A method and system provides for execution of calibration cycles from time to time during normal operation of the communication channel. The fan and the LED module are respectively disposed on two opposite sides of the heat sink. Data transmission between a port and a server is monitored. Modification software removes underlying stitches or a portion thereof in each identified grid section. For example, the transmission may be used in a motorized vehicle such as an automobile, motorcycle, or watercraft, a non-motorized vehicle such as a bicycle, tricycle, scooter, exercise equipment or industrial equipment, such as a drill press, power generating equipment, or textile mill. The width of the guide fixing bracket in the vicinity of the car guide rails is substantially equal to the width of the car guide rail plus the thickness of the rail clips in the guide fixing bracket.