開源LTE核心網路移動管理實體之應用層代碼重構

Abstract

隨著近年來多媒體影音及社群網路的爆發性成長，許多研究指出第四代行動通訊網路將無法滿足未來使用者們的需求。有鑑於此，全球的電信商、設備商、及學術界等都著手進行下世代5G行動網路的相關研究。綜觀未來5G需求，除了更高的傳輸速率及更低的延遲外，更彈性的核心網路是各界研究的重點、亦為眾人追求的目標：根據使用者需求提供客製化的服務、快速低成本的布建新服務、及有效率的分配硬體資源等。

然而對於想研究核心網路的學者而言，一個真實的核心網路往往要價不斐，既有的開源核心網路軟體又不夠彈性。因此我們提出可重組的核心網路概念以滿足未來5G對於彈性的需求，並基於此概念及既有的開源軟體實作可重組的移動管理實體。另外，為了讓其他開發者更容易地使用、修改、及擴充可重組的核心網路，我們針對可重組的移動管理實體進行代碼重構，並以物件化的語言改寫部分模組，以期增加代碼的可讀性及可修改性。

最後，為了驗證可重組的核心網路可行性，我們對實作的可重組的移動管理實體進行一系列的實驗，並從實驗結果中獲得正向的回饋。

With the increasing demands driven by the explosive development of multimedia and social networks, some research reveals that the current fourth-generation (4G) mobile technologies will not fulfill the expanding requirement in the near future. Consequently, organizations from industry to academia engage themselves in 5G research. Besides higher data rate and lower delay, 5G needs a more flexible architecture enough to deploy new services quickly, customize the network to satisfy different use cases, and utilize the hardware resources efficiently.

Nevertheless, it’s difficult for general researchers interested in the core network to get available resources due to two issues. First, proprietary core networks cost more than one million NT dollars, which is unaffordable to most researchers. Second, the existing open source is not flexible enough to meet the 5G demands. Thus, we propose the concept of the reconfigurable core network (RECO). To embody the idea, we build a RECO MME based on open source. Besides, to make RECO easier for other developers to understand, modify, and extend for future innovations, we modify RECO MME with object-oriented language and code refactoring techniques, which makes the implementation more readable and more modifiable.

In the end, we make several experiments to verify the feasibility of RECO and check the correctness of RECO MME. As a return for our efforts, we attain positive results.