---
config:
  theme: neutral
  themeVariables:
    fontFamily: arial
    fontSize: 13px
    primaryColor: '#ffffff'
    primaryTextColor: '#000000'
    primaryBorderColor: '#000000'
    lineColor: '#000000'
    secondaryColor: '#f2f2f2'
    tertiaryColor: '#ffffff'
    clusterBkg: none
    clusterBorder: '#000000'
  layout: fixed
---
flowchart LR
 subgraph C["Edge Clients (N heterogeneous devices)"]
        M["Client-side Model<br/>(L<sub>1</sub> .. L<sub>k</sub>)"]
        AC["Activation Compression<br/>float32 / float16 / int8 / topk"]
        P["Latency Profiler"]
  end
 subgraph S["Server / Coordinator"]
        SM["Server-side Model<br/>(L<sub>k+1</sub> .. L<sub>end</sub>)"]
        FA["FedAvg Aggregator<br/>every &rho; steps"]
        SCH["Scheduler<br/>thresholds 4 / 10 / 15 ms"]
        COOR["Training Coordinator"]
        REP["Server Reporter"]
  end
    M --> AC
    SM -- "Cut-layer Gradient + (mode, &rho;)" --> M
    SCH --> COOR
    COOR --> SM
    P -. "Runtime Metrics" .-> SCH
    REP --> COOR
    AC -- "Compressed Activation" --> SM
    SM --> FA
    FA -- "Synchronize (weights)" --> M
    M -. "weights" .-> FA