If you experience issues with a vTools.eNotice mailing that originates from vTools.Events, please contact staff for assistance.
Open Source Digital Radio Work: Opulent Voice Protocol Review
Open source digital radio work round table and reports. Agenda for this meeting is a review of recent work for the Opulent Voice Protocol.
Date and Time
Location
Hosts
Registration
-
Add Event to Calendar
- Contact Event Host
-
Round Table of technical reports for open source FPGA work involving DSES, ORI, ARRL, and other amateur radio related organizations.
- Co-sponsored by Open Research Institute, Inc.
- Starts 29 May 2025 07:00 PM UTC
- Ends 03 June 2025 05:00 PM UTC
- No Admission Charge
Agenda
Demonstration Code Notes for Raspberry Pi Human-Radio Interface
Protocol Frame Structure Review
All payloads follow the same underlying frame format in OpulentVoiceProtocol.create_frame() method.
Header: 14 bytes (sync word + station ID + type + sequence + length + reserved)
Payload: Variable length data specific to each message type
Payload Type Creation Methods
1. Audio Payloads (Highest Priority)
def create_audio_frame(self, opus_packet):
return self.create_frame(self.FRAME_TYPE_AUDIO, opus_packet)
Source: OPUS-encoded audio data from the microphone
Processing: Raw audio → PyAudio → OPUS encoder → binary packet
Priority: Immediate transmission (bypasses queue)
Usage: Real-time voice during PTT active
2. Text Payloads (Chat Messages)
def create_text_frame(self, text_data):
if isinstance(text_data, str):
text_data = text_data.encode('utf-8')
return self.create_frame(self.FRAME_TYPE_TEXT, text_data)
Source: Terminal chat input or buffered messages
Processing: String → UTF-8 encoding → binary payload
Priority: Queued (waits for PTT release)
Usage: Terminal chat interface
3. Control Payloads (System Commands)
def create_control_frame(self, control_data):
if isinstance(control_data, str):
control_data = control_data.encode('utf-8')
return self.create_frame(self.FRAME_TYPE_CONTROL, control_data)
Source: System events like "PTT_START", "PTT_STOP"
Processing: String → UTF-8 encoding → binary payload
Priority: High priority (queued but processed quickly)
Usage: PTT state changes, system notifications
4. Data Payloads (File Transfer)
def create_data_frame(self, data):
return self.create_frame(self.FRAME_TYPE_DATA, data)
Source: Raw binary data for file transfers
Processing: Binary data passed through unchanged
Priority: Lowest priority (queued)
Usage: Future file transfer capabilities
Message Flow Architecture:
The code uses a domain-driven approach with clear separation of data types.
Message Creation Flow:
Input Source → Different interfaces (GPIO, terminal, system events)
Domain Logic → ChatManager and MessagePriorityQueue handle routing
Protocol Layer → OpulentVoiceProtocol creates properly formatted frames
Transport Layer → NetworkTransmitter handles UDP delivery
Priority Queue System (Proposed)
class MessageType(Enum):
VOICE = (1, "VOICE") # Immediate transmission
CONTROL = (2, "CONTROL") # High priority queue
TEXT = (3, "TEXT") # Normal priority queue
DATA = (4, "DATA") # Low priority queue