| 摘要: | 在耐延遲網路環境下，節點間並不存在一條固定的資料路由路徑，且又因節點的密度及傳輸距離等的限制，嚴重影響封包路由機制的運作，因此傳統網路的路由協定並不適合耐延遲網路。為了改善資料傳輸效能，耐延遲路由的設計大多是利用增加封包複製數，或是與相遇節點建立連線時，利用效用值來選擇有利的轉送節點等方式來增加封包抵達率或減低封包傳輸的延遲。然而過度的封包複製數及選擇轉送節點所需額外記錄的節點資訊，將導致網路資源的浪費。本論文利用Epidemic, PRoPHET , Spray and Wait , DARS路由及Random walk , Random waypoint , TVCM , SLAW移動模型進行模擬量測，以及使用NCU-Trace追蹤人類的真實移動軌跡，以比較各路由在不同移動模型下的傳輸效能。本論文除了探討基本的封包抵達率，封包傳輸花費以及封包傳輸的延遲時間，另外還探討緩衝區使用的情況，丟棄封包與路由節點的關係;以及封包在緩衝區存活的時間。除此之外，亦針對DARS路由探討封包轉送(Handoff)的問題及緩衝區對DARS路由的影響。這些數據將讓我們了解耐延遲網路中，不同路由機制下的封包複製及傳遞會因為哪些參數設定而被影響，從而提供我們之後在設計路由上的參考依據，以設計效能更佳的路由機制。
;In delay tolerant network environment, no fixed data routing path exists, and due to the limitation of node density and transmission distance, seriously affect the operation of the packet routing mechanism, therefore the traditional network routing protocol is not suitable for use in delay tolerant network. To improve data transmission performance, delay tolerant routing is designed mostly by increasing the quantity of packet copies, or designed when connecting with the encounter node, evaluate the utility value to select favorable transfer node, with these methods to increase the packet delivery ratio or to reduce the delay of packet transmission. However, excessive packet copies and the additional recorded node data needed for selecting transfer node, will lead to a waste of network resources. In this paper, we use Epidemic, PRoPHET, Spray and Wait, DARS routing and Random walk, Random waypoint, TVCM, SLAW mobility models to simulate, and also use NCU-Trace to trace human’s real movement footmark, to compare the transfer performance of each router under different mobility models. In this paper, not only discuss packet delivery rate, packet transmission cost, packet latency rate, but also discuss the use status of buffer, the relationship between drop packet and routing node; and packet survival time in Buffer. In DARS routing, also discuss the packet handoff problem and the affect of Buffer toward DARS routing. These data let us know in delay tolerant network, packet copies and delivery are affected by which parameter settings in different routing mechanism, therefore can provide us as reference basis for better performance routing mechanism design in the future. |
