在臺大醫院無線感測網路中兩種資料傳輸方法的實作與研究

Abstract

近年來，老年人口的增加與醫護人員的不足已使得一般的老人安養中心難以有效的提供高品質的醫療照護。為了解決這個議題，我們在北護分院護理之家佈建了一個無線感測網路系統來協助醫護人員隨時掌握老人的生活作息與位置。然而，無線感測網路通常受限於感測裝置有限的運算能力，因此，將資料透過一個多重跳躍路由協定傳送到遠端電腦以做後續處理是不可或缺的。為了能準確的追蹤老人家的位置，路由協定必須符合即時性與高傳輸率。在此論文中實際評估並比較了magnetic diffusion(MD)和Collection Tree Protocol(CTP)兩種路由協定。在感測裝置處於靜態的實驗中，資料顯示CTP在200ms的延遲時間內有比MD還來得好的表現。而在移動的實驗中，CTP和MD在網路中有兩個感測裝置下是同樣好的。

Staff shortages and the increasingly aging population have strained the ability of elder-care center to provide high quality medical treatment. To deal with these issues, a wireless sensor network (WSN) is deployed in the Bei-Hu nursing home to assist the nursing staff in tracking the elder's daily life and mobility. The WSN is, however, constrained from the limited computation capability of the micro-controller in the sensor node. A multi-hop routing mechanism collecting data from the sensor node to a remote computer is thus indispensible. To conform with the requirement of mobility tracking, the collection protocol should satisfy both timely and high-delivery-rate transmissions. This work is intended to have a realistic evaluation of two collection protocols to see whether the above two requirements are achieved. The routing protocol we evaluate is called magnetic diffusion (MD), which is used in Bei-Hu hospital now. The state-of-the-art Collection Tree Protocol (CTP) is chosen as the comparison baseline. From the traces we collected, we find that CTP has a better performance than MD in the latency range of 200ms in the static experiments. In the mobile experiment, MD and CTP are comparable when there are two mobile sources in the network.