使用考量時間之相關性內容於鏈結共享之發佈/訂閱機制

Abstract

近年來物聯網發展十分興盛,在分散式系統中經常使用發佈/訂閱機制來散播 資訊。不同的節點若對同一主題訂閱,則能彼此交換資訊,形成一層主題覆蓋層。 當兩節點有訂閱許多相同的主題時,其內容相關性就會增加,不同的主題覆蓋層 在傳遞資訊時就能在這兩個節點之間共享鏈結,減少整體的鏈結數以降低網路傳 輸之成本。然而每個節點對於一主題的訂閱在某些情況下是有時效性的,甚至有 特定的訂閱週期與排程。在尋找相鄰節點建立鏈結時,過去單純的考量耗電量其 實並不足以滿足需求, 因此我們加上考量內容的時間因素形成不同的網路拓樸, 提出了一套全新的資料訂閱與蒐集機制, 並進行了相關模擬, 結果能有效降低因 為訂閱資訊的過時而必須重新建立網路拓樸的負擔。

In recent years, the development of Internet of Things grows rapidly, and we often use publish/subscribe mechanism to disseminate information in distributed system. Different nodes can exchange data when they subscribe to a same topic, and then form a topic overlay. When two nodes have many common subscribed topics, their content-correlation will increase, and different topic overlays may share links between both nodes to transmit data, which leads to decrease the amount of total links in order to make lower cost on network transmission. However, every node subscribes to a topic may be time-dependent in some scenarios, especially, has specific subscription period or schedule. When looking for neighbor nodes to build links, simply taking power-consuming into concern is no longer fit the requirement. Therefore we take time into concern to build a different network topology, and propose a new data publish/subscribe mechanism with some simulation. The result shows that it can lower the effort when the need to build new network graph due to the subscription time is expired.