"Non-Access Stratum (NAS)

## 定义 / Definition

### English The protocol layer between the UE (User Equipment) and the Core Network. NAS handles mobility management, session management, and interoperability between different access networks. It operates independently of the radio access technology.

### 中文 UE（用户设备）与核心网络之间的协议层。NAS处理移动性管理、会话管理以及不同接入网络之间的互操作性。它独立于无线接入技术运行。

## NAS 协议演进 / NAS Protocol Evolution

时代协议描述 ------------------ 2G/3GTS 24.007/008MM, CC, SM 4G (EPS)TS 24.301EMM, ESM 5G (5GS)TS 24.5015GMM, 5GSM

## 协议栈视图 / Protocol Stack View

+-------------------------+
Application
+-------------------------+
NAS (Non-Access
Stratum)
+-------------------------+
RRC / AS (Access
Stratum)
+-------------------------+
Layer 1/2 (PHY/MAC)
+-------------------------+

## NAS 功能 / NAS Functions

### English

功能描述 ------------ Mobility ManagementLocation update, attach/detach Session ManagementPDN connection, QoS SecurityEncryption, integrity protection Inter-RATHandover between access networks

### 中文

功能描述 ------------ 移动性管理位置更新、附着/分离 会话管理PDN连接、QoS 安全加密、完整性保护 跨RAT接入网络间切换

## 交叉引用 / Cross References

- TS 24.007 - NAS general aspects - TS 24.301 - EPS NAS - TS 24.501 - 5G NAS - Layer 3 (L3) - Mobility Management - Session Management