基於網路協助之媒體獨立換手管理於軟體定義無線網路

隨著近年的有線網路速度持續上升，採用軟體定義網路(Software-Define Network，SDN)作為行動通訊服務的核心網路的趨勢遂成為主要研究方向。為了讓SDN的路徑管理功能與行動通訊有更好的結合，能否有效地降低用戶端與基地台換手所消耗的時間，是一個重要的議題。為改善換手效能，在IEEE 802.21 中定義媒體獨立換手機制(Media Independent Handover，MIH) 。根據基地台與用戶端的資訊與狀態，MIH能有效預測下一個連接的候選基地台，加快用戶在基地台間換手的速度。在SDN中，控制器可以與MIH 的事件服務器與資訊服務器互動，交換路徑資訊並更改交換器之路徑轉發規則，加速移動管理的換手流程，達到有效的路徑管理目的。傳統MIH由用戶端觸發換手流程，故用戶端需要額外支援MIH協定才能完成換手流程。本論文將MIH換手流程改良成由基地台觸發，結合SDN作為核心網路，達到降低換手的耗費時間，以及提升資料傳輸的穩定度與速度。

關鍵字

媒體獨立換手；軟體定義無線網路；網路協助

並列摘要

With the speed of a wired network continued to rise in recent years, the use of Software-Defined Network (SDN) trend as a mobile communication core network services became the main research directions. In order to allow SDN communication path management functions and actions have a better combination, effectively reducing the UE and the base station handover time consumed is an important issue. To improve the handover performance, Media Independent Handover (MIH) is proposed in the IEEE 802.21 . According to the base station and the UE information and status, MIH can predict the next candidate base station is connected, and reduce user between base station handover time. To enhance the efficiency of mobility management on handover operation and manage paths effectively, SDN controller can interact with MIH event server and information server, exchange information and modify the route of the path switch forwarding rules. Typical MIH is host-assisted, because of completation of the handover process need to trigger event by the UE , and support MIH protocol particularly. This paper presents a new framework to enable MIH handover process is triggered by the base station, combined SDN as the core network, to reduce handover time-consuming, as well as to enhance the stability and speed of data transmission.