PURPOSE: A mobile smart gateway system is provided to access a communication network with an optimal receiving sensitivity by direct a gateway to check the receiving sensitivity of communications in each communication system. CONSTITUTION: A communication unit (100) switches an I/O interface (210) to an output channel with the strongest signal intensity in the case of a wireless modem. The communication unit provides the switched channel for a near field wireless modem. The I/O interface interfaces the input and output of the communication unit and a CPU (200). A memory unit (220) stores a program and data. The CPU measures each communication receiving intensity of the communication unit. The CPU directs the communication unit to communicate through a communication channel which is switched according to the receiving intensity of communications measured by the CPU. [Reference numerals] (100) Communication unit; (210) I/O interface; (220) Memory unit; (300) External storage device unit; (400) Graphic processing unit; (500) Audio processing unit; (600) External memory unit; (AA) System bus
