The goal of this thesis is to find and implement an optimal solution for efficient utilization of the varying bandwidth of a wireless network when streaming a video, between a streaming server and a mobile wireless device. The video used in the research is in a layer-encoded format, which makes it possible to achieve quality-adaptive streaming through priority dropping of video layers. The research is based on an existing streaming software called Qstream. This software supports quality-adaptive streaming, by making use of the layer-encoded video format SPEG for streaming and an algorithm known as Priority-Progress Streaming (PPS) for priority data dropping. This thesis contributes by providing an improvement code, which is added to this software to make the quality-adaptation work in a network with intensely varying bandwidth. The challenge also lies in the task of verifying how efficient the improved system is when handling different degrees of bandwidth variations.