周承復臺灣大學：資訊工程學研究所林芊秀Lin, Chien-HsiuChien-HsiuLin2007-11-262018-07-052007-11-262018-07-052007http://ntur.lib.ntu.edu.tw//handle/246246/54023傳統網際網路(internet)環境中假設節點(node)對節點之間任何時間都存在著完全連結(fully connected)的路徑(path)，但是在耐延遲網路(delay tolerant network)中節點為無線裝置且具有移動性(mobility)的情況之下，路徑可能會因為節點的移動而消失，甚至導致網路被分為兩個區塊，區塊與區塊之間的通訊完全斷絕，因此，傳統的路由機制(routing scheme)並不能提供令人滿意的資料傳送服務。但是在這樣的網路環境中，仍然希望有通訊的可能，所以需要在這樣的網路中路由(routing)的方法。在現今已發表的耐延遲網路路由機制中我們將機率性路由機制(probabilistic routing scheme)PROPHET[10]做改良，改變傳遞可預測性(delivery predictability)的評量方法，能更加精確的選擇適合的中繼節點(relay node)，以較少的資料傳輸次數，達到更高的資料送達率(delivery ratio)以及更低的傳輸延遲(transmission latency)。另外我們也跟其他不同類型的路由機制作綜合比較，分析不同類型路由機制的特性。In the conventional internet, it is assumed that there exists a fully connected path between any node pair at any time. In Delay Tolerant Network (DTN), however, nodes are wireless devices and mobile. Not only the connected path may be broken, but also nodes may be partitioned into two disconnected subsets, because of nodes’ movement. Thus, the data transmission service would not be satisfied by traditional routing schemes. However, it is still possible to communicate with each other in such network. To efficiently route data in DTN, we propose an enhanced approach of the probabilistic routing scheme (PROPHET)[10]. Within a new evaluation method of delivery predictability, nodes can choose more proper relay nodes to increase delivery ratio as well as shorten transmission latency with lower transmission overhead. We also simulate some different routing schemes and analyze their performance to characterize the property about them.口試委員審定書...........................................................................................I中文摘要......................................................................................................II 英文摘要.....................................................................................................III 第一章 緒論….............................................................................................1 第二章 相關研究.........................................................................................5 2.1 以資料複製為基礎的路由.............................................................5 2.2 以知識為基礎的路由.....................................................................7 2.3 以編碼為基礎的路由.....................................................................8 第三章 PROPHET改良版..........................................................................9 3.1 PROPHET概觀............................................................................9 3.2 傳遞可預測性計算.......................................................................11 3.2.1 接觸時間使用率.................................................................11 3.2.2 接觸時間比率.....................................................................14 第四章 實驗評估…...................................................................................15 4.1 實驗情境…...................................................................................15 4.2 評估ㄧ: PROPHET改良版本評比...............................................18 4.3 評估二: 耐延遲網路路由機制綜合分析....................................24 第五章 結論...............................................................................................31 參考文獻….................................................................................................321747550 bytesapplication/pdfen-US資料路由機率路由臨機網路耐延遲網路Data RoutingProbabilistic RoutingDelay Tolerant NetworkOpportunistic Networkthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54023/1/ntu-96-R94922063-1.pdf