Split Rendering Client

Description

The Split Rendering Client (SRC) is a functional component introduced in 3GPP Release 19 to support split rendering architectures for immersive media services, particularly extended reality (XR) and cloud gaming. Split rendering is a technique in which the rendering pipeline of a media application is partitioned between the user equipment (UE) and a remote rendering server, typically located at the network edge or in the cloud. The SRC resides on the UE side and is responsible for the client portion of this distributed rendering process, coordinating with a corresponding server-side rendering function over the network.

Architecturally, the SRC operates within the media services framework defined in specifications such as TS 26.565 (which addresses split rendering and related immersive media delivery) and TS 26.854 (which covers media handling aspects for such services). The SRC interacts with the application layer, the media pipeline, and the underlying transport and 5G system capabilities. It receives partially rendered content or rendering instructions from the server, performs local rendering of certain scene components (for example, late-stage reprojection, local view-dependent rendering, or UI overlays), and composites the result for display. This division of labour allows computationally intensive rendering tasks to be offloaded to more powerful edge servers while keeping latency-sensitive and device-specific rendering local.

The key motivation for split rendering is the tension between the high computational demands of photorealistic XR rendering and the constrained thermal, power, and processing budgets of mobile devices. By splitting the workload, the SRC helps ensure that immersive experiences can be delivered on lightweight devices without excessive battery drain or overheating. The SRC must also handle synchronization between locally and remotely rendered components, manage pose prediction and latency compensation, and adapt to varying network conditions — all of which are critical for maintaining visual coherence and user comfort in XR.

In the broader 3GPP ecosystem, the SRC is part of the Release 19 push toward native support for immersive and XR services over 5G-Advanced. It complements other enablers such as network slicing for media, QoS enhancements for low-latency traffic, and edge computing integration. The SRC's operation depends on tight coordination with the 5G core and radio access network to guarantee the latency and throughput needed for real-time split rendering.

Because the SRC is a relatively new concept in Release 19, its detailed procedures, interfaces, and interoperability requirements are still being refined in the relevant specifications. Nevertheless, it represents a significant step toward making high-fidelity XR a practical reality on mobile networks by distributing rendering intelligently across device and edge.

Purpose & Motivation

The Split Rendering Client exists to solve a fundamental problem in mobile immersive media: the mismatch between the enormous rendering requirements of high-fidelity XR and the limited compute, power, and thermal capacity of mobile devices. Traditional approaches either degraded visual quality or caused devices to overheat and drain batteries quickly. Split rendering addresses this by offloading heavy rendering to edge or cloud servers while keeping latency-critical rendering local.

Historically, XR and cloud gaming relied on either fully local rendering (limited by device capability) or fully remote rendering (limited by network latency and bandwidth). Neither approach was ideal for mobile networks. The SRC, introduced in Release 19, provides a standardized client-side framework for hybrid rendering, enabling a balanced distribution of workload that leverages both device and network resources.

By defining the SRC, 3GPP enables interoperability between devices, edge rendering servers, and network functions, paving the way for a consistent split rendering experience across vendors and operators. This is essential for scaling immersive services commercially over 5G-Advanced networks.