In a voice signal relay and transfer method for a voice call between a radio voice terminal and a remote device includes, a radio voice signal is received from the radio voice terminal and converting the radio voice signal into a digital voice signal. The digital voice signal is further converted into a group of voice packets in a streaming form. Then the group of voice packets is transmitted to a streaming server via a mobile communication network. The group of voice packets is further transferred from the streaming server to the remote device in a streaming form.