Enhanced Voice Services (EVS) Codec
EVS is the next-generation carrier voice codec after AMR-WB. Required for 5G voice debugging, operator IMS integrations, and understanding VoNR codec policies.
What It Defines
3GPP codec for 5G VoNR and VoLTE HD voice evolution: 5.9–128 kbps, 8–48 kHz bandwidth, integrated wideband/super-wideband/fullband modes with AMR-WB interworking. Stored in 3GPP `.evs` file format or carried in RTP (RFC 8130). Replaces AMR-WB as primary codec on many 5G deployments.
Canonical (Normative)
Convenient (Practical)
Related References
The global collaboration of telecommunications standards bodies that produces the mobile network specifications: GSM/EDGE, UMTS/HSPA, LTE/4G, 5G NR, and IMS. Technical specifications (TS) and reports (TR) are freely available at 3gpp.org. Releases (Rel-8, Rel-15, Rel-17…) provide versioned capability sets.
Related Specs
AMR-WB is mandatory for VoLTE — every LTE voice call uses it. Understanding rate adaptation and the AMR payload format (RFC 4867) is essential for mobile VoIP and operator codec policy.
5G is the foundation for edge compute, private networks, URLLC industrial automation, and mmWave backhaul. Understanding network slicing, SA vs NSA deployment modes, and QoS flows is critical for 5G-connected application design.
5G VoNR voice debugging requires RFC 8130 — EVS RTP framing differs substantially from RFC 4867 AMR. TOC parsing is essential for packet capture analysis.
3GP is the standard container for mobile-recorded video/voice messages, MMS media, and legacy carrier content. Shares ISO BMFF box structure with MP4 but restricted codec set.