Rich Call Data

Description

Rich Call Data (RCD) is a service capability standardized in 3GPP Release 17 as part of the evolution of communication services in the IP Multimedia Subsystem (IMS). It fundamentally extends traditional voice or video calls by allowing the exchange of structured, supplementary data alongside the primary media stream. This data is carried within the call signaling or in-session messaging, typically using protocols like Session Initiation Protocol (SIP) and Session Description Protocol (SDP), often encapsulated in formats such as JSON or XML. RCD enables a wide range of use cases: for instance, during a customer service call, a business can send its logo, name, and purpose; in emergency calls, precise location and medical data can be transmitted; or in social calls, users can share their status, a photo, or interactive buttons. Architecturally, RCD involves client support on user equipment (UE) and server-side functions in the IMS core, including application servers that may process or enrich the data. The data exchange is governed by IMS service profiles and policy controls to ensure security, privacy, and interoperability. RCD works by defining new SIP methods, headers, or body parts to carry the rich data, which is negotiated during call setup or exchanged mid-call. It leverages existing IMS authentication and authorization mechanisms, ensuring only authorized data is shared. The service is designed to be backward-compatible, so basic calls still work if one party does not support RCD. Key components include the RCD-enabled UE, IMS core elements (like CSCF), and potentially dedicated RCD application servers that provide data enrichment or storage. Its role is to transform telephony from a simple audio/video channel into a rich, contextual communication platform, forming a foundation for future interactive services.

Purpose & Motivation

RCD was developed to address the stagnation of traditional telephony services in the face of over-the-top (OTT) communication apps that offer rich features like file sharing, location pins, and interactive content during calls. Standard voice and video calls in IMS, while high-quality and reliable, lacked a standardized mechanism to exchange supplementary data, limiting service innovation and user engagement. The motivation was to enhance the native cellular calling experience to compete with OTT services and enable new commercial and emergency applications. For businesses, RCD solves the problem of impersonal customer interactions by allowing brand identity and contextual data to be shared, improving customer experience. In emergency services, it addresses critical limitations where voice-only calls may not convey sufficient information, enabling automatic transmission of location, medical details, or incident photos to first responders. Historically, previous approaches relied on proprietary solutions or separate data channels, which were not interoperable across networks and devices. RCD provides a universal, standards-based framework within IMS, ensuring global interoperability and security. It also paves the way for integrated communication suites, blending telephony with data services seamlessly, and supports regulatory requirements for advanced emergency calling (e.g., NG911).