隨著無線通訊技術的進步，越來越多的新應用陸續被提出來，例如：穿戴式或置入式的生理感測器。這些生理感測器被安置在人體皮膚上，或內置於身體內，或安裝在身體周圍收集資訊形成無線人體區域網路。這些生理感測器通常很輕薄，並且能源有限，因此能源效率就變成無線人體區域網路中最重要的問題了。 IEEE 802.15.6工作群組在2012年二月制定並發佈了第一套無線人體區域網路的國際標準。在IEEE 802.15.6標準當中，制定了單躍星狀拓墣和雙躍延伸樹狀拓墣，在雙躍延伸的協定中，中繼節點(relaying node)的身分類似於微型的集線器(hub)，必須要處理新雙躍節點(relayed node)的加入與安排雙躍節點的傳輸，這會增加中繼節點耗能並縮短中繼節點的工作時間。 本篇論文基於IEEE 802.15.6標準提出新的兩躍傳輸模型，希望能夠節省能源並改善傳輸效率，我們利用無線人體區域網路中的節點特性達成這兩個目標。在無線人體區域網路應用上，因為節點通常安裝在人體上或甚至放入體內，因此節點體積往往受限，造成能源與計算能力匱乏，而集線器則是人體外用來負責控制一切傳輸之節點，較容易進行更換電池或充電，因此我們假設集線器具有比一般節點更多的資源與能源，本論文根據此假設，將所有兩躍控制所需執行的運算與控制，儘可能的交由資源較多的集線器去執行，藉此降低一般節點的能源消耗，並且透過適當的安排，讓各種存取方式能夠順利且有效率的套用到新的兩躍傳輸模型上。 效能分析及實驗評估的結果顯示新的兩躍傳輸模型能夠有效降低一般節點的能源消耗，將能源消耗集中到集線器上，在傳輸效能方面的表現，新協定能夠有效降低兩躍傳輸時的網路成本(overhead)，而且在新協定中，中繼節點不需具備額外複雜的功能即可幫忙轉傳資料給集線器，可以降低中繼節點的複雜度並降低能源消耗，延長中繼節點的工作時間。 Wireless body area networks (WBANs) are small range communication, and the number of nodes is typically 10-15, fewer than 256. The main challenge in WBANs is to balance the energy efficiency and quality of service. In some applications, battery powered nodes are impossible to replace batteries or recharge, and therefore to reduce energy consumption is an important requirement. There are many WBANs applications with data rate from 0.01bps to 10 Mbps. In order to satisfy each application requirement, WBANs need considering transmission efficiency. Energy efficiency and transmission throughput are important in WBANs. Based on the above observation, this thesis presents a novel two-hop extension model which utilizes the special usage of wireless body area networks to achieve power efficiency and high throughput. In WBANs applications, sometimes nodes wear or implant on human body restricting the volume, energy, and computing ability of nodes. Hubs are used to collect the data from sensors, it have sufficient energy, higher computing ability and can be recharged easily. Therefore the proposed model tries to move all of the complicated computing from relaying nodes to the hub, and reduce the energy consumption of nodes. This thesis modifies each kind of access methods, and let those methods workable on new two-hop extension model. Performance analysis and experimental evaluation shows that the proposed model can reduce energy consumption of each node and move the energy consumption to hub. The transmit performance is almost the same as IEEE 802.15.6 draft. The relaying nodes of the proposed model can help relaying data to hub without any other equipment, therefore the proposed two-hop extended model can lower the complexity of node and also can reduce the energy consumption.
