傳統的IEEE802.15.4標準所建立的無線感測網路在感測節點都是固定的情況下可以良好的運作，然而當感測網路中出現移動感測節點時會衍生一些問題，移動感測節點相較固定網路節點更容易失去連線能力，而為了恢復連線能力移動感測節點必須要花更多的時間和電力來發動重新關聯程序，造成感測網路整體效率的低落。為了解決這個問題，我們參考了前人的相關研究成果，設計出一個在媒體存取控制層中以連線品質指標為基底的調適性權重預測機制，藉由提早發動重新關聯程序來減少移動感測節點失去連線能力的時間。另外以不會額外增加計算負擔的方式設計了簡單的乒乓效應問題減輕程序來強化我們的機制，進而改善移動感測節點與其網路協調者之間連線的穩定性。

Conventional IEEE802.15.4 wireless sensor network is suitable for fixed sensor nodes. However, there are some issues with mobile sensor nodes joining or leaving the sensor network since the mobile sensor node is easier to lose its connectivity compared to the fixed sensor nodes. In order to regain its connectivity, the mobile sensor nodes must spend more time and energy to perform the re-association procedure, resulting in a decade efficiency of the sensor network. To solve this problem, we refer to the previous research to design an adaptive weighted link quality indicator prediction based scheme in the media access layer. The proposed scheme can reduce the non-connectivity time of mobile sensor node by early performing the re-association procedure. Additionally, we design a simple procedure to lessen the Ping-Pong effect problem without additional computation overhead, thereby improving stability of the connection between the mobile sensor node and its corresponding coordinator.

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