Root Cause Analysis

for Bluetooth Classic (BR/EDR) Continuous Data Streaming Issues

Scenario: Testing the continuous data streaming functionality of a device using Bluetooth Classic (BR/EDR) and encounter problems => identify the root cause.

1. Problem Statement:

Clearly define the problem you are experiencing.

Example: “Continuous data streaming over Bluetooth Classic fails intermittently after 5 minutes of operation.”

2. Data Collection:

Gather relevant information to understand the problem better.

• Symptoms:
  • What are the specific error messages or behaviors you observe?
  • Does the data stream completely stop or is it just fragmented/corrupted?
  • Does the connection drop altogether, or just the data stream?
  • Is there any specific pattern to the failures (e.g., time of day, specific data content)?
• Environment:
  • Which devices are involved (sender, receiver, any intermediary devices)?
  • What are their operating systems and firmware versions?
  • What is the distance between the devices?
  • Are there any other Bluetooth devices operating in the same vicinity?
  • What are the specific Bluetooth profiles and services used?
  • What is the data rate and packet size used for streaming?
• Logs:
  • Collect any relevant logs from the devices (bugreport).

3. Analysis:

Analyze the collected data to narrow down the possible root causes.

• Data Stream Integrity:
  • Analyze the data received to identify any patterns or errors in the data stream.
• Connection Stability:
  • Examine the Bluetooth connection logs for any disconnections or connection issues.
  • Analyze network traces to identify connection establishment and termination events.
• Resource Constraints:
  • Check for any memory leaks, buffer overflows, or other resource issues on either device.
• Interference:
  • Analyze the network trace for any other Bluetooth devices interfering with the communication.
• Bluetooth Stack Issues:
  • Review the Bluetooth stack logs for any errors or warnings.

4. Root Cause Identification:

identify the most likely root cause of the problem.

Example Root Causes:

• Bluetooth Stack Issues:
  • Incorrectly configured Bluetooth stack parameters (e.g., data rate, buffer size).
  • Bugs in the Bluetooth stack implementation connection instability.
• Interference:
  • Other Bluetooth devices interfering with the communication.
• Hardware Issues:
  • Faulty Bluetooth transceiver on one of the devices.

5. Verification:

After implementing the solution, retest the data streaming functionality to verify that the issue has been resolved.