在無線移動隨建即用網路 (Wireless Mobile Ad hoc Networks)中，所謂拓樸控制 (topology control)在強調如何於每個節點上調整適當的封包發送電量。採用拓樸控制不僅能達成節省節點電量的目的，同時也具有提高頻道空間利用度以提升系統傳輸率(system throughput)的優點。但是，若僅單純於網路層(network layer)考慮電量控制議題，則在媒介存取控制層(medium access control layer, MAC)可能發生隱藏節點問題(hidden terminal problem)。此篇論文中，我們提出了一個分散式的協定，來處理網路層上拓樸控制的議題；同時，我們也一併解決作拓樸控制後在媒介存取控制層上可能出現的隱藏節點問題。在我們方法中，每個節點會依據從鄰居收到的訊息，最終決定自己最佳的資料封包和控制封包的發送電量。特別地，此協定中不需全球定位系統 (Global Positioning System)輔助即可進行拓樸控制，且僅需極少的額外封包成本(packets overhead)便可避免因隱藏節點存在而造成的資料碰撞問題。經過模擬的結果證明，使用我們所提出的協定可有效的降低整體網路能量耗損。與其他協定相較，我們的協定也具備更佳的網路傳輸率優勢。 Topology control emphasizes the proper adjustment the transmission power of each node in wireless mobile ad hoc networks. It not only achieves the objective of power saving but also increases system throughput by increasing the spatial reuse of communication channels. However, there exists the hidden terminal problem at the medium access control (MAC) layer if we merely consider the topology control issue at the network layer. This thesis proposes a distributed protocol that deals with topology control at the network layer and overcomes the consequent hidden terminal problem at the MAC layer. Each node in the networks determines its power for data transmission and control packets transmission according to the received beacon messages from its neighbors. The proposed protocol works without aid of the global positioning system (GPS) and uses little packets overhead to prevent the potential collisions due to the hidden terminals. Simulation results demonstrate that our protocol significantly decreases total power consumption in the networks and has better network throughput compared to other protocol.
