"Service Access Point (SAP)

## 定义 / Definition

### English A logical interface between two adjacent layers in the protocol stack where service primitives are exchanged. SAP defines the boundary between layers and the services provided across that boundary.

### 中文 协议栈中相邻两层之间的逻辑接口，用于交换服务原语。SAP定义层之间的边界以及跨越该边界提供的服务。

## 常见 SAP / Common SAPs

SAP英文全称中文全称用途 ------------------------------- MM-SAPMobility Management SAP移动性管理SAPMM层与CC层之间 RR-SAPRadio Resource SAP无线资源SAPRR层与L2之间 CC-SAPCall Control SAP呼叫控制SAPCC层与应用层 SM-SAPSession Management SAP会话管理SAPSM层与传输层

## 协议栈中的 SAP / SAP in Protocol Stack

+------------------+
Application
+---------|--------+
          |
    +-----+-----+
    CC-SAP
    +-----+-----+
          |
    +-----+-----+
    MM-SAP
    +-----+-----+
          |
    +-----+-----+
    RR-SAP
    +-----+-----+
          |
    +-----+-----+
    L2 SAP
    +-----+-----+

## 交叉引用 / Cross References

- TS 24.007 - SAP definitions - Service Primitive - Layer 3 (L3)