裝置間直連通訊技術能讓本地端裝置在缺少網際網路基礎設施的情況下彼此進行資料傳遞，然而其可用範圍，侷限於兩個近距離直連通訊裝置的有限直接通訊範圍內。為延伸裝置間的通訊範圍，讓更多裝置可彼此間通訊，本研究開發此D2D中繼閘道器，使裝置間直連通訊可經由串接形成D2D中繼網路，擴大裝置間直連通訊範圍。以此形成之D2D中繼網路架構將具有可快速布建、可彈性調整、易於串接延伸網路覆蓋範圍等優點。此外，要在此D2D中繼網路中順利傳遞封包，有賴一個智慧的路由演算法，協助D2D中繼閘道器判定封包之路由方向，當有多路徑可供選擇時，更可以根據D2D中繼網路之特性，選擇較佳之路徑進行封包傳遞。

Direct Communication Technology allows communications between devices in the absence of local Internet infrastructure, but the usable range is limited to within some distance of direct communication devices. To extend the communication range between devices, so that more devices can communicate with each other , a D2D relay gateway is developed in this study which enables communications between devices by directly connecting D2D relay gateways in series to form a D2D relay network, and then the inter-device communication range is expanded. The D2D relay network architecture has advantages including quick deployment, elastic adjustment, and easiness in network coverage extension and so on. To successfully pass packets in the D2D relay network, an intelligent routing algorithm is necessary to help D2D relay gateways determine the direction of the packet's route. When there are multiple paths to choose from, it can help select the preferred path of packet delivery according to D2D relay network’s features.