目前被廣泛運用的機器類型通訊(MTC)裝置會定期和其他裝置進行少量資料的傳輸。然而目前3GPP所制定的資料傳輸方式並不適合機器類型通訊裝置進行小資料傳輸。當很多個機器類型通訊裝置要進行小資料傳輸時，這些裝置必須透過隨機存取步驟來建立無線資源控制(RRC)連結，因而導致網路壅塞、增加裝置的功率消耗。在3GPP TR23.887這份規格文件提出非存取層(NAS)方法可以改善小資料傳輸情境所造成的網路壅塞。小資料可以透過非存取層封包做傳送、非存取層封包擁有加密功能可保護資料。所以建立無線承載和安全模式的傳輸步驟是多餘的。但是這份文件卻沒有足夠模擬數據證實此方法是有效率的。
本篇論文主要是設計數學模組來探討非存取層方法是否適用於小資料傳輸。模擬數據顯示當裝置進行小資料傳輸時，在不影響延遲的情況下，非存取層方法能夠延長機器類型通訊裝置的壽命。

Machine Type Communication (MTC) devices which have been applied extensively generate a small amount of data exchanged periodically. However, legacy transmission method used in 3GPP is not suitable for MTC device to perform small data transmission. The reason is these devices will have to perform random access procedures to establish the Radio Resource Control (RRC) connection. This scenario will increase network overhead and power consumption of MTC device. Non-Access Stratum (NAS) method proposed from 3GPP TR23.887 document can improve network overhead. Small data can be added into NAS packet and NAS packet supports the encrypted function for protecting data. Hence, the transmission procedures which included the establishment of the radio bearers and security mode are redundant. Nevertheless, this document does not show sufficient simulation statistics which prove this method is efficient.
The objective of this thesis is to devise an analytical model used to explore if NAS method can be applied to small data transmission. Numerical result shows that NAS method can extend the lifetime of device without causing the increment of access delay when infrequently small data being produced.

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