Talk now
Direct, group and Allcall conversations. In a supported direct packet chat, request confirmed receipt with Verified.
From JS8 and FSQ.
One JSQ transport.
JSQ brings their commands and capabilities into a common service layer: who a message is for, what a station can do, and what happened to your traffic stay meaningful as you change modems. OpenJSQ is the application that puts it to work.
Two foundations
Conversation meets cooperation.
JS8 / JS8Call
Messages with somewhere to go.
Directed messages, acknowledgements, stored messages and relays help a conversation continue when the operator is away or the direct path is missing.
The shared design goalFSQ / FSQCall
A channel where stations cooperate.
Live keyboard conversation sits alongside callsign addressing, signal reports, heard lists and requests for station information.
The FSQ-derived actionsThese traditions overlap: JS8Call also supports conversation and station queries; FSQ also has stored-message and relay commands. JSQ brings those operating ideas together without tying them to one waveform.
What JSQ combines.
Leave it for later
Hold mail for a station that is away, or deposit it with a capable mailbox. Storage and final delivery remain separate.
Share the details
Send a file, recover missing blocks, or browse files a peer has chosen to offer—like a small radio bulletin board.
Find a path
Use presence, heard lists and network observations to find another station or choose a willing relay.
A service needs support from both your active connection and the other station. How capabilities work
An example operating session
Start with hello.
Keep going from there.
Find your stations
Listen on an agreed channel. Look at Network, then ask a peer for its signal report or heard list.
Talk and confirm
Start a Live conversation. For an important direct message on AX1200 or JG25, choose Verified and watch for acknowledgement.
Send the details
Send the net roster as a file to a capable peer. Recover missing blocks and verify the complete result.
Include someone who is away
Leave a letter for later. Keep it at your station or use a peer offering mailbox custody.
The modem carries the signal.
JSQ carries the meaning.
A file still needs to arrive complete. A letter still has an author and recipient. A relay still needs to preserve the original sender. Those rules belong above the modem, so each radio link can carry the same service model.
JSQAddressing · Service capabilities · Delivery evidence
Your modemRadio signal · Link framing · Channel access
Both ends still need a compatible waveform and supported services. JS8/FSQ ancestry is not JS8 waveform compatibility, and legacy FSQ or ordinary AX.25 equipment does not acquire JSQ services just by decoding the signal.
Inside the layers: adapters and wire formats
Chat · Mail · Files · Relay · Network
JSQ transport
FSQ / FastFM / HFAX1200FM · AX.25JG25FM
Adapters translate common operations into each link’s representation and report capabilities, timing, integrity and transmit-completion evidence. The modem handles modulation, frames, channel access and payload limits.
For example, sending a file uses different over-the-air formats on AX.25 and FSQ. JSQ handles those differences while keeping the same rules for recovering missing pieces, resuming a transfer, and checking that the complete file arrived intact.
Adapter contractLayer responsibilitiesShared encodingsModem choices
Know what actually happened.
In OpenJSQ, Verified direct chat on AX1200 and JG25 uses acknowledgements and retries. FSQ chat is best effort; groups, Allcall and relayed chat use Live. An optional end-to-end receipt is a separate service, not the Verified chat mode.
- Handed to modem
- The connection accepted the work. Transmission is not yet established.
- Sent
- Transmit completion was reported. It does not prove reception.
- Integrity verified
- The received content passed its applicable integrity check.
- Delivered
- The destination acknowledged reception under the relevant service.
- Mail custody
- A mailbox accepted storage responsibility. Final delivery is still separate.
These are different kinds of evidence, not five guaranteed steps for every message. A receipt does not prove that a human read the message or authenticate the operator.
Verified chat versus optional delivery receipts
Verified packet chat uses service acknowledgements and automatic retransmission. JSQ Delivery Receipt v1 instead reports acceptance of an identified message at the destination application, when supported and advertised; it does not itself add retransmission. Broadcast and group traffic is not receipted. A missing optional receipt is not proof of non-delivery and does not itself trigger a retry.
On AX1200 the receipt is an OFQ2 packet type; on FSQ it is carried in a directed jsqr1: envelope. This does not turn FSQ chat into Verified packet chat.
Useful beyond the live conversation.
Mail that waits
Your station can hold a letter until its recipient is heard. A capable mailbox can accept custody for later delivery; the sender keeps its copy until that handoff is accepted and stored.
“Leave the meeting details for the station joining later.”
Mailbox custodyFiles you can finish
Recover missing blocks, resume an interrupted transfer and check the complete file. A station can advertise a shared folder for direct browsing and retrieval within its access policy.
“Fetch the updated roster from the club station.”
Reliable files · Sharing in OpenJSQA callsign, and what it can do.
Address the station
Use a callsign for a direct conversation, a shared group destination for a net, or Allcall for everyone listening. Groups are self-enrolled; there is no membership server.
Discover its services
A peer advertises what it supports. A modem capable of moving a file does not prove that its operator is serving shared files. Sharing is advertised only while available under the station’s policy.
Addressing, capability tokens and trust
Groups use @GROUPNAME. A callsign checksum detects errors; it is not authentication. Received content remains untrusted input and is not executed.
Service names such as file.reliable and mail.custody express meaning. AX1200 uses a 16-byte capability payload; FSQ carries a compact token in presence or version replies; JG25 uses its own capability response.
Station identityGroupsCapabilitiesAX1200 encodingFSQ tokensJG25 capabilities
Another station. A possible path.
Choose a willing station that can hear both ends. It receives the message and transmits it onward, preserving the original sender and final destination.
- Your stationOriginal sender
- Willing relayReceives and forwards
- DestinationIntended recipient
In the current app, AX1200 and JG25 use one relay; FSQ can carry a chain. Relayed chat is Live, and shared-file browsing requires a direct connection. Each hop takes airtime and depends on the relay’s settings.
Relay limits, digipeating and future bridges
JSQ application relay is separate from AX.25 link-layer digipeating. The service model requires provenance, bounded hops, duplicate suppression and loop prevention.
The architecture allows a relay implementation to receive through one modem and forward through another. That is an architectural possibility, not a claim that the current OpenJSQ app runs a simultaneous cross-modem bridge.
Current relay behavior and limitsRelay serviceRelay architecturePacket limits
Cooperation, under your control.
Automatic behavior is bounded, visible and governed by station policy. Some replies transmit information; other enabled services store or forward traffic.
Information queries
Answer requests for signal reports, heard stations, location, status and software information.
Enabled station actions
Accept notes and files, hold mail, serve shared files or relay traffic according to your settings. AX1200 relay has a separate forwarding switch.
OpenJSQ shows automatic activity. Net mode holds automatic traffic for a directed net while leaving deliberate operator messages available. Operating controls
Action encodings and safeguards
Adapters map semantic requests to each bearer. Legacy FSQ uses punctuation such as ? for signal reports and $ for heard lists. Do not assume every trigger has identical legacy behavior: OpenJSQ’s repeat action repeats its last transmission to the requester, while FSQCall echoes supplied text.
Automatic services have limits and must not create reply loops. Protocol actions do not authorize arbitrary software execution.
Explore the public service model.
Read the specifications, or see these ideas in OpenJSQ.