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Link’d DMR
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Link’d DMR docs

Documentation grows alongside the app. This page covers the approved Android beta, the professional radio-style Cellular experience, managed Site, Team, and Channel access, the compact exact-CJ radio home, setup essentials, and common questions.

About

What is Link’d DMR?

Link’d DMR is an independent project building a hybrid push-to-talk communications platform for Android. The approved beta focuses on account-authorized cellular push-to-talk over Wi-Fi, 4G, or 5G, with a separate exact-device local RF path for verified CJ-1 hardware. Offline phone-to-phone mesh and broader radio gateway bridging remain development targets, not current production capabilities.

Link’d DMR 0.2.65 Code68 is an approved or invite-only public beta for Android 8.0 and newer; there is no iPhone app. All seven reviewed CJ-1 tracks are included: Dispatcher Lite expansion, manual RF/Cellular handoff, bounded direct Nearby coordination, better physical controls, Bluetooth PTT and audio, signed configuration handoff, and privacy-safe field diagnostics. Automatic path selection and Nearby remain safely unavailable when their production adapters are not configured. Verified CJ_1UV hardware with a supported DMR003N.UV4P.V### live firmware layout can test the exact-device RF path after selector 01 verification. This beta is not an emergency-communications service and makes no multi-hop claim.

Setup guide

Android public-beta setup

Verify the signed APK, install it on Android 8.0 or newer, and receive approval or an invitation to an assigned Site, Team, and Channel. The CJ compatibility check applies only to RF features. Link’d does not offer an iPhone app in this beta.

  1. Download the versioned APK and compare its SHA-256 checksum with the value published on this page.

  2. Install the APK on Android 8.0 or newer. Existing approved testers can update in place because the package and signing identity are unchanged. Link’d does not offer an iPhone app in this beta.

  3. Receive beta approval or an email-bound invitation, then sign in with your Link’d identity and register the Android phone.

  4. Open the assigned Site and Team, then test its private cellular Channel over Wi-Fi or mobile data. Each Business Team currently receives exactly one Channel; membership and the registered Android device authorize access.

  5. CJ-1 RF testers only: run the website compatibility tool first and continue only after it confirms CJ_1UV, a supported DMR003N.UV4P.V### live firmware layout, and selector 01.

  6. On an eligible CJ-1, connect the radio and arm its physical side key while the app is open before testing locked-screen, screen-off, or background PTT.

  7. After a reboot or force-stop, reopen Link’d DMR. CJ-1 RF users must also reconnect the radio and arm physical PTT again.

  8. Use the release only within the approved pilot scope. It is beta software and must not be relied on for emergency communications.

FAQ

Frequently asked questions

Can I download the app right now?

Yes. The signed 0.2.65 Public Beta APK is available on the download page. Account-authorized cellular PTT is available to approved or invited Android 8.0+ testers; there is no iPhone app. Local RF, Enhanced Privacy, and screen-off physical side-key PTT remain limited to the exact Android 14 / API 34 CJ_1UV hardware and a supported DMR003N.UV4P.V### live firmware layout after selector 01 verification.

Does it work with my existing DMR radios?

Radio bridging requires a compatible, validated gateway such as the CJ-1. Support depends on the exact device, radio interface, licensing, and configuration — universal radio compatibility is not claimed.

How far does the offline mesh reach?

Offline mesh remains in development and is not an available production capability. Link’d does not claim a verified field range yet; eventual results will depend on terrain, hardware, mounting, interference, and line of sight.

Do I need to create an account?

No account is needed to download the APK or use the eligible local CJ-1 RF path. Managed cellular service requires an approved or invited Link’d account and a registered Android device. Business organization creation requires an approved beta entitlement; members join assigned Sites and Teams through scoped invitations.

How are Business communications organized?

Approved organizations use Site, Team, and Channel. Each Team currently receives exactly one private cellular Channel. Current Team membership, an active account session, and a registered Android device authorize its PTT floor; Team Channel membership does not authorize RF bridging.

What does the exact-CJ radio home add?

On verified exact CJ-1 hardware, the compact radio home shows a saved caller name when known while keeping the numeric Radio ID visible, distinguishes GROUP / TG from PRIVATE / ID destinations, and provides working Last Heard, Contacts or Save ID, Channels, Scan, Settings, and guarded Cellular shortcuts. Regular Android remains cellular-first.

Is my voice audio stored on servers?

The LiveKit server does not make general room recordings. One owner-authorized CJ-1 can archive its incoming cellular and decoded RF receptions only with a visible Android system recording notification; those bounded archives are authority-correlated, encrypted before database storage, and expire after at most 30 days. Transport is encrypted, but the cellular path is not end-to-end encrypted, so the service, receiving devices, or participants can process or capture it.

Will cellular PTT work on every network?

No. The beta has no TURN/TLS fallback, so restrictive networks may fail. A cellular Channel is limited to 64 concurrent participants, and this beta must not be relied on for emergency communications.

Is this a Motorola product?

No. Link’d DMR is an independent project and is not affiliated with or endorsed by Motorola Solutions. MOTOTRBO is a trademark of Motorola Solutions, Inc.

Changelog

Release history

August 27, 2026 · Code67 crash recovery

Link’d DMR 0.2.65 Public Beta (build 68)

Fixes the withdrawn Code67 startup crash by restoring database schema 12 and the original Code66 all-features baseline. Install Code68 directly over Code66 or Code67 without uninstalling or clearing app storage. Existing user-created Enhanced Privacy keys are preserved; no key is created or shown as saved for customers who never saved one. Scanner V2 and the widget are deferred until they are correctly rebased and live-device tested. Open the release center for the exact checksum and previous signed builds.

August 23, 2026 · V1/V2 operations public beta

Link’d DMR 0.2.62 Public Beta (build 65)

Fixed a stale connection-generation race that could leave Cellular PTT offline after a valid grant, and made the supported CJ-1 Diagnostics Restart restore the exact durable zone and channel through one accepted successor radio service. Failed or superseded restart work remains locked and unkeyed. Business schema, account authorization, PTT-floor, RF, privacy, CPS, and owner-data boundaries are unchanged. Open the release center for the exact checksum and previous signed builds.

August 21, 2026 · Business compatibility hotfix

Link’d DMR 0.2.57 Business Compatibility Public Beta (build 60)

Added the explicit Business schema 2 contract used by Code63 so Android retains each organization's industry and server-provided Site, Team, and Channel labels. Authorized Team Channels now load reliably during workspace refresh and invitation acceptance. Account, membership, registered-device, PTT-floor, exact-CJ RF, privacy, and owner-data boundaries are unchanged. Open the release center for the exact checksum and previous signed builds.

August 20, 2026 · Professional radio + Business beta

Link’d DMR 0.2.56 Professional Radio Public Beta (build 59)

Shipped the signed Android-only beta with a professional radio-style Cellular screen for regular Android phones and the existing compact radio home for verified CJ-1 hardware. Approved or invited Business pilots now use a Security-first Site, Team, and Channel model across security, hospitality, construction, warehouse, event, education, transportation, retail, and other operations. Each Team currently receives exactly one private cellular Channel. There is no iPhone app, RF remains exact-device and selector-gated, and the beta is not an emergency-communications service. Open the release center for the exact checksum and previous signed builds.

August 13, 2026 · Cellular and privacy update

LinkdDMR 0.2.52 Public Beta (build 55)

Shipped the compact Cellular experience with a fixed bottom PTT dock, simplified Enhanced Privacy controls without beta framing, and optional local radio cues including the custom post-transmit key sound. Incoming recording behavior remains unchanged. Open the release center for the exact checksum and previous signed builds.

August 11, 2026 · Universal public beta

LinkdDMR 0.2.50 Public Beta (build 53)

Shipped the current signed universal beta with Android 8.0+ cellular PTT, the compact exact-CJ radio home, tighter cellular session and floor-cycle recovery, live caller and destination context, bounded manager actions, and guarded RF-to-Cellular navigation. Open the release center for the exact checksum and previous signed builds.

August 10, 2026 · Exact-CJ radio home beta

Link’d DMR 0.2.47 Public Beta (build 50)

Added a compact, performance-first radio home for verified exact CJ-1 hardware while keeping regular Android cellular-first. The radio view shows a saved caller name when known and always keeps the numeric Radio ID visible; destination context is labeled as GROUP / TG or PRIVATE / ID. Last Heard, Contacts or Save ID, Channels, Scan, Settings, and the guarded Cellular shortcut open real app actions. Token-free website-and-app signup, private groups, and account-authorized cellular PTT remain available. Cellular audio is transport-encrypted through the self-hosted selective-forwarding service but is not end-to-end encrypted, has no TURN/TLS fallback, and must not be used for emergency communications. The existing exact-device RF, Enhanced Privacy, and physical side-key safety boundaries remain in place. Read the release announcement or open the signed download.

August 10, 2026 · Public cellular beta

Link’d DMR 0.2.45 Public Beta (build 48)

Opened account-authorized cellular PTT to Android 8.0+ testers. Public signup works on linkddmr.com and in the Android app without a token; the same account manages registered devices, private groups, and optional email-bound friend invitations. Current membership and a registered signed-in Android device authorize a group's live cellular room and PTT floor. The exact verified CJ-1 V012 local-RF, legacy ARC4-40 Enhanced Privacy, and physical side-key path remains available, including signed-out RF operation. The self-hosted cellular path is transport-encrypted but not end-to-end encrypted, has no TURN/TLS fallback, and limits a talkgroup room to 64 concurrent participants. It is beta software, not an emergency communications service. Read the release announcement or open the signed download.

August 10, 2026 · Public beta update

Link’d DMR 0.2.35 CJ-1 Public Beta (build 38)

Added one public-beta account shared by linkddmr.com and the Android app, including signup, sign-in, device management, private account groups, and optional email-bound friend invitations. Signup no longer requires a token. Signed-out local CJ-1 RF remains available. In that build, cloud groups did not yet authorize cellular audio, PTT floor control, or RF bridge traffic. The exact Android 14 / API 34 CJ_1UV, V012, and selector 01 requirement remains unchanged, and Enhanced Privacy remains legacy ARC4-40 interoperability. Read the release announcement or open the signed download.

August 9, 2026 · Public beta

Link’d DMR 0.2.34 CJ-1 Public Beta (build 37)

Published the exact CJ-1 V012 field-test path for Enhanced Privacy, per-channel privacy controls, and physical-PTT testing while locked, screen-off, or outside the app.