Guiding navigation is an important application in wireless sensor networks to make moving objects leave dangerous areas safely and quickly. However, previous works do not consider traffic congestion. In this thesis, we propose a flow-based distributed guiding protocol for indoor environments based on flow velocity to evacuate people. Our goal is to construct a less congested path to decrease escape time and congestion time. Each road is equipped with one sensor which holds an artificial potential value determined by the flow velocity of the road, the distances to exits, and the capacity of exits. We assume potential values of all exits are a maximum value, and each person is guided from its location to an adjacent road with a highest potential value. Nevertheless, our approach may cause a local maximum problem that some people are trapped at a specific location which is not an exit but holds the local maximum potential value. And this problem can be solved by reversing the incoming link. In addition, the characteristics of the relationship between density and velocity are used to reduce computational cost and communication overhead. Simulation results show the escape time and congestion time can be efficiently decreased and average velocity of people can be increased by our flow-based protocol.

導引服務(guiding navigation service)是無線感測網路(wireless sensor networks)中的一個應用，它可以導引移動物體，避免進入危險區域。然而以前並沒有特別考量擁塞的問題。我們提出一個基於流量考量的無線網路導引協定(flow-based guiding protocol)，它利用流速來疏散人群。目標是能找出一條較不擁塞的道路來降低逃生時間。每條路上都配有一個感測器，感測器帶有一個由流速、出口距離與出口大小決定而來的位能值。我們假設出口感測器的位能值是一個極大值，且每個人都從位能低的地方被導引到位能高的地方，就可以儘量遠離危險區域並逃離這個環境。除此之外，這種基於位能的協定，還會有區域極大值的問題(local maximum problem)，導致一些人會被困在某些位能極大卻不是出口的地方。我們可以藉由倒轉導引的方法來解決這個區域極大值的問題。此外我們還利用流速-密度的關係特性來降低系統的計算成本與通訊負擔。模擬的結果顯示，我們這基於流速的導引協定可有效地降低逃生時間與擁塞時間，並提升整體平均移動速度。

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