5G SM策略关联建立与PCC规则编排拆解：N7接口SmPolicyDecision全链路解析

graph TB
    AF[AF<br/>应用功能] -->|N5/N28| PCF
    PCF[PCF<br/>策略控制功能] -->|N7<br/>SM Policy Control| SMF
    PCF -->|N15<br/>AM Policy Control| AMF
    PCF -->|N36| UDR[UDR<br/>统一数据存储]
    SMF -->|N4<br/>PFCP| UPF[UPF<br/>用户面功能]
    SMF -->|N10| UDM[UDM<br/>统一数据管理]
    SMF -->|NAS| UE[UE<br/>终端]
    CHF[CHF<br/>计费功能] -->|Nchf| SMF
    style PCF fill:#FF6B6B,color:#fff
    style SMF fill:#4ECDC4,color:#fff
    style UPF fill:#45B7D1,color:#fff

stateDiagram-v2
    [*] --> Idle: UE附着完成
    Idle --> AssociationEstablishment: PDU Session建立触发<br/>SMF发起Npcf_SMPolicyControl_Create
    AssociationEstablishment --> Active: PCF返回SmPolicyDecision
    Active --> Active: SMF发起Modification<br/>(PDU Session Modification)
    Active --> Active: PCF发起UpdateNotification<br/>(AF触发/策略变更)
    Active --> AssociationTermination: PDU Session释放<br/>SMF发起Delete
    AssociationTermination --> [*]

    note right of Active
        活跃状态下的操作：
        - SMF主动请求策略更新
        - PCF推送PCC规则变更
        - 计费报告上报
        - 用量监控上报
    end note

sequenceDiagram
    participant UE
    participant AMF
    participant SMF
    participant PCF
    participant UDM
    participant UDR
    participant UPF

    UE->>AMF: NAS: PDU Session Establishment Request
    Note over AMF: SMF选择（NRF发现）
    AMF->>SMF: Nsmf_PDUSession_CreateSMContext Request
    Note over SMF: 1. 解析DNN、S-NSSAI、SUPI
    SMF->>UDM: Nudm_SDM_Get (订阅数据)
    UDM-->>SMF: SessionManagementSubscriptionData
    Note over SMF: 2. 判断需要PCC授权
    SMF->>PCF: POST /npcf-smpolicycontrol/v1/sm-policies<br/>SmPolicyContextData
    Note over PCF: 3. PCF策略决策引擎处理
    PCF->>UDR: Nudr_DataQuery (策略数据)
    UDR-->>PCF: PolicyDataSubscription
    Note over PCF: 4. 匹配PCC规则模板<br/>计算QoS参数
    PCF-->>SMF: 201 Created<br/>SmPolicyDecision
    Note over SMF: 5. 解析SmPolicyDecision<br/>执行QoS Flow Binding
    SMF->>UPF: N4 Session Establishment Request<br/>(PDR/FAR/QER/URR)
    UPF-->>SMF: N4 Session Establishment Response
    SMF-->>AMF: Nsmf_PDUSession_CreateSMContext Response
    AMF-->>UE: NAS: PDU Session Establishment Accept<br/>(含QoS Rules)

POST /npcf-smpolicycontrol/v1/sm-policies
Content-Type: application/json

{
  "supi": "imsi-460110123456789",
  "pduSessionType": "IPV4",
  "dnn": "internet",
  "snssai": { "sst": 1, "sd": "010203" },
  "AccessType": "3GPP_ACCESS",
  "ratType": "NR",
  "ipv4Address": "10.1.2.100",
  "subsSessAmbr": {
    "uplink": "100000000",
    "downlink": "200000000"
  },
  "subsDefQos": {
    "5qi": 9,
    "arp": { "priorityLevel": 15, "preemptCap": "NOT_PREEMPT", "preemptVuln": "PREEMPTABLE" },
    "priorityLevel": 15
  },
  "chargingInformation": {
    "primaryChfAddress": "chf.operator.com",
    "secondaryChfAddress": "chf2.operator.com"
  },
  "online": true,
  "offline": false
}

flowchart TD
    A[收到SmPolicyContextData] --> B{验证SUPI<br/>与DNN合法性}
    B -->|合法| C{查询UDR策略数据}
    B -->|非法| ERR[返回400 Bad Request]
    C --> D[获取用户签约策略<br/>PolicyDataSubscription]
    D --> E{匹配PCC规则模板}
    E --> F[基于DNN+S-NSSAI<br/>匹配初始PCC规则]
    F --> G[基于订阅QoS<br/>计算session规则]
    G --> H[确定计费策略<br/>Online/Offline/Both]
    H --> I[确定用量监控策略<br/>MonitoringKey]
    I --> J[生成SmPolicyDecision]
    J --> K[存储策略关联上下文<br/>关联ID = policyAssosId]
    K --> L[返回201 Created]

    style A fill:#FFE66D
    style J fill:#FF6B6B,color:#fff
    style L fill:#4ECDC4,color:#fff

HTTP/1.1 201 Created
Location: {apiRoot}/npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}
Content-Type: application/json

classDiagram
    class SessionRule {
        +String ruleId
        +String refUmData
        +String refCondData
        +Ambr authSessAmbr
        +AuthDefQos authDefQos
        +boolean sessionRuleState
    }
    class Ambr {
        +String uplink
        +String downlink
    }
    class AuthDefQos {
        +integer 5qi
        +Arp arp
        +integer priorityLevel
        +boolean defQosFlowIndication
    }
    class Arp {
        +integer priorityLevel
        +PreemptCap preemptCap
        +PreemptVuln preemptVuln
    }
    SessionRule --> Ambr
    SessionRule --> AuthDefQos
    AuthDefQos --> Arp

flowchart TD
    A[SMF遍历PCC Rules] --> B{PCC规则是否指定<br/>defQosFlowIndication=true?}
    B -->|是| C[绑定到默认QoS Flow<br/>QFI=default]
    B -->|否| D{是否存在匹配的<br/>QoS Flow?}
    D -->|匹配条件: 5QI + ARP一致| E[绑定到已有QoS Flow]
    D -->|不匹配| F{是否为GBR类型?}
    F -->|GBR| G[创建新的GBR QoS Flow<br/>专用QFI]
    F -->|Non-GBR| H{是否允许复用?}
    H -->|允许| I[创建新的Non-GBR QoS Flow<br/>可被后续规则复用]
    H -->|不允许| I
    E --> J[生成N4 Rule<br/>PDR+FAR+QER]
    G --> J
    I --> J
    C --> J
    J --> K[生成QoS Rule<br/>下发给UE]
    K --> L[完成Binding]

    style A fill:#FFE66D
    style L fill:#4ECDC4,color:#fff

Binding Key = Hash(5QI, ARP.priorityLevel, ARP.preemptCap, ARP.preemptVuln)

POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/modify

POST /nsmf-policycontrol/v1/sm-policies/{smPolicyId}/update

sequenceDiagram
    participant AF
    participant PCF
    participant SMF
    participant UPF
    participant UE
    participant AN as RAN

    AF->>PCF: N5: AppSessionContext Update<br/>(请求更高带宽)
    Note over PCF: 策略决策：新增PCC Rule<br/>5QI=4(Non-GBR) ARP=10
    PCF->>SMF: Npcf_SMPolicyControl_UpdateNotify<br/>SmPolicyNotification
    Note over SMF: 解析新的PCC Rule<br/>执行QoS Flow Binding
    Note over SMF: 无匹配QoS Flow<br/>创建新QFI=4
    SMF->>UPF: N4 Session Modification<br/>(新增PDR/QER for QFI=4)
    UPF-->>SMF: N4 Session Modification Response
    SMF->>AN: N2 SM Information<br/>(QoS Flow Setup Request)
    AN-->>SMF: N2 SM Information Ack
    AN->>UE: RRC Reconfiguration<br/>(DRB配置 for QFI=4)
    UE-->>AN: RRC Reconfiguration Complete
    SMF->>PCF: Npcf_SMPolicyControl_Update Notify Response<br/>(执行结果确认)
    PCF->>AF: N5: AppSessionContext Update Response<br/>(授权确认)

flowchart LR
    subgraph PCF_PCC["PCF层：PCC规则"]
        PCC_Rule[PccRule<br/>flowInfos + refQosData<br/>+ refChgData]
    end
    subgraph SMF_Binding["SMF层：QoS Flow Binding"]
        QoS_Flow[QoS Flow<br/>QFI + QoS参数]
        QoS_Rule[QoS Rule<br/>下发给UE]
    end
    subgraph UPF_N4["UPF层：N4规则"]
        PDR[PDR<br/>包检测规则]
        FAR[FAR<br/>转发动作规则]
        QER[QER<br/>QoS执行规则]
        URR[URR<br/>用量报告规则]
    end

    PCC_Rule --> QoS_Flow
    PCC_Rule --> QoS_Rule
    QoS_Flow --> PDR
    QoS_Flow --> FAR
    QoS_Flow --> QER
    QoS_Flow --> URR

# 过滤SM Policy Association Establishment
http2.headers contains "sm-policies"

# 过滤SM Policy Modification
http2.headers contains "sm-policies" && http2.headers contains "modify"

# 过滤PCF推送的策略更新
http2.headers contains "sm-policies" && http2.headers contains "update"