How to Monitor and Log Protocol Activity

This guide explains best practices for monitoring and logging SAS-CBSD protocol activity to ensure reliability, debugging, and performance optimization.

Overview

Effective monitoring and logging provide visibility into:

Protocol health (success rates, latency)
Error patterns
Grant lifecycle events
Compliance auditing

Key Bridge SAS Note: We log all activity server-side. Detailed client-side logs help support resolve issues quickly.

What to Log

Essential Items Per Message

Item	Why Log It	Example
Timestamp (UTC)	Correlation and timing analysis	2026-01-07T14:30:00Z
Message Type	Identify flow stage	registrationRequest
Direction	Request vs Response	OUT / IN
cbsdId / grantId	Trace specific device/grant	SAS123/CBSD-001 / GRANT-789
responseCode	Success/failure detection	0
responseMessage	Human-readable detail	Success
Latency (ms)	Performance monitoring	245
Full Request/Response JSON	Deep debugging	(truncated if large)
Measurements Sent	Correlation with grant quality	rcvdPower -55.2 dBm

Tip: Use structured logging (JSON lines) for easy parsing.

Example Log Entry

{
  "timestamp": "2026-01-07T14:30:00Z",
  "direction": "OUT",
  "type": "heartbeatRequest",
  "cbsdId": "SAS123/CBSD-001",
  "grantId": "GRANT-789",
  "latency_ms": null,
  "responseCode": null
}

{
  "timestamp": "2026-01-07T14:30:02Z",
  "direction": "IN",
  "type": "heartbeatResponse",
  "cbsdId": "SAS123/CBSD-001",
  "grantId": "GRANT-789",
  "latency_ms": 245,
  "responseCode": 0,
  "maxEirp": 30.0
}

Monitoring Metrics

Key Metrics to Track

Metric	Target	Alert Threshold
Heartbeat Success Rate	>99.9%	<99% over 5min
Grant Approval Rate	>90%	<80% over hour
Average Latency	<500ms	>1000ms
Error Rate (non-0 codes)	<1%	>5%
Active Grants per CBSD	3-10	>15 or <1 in contested area
Measurement Submission Rate	100% when configured	<80%

Tip: Export to Prometheus/Grafana or cloud monitoring.

Alerting Examples

Critical: responseCode 101 (BLACKLISTED) or persistent 501 (TERMINATED_GRANT)
Warning: Frequent 400 (GRANT_FAILURE) → possible interference
Info: New grant approved, EIRP change

Best Practices & Tips

Log Rotation: Keep 7-30 days locally; archive older
Redact Sensitive Data: Mask exact coordinates if needed
Correlation ID: Add unique requestId per message flow
Include Radio State: TX on/off, current channel/EIRP
DPA Events: Alert on sudden terminations in neighborhood
Key Bridge SAS: Share log snippets with support — speeds resolution dramatically

Tools & Implementation

Structured Logging Libraries: logrus (Go), structlog (Python), serilog (C#)
Centralized Logging: ELK stack, Splunk, or cloud (CloudWatch, Datadog)
Dashboards: Visualize success rates, latency trends, grant counts

Next Steps

Add structured logging to your protocol handler
Set up basic alerts for critical codes
Review logs after next deployment