2.1 RCS architecture / RCS架构

For RCS, the one mandatory network element is the IMS core system which enables peer- to-peer communication between RCS clients. Other network nodes can be deployed by the Service Provider to provide additional parts of the RCS feature set. Figure 3 illustrates a simplified example of the RCS architecture; a Service Provider may choose a different approach to implement a function within the Service Provider domain not influencing the interoperable NNI aspects.
对于RCS，一个强制网元是IMS核心系统，其实现RCS客户端之间的对等通信。 服务提供商可以部署其他网络节点，以提供RCS功能集的附加部分。 图3示出了RCS架构的简化示例; 服务提供商可以选择不同的方法来实现不影响可互操作的NNI方面的服务提供商域内的功能。

Figure 3: Simplified Example of RCS Architecture / 图3：RCS架构的简化示例

The PS/CS gateway (GW) is used for interworking between Circuit Switched (CS) and Packet Switched (PS) voice, for example, Voice over Long Term Evolution (VoLTE). Msg Store relates to the CPM (Converged IP Messaging) Message Store Server as illustrated in section 3.2. Legacy Msg refers to the Short Message Service (SMS)/Multimedia Message Service (MMS) services that may be utilized via an IWF (Interworking Function) located in the group of Application Servers (ASs) which in addition to these IWF node(s) may also include various other nodes used by the RCS services, for example:
PS / CS网关（GW）用于在电路交换（CS）和分组交换（PS）语音之间的互通，例如，长期演进语音（VoLTE）。 消息存储涉及CPM（融合IP消息）消息存储服务器，如第3.2节所示。 遗留消息是指可以经由位于应用服务器（AS）组中的IWF（互通功能）来利用的短消息服务（SMS）/多媒体消息服务（MMS）服务，除了这些IWF节点之外， 还可以包括由RCS服务使用的各种其他节点，例如：

• Presence Server
  存在服务器
• Messaging Server
  消息服务器
• XML (Extensible Markup Language) Document Management (XDM) Server (XDMS)
  XML（可扩展标记语言）文档管理（XDM）服务器（XDMS）
• Multimedia Telephony (MMTEL) Application Server
  多媒体电话（MMTEL）应用服务器

Figure 3 shows examples of two RCS Service Providers exchanging traffic with each other using the standard Network-to-Network Interface (NNI) mechanisms (IPX, IP Packet Exchange) as documented in [PRD-IR.90].
图3示出了两个RCS服务提供商使用如[PRD-IR.90]中所述的标准网络到网络接口（NNI）机制（IPX，IP分组交换）来彼此交换流量的示例。

RCS compliant access networks include, but are not limited to, those illustrated in the Figure 3. Thus, deploying the RCS service does not indicate a 3G network should always be deployed. Further details of RCS services relating to particular access networks are found in section 2.7. It is recommended to follow the IMS node naming guidelines as defined in [PRD-IR.67] for naming the Messaging Server, since this server is required to be addressable across IPX.
RCS兼容的接入网络包括但不限于图3中所示的接入网络。因此，部署RCS服务不指示应当总是部署3G网络。 有关特定接入网络的RCS服务的更多详细信息，请参见第2.7节。 建议按照[PRD-IR.67]中定义的IMS节点命名准则来命名消息服务器，因为该服务器需要在IPX之间寻址。