push.tt / Solutions
In beta
Keep the radios. Add everywhere they cannot reach
A DMR or analogue system covers the site it was built for and stops at the fence. push.tt covers wherever there is cellular. A bridge joins the two, so the crew on handhelds and the driver two counties away are on the same conversation — without replacing equipment that works.
In beta. Radio bridging is implemented and in beta. Android Phone Bridge handles an isolated audio-and-VOX path; the packaged Linux gateway handles donor radios and direct-IP profiles for JPS RSP-Z2, JPS ACU-Z1, Raven FlexGate and standards-based G.711 RTP appliances. Every installation still needs a supervised two-way audio and RF commissioning test: software preflight does not certify the physical radio, interface or appliance. Protocol-native DMR, P25 and TETRA integrations, and native proprietary JPS RoIP, remain future work.
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What a bridge actually is
Three gateway paths are available. The right one depends on the radio system, the interfaces it exposes and what the field commissioning test proves.
- Android Phone Bridge. A dedicated Android install connects through an isolated, levelled audio interface and uses radio-side VOX. It is the simpler path, but commissioning has to prove audio routing, levels, VOX key-up and recovery after a reboot
- The packaged donor-radio gateway. The Linux or Raspberry Pi field package connects one authorized donor or base radio through audio plus radio-side VOX or wired PTT and optional COS. The path is air-interface agnostic, so analogue, DMR, P25 or TETRA can connect when the radio exposes the required accessory signals; that is not a claim that every model or cable is certified
- Direct-IP gateway profiles. The same package supports JPS RSP-Z2 and ACU-Z1 through standard G.711 PCMU RTP, Raven FlexGate through RTP plus its published SVoIP PTT/COR control, and generic G.711 RTP appliances using device-side silence suppression. These are software profiles whose physical installation still has to be commissioned
- Protocol-native adapters remain future work. The bridge does not implement DMR Tier III, P25 ISSI/CSSI, TETRA or proprietary JPS RoIP signalling. An NXU-2B needs a vendor-authorized adapter that exposes audio and PTT/COR; the runtime refuses guessed native framing
- Mapping is per talkgroup, not per system. One radio talkgroup to one push.tt channel, so an operation can bridge dispatch without bridging everything
Legacy Radio Bridge
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01Android Phone Bridge02The packaged donor-radio gateway03Direct-IP gateway profiles
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What a bridge costs you
This is the boundary that should decide whether you commission it.
- The privacy ends where the radio begins. The box on your site is treated like any other handset — our servers still never hear your audio. But the box has to turn it back into sound to feed the radio, and from there anyone with a scanner on that frequency can listen. That is the radio’s nature, not something we can fix
- The boundary stays visible. The gateway runs on your premises, every bridged channel permanently discloses that audio leaves push.tt encryption at the gateway, and unbridged channels are unaffected
- Vocoders are licensed. DMR and P25 use AMBE codecs that are proprietary. Transcoding needs licensed hardware or software, and that is a per-channel cost somebody has to pay — a donor radio sidesteps it entirely by staying in the analogue domain
- Latency stacks. Cellular, plus the gateway, plus the radio system's own delay. Fine for dispatch; noticeable if two people are used to instant hand-offs
- Two sides can press at the same moment. Neither knows about the other, so one of them has to lose — and you want to have decided which, before it happens in the middle of something
Legacy Radio Bridge
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01The privacy ends where the radio…02The boundary stays visible03Vocoders are licensed
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What you get for it
Once supervised commissioning proves the installed path, the reason to use it is:
- Cellular extends the conversation. A push.tt member can join from anywhere with a data connection without extending the radio system with another repeater; the existing radio system and its licensing remain in place
- The people who need radios can keep them where the approved installation allows it. Intrinsic-safety, spectrum and accessory-interface approvals remain the customer's and radio vendor's responsibility; the bridge does not extend or certify them
- Dispatch uses the same channel. The command console talks through the bridged push.tt channel and shows gateway health. A donor-radio path does not preserve each radio user's identity, emergency state or GPS
- Retention and audit can cover the push.tt side of the bridged channel under the organisation's configured policy; they do not turn the external radio network into an end-to-end encrypted or protocol-native system
Legacy Radio Bridge
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01Cellular extends the conversation02The people who need radios can…03Dispatch uses the same channel
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What commissioning needs to establish
These questions select an implemented path or expose where a protocol-native adapter is still required:
- Which system, and whether it is analogue, DMR (Tier II or III), P25 or TETRA
- Whether Phone Bridge, a donor radio, a supported direct-IP profile or a vendor-authorized adapter fits the available interfaces
- How many talkgroups actually need bridging — it is usually one or two, not all of them
- Whether you are happy that the box turns speech back into sound to feed the radio, and that anyone in range of that frequency can then hear it
- Who will supervise the two-way audio and RF test, tune levels and timing, and verify PTT, COS or VOX releases safely
Legacy Radio Bridge
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01Which system, and whether it is…02Whether Phone Bridge, a donor radio,…03How many talkgroups actually need bridging
Solutions · push.tt
Describe the system
Make, model, and whether you have network access or only a spare radio. That is enough to identify a candidate profile and plan supervised commissioning; exact hardware and interface compatibility is verified on site before operational use. If you are also looking at rugged cellular handsets for the crews who do not need a licensed radio, see PoC radios.