Add signal guessing engine for frequency identification

Implements heuristic-based signal identification that provides
plain-English guesses for detected signals based on frequency,
modulation, bandwidth, and burst behavior.

Features:
- Python backend engine (utils/signal_guess.py)
- JavaScript client-side engine with UI components
- Hedged language output (never claims certainty)
- UK/EU and US region support
- Confidence levels (LOW/MEDIUM/HIGH)
- 50+ unit tests for deterministic verification

Supported signal types: FM broadcast, airband, cellular/LTE,
ISM bands (433/868/915/2.4GHz), TPMS, amateur radio, marine VHF,
DAB, pager networks, weather satellites, ADS-B, and more.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Smittix
2026-01-20 23:38:02 +00:00
parent 4c0d44a99d
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"""
Comprehensive tests for the Signal Guessing Engine.
Tests cover:
- FM broadcast frequency detection
- Airband frequency detection
- ISM band devices (433 MHz, 868 MHz, 2.4 GHz)
- TPMS / short-burst telemetry
- Cellular/LTE detection
- Modulation and bandwidth scoring
- Burst behavior detection
- Region-specific allocations
- Confidence level calculations
"""
import pytest
from utils.signal_guess import (
SignalGuessingEngine,
SignalGuessResult,
SignalAlternative,
Confidence,
guess_signal_type,
guess_signal_type_dict,
)
class TestFMBroadcast:
"""Tests for FM broadcast radio identification."""
def test_fm_broadcast_center_frequency(self):
"""Test FM broadcast at typical frequency."""
result = guess_signal_type(
frequency_hz=98_500_000, # 98.5 MHz
modulation="WFM",
bandwidth_hz=200_000,
)
assert result.primary_label == "FM Broadcast Radio"
assert result.confidence == Confidence.HIGH
assert "broadcast" in result.tags
def test_fm_broadcast_edge_frequencies(self):
"""Test FM broadcast at band edges."""
# Low edge
result_low = guess_signal_type(frequency_hz=88_000_000)
assert result_low.primary_label == "FM Broadcast Radio"
# High edge
result_high = guess_signal_type(frequency_hz=107_900_000)
assert result_high.primary_label == "FM Broadcast Radio"
def test_fm_broadcast_without_modulation(self):
"""Test FM broadcast without modulation hint - lower confidence."""
result = guess_signal_type(frequency_hz=100_000_000)
assert result.primary_label == "FM Broadcast Radio"
# Without modulation hint, confidence should be MEDIUM or lower
assert result.confidence in (Confidence.MEDIUM, Confidence.HIGH)
def test_fm_broadcast_explanation(self):
"""Test explanation uses hedged language."""
result = guess_signal_type(
frequency_hz=95_000_000,
modulation="FM",
)
explanation = result.explanation.lower()
# Should contain hedged language
assert any(word in explanation for word in ["consistent", "could", "may", "indicate"])
assert "95.000 mhz" in explanation
class TestAirband:
"""Tests for civil aviation airband identification."""
def test_airband_typical_frequency(self):
"""Test airband at typical tower frequency."""
result = guess_signal_type(
frequency_hz=118_750_000, # 118.75 MHz
modulation="AM",
bandwidth_hz=8_000,
)
assert result.primary_label == "Airband (Civil Aviation Voice)"
assert result.confidence == Confidence.HIGH
assert "aviation" in result.tags
def test_airband_approach_frequency(self):
"""Test airband at approach control frequency."""
result = guess_signal_type(
frequency_hz=128_550_000, # 128.55 MHz
modulation="AM",
)
assert result.primary_label == "Airband (Civil Aviation Voice)"
assert result.confidence in (Confidence.MEDIUM, Confidence.HIGH)
def test_airband_guard_frequency(self):
"""Test airband at international distress frequency."""
result = guess_signal_type(
frequency_hz=121_500_000, # 121.5 MHz guard
modulation="AM",
)
assert result.primary_label == "Airband (Civil Aviation Voice)"
def test_airband_wrong_modulation(self):
"""Test airband with wrong modulation still matches but lower score."""
result_am = guess_signal_type(
frequency_hz=125_000_000,
modulation="AM",
)
result_fm = guess_signal_type(
frequency_hz=125_000_000,
modulation="FM",
)
# AM should score higher for airband
assert result_am._scores.get("Airband (Civil Aviation Voice)", 0) > \
result_fm._scores.get("Airband (Civil Aviation Voice)", 0)
class TestISMBands:
"""Tests for ISM band device identification."""
def test_433_mhz_ism_eu(self):
"""Test 433 MHz ISM band (EU)."""
result = guess_signal_type(
frequency_hz=433_920_000, # 433.92 MHz
modulation="NFM",
region="UK/EU",
)
assert "ISM" in result.primary_label or "TPMS" in result.primary_label
assert any(tag in result.tags for tag in ["ism", "telemetry", "tpms"])
def test_433_mhz_short_burst(self):
"""Test 433 MHz with short burst pattern -> TPMS/telemetry."""
result = guess_signal_type(
frequency_hz=433_920_000,
modulation="NFM",
duration_ms=50, # 50ms burst
repetition_count=3,
region="UK/EU",
)
# Short burst at 433.92 should suggest TPMS or ISM telemetry
assert any(word in result.primary_label.lower() for word in ["tpms", "ism", "telemetry"])
# Should have medium confidence due to burst behavior match
assert result.confidence in (Confidence.MEDIUM, Confidence.HIGH)
def test_868_mhz_ism_eu(self):
"""Test 868 MHz ISM band (EU)."""
result = guess_signal_type(
frequency_hz=868_300_000,
modulation="FSK",
region="UK/EU",
)
assert "868" in result.primary_label or "ISM" in result.primary_label
assert "ism" in result.tags or "iot" in result.tags
def test_915_mhz_ism_us(self):
"""Test 915 MHz ISM band (US)."""
result = guess_signal_type(
frequency_hz=915_000_000,
modulation="FSK",
region="US",
)
assert "915" in result.primary_label or "ISM" in result.primary_label
def test_24_ghz_ism(self):
"""Test 2.4 GHz ISM band."""
result = guess_signal_type(
frequency_hz=2_437_000_000, # WiFi channel 6
modulation="OFDM",
bandwidth_hz=20_000_000,
)
assert "2.4" in result.primary_label or "ISM" in result.primary_label
assert any(tag in result.tags for tag in ["ism", "wifi", "bluetooth"])
def test_24_ghz_narrow_bandwidth(self):
"""Test 2.4 GHz with narrow bandwidth (Bluetooth-like)."""
result = guess_signal_type(
frequency_hz=2_450_000_000,
modulation="GFSK",
bandwidth_hz=1_000_000,
)
assert "2.4" in result.primary_label
# Should match ISM 2.4 GHz
assert result.confidence in (Confidence.LOW, Confidence.MEDIUM, Confidence.HIGH)
class TestTPMSTelemetry:
"""Tests for TPMS and short-burst telemetry."""
def test_tpms_433_short_burst(self):
"""Test TPMS-like signal at 433.92 MHz with short burst."""
result = guess_signal_type(
frequency_hz=433_920_000,
modulation="OOK",
bandwidth_hz=20_000,
duration_ms=100, # Short burst
repetition_count=4, # Multiple bursts
region="UK/EU",
)
# Should identify as TPMS or ISM telemetry
assert any(word in result.primary_label.lower() for word in ["tpms", "ism", "telemetry", "remote"])
def test_tpms_315_us(self):
"""Test TPMS at 315 MHz (US)."""
result = guess_signal_type(
frequency_hz=315_000_000,
modulation="ASK",
duration_ms=50,
repetition_count=2,
region="US",
)
assert any(word in result.primary_label.lower() for word in ["tpms", "ism", "315", "remote"])
def test_burst_detection_scoring(self):
"""Test that burst behavior increases scores for burst-type signals."""
# Without burst behavior
result_no_burst = guess_signal_type(
frequency_hz=433_920_000,
modulation="OOK",
region="UK/EU",
)
# With burst behavior
result_burst = guess_signal_type(
frequency_hz=433_920_000,
modulation="OOK",
duration_ms=50,
repetition_count=5,
region="UK/EU",
)
# Burst scores should be higher for burst-type signals
burst_score = result_burst._scores.get("TPMS / Vehicle Telemetry", 0) + \
result_burst._scores.get("Remote Control / Key Fob", 0)
no_burst_score = result_no_burst._scores.get("TPMS / Vehicle Telemetry", 0) + \
result_no_burst._scores.get("Remote Control / Key Fob", 0)
assert burst_score > no_burst_score
class TestCellularLTE:
"""Tests for cellular/LTE identification."""
def test_lte_band_20_eu(self):
"""Test LTE Band 20 (800 MHz) detection."""
result = guess_signal_type(
frequency_hz=806_000_000,
modulation="LTE",
bandwidth_hz=10_000_000,
region="UK/EU",
)
assert "Cellular" in result.primary_label or "Mobile" in result.primary_label
assert "cellular" in result.tags
def test_lte_band_3_eu(self):
"""Test LTE Band 3 (1800 MHz) detection."""
result = guess_signal_type(
frequency_hz=1_815_000_000,
bandwidth_hz=15_000_000,
region="UK/EU",
)
assert "Cellular" in result.primary_label or "Mobile" in result.primary_label
def test_cellular_wide_bandwidth_boost(self):
"""Test that wide bandwidth boosts cellular confidence."""
result_wide = guess_signal_type(
frequency_hz=850_000_000,
bandwidth_hz=10_000_000, # 10 MHz LTE
)
result_narrow = guess_signal_type(
frequency_hz=850_000_000,
bandwidth_hz=25_000, # 25 kHz narrowband
)
# Wide bandwidth should score higher for cellular
cell_score_wide = result_wide._scores.get("Cellular / Mobile Network", 0)
cell_score_narrow = result_narrow._scores.get("Cellular / Mobile Network", 0)
assert cell_score_wide > cell_score_narrow
class TestConfidenceLevels:
"""Tests for confidence level calculations."""
def test_high_confidence_requires_margin(self):
"""Test that HIGH confidence requires good margin over alternatives."""
# FM broadcast with strong evidence
result = guess_signal_type(
frequency_hz=100_000_000,
modulation="WFM",
bandwidth_hz=200_000,
)
assert result.confidence == Confidence.HIGH
def test_medium_confidence_with_ambiguity(self):
"""Test MEDIUM confidence when alternatives are close."""
# Frequency in ISM band with less specific characteristics
result = guess_signal_type(
frequency_hz=433_500_000, # General 433 band
region="UK/EU",
)
# Should have alternatives, potentially MEDIUM confidence
assert result.confidence in (Confidence.LOW, Confidence.MEDIUM)
assert len(result.alternatives) > 0
def test_low_confidence_unknown_frequency(self):
"""Test LOW confidence for unrecognized frequency."""
result = guess_signal_type(
frequency_hz=50_000_000, # 50 MHz - not in common allocations
)
assert result.confidence == Confidence.LOW
def test_alternatives_have_lower_confidence(self):
"""Test that alternatives have appropriate confidence levels."""
result = guess_signal_type(
frequency_hz=433_920_000,
modulation="OOK",
region="UK/EU",
)
if result.alternatives:
for alt in result.alternatives:
# Alternatives should generally have same or lower confidence
assert isinstance(alt.confidence, Confidence)
class TestRegionSpecific:
"""Tests for region-specific frequency allocations."""
def test_315_mhz_us_only(self):
"""Test 315 MHz ISM only matches in US region."""
result_us = guess_signal_type(
frequency_hz=315_000_000,
region="US",
)
result_eu = guess_signal_type(
frequency_hz=315_000_000,
region="UK/EU",
)
# Should match in US
assert "315" in result_us.primary_label or "ISM" in result_us.primary_label or "TPMS" in result_us.primary_label
# Should not match well in EU
assert result_eu.primary_label == "Unknown Signal" or result_eu.confidence == Confidence.LOW
def test_pmr446_eu_only(self):
"""Test PMR446 only matches in EU region."""
result_eu = guess_signal_type(
frequency_hz=446_100_000,
modulation="NFM",
region="UK/EU",
)
result_us = guess_signal_type(
frequency_hz=446_100_000,
modulation="NFM",
region="US",
)
# Should match PMR446 in EU
assert "PMR" in result_eu.primary_label
# Should not match PMR446 in US
assert "PMR" not in result_us.primary_label
def test_dab_eu_only(self):
"""Test DAB only matches in EU region."""
result_eu = guess_signal_type(
frequency_hz=225_648_000, # DAB 12C
modulation="OFDM",
bandwidth_hz=1_500_000,
region="UK/EU",
)
assert "DAB" in result_eu.primary_label
class TestExplanationLanguage:
"""Tests for hedged, client-safe explanation language."""
def test_no_certainty_claims(self):
"""Test that explanations never claim certainty."""
result = guess_signal_type(
frequency_hz=100_000_000,
modulation="FM",
)
explanation = result.explanation.lower()
# Should NOT contain definitive language
forbidden_words = ["definitely", "certainly", "absolutely", "is a", "this is"]
for word in forbidden_words:
assert word not in explanation, f"Found forbidden word '{word}' in explanation"
def test_hedged_language_present(self):
"""Test that explanations use hedged language."""
result = guess_signal_type(
frequency_hz=118_500_000,
modulation="AM",
)
explanation = result.explanation.lower()
# Should contain hedged language
hedged_words = ["consistent", "could", "may", "likely", "suggest", "indicate"]
assert any(word in explanation for word in hedged_words)
def test_explanation_includes_frequency(self):
"""Test that explanations include the frequency."""
result = guess_signal_type(
frequency_hz=433_920_000,
modulation="NFM",
region="UK/EU",
)
assert "433.920" in result.explanation
class TestUnknownSignals:
"""Tests for unknown signal handling."""
def test_completely_unknown_frequency(self):
"""Test handling of frequency with no allocations."""
result = guess_signal_type(
frequency_hz=42_000_000, # Random frequency
)
assert result.primary_label == "Unknown Signal"
assert result.confidence == Confidence.LOW
assert result.alternatives == []
assert "unknown" in result.tags
def test_unknown_includes_frequency_in_explanation(self):
"""Test that unknown signal explanation includes frequency."""
result = guess_signal_type(
frequency_hz=42_000_000,
)
assert "42.000" in result.explanation
class TestDictOutput:
"""Tests for dictionary output format."""
def test_dict_output_structure(self):
"""Test that dict output has correct structure."""
result = guess_signal_type_dict(
frequency_hz=100_000_000,
modulation="FM",
)
assert isinstance(result, dict)
assert "primary_label" in result
assert "confidence" in result
assert "alternatives" in result
assert "explanation" in result
assert "tags" in result
def test_dict_confidence_is_string(self):
"""Test that confidence in dict is string, not enum."""
result = guess_signal_type_dict(
frequency_hz=100_000_000,
)
assert isinstance(result["confidence"], str)
assert result["confidence"] in ("LOW", "MEDIUM", "HIGH")
def test_dict_alternatives_structure(self):
"""Test alternatives in dict output."""
result = guess_signal_type_dict(
frequency_hz=433_920_000,
region="UK/EU",
)
for alt in result["alternatives"]:
assert "label" in alt
assert "confidence" in alt
assert isinstance(alt["confidence"], str)
class TestEngineInstance:
"""Tests for SignalGuessingEngine class."""
def test_engine_default_region(self):
"""Test engine uses default region."""
engine = SignalGuessingEngine(region="UK/EU")
result = engine.guess_signal_type(frequency_hz=433_920_000)
assert "ISM" in result.primary_label or "TPMS" in result.primary_label
def test_engine_override_region(self):
"""Test engine allows region override."""
engine = SignalGuessingEngine(region="UK/EU")
result = engine.guess_signal_type(
frequency_hz=315_000_000,
region="US", # Override default
)
# Should match US allocation
assert "315" in result.primary_label or "ISM" in result.primary_label or "TPMS" in result.primary_label
def test_get_frequency_allocations(self):
"""Test get_frequency_allocations method."""
engine = SignalGuessingEngine(region="UK/EU")
allocations = engine.get_frequency_allocations(frequency_hz=433_920_000)
assert len(allocations) > 0
assert any("ISM" in a or "TPMS" in a for a in allocations)
class TestEdgeCases:
"""Tests for edge cases and boundary conditions."""
def test_exact_band_edge(self):
"""Test frequency at exact band edge."""
# FM band starts at 87.5 MHz
result = guess_signal_type(frequency_hz=87_500_000)
assert result.primary_label == "FM Broadcast Radio"
def test_very_narrow_bandwidth(self):
"""Test very narrow bandwidth handling."""
result = guess_signal_type(
frequency_hz=433_920_000,
bandwidth_hz=100, # Very narrow
region="UK/EU",
)
# Should still match but may have lower score
assert result.primary_label != "Unknown Signal"
def test_very_wide_bandwidth(self):
"""Test very wide bandwidth handling."""
result = guess_signal_type(
frequency_hz=2_450_000_000,
bandwidth_hz=100_000_000, # 100 MHz - very wide
)
# Should still identify ISM but may penalize
assert "ISM" in result.primary_label or "Unknown" in result.primary_label
def test_zero_duration(self):
"""Test zero duration handling."""
result = guess_signal_type(
frequency_hz=433_920_000,
duration_ms=0,
region="UK/EU",
)
assert result.primary_label != "Unknown Signal"
def test_high_repetition_count(self):
"""Test high repetition count."""
result = guess_signal_type(
frequency_hz=433_920_000,
repetition_count=1000,
region="UK/EU",
)
# Should handle gracefully
assert result.primary_label != "Unknown Signal"
def test_all_optional_params_none(self):
"""Test with only frequency provided."""
result = guess_signal_type(frequency_hz=100_000_000)
assert result.primary_label is not None
assert result.confidence is not None
class TestSpecificSignalTypes:
"""Tests for specific signal type identifications."""
def test_marine_vhf_channel_16(self):
"""Test Marine VHF Channel 16 (distress)."""
result = guess_signal_type(
frequency_hz=156_800_000, # CH 16
modulation="NFM",
)
assert "Marine" in result.primary_label
def test_amateur_2m_calling(self):
"""Test amateur radio 2m calling frequency."""
result = guess_signal_type(
frequency_hz=145_500_000,
modulation="FM",
)
assert "Amateur" in result.primary_label or "2m" in result.primary_label
def test_amateur_70cm(self):
"""Test amateur radio 70cm band."""
result = guess_signal_type(
frequency_hz=438_500_000,
modulation="NFM",
)
# Could be amateur 70cm or ISM 433 (they overlap)
assert "Amateur" in result.primary_label or "ISM" in result.primary_label
def test_noaa_weather_satellite(self):
"""Test NOAA weather satellite frequency."""
result = guess_signal_type(
frequency_hz=137_500_000,
modulation="FM",
bandwidth_hz=38_000,
)
assert "Weather" in result.primary_label or "NOAA" in result.primary_label or "Satellite" in result.primary_label
def test_adsb_1090(self):
"""Test ADS-B at 1090 MHz."""
result = guess_signal_type(
frequency_hz=1_090_000_000,
duration_ms=50, # Short burst
)
assert "ADS-B" in result.primary_label or "Aircraft" in result.primary_label
def test_dect_cordless(self):
"""Test DECT cordless phone frequency."""
result = guess_signal_type(
frequency_hz=1_890_000_000,
modulation="GFSK",
)
assert "DECT" in result.primary_label
def test_pager_uk(self):
"""Test UK pager frequency."""
result = guess_signal_type(
frequency_hz=153_350_000,
modulation="FSK",
)
assert "Pager" in result.primary_label

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"""
Signal Guessing Engine
Heuristic-based signal identification that provides plain-English guesses
for detected signals based on frequency, modulation, bandwidth, and behavior.
All outputs use hedged language - never claims certainty, uses
"likely", "consistent with", "could be" phrasing.
"""
from __future__ import annotations
from dataclasses import dataclass, field
from enum import Enum
from typing import Optional
# =============================================================================
# Confidence Levels
# =============================================================================
class Confidence(Enum):
"""Signal identification confidence level."""
LOW = "LOW"
MEDIUM = "MEDIUM"
HIGH = "HIGH"
# =============================================================================
# Signal Type Definitions
# =============================================================================
@dataclass
class SignalTypeDefinition:
"""Definition of a known signal type with matching criteria."""
label: str
tags: list[str]
description: str
# Frequency ranges in Hz: list of (min_hz, max_hz) tuples
frequency_ranges: list[tuple[int, int]]
# Optional modulation hints (if provided, boosts confidence)
modulation_hints: list[str] = field(default_factory=list)
# Optional bandwidth range (min_hz, max_hz) - if provided, used for scoring
bandwidth_range: Optional[tuple[int, int]] = None
# Base score for frequency match
base_score: int = 10
# Is this a burst/telemetry type signal?
is_burst_type: bool = False
# Region applicability
regions: list[str] = field(default_factory=lambda: ["UK/EU", "US", "GLOBAL"])
# =============================================================================
# Frequency Range Tables (UK/EU focus, with US variants)
# =============================================================================
# All frequencies in Hz
SIGNAL_TYPES: list[SignalTypeDefinition] = [
# FM Broadcast Radio
SignalTypeDefinition(
label="FM Broadcast Radio",
tags=["broadcast", "commercial", "wideband"],
description="Commercial FM radio station transmission",
frequency_ranges=[
(87_500_000, 108_000_000), # 87.5 - 108 MHz
],
modulation_hints=["WFM", "FM", "WBFM"],
bandwidth_range=(150_000, 250_000), # ~200 kHz typical
base_score=15,
regions=["UK/EU", "US", "GLOBAL"],
),
# Civil Aviation / Airband
SignalTypeDefinition(
label="Airband (Civil Aviation Voice)",
tags=["aviation", "voice", "aeronautical"],
description="Civil aviation voice communications",
frequency_ranges=[
(118_000_000, 137_000_000), # 118 - 137 MHz (international)
],
modulation_hints=["AM", "A3E"],
bandwidth_range=(6_000, 10_000), # ~8 kHz AM voice
base_score=15,
regions=["UK/EU", "US", "GLOBAL"],
),
# ISM 433 MHz (EU)
SignalTypeDefinition(
label="ISM Device (433 MHz)",
tags=["ism", "short-range", "telemetry", "consumer"],
description="Industrial, Scientific, Medical band device",
frequency_ranges=[
(433_050_000, 434_790_000), # 433.05 - 434.79 MHz (EU ISM)
],
modulation_hints=["OOK", "ASK", "FSK", "NFM", "FM"],
bandwidth_range=(10_000, 50_000),
base_score=12,
is_burst_type=True,
regions=["UK/EU"],
),
# ISM 315 MHz (US)
SignalTypeDefinition(
label="ISM Device (315 MHz)",
tags=["ism", "short-range", "telemetry", "consumer"],
description="Industrial, Scientific, Medical band device (US)",
frequency_ranges=[
(315_000_000, 316_000_000), # 315 MHz US ISM
],
modulation_hints=["OOK", "ASK", "FSK"],
bandwidth_range=(10_000, 50_000),
base_score=12,
is_burst_type=True,
regions=["US"],
),
# ISM 868 MHz (EU)
SignalTypeDefinition(
label="ISM Device (868 MHz)",
tags=["ism", "short-range", "telemetry", "iot"],
description="868 MHz ISM band device (LoRa, sensors, IoT)",
frequency_ranges=[
(868_000_000, 868_600_000), # 868 MHz EU ISM
(869_400_000, 869_650_000), # 869 MHz EU ISM (higher power)
],
modulation_hints=["FSK", "GFSK", "LoRa", "OOK", "NFM"],
bandwidth_range=(10_000, 150_000),
base_score=12,
is_burst_type=True,
regions=["UK/EU"],
),
# ISM 915 MHz (US)
SignalTypeDefinition(
label="ISM Device (915 MHz)",
tags=["ism", "short-range", "telemetry", "iot"],
description="915 MHz ISM band device (US/Americas)",
frequency_ranges=[
(902_000_000, 928_000_000), # 902-928 MHz US ISM
],
modulation_hints=["FSK", "GFSK", "LoRa", "OOK", "NFM", "FHSS"],
bandwidth_range=(10_000, 500_000),
base_score=12,
is_burst_type=True,
regions=["US"],
),
# ISM 2.4 GHz (Global)
SignalTypeDefinition(
label="ISM Device (2.4 GHz)",
tags=["ism", "wifi", "bluetooth", "wireless"],
description="2.4 GHz ISM band (WiFi, Bluetooth, wireless devices)",
frequency_ranges=[
(2_400_000_000, 2_483_500_000), # 2.4 GHz ISM
],
modulation_hints=["OFDM", "DSSS", "FHSS", "GFSK", "WiFi", "BT"],
bandwidth_range=(1_000_000, 40_000_000), # 1-40 MHz depending on protocol
base_score=10,
regions=["UK/EU", "US", "GLOBAL"],
),
# ISM 5.8 GHz (Global)
SignalTypeDefinition(
label="ISM Device (5.8 GHz)",
tags=["ism", "wifi", "wireless", "video"],
description="5.8 GHz ISM band (WiFi, video links, wireless devices)",
frequency_ranges=[
(5_725_000_000, 5_875_000_000), # 5.8 GHz ISM
],
modulation_hints=["OFDM", "WiFi"],
bandwidth_range=(10_000_000, 80_000_000),
base_score=10,
regions=["UK/EU", "US", "GLOBAL"],
),
# TPMS / Tire Pressure Monitoring
SignalTypeDefinition(
label="TPMS / Vehicle Telemetry",
tags=["telemetry", "automotive", "burst", "tpms"],
description="Tire pressure monitoring or similar vehicle telemetry",
frequency_ranges=[
(314_900_000, 315_100_000), # 315 MHz (US TPMS)
(433_800_000, 434_000_000), # 433.92 MHz (EU TPMS)
(433_900_000, 433_940_000), # Narrow 433.92 MHz
],
modulation_hints=["OOK", "ASK", "FSK", "NFM"],
bandwidth_range=(10_000, 40_000),
base_score=10,
is_burst_type=True,
regions=["UK/EU", "US"],
),
# Cellular / LTE (broad category)
SignalTypeDefinition(
label="Cellular / Mobile Network",
tags=["cellular", "lte", "mobile", "wideband"],
description="Mobile network transmission (2G/3G/4G/5G)",
frequency_ranges=[
# UK/EU common bands
(791_000_000, 862_000_000), # Band 20 (800 MHz)
(880_000_000, 960_000_000), # Band 8 (900 MHz GSM/UMTS)
(1_710_000_000, 1_880_000_000), # Band 3 (1800 MHz)
(1_920_000_000, 2_170_000_000), # Band 1 (2100 MHz UMTS)
(2_500_000_000, 2_690_000_000), # Band 7 (2600 MHz)
# US common bands
(698_000_000, 756_000_000), # Band 12/17 (700 MHz)
(824_000_000, 894_000_000), # Band 5 (850 MHz)
(1_850_000_000, 1_995_000_000), # Band 2/25 (1900 MHz PCS)
],
modulation_hints=["OFDM", "QAM", "LTE", "4G", "5G", "GSM", "UMTS"],
bandwidth_range=(200_000, 20_000_000), # 200 kHz (GSM) to 20 MHz (LTE)
base_score=8, # Lower base due to broad category
regions=["UK/EU", "US", "GLOBAL"],
),
# PMR446 (EU license-free)
SignalTypeDefinition(
label="PMR446 Radio",
tags=["pmr", "voice", "handheld", "license-free"],
description="License-free handheld radio communications",
frequency_ranges=[
(446_000_000, 446_200_000), # PMR446 EU
],
modulation_hints=["NFM", "FM", "DPMR", "dPMR"],
bandwidth_range=(6_250, 12_500),
base_score=14,
regions=["UK/EU"],
),
# Marine VHF
SignalTypeDefinition(
label="Marine VHF Radio",
tags=["marine", "maritime", "voice", "nautical"],
description="Marine VHF voice communications",
frequency_ranges=[
(156_000_000, 162_025_000), # Marine VHF band
],
modulation_hints=["NFM", "FM"],
bandwidth_range=(12_500, 25_000),
base_score=14,
regions=["UK/EU", "US", "GLOBAL"],
),
# Amateur Radio 2m
SignalTypeDefinition(
label="Amateur Radio (2m)",
tags=["amateur", "ham", "voice", "vhf"],
description="Amateur radio 2-meter band",
frequency_ranges=[
(144_000_000, 148_000_000), # 2m band (Region 1 & 2 overlap)
],
modulation_hints=["NFM", "FM", "SSB", "USB", "LSB", "CW"],
bandwidth_range=(2_400, 15_000),
base_score=12,
regions=["UK/EU", "US", "GLOBAL"],
),
# Amateur Radio 70cm
SignalTypeDefinition(
label="Amateur Radio (70cm)",
tags=["amateur", "ham", "voice", "uhf"],
description="Amateur radio 70-centimeter band",
frequency_ranges=[
(430_000_000, 440_000_000), # 70cm band
],
modulation_hints=["NFM", "FM", "SSB", "USB", "LSB", "CW", "D-STAR", "DMR"],
bandwidth_range=(2_400, 15_000),
base_score=12,
regions=["UK/EU", "US", "GLOBAL"],
),
# DECT Cordless Phones
SignalTypeDefinition(
label="DECT Cordless Phone",
tags=["dect", "cordless", "telephony", "consumer"],
description="Digital Enhanced Cordless Telecommunications",
frequency_ranges=[
(1_880_000_000, 1_900_000_000), # DECT EU
(1_920_000_000, 1_930_000_000), # DECT US
],
modulation_hints=["GFSK", "DECT"],
bandwidth_range=(1_728_000, 1_728_000), # Fixed 1.728 MHz
base_score=12,
regions=["UK/EU", "US"],
),
# DAB Digital Radio
SignalTypeDefinition(
label="DAB Digital Radio",
tags=["broadcast", "digital", "dab", "wideband"],
description="Digital Audio Broadcasting radio",
frequency_ranges=[
(174_000_000, 240_000_000), # DAB Band III
],
modulation_hints=["OFDM", "DAB", "DAB+"],
bandwidth_range=(1_500_000, 1_600_000), # ~1.5 MHz per multiplex
base_score=14,
regions=["UK/EU"],
),
# Pager (POCSAG/FLEX)
SignalTypeDefinition(
label="Pager Network",
tags=["pager", "pocsag", "flex", "messaging"],
description="Paging network transmission (POCSAG/FLEX)",
frequency_ranges=[
(153_000_000, 154_000_000), # UK pager frequencies
(466_000_000, 467_000_000), # Additional pager band
(929_000_000, 932_000_000), # US pager band
],
modulation_hints=["FSK", "POCSAG", "FLEX"],
bandwidth_range=(12_500, 25_000),
base_score=13,
regions=["UK/EU", "US"],
),
# Weather Satellite (NOAA APT)
SignalTypeDefinition(
label="Weather Satellite (NOAA)",
tags=["satellite", "weather", "apt", "noaa"],
description="NOAA weather satellite APT transmission",
frequency_ranges=[
(137_000_000, 138_000_000), # NOAA APT
],
modulation_hints=["APT", "FM", "NFM"],
bandwidth_range=(34_000, 40_000),
base_score=14,
regions=["GLOBAL"],
),
# ADS-B
SignalTypeDefinition(
label="ADS-B Aircraft Tracking",
tags=["aviation", "adsb", "surveillance", "tracking"],
description="Automatic Dependent Surveillance-Broadcast",
frequency_ranges=[
(1_090_000_000, 1_090_000_000), # 1090 MHz exactly
],
modulation_hints=["PPM", "ADSB"],
bandwidth_range=(1_000_000, 2_000_000),
base_score=15,
is_burst_type=True,
regions=["GLOBAL"],
),
# LoRaWAN
SignalTypeDefinition(
label="LoRaWAN / LoRa Device",
tags=["iot", "lora", "lpwan", "telemetry"],
description="LoRa long-range IoT device",
frequency_ranges=[
(863_000_000, 870_000_000), # EU868
(902_000_000, 928_000_000), # US915
],
modulation_hints=["LoRa", "CSS", "FSK"],
bandwidth_range=(125_000, 500_000), # LoRa spreading bandwidths
base_score=11,
is_burst_type=True,
regions=["UK/EU", "US"],
),
# Key Fob / Remote
SignalTypeDefinition(
label="Remote Control / Key Fob",
tags=["remote", "keyfob", "automotive", "burst", "ism"],
description="Wireless remote control or vehicle key fob",
frequency_ranges=[
(314_900_000, 315_100_000), # 315 MHz (US)
(433_050_000, 434_790_000), # 433 MHz (EU)
(867_000_000, 869_000_000), # 868 MHz (EU)
],
modulation_hints=["OOK", "ASK", "FSK", "rolling"],
bandwidth_range=(10_000, 50_000),
base_score=10,
is_burst_type=True,
regions=["UK/EU", "US"],
),
]
# =============================================================================
# Signal Guess Result
# =============================================================================
@dataclass
class SignalAlternative:
"""An alternative signal type guess."""
label: str
confidence: Confidence
score: int
@dataclass
class SignalGuessResult:
"""Complete signal guess result with hedged language."""
primary_label: str
confidence: Confidence
alternatives: list[SignalAlternative]
explanation: str
tags: list[str]
# Internal scoring data (useful for debugging/testing)
_scores: dict[str, int] = field(default_factory=dict, repr=False)
# =============================================================================
# Signal Guessing Engine
# =============================================================================
class SignalGuessingEngine:
"""
Heuristic-based signal identification engine.
Provides plain-English guesses for detected signals based on frequency,
modulation, bandwidth, and behavioral characteristics.
All outputs use hedged language - never claims certainty.
"""
def __init__(self, region: str = "UK/EU"):
"""
Initialize the guessing engine.
Args:
region: Default region for frequency allocations.
Options: "UK/EU", "US", "GLOBAL"
"""
self.region = region
self._signal_types = SIGNAL_TYPES
def guess_signal_type(
self,
frequency_hz: int,
modulation: Optional[str] = None,
bandwidth_hz: Optional[int] = None,
duration_ms: Optional[int] = None,
repetition_count: Optional[int] = None,
rssi_dbm: Optional[float] = None,
region: Optional[str] = None,
) -> SignalGuessResult:
"""
Guess the signal type based on detection parameters.
Args:
frequency_hz: Center frequency in Hz (required)
modulation: Modulation type string (e.g., "FM", "AM", "NFM")
bandwidth_hz: Estimated signal bandwidth in Hz
duration_ms: How long the signal was observed in milliseconds
repetition_count: How many times seen recently
rssi_dbm: Signal strength in dBm
region: Override default region
Returns:
SignalGuessResult with primary guess, alternatives, and explanation
"""
effective_region = region or self.region
# Score all signal types
scores: dict[str, int] = {}
matched_types: dict[str, SignalTypeDefinition] = {}
for signal_type in self._signal_types:
score = self._score_signal_type(
signal_type,
frequency_hz,
modulation,
bandwidth_hz,
duration_ms,
repetition_count,
effective_region,
)
if score > 0:
scores[signal_type.label] = score
matched_types[signal_type.label] = signal_type
# If no matches, return unknown
if not scores:
return SignalGuessResult(
primary_label="Unknown Signal",
confidence=Confidence.LOW,
alternatives=[],
explanation=self._build_unknown_explanation(frequency_hz, modulation),
tags=["unknown"],
_scores={},
)
# Sort by score descending
sorted_labels = sorted(scores.keys(), key=lambda x: scores[x], reverse=True)
# Primary guess
primary_label = sorted_labels[0]
primary_score = scores[primary_label]
primary_type = matched_types[primary_label]
# Calculate confidence based on score and margin
confidence = self._calculate_confidence(
primary_score,
scores,
sorted_labels,
modulation,
bandwidth_hz,
)
# Build alternatives (up to 3, excluding primary)
alternatives = []
for label in sorted_labels[1:4]: # Next 3 candidates
alt_score = scores[label]
# Alternative confidence is always at most one level below primary
# unless scores are very close
alt_confidence = self._calculate_alternative_confidence(
alt_score, primary_score, confidence
)
alternatives.append(SignalAlternative(
label=label,
confidence=alt_confidence,
score=alt_score,
))
# Build explanation
explanation = self._build_explanation(
primary_type,
confidence,
frequency_hz,
modulation,
bandwidth_hz,
duration_ms,
repetition_count,
)
return SignalGuessResult(
primary_label=primary_label,
confidence=confidence,
alternatives=alternatives,
explanation=explanation,
tags=primary_type.tags.copy(),
_scores=scores,
)
def _score_signal_type(
self,
signal_type: SignalTypeDefinition,
frequency_hz: int,
modulation: Optional[str],
bandwidth_hz: Optional[int],
duration_ms: Optional[int],
repetition_count: Optional[int],
region: str,
) -> int:
"""Calculate score for a signal type match."""
score = 0
# Check region applicability
if region not in signal_type.regions and "GLOBAL" not in signal_type.regions:
return 0
# Check frequency match (required)
freq_match = False
for freq_min, freq_max in signal_type.frequency_ranges:
if freq_min <= frequency_hz <= freq_max:
freq_match = True
break
if not freq_match:
return 0
# Base score for frequency match
score = signal_type.base_score
# Modulation bonus
if modulation:
mod_upper = modulation.upper()
for hint in signal_type.modulation_hints:
if hint.upper() in mod_upper or mod_upper in hint.upper():
score += 5
break
# Bandwidth bonus/penalty
if bandwidth_hz and signal_type.bandwidth_range:
bw_min, bw_max = signal_type.bandwidth_range
if bw_min <= bandwidth_hz <= bw_max:
score += 4 # Good match
elif bandwidth_hz < bw_min * 0.5 or bandwidth_hz > bw_max * 2:
score -= 3 # Poor match
# Otherwise neutral
# Burst behavior bonus for burst-type signals
if signal_type.is_burst_type:
if duration_ms is not None and duration_ms < 1000: # Short burst < 1 second
score += 3
if repetition_count is not None and repetition_count >= 2:
score += 2 # Multiple bursts suggest telemetry/periodic
return max(0, score)
def _calculate_confidence(
self,
primary_score: int,
all_scores: dict[str, int],
sorted_labels: list[str],
modulation: Optional[str],
bandwidth_hz: Optional[int],
) -> Confidence:
"""Calculate confidence level based on scores and data quality."""
# High confidence requires:
# - High absolute score (>= 18)
# - Good margin over second place (>= 5 points)
# - Some supporting data (modulation or bandwidth)
if len(sorted_labels) == 1:
# Only one candidate
if primary_score >= 18 and (modulation or bandwidth_hz):
return Confidence.HIGH
elif primary_score >= 14:
return Confidence.MEDIUM
return Confidence.LOW
second_score = all_scores[sorted_labels[1]]
margin = primary_score - second_score
if primary_score >= 18 and margin >= 5:
return Confidence.HIGH
elif primary_score >= 14 and margin >= 3:
return Confidence.MEDIUM
elif primary_score >= 12 and margin >= 2:
return Confidence.MEDIUM
return Confidence.LOW
def _calculate_alternative_confidence(
self,
alt_score: int,
primary_score: int,
primary_confidence: Confidence,
) -> Confidence:
"""Calculate confidence for an alternative guess."""
score_ratio = alt_score / primary_score if primary_score > 0 else 0
if score_ratio >= 0.9:
# Very close to primary - same confidence or one below
if primary_confidence == Confidence.HIGH:
return Confidence.MEDIUM
return primary_confidence
elif score_ratio >= 0.7:
# Moderately close
if primary_confidence == Confidence.HIGH:
return Confidence.MEDIUM
return Confidence.LOW
else:
return Confidence.LOW
def _build_explanation(
self,
signal_type: SignalTypeDefinition,
confidence: Confidence,
frequency_hz: int,
modulation: Optional[str],
bandwidth_hz: Optional[int],
duration_ms: Optional[int],
repetition_count: Optional[int],
) -> str:
"""Build a hedged, client-safe explanation."""
freq_mhz = frequency_hz / 1_000_000
# Start with frequency observation
if confidence == Confidence.HIGH:
explanation = f"Frequency of {freq_mhz:.3f} MHz is consistent with {signal_type.description.lower()}."
elif confidence == Confidence.MEDIUM:
explanation = f"Frequency of {freq_mhz:.3f} MHz could indicate {signal_type.description.lower()}."
else:
explanation = f"Frequency of {freq_mhz:.3f} MHz may be associated with {signal_type.description.lower()}."
# Add supporting evidence
evidence = []
if modulation:
evidence.append(f"{modulation} modulation")
if bandwidth_hz:
bw_khz = bandwidth_hz / 1000
evidence.append(f"~{bw_khz:.0f} kHz bandwidth")
if duration_ms is not None and duration_ms < 1000:
evidence.append("short-burst pattern")
if repetition_count is not None and repetition_count >= 3:
evidence.append("repeated transmission")
if evidence:
evidence_str = ", ".join(evidence)
if confidence == Confidence.HIGH:
explanation += f" Observed characteristics ({evidence_str}) support this identification."
else:
explanation += f" Observed {evidence_str}."
return explanation
def _build_unknown_explanation(
self,
frequency_hz: int,
modulation: Optional[str],
) -> str:
"""Build explanation for unknown signal."""
freq_mhz = frequency_hz / 1_000_000
if modulation:
return (
f"Signal at {freq_mhz:.3f} MHz with {modulation} modulation "
f"does not match common allocations for this region."
)
return (
f"Signal at {freq_mhz:.3f} MHz does not match common allocations "
f"for this region. Additional characteristics may help identification."
)
def get_frequency_allocations(
self,
frequency_hz: int,
region: Optional[str] = None,
) -> list[str]:
"""
Get all possible allocations for a frequency.
Useful for displaying what services could operate at a given frequency.
"""
effective_region = region or self.region
allocations = []
for signal_type in self._signal_types:
if effective_region not in signal_type.regions and "GLOBAL" not in signal_type.regions:
continue
for freq_min, freq_max in signal_type.frequency_ranges:
if freq_min <= frequency_hz <= freq_max:
allocations.append(signal_type.label)
break
return allocations
# =============================================================================
# Convenience Functions
# =============================================================================
# Default engine instance
_default_engine: Optional[SignalGuessingEngine] = None
def get_engine(region: str = "UK/EU") -> SignalGuessingEngine:
"""Get or create the default engine instance."""
global _default_engine
if _default_engine is None or _default_engine.region != region:
_default_engine = SignalGuessingEngine(region=region)
return _default_engine
def guess_signal_type(
frequency_hz: int,
modulation: Optional[str] = None,
bandwidth_hz: Optional[int] = None,
duration_ms: Optional[int] = None,
repetition_count: Optional[int] = None,
rssi_dbm: Optional[float] = None,
region: str = "UK/EU",
) -> SignalGuessResult:
"""
Convenience function to guess signal type.
See SignalGuessingEngine.guess_signal_type for full documentation.
"""
engine = get_engine(region)
return engine.guess_signal_type(
frequency_hz=frequency_hz,
modulation=modulation,
bandwidth_hz=bandwidth_hz,
duration_ms=duration_ms,
repetition_count=repetition_count,
rssi_dbm=rssi_dbm,
region=region,
)
def guess_signal_type_dict(
frequency_hz: int,
modulation: Optional[str] = None,
bandwidth_hz: Optional[int] = None,
duration_ms: Optional[int] = None,
repetition_count: Optional[int] = None,
rssi_dbm: Optional[float] = None,
region: str = "UK/EU",
) -> dict:
"""
Convenience function returning dict (for JSON serialization).
"""
result = guess_signal_type(
frequency_hz=frequency_hz,
modulation=modulation,
bandwidth_hz=bandwidth_hz,
duration_ms=duration_ms,
repetition_count=repetition_count,
rssi_dbm=rssi_dbm,
region=region,
)
return {
"primary_label": result.primary_label,
"confidence": result.confidence.value,
"alternatives": [
{
"label": alt.label,
"confidence": alt.confidence.value,
}
for alt in result.alternatives
],
"explanation": result.explanation,
"tags": result.tags,
}