个人在学习5G标准3GPP TS 23501-g51过程中，也发现google的机器翻译实在晦涩难懂，所以个人在借助百度翻译（中国人更懂中文）的同时，人工对每句话进行了校对。
在自己学习的同时，也将翻译内容分享给给广大网友。由于个人能力有限，翻译不到位的地方还请各位网友们指正。
4.3.1Non-roaming architecture
Figure 4.3.1-1 represents the non-roaming architecture for interworking between 5GS and EPC/E-UTRAN.
图4.3.1-1表示5GS和EPC/E-UTRAN之间互通的non-roaming架构。
NOTE1:N26 interface is an inter-CN interface between the MME and 5GS AMF in order to enable interworking between EPC and the NG core. Support of N26 interface in the network is optional for interworking. N26 supports subset of the functionalities (essential for interworking) that are supported over S10.
Figure 4.3.1-1:Non-roaming architecturefor interworking between 5GS and EPC/E-UTRAN
NOTE1: N26 interface is an inter-CN interface between the MME and 5GS AMF in order to enable interworking between EPC and the NG core. Support of N26 interface in the network is optional for interworking. N26 supports subset of the functionalities (essential for interworking) that are supported over S10.
注1:N26接口是MME和5GS AMF之间的一个inter-CN接口，以实现EPC和NG核心之间的互通。网络中N26接口的支持对于互通是可选的。N26支持S10上支持的功能子集（对互通至关重要）。
NOTE2: PGW-C + SMF and UPF + PGW-U are dedicated for interworking between 5GS and EPC, which are optional and are based on UE MM Core Network Capability and UE subscription. UEs that are not subject to 5GS and EPC interworking may be served by entities not dedicated for interworking, i.e. by either by PGW or SMF/UPF.
注2:PGW-C+SMF和UPF+PGW-U专用于5GS和EPC之间的互通，这是可选的，基于UE MMCore Netowrk Capability和UE订阅。不受5GS和EPC互通约束的UE可由非专用于互通的实体提供服务，即由PGW或SMF/UPF提供服务。
NOTE3: There can be another UPF (not shown in the figure above) between the NG-RAN and the UPF + PGW-U, i.e. the UPF + PGW-U can support N9 towards anadditional UPF, if needed.
注3：NG-RAN和UPF+PGW-U之间可以有另一个UPF（上图中未显示），也就是说，如果需要，UPF+PGW-U可以支持N9走向另一个UPF。
NOTE4: Figures and procedures in this specification that depict an SGW make no assumption whether the SGW is deployed as a monolithic SGW or as an SGW split into its control-plane and user-plane functionality as described in TS23.214[32].
注4：本规范中描述SGW的图和程序不假设SGW是作为单片SGW部署，还是将SGW拆分为其control-plane和user-plane功能。
