# Report from Audio SWG Teleconference on DaCAS (13 January 2026)

## Meeting Overview

The Audio SWG teleconference on DaCAS (Diverse audio CApturing system for Smartphone devices) was held on 13 January 2026 with 20 participants for 1 hour. The meeting processed two input documents and produced two agreed output documents with revisions to be implemented in DaCAS-2 and DaCAS-3.

## DaCAS Example Solution Evaluation Procedures (S4aA260001 → S4aA260008)

**Contributors:** Nokia, Fraunhofer IIS, Dolby Laboratories

### Main Technical Contributions

This contribution established the framework for evaluating DaCAS example solutions through a combined approach:

#### Evaluation Methodology
- **Combined evaluation approach** comprising both self-evaluation and cross-evaluation
- **Cross-evaluation as optional task** depending on available effort from cross-evaluation laboratories
- Three-tiered cross-evaluation approach (hierarchical structure):
  1. Minimum requirement: Cross-evaluation based on output signals provided by solution proponents
  2. Cross-evaluation using input signals and upmix methods
  3. Running executables to generate outputs for evaluation

#### Key Discussion Points and Resolutions

**Cross-Evaluation Flexibility:**
- Cross-evaluation labs have freedom to conduct evaluation based on already provided signals or process evaluation signals with submitted solutions
- The approach depends on available effort and resources at the cross-evaluation laboratory

**Dataset Requirements:**
- Mandatory minimum evaluation dataset to be defined
- Cross-evaluation limited to datasets that solution proponents have provided
- Proponents must process recordings from the evaluation database
- Cross-evaluation labs may use mandatory dataset and potentially additional signals

**Clarifications Added:**
- Editor's note added to Clause 2.1 regarding cross-evaluation procedures
- Clarification that recordings shared in the database should be used for processing with example solutions
- Any company (proponent) can conduct cross-evaluation if desired

### Agreement Status
The revised document (S4aA260008) was **agreed** with changes in brackets to be implemented in DaCAS-2.

## DaCAS Example Solution Deliverables (S4aA260002 → S4aA260009)

**Contributors:** Bytedance, Beijing Xiaomi Mobile Software

### Main Technical Contributions

This contribution defined the package and deliverables required for DaCAS example solutions.

#### Deliverable Components

**1. Target Device Information:**
- List of supported target devices (revised from "target device to provide")
- Device specifications and characteristics

**2. Dataset Description:**
- Clarification that this refers to recordings used to develop example solutions
- Discussion on whether to include external data used for development
- Distinction between:
  - Common database for algorithmic development (transparent, shared data)
  - External data (e.g., for neural network training)
  - Geometric/analytical data (part of algorithmic description)

**3. Algorithmic Description:**
- High-level description of solution development approach
- Differentiation between signal processing and neural network solutions
- For signal processing: description of methods (e.g., FEM method, upmix matrices)
- For neural networks: indication of training data usage

#### Key Discussion Points and Resolutions

**External Data Usage:**
- Proponents allowed to use external data (e.g., for neural network development)
- Current common database amount may be insufficient for neural network training
- No prohibition on external data, but transparency required
- Common database serves as baseline, not as closed/exclusive dataset

**Unified Deliverables:**
- Suggestion to combine deliverables for signal processing and neural network solutions
- Recognition that solutions may combine both approaches
- Need for unified set of deliverables across solution types

**Documentation Requirements:**
- Code package contents to be specified
- Similar to table format used for dataset descriptions
- High-level description of how solution was developed
- Reference to potential datasets used

**Outstanding Items:**
- Bullet 2 (dataset description) placed in brackets for further discussion
- Need to combine and unify deliverable descriptions
- Editor notes inserted for future clarification

### Agreement Status
The revised document (S4aA260009) was **agreed** with changes in brackets to be implemented in DaCAS-3.

## Administrative Matters

### IPR and Compliance
Standard 3GPP reminders provided regarding:
- IPR disclosure obligations
- Antitrust and competition law compliance
- Consensus-based decision making

### Next Steps
- DaCAS meeting scheduled at SA4#135
- Submission deadline: February 3, 2026
- DaCAS-2 Editor to implement S4aA260008 revisions
- DaCAS-3 Editor to implement S4aA260009 revisions

## Participation
20 participants from organizations including: Bytedance, Dolby, Ericsson, Fraunhofer IIS, Nokia, NTT, Orange, Panasonic, Qualcomm, Philips, and Xiaomi.