Rooted Android — Modem/RIL-level GSM SIP Audio Bridge
Budget: $250 – $750 USD
Implement a modem-level GSM ↔ SIP two-way audio bridge by controlling the device RIL/modem (QMI/diag) so the modem internally mixes GSM and SIP audio legs. This is a single-device project (OnePlus 5T, Android 9, rooted). No gateway/server bridging — the modem must perform the audio mixing
Why this is required :
Stock Android prevents third-party apps from accessing GSM voice audio. To guarantee reliable two-way audio on a single device, we require a low-level solution that instructs the modem/RIL to create an internal bridge/conference so GSM audio never has to pass through Android’s public audio stack.
Please do not send proposal unless you have experience on this fields
Who should apply :
• Qualcomm/QMI / RIL / rild internals
• Modem/Radio Interface Layer reverse-engineering and QMI voice APIs
• Native Android system development (Magisk modules, LD_PRELOAD, rild hooks)
• SIP integration (PJSIP or Linphone) and RTP/PCM handling
• Real-time audio streaming, jitter/drift handling, echo/AEC
Why this is required :
Stock Android prevents third-party apps from accessing GSM voice audio. To guarantee reliable two-way audio on a single device, we require a low-level solution that instructs the modem/RIL to create an internal bridge/conference so GSM audio never has to pass through Android’s public audio stack.
Please do not send proposal unless you have experience on this fields
Who should apply :
• Qualcomm/QMI / RIL / rild internals
• Modem/Radio Interface Layer reverse-engineering and QMI voice APIs
• Native Android system development (Magisk modules, LD_PRELOAD, rild hooks)
• SIP integration (PJSIP or Linphone) and RTP/PCM handling
• Real-time audio streaming, jitter/drift handling, echo/AEC