The present invention relates to a method for controlling an overload of a network, which may be generated due to a service request of a terminal in a mobile communication system of machine type communication. The delta sigma modulator includes a switched capacitor circuit that integrates a difference between the single-ended input signal and the single-ended analog feedback signal derived from a quantization output of the delta sigma modulator. The transferring unit includes a driving member and a transferring member connected to the driving member. Other participants in the instant messaging session receive the activity message and generate an activity indicator on their respective displays.