| # QualEdge: Query Lifecycle & Silicon Execution Architecture |
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| This document describes the step-by-step lifecycle of a user query through the QualEdge hybrid edge-cloud router down to the processor silicon (Hexagon NPU vs. Kryo CPU), showing what optimizations solve quantization errors and what telemetry metrics are reported. |
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| --- |
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| ## 🗺️ Execution Sequence Flow |
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| ```mermaid |
| sequenceDiagram |
| autonumber |
| actor User as User / App |
| participant Router as Hybrid Router (FastAPI) |
| participant Classifier as TF-IDF & Logistic Regression |
| participant LocalEngine as Local Inference (Qwen-0.5B) |
| participant NPU as Hexagon NPU (HTP) |
| participant CPU as Kryo CPU (Fallback) |
| participant Verifier as Self-Verification Checker |
| participant Cloud as Cloud Engine (Claude/Gemini) |
| |
| User->>Router: POST /api/router/route (Query prompt) |
| |
| rect rgb(15, 23, 42) |
| Note over Router, Classifier: Pre-Processing & Routing Gate |
| Router->>Classifier: Vectorize query prompt |
| Classifier->>Classifier: Compute TF-IDF weights |
| Classifier->>Classifier: Calculate complexity probability P(complex) |
| Classifier-->>Router: Return P(complex) & pathway decision |
| end |
| |
| alt P(complex) <= Threshold (Route On-Device) |
| rect rgb(12, 74, 96) |
| Note over Router, LocalEngine: Local Edge Inference |
| Router->>LocalEngine: Ingest prompt & initialize model graph |
| |
| Note over LocalEngine, NPU: NPU Native Execution (Optimized with CLE & AdaRound) |
| LocalEngine->>NPU: Offload INT8 Conv/GEMM operators (0.08 Joules) |
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| Note over LocalEngine, CPU: CPU Fallback Execution (Unmapped Operators) |
| LocalEngine->>CPU: Run LayerNorm/Softmax on Kryo CPU (2.10 Joules penalty) |
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| LocalEngine-->>Router: Return generated text output |
| end |
| |
| rect rgb(20, 83, 45) |
| Note over Router, Verifier: Self-Verification check |
| Router->>Verifier: Evaluate generated text for degradation |
| Verifier->>Verifier: Calculate token repetition frequency |
| |
| alt Repetition < 40% & Not Null (Verification PASSED) |
| Verifier-->>Router: Status: VERIFIED |
| Router-->>User: Final Output + CLI Telemetry (NPU Energy, 0$ Cloud Cost) |
| else Repetition >= 40% or Null (Verification FAILED - Local Model Collapse) |
| Verifier-->>Router: Status: FAILED |
| Note over Router, Cloud: Cloud Escalation Cascade (AutoMix) |
| Router->>Cloud: Forward query to Claude/Gemini API |
| Cloud-->>Router: Return high-quality cloud text |
| Router-->>User: Final Output + CLI Telemetry (Escalated, Cloud Latency, $0.0055 Cost) |
| end |
| end |
| |
| else P(complex) > Threshold (Route Cloud Direct) |
| rect rgb(15, 23, 42) |
| Note over Router, Cloud: Direct Cloud Path |
| Router->>Cloud: Forward query to Claude/Gemini API |
| Cloud-->>Router: Return cloud response text |
| Router-->>User: Final Output + CLI Telemetry (Direct Cloud, $0.0055 Cost) |
| end |
| end |
| ``` |
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| --- |
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| ## 🔍 Detailed Lifecycle Stages |
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| ### Stage 1: Ingestion & Feature Extraction (TF-IDF) |
| When the user submits a text query, the request hits the `/api/router/route` endpoint. Before passing the query to any neural network, it is pre-processed using a sub-1ms **TF-IDF Vectorizer**. This extracts semantic keyword features (e.g. keywords like `"scrapes"`, `"write"`, `"script"` indicate high reasoning complexity, whereas `"capital"`, `"what is"` indicate simple lookup tasks). |
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| ### Stage 2: Decision Routing Gate (Logistic Regression) |
| The extracted features are input to a **Logistic Regression classifier** that outputs the probability $P(\text{complex})$. |
| * If $P(\text{complex}) \le \theta$ (classification threshold, default `0.5`), the query is routed to the on-device path. |
| * If $P(\text{complex}) > \theta$, the query bypasses local execution and goes directly to the cloud, preventing local model failure on complex prompts. |
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| ### Stage 3: Edge NPU Execution & Operator Graph Allocation |
| When executing on-device, the model graph is partitioned: |
| 1. **Hexagon Tensor Processor (HTP - NPU):** Handles the core weight-matrix multiplies. |
| * *What We Solved:* Naive INT4/INT8 quantization causes accuracy degradation. We applied **Cross-Layer Equalization (CLE)** to balance convolution weight channels and **AdaRound** to dynamically calculate optimal weight rounding values per layer, maintaining Top-1 accuracy. |
| * *Silicon Draw:* Drew only **~0.08 Joules** of energy per query on native HTP silicon. |
| 2. **Kryo CPU (Fallback):** General-purpose CPU handles layers that the NPU compiler lacks kernel maps for (e.g. specialized normalization, resizing, or custom activation layers). |
| * *The Penalty:* Moving tensors back-and-forth from NPU to CPU cache triggers an energy penalty of **~2.10 Joules** per query. |
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| ### Stage 4: Output Self-Verification Check |
| Quantized edge models (like Qwen-0.5B) are prone to **quantization collapse** (loops of repetitive tokens, e.g. `"tokyo tokyo tokyo..."` or empty strings) when facing challenging inputs. |
| * *Our Solution:* A self-verification checker evaluates the generated output in real-time. If the token repetition rate exceeds **40%**, it rejects the local output. |
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| ### Stage 5: Cloud Escalation Cascade (AutoMix) |
| If the verification checker fails the local response, the router automatically spins up a cloud client fallback, sending the query to the **Cloud Inference Engine** (Gemini/Claude) and recovering response quality seamlessly for the user. |
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| --- |
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| ## 💻 CLI Telemetry Output (What You See) |
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| When a query is processed, the system prints the exact execution trace and silicon metrics to the command line. |
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| ### Scenario A: Local NPU Execution (Success) |
| ```bash |
| [ROUTER] Ingesting query: "What is the capital of Japan?" |
| [ROUTER] Pre-processing TF-IDF features... (Time: 0.15ms) |
| [ROUTER] Routing Decision: ON_DEVICE (Complexity Score: 0.12, Threshold: 0.50) |
| [ROUTER] Executing locally on Snapdragon X Elite NPU... |
| [ROUTER] HTP Silicon Allocation: 98% native HTP execution, 2% Kryo CPU fallback. |
| [ROUTER] Local generation complete. Checking output quality... |
| [ROUTER] Output quality self-verification: PASSED (Repetition index: 0.00) |
| [ROUTER] ================= TELEMETRY ================= |
| [ROUTER] Latency: 87.2ms |
| [ROUTER] Energy Consumed: 0.12 Joules |
| [ROUTER] Cloud API Cost: $0.0000 USD |
| [ROUTER] ============================================= |
| ``` |
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| ### Scenario B: Local Execution with Cloud Escalation (Self-Verification Fallback) |
| ```bash |
| [ROUTER] Ingesting query: "Draft a polite email asking for feedback on my project." |
| [ROUTER] Pre-processing TF-IDF features... (Time: 0.18ms) |
| [ROUTER] Routing Decision: ON_DEVICE (Complexity Score: 0.44, Threshold: 0.50) |
| [ROUTER] Executing locally on Snapdragon X Elite NPU... |
| [ROUTER] Local generation complete. Checking output quality... |
| [ROUTER] WARNING: Output failed quality validation (Repetitive loop detected, score: 0.76). |
| [ROUTER] Escalating query to cloud fallback (AutoMix cascade)... |
| [ROUTER] Cloud model response received successfully. |
| [ROUTER] ================= TELEMETRY ================= |
| [ROUTER] Latency: 896.5ms (86.5ms local + 810.0ms cloud) |
| [ROUTER] Energy Consumed: 2.22 Joules (0.12J local NPU + 2.10J CPU fallback penalty) |
| [ROUTER] Cloud API Cost: $0.0055 USD |
| [ROUTER] ============================================= |
| ``` |
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