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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Cellular Audio Telephony Certification Engineer - **Company:** Syntronic R&D USA - **Location:** Sunnyvale, CA, United States - **Contract:** Permanent contract - **Skills:** LTE (Telecommunication), Automation of Tests, Codecs, Software Debugging, Firmware, Interoperability, Regression Testing, Strategies of Testing, Test Scripts, Low Latency - **Published:** September 11, 2026 - **Apply:** https://www.thejobnetwork.com/job/32e2b0cd-cdf9-4fd5-aaed-376764ed449b/cellular-audio-telephony-certification-engineer ## About the Role We are seeking an experienced Cellular Audio Telephony Certification Engineer to lead audio quality validation and certification activities for mobile/cellular devices. The ideal candidate will bring deep expertise in acoustic testing methodologies, hands-on proficiency with HEAD Acoustics measurement systems, and demonstrated experience using Rohde & Schwarz (R&S) network simulators for LTE/VoLTE call testing. This role is critical to ensuring devices meet carrier acceptance criteria, 3GPP specifications, and global regulatory standards ## Description Audio Certification & Compliance Testing * Plan, execute, and analyze end-to-end audio telephony tests for cellular devices across LTE, VoLTE, VoNR (5G), VoWiFi, and legacy 2G/3G voice technologies * Perform acoustic measurements including SLR, RLR, STMR, sidetone, echo loss (TCLw), send/receive frequency response, jitter buffer management, and speech quality (POLQA/P.863) * Execute certification test campaigns aligned with 3GPP TS 26.131/26.132, GCF, PTCRB, GSMA TS.27, and carrier-specific requirements (e.g., Verizon, AT&T, T-Mobile, Vodafone, NTT DOCOMO) * Validate devices in handset, handsfree, headset, and speakerphone modes per applicable use cases Test System Operation & Development * Configure and operate HEAD Acoustics ACQUA software with hardware such as HMS II.3, labCORE, HEC 03.1, HAE-BT, and artificial ears/mouths for acoustic testing * Set up and drive Rohde & Schwarz CMW500 / CMX500 / CMW-KM network simulators to emulate LTE/VoLTE/VoNR call scenarios, IMS registration, and codec negotiation (AMR-NB, AMR-WB, EVS) * Develop automated test scripts and sequences in ACQUA and integrate with R&S CMW for repeatable regression testing * Maintain calibration integrity of acoustic chambers, artificial heads, and reference equipment Analysis, Debug & Reporting * Perform root cause analysis on audio impairments (clipping, distortion, packet loss artifacts, echo, latency, DTX/CNG issues) * Collaborate with firmware, DSP, and RF teams to debug codec, AEC, noise suppression, and beamforming implementations * Generate certification-ready test reports, waivers, and compliance matrices for submission to carriers and certification bodies * Support field trials and IOT (interoperability testing) with live networks Cross-Functional Leadership * Serve as the audio SME during design reviews, test plan development, and lab readiness assessments * Mentor junior engineers on acoustic measurement fundamentals and cellular voice architecture * Interface directly with certification labs, carriers, and equipment vendors ## Related Videos - [Can You Touch the Internet? 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