Good quality of service for a video streaming application under time-varyingnetwork bandwidth capacity is often required in many real-world scenarios, e.g., streaming in a typical high-speed vehicular environment. However, developing the enabling algorithms and techniques have been proven tobe very challenging. Adaptive bitrate streaming methodcan detect a user's network bandwidth availability in real time and then adjustthe quality of a video stream accordingly. Although this method brings in many advantages, itsuffers from additional storage and encoding costs, and challenges with maintaining quality globally. We propose NBS (a Network-Bandwidth-aware streaming version Switcher) system for videostreaming applications. Compared with adaptive bitrate streaming method, our method is a lightweight oneby switching among different versions (e.g., high quality, medium quality, low quality) that a video streaming server provides. Moreover, our method works in an appropriate way that can balance both the responsivenessand the stability. On one hand, responsiveness is necessary because adaptiveactions should be taken in a real-time manner to sustain the live streamingwhen the network bandwidth changes. On the other hand,too sensitive actions willdeteriorate the stability and affect the perceptual quality. NBS is developed based on afeedback fuzzy controller to support the dynamic and adaptive switching. Comparing with thetraditional control approaches, the fuzzy logic enables NBS to enjoy much better responsivenessand stability. We have conducted comprehensive experiments to evaluate our approach and theexperimental results show that the proposed approach can effectively up-scaling or down-scaling the quality of the streamaccording to the network bandwidth availability by a smooth and nearly unnoticeable switch without disrupting the continuous playback.