5G PCF策略关联与动态PCC规则触发N7信令全链路拆解

graph TB
    subgraph "应用层触发"
        AF[AF<br/>应用功能]
        NEF[NEF<br/>网络开放功能]
    end

    subgraph "策略决策层"
        PCF[PCF<br/>策略控制功能]
        BSF[BSF<br/>绑定支持功能]
        UDR[UDR<br/>统一数据仓库]
    end

    subgraph "会话管理层"
        SMF[SMF<br/>会话管理功能]
        CHF[CHF<br/>计费功能]
    end

    subgraph "用户面"
        UPF[UPF<br/>用户面功能]
    end

    AF -->|"N5/Npcf_PolicyAuthorization"| PCF
    NEF -->|"N30"| PCF
    PCF -->|"N7/Npcf_SMPolicyControl"| SMF
    PCF -->|"N28"| CHF
    PCF <-->|"Nudr_DataRepository"| UDR
    PCF <-->|"Nbsf_Management"| BSF
    SMF -->|"N4/PFCP"| UPF

    style PCF fill:#e74c3c,color:#fff
    style SMF fill:#3498db,color:#fff
    style UPF fill:#2ecc71,color:#fff

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

    UE->>AMF: NAS PDU Session Establishment Request
    AMF->>SMF: Namf_Communication_N1N2MessageTransfer<br/>(含DNN, S-NSSAI, SUPI)

    rect rgb(230, 240, 255)
        Note over SMF: Step 1: 获取签约数据
        SMF->>UDM: Nudm_SDM_Get(SUPI, DNN)
        UDM-->>SMF: 签约数据(默认5QI, ARP, Session-AMBR)
    end

    rect rgb(255, 240, 230)
        Note over SMF: Step 2: 建立SM策略关联
        SMF->>PCF: POST /npcf-smpolicycontrol/v1/sm-policies<br/>Npcf_SMPolicyControl_Create

        Note right of SMF: SmPolicyContextData:<br/>supi, dnn, snssai,<br/>ipv4Address/ipv6AddressPrefix,<br/>ratType, userLocationInfo,<br/>servingNetwork,<br/>subsDefQosInfo,<br/>sessAMBR

        par PCF内部策略决策
            PCF->>UDR: Nudr_DataRepository_Query<br/>(策略数据集)
            UDR-->>PCF: 策略计数器状态、预定义规则
        end

        PCF-->>SMF: 201 Created<br/>SmPolicyDecision

        Note left of PCF: SmPolicyDecision包含:<br/>sessRules[], pccRules[],<br/>qosDecs[], chgDecs[],<br/>traffContDecs[], umDecs[]
    end

    rect rgb(230, 255, 230)
        Note over SMF,UPF: Step 3: N4规则映射与下发
        SMF->>UPF: N4 Session Establishment Request<br/>(PDR, FAR, QER, URR, BAR)
        UPF-->>SMF: N4 Session Establishment Response
    end

    SMF-->>AMF: Namf_Communication_N1N2MessageTransfer<br/>(N2 SM Info + NAS PDU Session Accept)
    AMF->>RAN: N2 PDU Session Resource Setup Request
    RAN->>UE: RRC Reconfiguration (含NAS Accept)

flowchart TD
    A[PCF收到SmPolicyContextData] --> B{查询策略计数器状态}
    B --> C{匹配策略基础<br/>Policy Base}
    C --> D[生成Session Rule<br/>默认QoS + Session-AMBR]
    C --> E[匹配PCC Rule<br/>基于签约业务/预定义规则]
    E --> F{有AF会话绑定?}
    F -->|是| G[查询BSF获取绑定信息<br/>AF Session ↔ PCF绑定]
    G --> H[生成动态PCC Rule<br/>包含AF请求的QoS/流描述]
    F -->|否| I[仅生成签约级PCC Rule]
    D --> J[组装SmPolicyDecision]
    H --> J
    I --> J
    J --> K[返回201 Created给SMF]

sequenceDiagram
    participant AF as AF<br/>应用功能
    participant BSF as BSF<br/>绑定支持功能
    participant PCF as PCF<br/>策略控制功能
    participant SMF as SMF<br/>会话管理功能
    participant UPF as UPF<br/>用户面功能
    participant CHF as CHF<br/>计费功能

    rect rgb(255, 245, 230)
        Note over AF,BSF: 阶段1: AF会话发现
        AF->>BSF: GET /npcf-bsf/v1/bindings<br/>?ipv4Addr=x.x.x.x&dnn=internet
        BSF-->>AF: 200 OK<br/>(返回PCF ID + Binding ID)
    end

    rect rgb(230, 245, 255)
        Note over AF,PCF: 阶段2: AF策略授权请求
        AF->>PCF: POST /npcf-policyauthorization/v1/app-sessions<br/>Npcf_PolicyAuthorization_Create

        Note right of AF: AppSessionContext:<br/>afAppId, afReqId,<br/>medComponents[],<br/>sipForkInd,<br/>tsnPortManCont<br/>(含SDF过滤器、请求带宽、5QI)

        PCF->>PCF: 策略决策:<br/>1. 校验AF请求合法性<br/>2. 检查签约允许的QoS<br/>3. 生成动态PCC Rule
    end

    rect rgb(255, 230, 230)
        Note over PCF,SMF: 阶段3: PCF推送策略更新
        PCF->>SMF: POST /npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/update<br/>Npcf_SMPolicyControl_UpdateNotify

        Note left of PCF: SmPolicyNotification:<br/>pccRules:{add:[新PCC Rule],<br/>mod:[修改PCC Rule],<br/>remove:[删除PCC Rule]}<br/>qosDecs, chgDecs

        SMF->>SMF: PCC Rule → N4 Rule映射:<br/>PCC Rule → QER(QoS Enforcement)<br/>SDF → PDR(Packet Detection)<br/>chgDecs → URR(Usage Report)
    end

    rect rgb(230, 255, 240)
        Note over SMF,UPF: 阶段4: N4会话修改
        SMF->>UPF: N4 Session Modification Request<br/>(新增/修改PDR+QER+URR)
        UPF-->>SMF: N4 Session Modification Response
    end

    rect rgb(240, 230, 255)
        Note over PCF,AF: 阶段5: 策略授权响应
        PCF-->>AF: 201 Created<br/>AppSessionContextResp<br/>(含授权的QoS参数)
    end

    rect rgb(255, 255, 230)
        Note over UPF,CHF: 阶段6: 使用量上报
        UPF->>SMF: N4 Usage Report (URR触发)
        SMF->>CHF: Nchf_ConvergedCharging<br/>(在线计费信用管理)
    end

stateDiagram-v2
    [*] --> Idle: PDU会话未建立

    Idle --> Creating: SMF发送<br/>Npcf_SMPolicyControl_Create
    Creating --> Active: PCF返回<br/>201 Created
    Creating --> Failed: PCF返回<br/>4xx/5xx错误

    Active --> Modifying_SMF: SMF发起<br/>Npcf_SMPolicyControl_Update
    Modifying_SMF --> Active: PCF返回<br/>200 OK

    Active --> Modifying_PCF: PCF发起<br/>Npcf_SMPolicyControl_UpdateNotify
    Modifying_PCF --> Active: SMF返回<br/>200 OK

    Active --> Deleting: SMF发起<br/>Npcf_SMPolicyControl_Delete
    Deleting --> Idle: PCF返回<br/>204 No Content

    Active --> Terminated: PDU会话释放

    note right of Active
        活跃状态可同时接受
        SMF-initiated和
        PCF-initiated更新
    end note

{
  "policyCtrlReqTrigger": ["UE_REQ"],
  "repPolicyCtrlReqTriggers": ["REACT_TIME", "PLMN_CH"],
  "qosFlowUsage": ["IMS_SIG"],
  "userLocationInfo": {
    "tai": {"plmnId": {"mcc": "460", "mnc": "00"}, "tac": "A001"},
    "ncgi": {"plmnId": {"mcc": "460", "mnc": "00"}, "nrCellId": "00A01000"}
  },
  "ratType": "NR"
}

{
  "pccRules": {
    "add": [
      {
        "pccRuleId": "freeDataRule-001",
        "flowInfos": [{"flowDescription": "permit out ip from any to any"}],
        "qosDec": {"5qi": 9, "arp": {"priorityLevel": 15}},
        "chgDec": {"ratingGroup": "RG-FREE", "offlinChg": true}
      }
    ]
  },
  "traffContDecs": {
    "add": [
      {"tcDecId": "gateOpen-001", "gateStatus": "OPEN", "flowInfos": [...]}
    ]
  }
}

PCF → BSF: POST /npcf-bsf/v1/bindings
{
  "ipv4Addr": "10.1.2.3",
  "supi": "imsi-460001234567890",
  "dnn": "internet",
  "snssai": {"sst": 1, "sd": "010203"},
  "pcfId": "pcp-001.cluster-a",
  "pcfFqdn": "pcf5g.mnc00.mcc460.3gppnetwork.org"
}

AF → BSF: GET /npcf-bsf/v1/bindings?ipv4Addr=10.1.2.3&dnn=internet
BSF → AF: 200 OK
{
  "bindingId": "bind-12345",
  "pcfId": "pcp-001.cluster-a",
  "pcfFqdn": "pcf5g.mnc00.mcc460.3gppnetwork.org",
  "supi": "imsi-460001234567890"
}

{
  "condData": {
    "condId": "cond-nightfree",
    "activationTime": "23:00:00+08:00",
    "deactivationTime": "07:00:00+08:00",
    "validityArea": {
      "taiList": [
        {"plmnId": {"mcc": "460", "mnc": "00"}, "tac": "A001"}
      ]
    }
  }
}

http2.headers contains "npcf-smpolicycontrol" 
或 
http.request.uri contains "sm-policies"