readable by a computer system examples of the computer readable recording medium include a read only memory rom a random access memory ram a compact disk read only memory cd rom a magnetic tape a floppy disk an optical storage device media etc the medium may be a transmission medium based on carrier wave transmission e g internet based transmission furthermore computer readable recording mediums may be distributed over computer systems connected to a network and computer readable codes distributively stored and executed therein also functional programs codes and code segments for implementing the present invention may be inferred by programmers skilled in the art to which the present invention pertains according to the present invention an algorithm with the.