| Abstract: | 近年來無線網路與3G 網路的興起，以及智慧型手機漸漸在手機市場中嶄露頭角，利用GPS(Global Position System)系統搭配地圖程式功能來規劃旅遊路線、玩遊戲、聽音樂等，現在在智慧型手機上就可以完成。然而，因為成本的考量與實際上的限制，未必所有的地點都適合架設無線的AP，這些沒涵蓋到的部分形成了通訊上的黑洞。特別是在一個群組出遊的活動中，P2P 或群組通訊是重要的需求，但不一定要利用到基地台或AP 來作群組通訊，更有可能是出遊地點並無法有這些無線網路的完整服務。例如登山或腳踏車隊出遊的活動，通常只在登山口/休息站設立無線AP 供上網，若是在活動沿途想要上傳一些照片與朋友分享、跟群組朋友通訊或個人化的現況詢問，只能由各個節點彼此合作，透過multihop 的方式來傳送訊息。然而，發送端到目的端之間不一定一直存在有一條端點到端點的路徑可供路由傳送。解決在這樣的不穩定網路架構下傳輸問題的概念，就稱為耐延遲網路delay tolerant networks /disruption tolerant networks(DTN)。基於上述，本研究的目的為：在資源受限的DTN環境下，利用分群的概念、 opportunistic network及network coding，來解決網路頻寬，網路連線變化的問題，並且考量行動設備的有限電力，希望設計兼顧energy-efficiency的一套有效提升群組通訊傳輸效能的機制。本計畫將分三年來進行。第一年將研究標靶式定位演算法，並依網路拓樸穩定度的高低不同，分別研究群體通訊的傳輸方式，包含利用機會編碼(opportunistic coding) 設計P2P間斷式影音串流傳輸方式，及利用位置資訊結合網路編碼(network coding)來設計DTN路徑規劃。第二年將以自行車行動網路(BikeNet)為焦點，以地理位置及信賴關係來分群，並研究群內及群間的通訊協定。第三年將引進人智運算的概念，設計 GWAP(Game with a purpose)的輔助定位系統，及大範圍的WiFi定位演算法，藉使BikeNet 的分群與DTN的傳輸機制更可靠。相關的技術將整合實作在BikeNet的平台上實驗評估。
Recently the wireless and 3G networks have been developed successfully, the mobile smart phones are becoming popular and can play almost everything on them, including using GPS (Global Position System) and e-Map to plan travel routes, gaming, music, etc. However, due to the constraints of cost and practice, not all places are suitable to deploy infrastructure like APs or base-stations. Those areas which have not been covered by wireless infrastructure will become the communication holes. Especially, for the group activities, the P2P or group communication is the important demand. It does not necessarily utilize the APs or base-stations to transport their data, or even it can not use the wireless services due to lack of infrastructure. For example, a mountain-climbing or bike activity, usually wireless APs are only installed at the entrance or rest areas, not the entire trail. If someone wants to share the pictures they take with friends during the activity or query some information, the data transmission can only be done by peer members’ cooperation, namely, multihop relay to forward data to the designated group member(s) or node(s). Moreover, there usually does not exist a stable path from source to destination node. To solve the transport problem in such an unstable or disconnected network environment, a concept of delay/disruption tolerant networks (DTN) is proposed. Based on the aboves, the research goals of the subproject will be: In the resource-constrained DTN environment, how to develop good clustering/grouping algorithms to design the P2P and group communication protocols in order to achieve performance enhancement. How to utilize opportunistic network and network coding to solve network instability and limited bandwidth challenges. We should also take into considerations the energy-efficiency for the mobile devices. This subproject will proceed for three years. In the first year, we will develop a bulls’ eye locating technique, and also design the group communication protocols for different network topology stabilities. They will include P2P interrupted streaming mechanism using opportunistic coding and location-based DTN routing using network coding. In the second year, we will advance to focus the development of a BikeNet. We will use geo-information and group relationships to do clustering or grouping. Then an energy-efficient intra-cluster protocol and a high heuristically reliable inter-cluster protocol will be developed. In the 3rd year, by using the concept of human computation, we will design a game with a purpose (GWAP) which will assist on building Wi-Fi radio maps to enhance the accuracy and extend the coverage of the locating system we developed in the previous year. With the more accurate location information, the clustering and DTN routing mechanism for the BikeNet will achieve more reliable and better performance. We will also integrate the important techniques and practice a real system to prove the concept. |
