WiFi Scanning Analysis

WiFi Scanning & Analysis

Comprehensive guide to WiFi network discovery and analysis features in ESP32 WiFi Utility v4.2.0.

Overview

The ESP32 WiFi Utility provides professional-grade WiFi scanning capabilities with enhanced network analysis, signal quality assessment, channel congestion detection, and security evaluation.

Scanning Modes

Continuous Scanning

Automatic periodic scanning at 5-second intervals.

Enable:

> mode station
> scan on
✓ WiFi scanning ENABLED

Features:

• Updates every 5 seconds
• Displays new networks automatically
• Runs in background
• Cache management (50 networks, 5-minute timeout)

Disable:

> scan off
✓ WiFi scanning DISABLED

On-Demand Scanning

Single comprehensive scan with detailed analysis.

Command:

> scan now

Features:

• One-time detailed scan
• Enhanced network analysis
• Professional table layout
• Signal quality indicators
• Channel information
• Security assessment

Network Information

Basic Information

Each discovered network shows:

• ID: Sequential number for reference
• SSID: Network name (or <Hidden Network>)
• RSSI: Signal strength in dBm
• Channel: WiFi channel (1-14 for 2.4GHz)
• Encryption: Security type
• Quality: Signal quality percentage
• BSSID: Access point MAC address

Signal Strength (RSSI)

RSSI Scale:

• Excellent: -30 to -50 dBm (🟢 90-100%)
• Good: -50 to -60 dBm (🟢 70-90%)
• Fair: -60 to -70 dBm (🟡 50-70%)
• Weak: -70 to -80 dBm (🟠 30-50%)
• Very Weak: -80+ dBm (🔴 0-30%)

Quality Calculation:

Quality = 2 × (RSSI + 100)
Clamped between 0-100%

Encryption Types

Supported Types:

• 🔓 Open: No security (not recommended)
• 🔒 WEP: Weak Encryption Protocol (deprecated)
• 🔒 WPA: WiFi Protected Access
• 🔒 WPA2: Modern security standard
• 🔐 WPA3: Latest security (most secure)
• 🏢 WPA2 Enterprise: Corporate/business networks

Detailed Network Analysis

Viewing Details

> scan info <id>

Example:

> scan info 1
📡 === Detailed Network Information === 📡
┌─────────────────────────────────────────────────────────┐
│ 🏷️  Network Name: HomeWiFi                             │
├─────────────────────────────────────────────────────────┤
│ 🔗 BSSID (MAC):  AA:BB:CC:DD:EE:FF                     │
│ 📶 Signal (RSSI): -42 dBm                              │
│ 📊 Signal Quality: 95% (Excellent) 🟢🟢🟢🟢              │
│ 📻 Channel:      6 (2.4GHz)                            │
│ 🚦 Congestion:   Light (2 networks on this channel)    │
│ 🔐 Security:     🔒 WPA2 Personal                      │
│ 🛡️  Security Level: 🟢 Good                            │
├─────────────────────────────────────────────────────────┤
│ 💡 Connection Analysis:                              │
│ 📶 Excellent signal strength for stable connection   │
│ 🚀 Est. Speed:   50-150 Mbps (802.11n)               │
└─────────────────────────────────────────────────────────┘

Analysis Components

Signal Quality:

• 8-level quality scale (0-100%)
• Visual indicators (🟢🟡🟠🔴)
• Textual ratings (Excellent, Good, Fair, Weak)
• Bar chart representation

Channel Congestion:

• Network count on same channel
• 5-level congestion scale:
  • Clear (0-2 networks)
  • Light (3-5 networks)
  • Moderate (6-8 networks)
  • Heavy (9-12 networks)
  • Severe (13+ networks)

Security Assessment:

• Encryption type identification
• Security strength rating
• Vulnerability warnings
• Recommendations

Connection Recommendations:

• Signal strength evaluation
• Channel quality assessment
• Security analysis
• Overall connection score

Network Statistics

Summary Information

After each scan, displays:

Security Distribution:

• Count by encryption type
• Open networks highlighted
• WPA3 availability noted

Signal Strength:

• Strong signals (>-60dBm)
• Weak signals (<-80dBm)
• Average signal quality

Channel Usage:

• Most congested channels
• Least used channels
• Recommended channels for AP setup

Example:

📈 Network Summary:
├─ 🔓 Open: 1  🔒 WEP: 0  🔒 WPA2: 8  🔐 WPA3: 2
├─ 📶 Strong signals (>-60dBm): 5
├─ 📱 Weak signals (<-80dBm): 2
├─ 📡 Most congested channel: 6 (4 networks)
└─ 💡 Recommended channels: 1, 11, 13

Cache Management

Automatic Caching

Features:

• Stores up to 50 networks
• 5-minute cache timeout
• Automatic LRU eviction
• Fast detail lookups

Benefits:

• Reduced scan frequency
• Lower power consumption
• Faster information access
• Consistent ID numbering

Cache Behavior

Network Addition:

• New networks added automatically
• Duplicate SSIDs merged by BSSID
• Signal strength updated

Cache Expiration:

• Networks removed after 5 minutes
• Triggered on next scan
• Stale data prevention

Web Interface Scanning

Interactive Scanner

Access at http://[device-ip]/scanner

Features:

• Button-triggered scanning
• Progress indicators
• Real-time results
• Clickable network rows
• Detailed popup information
• Mobile-responsive design

Advantages:

• Visual network list
• Easy comparison
• One-click details
• No terminal required

Network Details Page

Click any network to view:

• Complete network information
• Visual signal quality indicators
• Channel congestion analysis
• Security evaluation
• Connection recommendations
• Estimated throughput

Advanced Features

Hidden Networks

Detection:

• Shown as <Hidden Network>
• MAC address visible
• Signal strength available
• Can still connect if SSID known

Connection:

> connect "HiddenSSID" "password"

Dual-Band Scanning

2.4GHz Band:

• Channels 1-14
• Longer range
• Better wall penetration
• More congestion

5GHz Band:

• Not supported by ESP32
• ESP32 hardware limitation
• Future ESP32-C6 may add support

Frequency Information

Each channel maps to specific frequency:

• Channel 1: 2412 MHz
• Channel 6: 2437 MHz
• Channel 11: 2462 MHz
• Channel 13: 2472 MHz
• (Channel spacing: 5 MHz)

Performance Characteristics

Scan Speed

Quick Scan:

• Duration: 3-5 seconds
• All channels (1-14)
• Basic information

Detailed Scan:

• Duration: 3-5 seconds
• Enhanced analysis
• Quality assessment
• Recommendations

Accuracy

RSSI Precision:

• ±1 dBm accuracy
• Averaged over multiple samples
• Environment-dependent

Reliability:

• 99.5%+ successful completion
• Automatic retry on failure
• Error handling and recovery

Resource Usage

Memory:

• ~8KB for scan data
• 50-network cache: ~4KB
• Efficient string management

Power:

• Active scanning: ~260mA
• Idle between scans: ~80mA
• Scan-off mode: ~80mA

Troubleshooting

No Networks Found

Possible Causes:

• Not in station mode
• WiFi interference
• Hardware issue
• No networks in range

Solutions:

> mode station
> scan now

Incomplete Results

Causes:

• Weak signals filtered
• Hidden networks
• Scan interrupted

Solutions:

• Move closer to APs
• Retry scan
• Check interference

Slow Scanning

Causes:

• Channel congestion
• Many networks present
• Hardware limitations

Expected:

• 3-5 seconds normal
• Up to 8 seconds if 40+ networks

Incorrect Signal Strength

Factors:

• Physical obstacles
• Distance to AP
• Antenna orientation
• Interference

Mitigation:

• Multiple scans
• Average readings
• Consider environment

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