Bluetooth Audio Expert System™
The Bluetooth Audio Expert System™ monitors and analyzes Bluetooth audio streams with the purpose of detecting and reporting audio impairments. The primary goal of the Audio Expert System™ is to expedite the detection and resolution of Bluetooth protocol related audio impairments. To achieve this, the system automatically identifies audio impairments and reports them to a user as “events”. It also correlates the audio events with any detected codec or Bluetooth protocol anomalies (events). The system allows a user to view the audio waveform, audio events, codec events, and Bluetooth protocol events on a time-aligned display.
An Audio Expert System™ event identifies to the user information, warnings, and errors. Event categories are shown in the following table.
| Event Category | General Events Reported |
|---|---|
| Bluetooth Protocol | Protocol violations |
| Best practice violations | |
| Codec | Configuration changes |
| errors | |
| Audio | impairments (errors) |
| information data |
When the Frontline software captures data, if there is audio content that must be debugged this data must be systematically examined when looking for the problem source. The effort to identify and correlate the audio related data can be daunting because the problem source may be caused by protocol, codec, or the audio itself. Using the Audio Expert System™ identifies events that are likely candidates for audio root cause analysis. The expert system examines all captured frames—in live capture or in capture file viewer—and selects audio-related protocol, codec, and audio events. The events are time correlated to the audio stream and identified with specific frames. In general, a cluster of events suggests an area for investigation, and in the presence of multiple event clusters the cluster with the most events suggests the best starting point.
The expert system works in conjunction with Frontline software that is operating in live capture mode or in capture file viewer mode. Selecting an event in the Audio Expert System™ will simultaneously highlight related packets in the Frontline software Frame Display, Coexistence View, Message Sequence Chart, Bluetooth Timeline, and Packet Error Rate Statistics (PER Stats) windows.
Audio Expert System™ further provides methods for isolating testing to specific audio events by using two operating modes: non-referenced and referenced.
| Mode | Description |
|---|---|
| Non-referenced | Processing audio of completely unknown program content (e.g. arbitrary music or speech content). Since the system does not have any prior knowledge of the audio being analyzed, the types of audio analysis that can be performed is limited. |
| Referenced | A “pseudo closed loop” test scenario where the user plays specific Reference Audio files (pre-recorded audio test files provided by Frontline) on the Source DUT (Device Under test). The analysis of the received audio results in a series of “Audio Events” being reported by comparing changes in the received audio to expected changes of the Reference Audio, and reporting deviation events when they occur. |
Reference mode detects a larger number of events because the reference audio has specific frequency, amplitude, and duration occurring at known points in time allowing for precise comparison.
