Uniline

Universal analog-line communication: encrypted data, voice, and TTY text over any surviving phone line. A resilience-focused open project from dev://systems.

Uniline is a compact, multi‑mode analog communication node that turns any working POTS/copper line into a channel for:

• Encrypted low-bandwidth data (text, telemetry, coordination)
• TTY text calls (Baudot tones for degraded or accessibility communication)
• Voice calls and buttset functionality, using a smartphone or laptop as the handset
• High‑impedance line monitoring for diagnostics and safety

It is a single device capable of DATA, VOICE, and TTY across one unified physical interface.

No native apps are required — all interaction happens through a single-file Web GUI (web/index.html) that runs fully offline in any modern browser.

**, VOICE, and TTY across one unified physical interface.

No cell service, Wi‑Fi, or internet required — just the Uniline device, a phone or laptop, and an analog line.

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Status

⚠️ Early conceptual design. Hardware, firmware, API, and crypto components are not production‑ready.

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Why Uniline Exists

Modern communication depends on:

• Cell towers
• Power grid
• Routers and IP networks
• Cloud services

These layers fail in:

• Natural disasters
• Grid collapse
• Conflict zones
• Infrastructure outages
• Remote or underserved regions

Yet copper lines (POTS) often remain functional because they are:

• Centrally powered
• Shockingly robust
• Built for emergency survivability
• Routed through diverse infrastructure

Uniline explores how these surviving lines can carry essential communication when everything else is offline.

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Capabilities

Uniline integrates three communication layers:

1. Encrypted Low‑Bandwidth Data

Two Uniline nodes dial each other, negotiate an analog modem link, then establish an encrypted digital channel.

Throughput: 300 bps → ~33.6 kbps

Suitable for:

• Text messages
• Status beacons
• GPS/location bursts
• Sensor telemetry
• Command/control packets
• Minimal protocol tunneling

Encryption sits above the modem for simplicity and resilience.

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2. Voice + Buttset Functionality

Uniline can emulate a lineman’s handset.

Monitor Mode (High‑Impedance)

• Passive listening
• Does not seize the line
• Diagnose dial tone, noise, alarms, modem activity, and TTY

Talk Mode (Off‑Hook Voice)

• Seizes the line
• Allows normal voice calls
• Phone acts as headset/microphone

Supported Audio Paths

• USB‑C digital audio
• Bluetooth HFP (offline-capable)

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3. Integrated TTY Support

TTY is part of Uniline’s modem/audio stack.

• Full Baudot send/receive
• Auto-detection of incoming TTY tones
• Relay center compatibility
• VCO/HCO hybrid modes
• Text ↔ tone conversion

TTY operates across:

• Talk Mode (primary TTY mode)
• Monitor Mode (passive decode)
• Data Mode (TTY‑over‑data fallback)

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Operating Modes

Uniline is multi‑mode, but DATA/VOICE/TTY share a unified interface.

1. DATA MODE — encrypted digital link

• Modem DSP + crypto layer
• Host communicates over USB‑C/BLE
• Optional TTY‑over‑data

2. MONITOR MODE — passive listening

• High‑impedance
• Safe diagnostics
• Detects tone/noise/modem/TTY activity

3. TALK MODE — voice + tty

• Off‑hook control
• Voice calls
• TTY calls
• VCO/HCO hybrids
• DTMF dialing

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System Overview

PHONE / LAPTOP
   │ USB‑C / Bluetooth
   ▼
+--------------------------+
|       Uniline Node       |
|   modem • tty • buttset  |
+--------------------------+
   │
   ▼
Analog Phone Line (RJ11 / 66 / 110)
   │
   ▼
         PSTN
   │
   ▼
 Another Uniline Node

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Architecture

PHONE (Android / Laptop)
   │  USB‑C Serial + Digital Audio
   │  Bluetooth BLE + HFP
   ▼
┌────────────────────────────┐
│        Uniline Node        │
├────────────────────────────┤
│ Mode Controller (Data/Monitor/Talk)
│ Crypto Layer (E2EE)
│ Modem + TTY DSP
├────────────────────────────┤
│ Analog Audio Switch
│ FXO Line Interface
│ Isolation + Off‑Hook Control
└────────────────────────────┘
   │
   ▼
Analog Line / PSTN

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Why Uniline Matters in Crisis Environments

Uniline is designed for resilience and humanitarian use. In conflict zones, civil unrest, or infrastructure collapse, it can:

• Support medical/shelter communication when cell networks fail
• Enable long‑distance PSTN‑based contact between communities
• Provide emergency text/voice channels for NGOs and relief teams
• Support accessibility via TTY when voice or data fail
• Operate during long power outages due to PSTN’s centralized power
• Act as a fallback coordination tool for community hubs

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Intended Uses

Ethical, non‑destructive use only:

• Disaster response
• Community resilience
• Humanitarian coordination
• Crisis shelters and clinics
• Power + internet outages
• PSTN research
• Accessibility/TTY studies

Life‑safety systems (e.g., fire panels) must be monitored passively unless in legitimate emergencies.

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Non‑Goals

Uniline is not for:

• Unauthorized telecom access
• Unlawful communication
• High‑speed networking
• Interfering with life‑safety systems

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Project Philosophy

Uniline is part of dev://systems, exploring:

• Universal coherence in infrastructure
• Humane, resilient engineering
• Open tools for public benefit
• Communication layers that survive systemic failure

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Repo Structure

Uniline/
  README.md
  LICENSE
  docs/
    overview.md
    architecture.md
    protocol.md
    threat-model.md
    use-cases.md
  hardware/
    schematics/
    bom.md
  firmware/
    endpoint/
  host/
    cli/
    gui/
    mobile/
  web/
    index.html
    README.md
  examples/
    demo-topologies.md
    sample-workflows.md

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Contributing

Looking for contributors with experience in:

• Telephony / PSTN systems
• Modem DSP
• Crypto protocol design
• Embedded systems
• Disaster-resilient communication
• Accessibility / TTY research

Please open an issue before large contributions.

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License

Released under CC0 1.0 Universal (Public Domain Dedication). You may copy, modify, distribute, and use the work without restriction. See: https://creativecommons.org/publicdomain/zero/1.0/