多媒體感測器網路中服務感知的自適應QoS保障

Abstract

多媒體感測器網路中同時存在端到端的多媒體流和事件到彙聚點的事件流，這對多媒體感測器網路服務質量保障帶來了新的挑戰。本文針對兩類服務的特點，設計了一種聯合應用層和傳輸層的自適應QoS保障機制，通過兩級調整，滿足用戶的QoS要求。第一級調整發生在感測器節點和彙聚節點的傳輸層，用於調整流媒體資料的可容忍差錯率和事件資料的速率調整係數；第二級調整發生在應用層，用於調整流媒體資料的QoS參數。最後對多媒體資料包的端到端傳輸時延進行了仿真，驗證QoS保障機制的有效性。In a multimedia sensor network, there may exist simultaneously two kinds of streams: end-to-end stream and event-to-sink stream. It brings new challenges for QoS guarantees in multimedia transmission. Aiming at the property of two services, we design an adaptive QoS guarantee mechanism merging application layer and transport layer, in order to meet the user's QoS requirements by two level adjustments. The first level adjustment, which happens at the transport layer of sensor nodes and cluster nodes, is used to adjust tolerable error rate and coefficient for event data rate. And the second level adjustment, which happens at the application layer, is used to adjust QoS parameters of streaming media data. Finally, end-toend transmission delay of multimedia packet is simulated in order to verify the effectiveness of our QoS guarantee mechanism. In a multimedia sensor network, there may exist simultaneously two kinds of streams: end-to-end stream and event-to-sink stream. It brings a new set of challenges for QoS guarantees in multimedia transmission.