Object Transmission Information

Description

Object Transmission Information (OTI) is a 3GPP Release 19 concept introduced in the context of 5G media streaming and multicast/broadcast service delivery. It refers to the set of metadata and transmission parameters that describe how a media object — such as a video segment, audio track, subtitle file, or immersive media component — is to be packaged, addressed, and delivered over 3GPP networks. OTI is specified in 3GPP TS 26.517 (5G Media Streaming: Object-based media delivery) and TS 26.804 (Study on object-based media delivery), which define the information model and delivery procedures.

Architecturally, OTI operates at the application and transport layers of the 3GPP media delivery stack. When a media object is prepared for transmission, the sender generates an OTI record that includes object identity, object type, size, encoding format, timing information, dependency relationships with other objects, and delivery constraints such as priority and deadline. This OTI is then associated with the object payload and transmitted to the receiver, either in-band (multiplexed with the object data) or out-of-band (via a separate signaling channel). The receiver uses the OTI to reconstruct the object, schedule its decoding, and manage buffering and rendering.

Key components of the OTI framework include: object identifiers that uniquely reference objects within a media session; object descriptors that specify media type, codec, and quality parameters; dependency descriptors that indicate relationships between objects (e.g., a base layer and enhancement layers); timing descriptors that define presentation and decoding timestamps; and delivery descriptors that specify transport requirements such as reliability, latency, and priority. These components are encoded in a structured format that can be parsed by both network elements and client devices.

OTI plays a central role in object-based media delivery, which is a paradigm shift from traditional stream-based delivery. In stream-based delivery, media is delivered as a continuous byte stream, and the receiver has limited ability to selectively process individual components. In object-based delivery, media is decomposed into discrete objects that can be independently requested, cached, processed, and rendered. This enables advanced use cases such as personalized media composition, selective content replacement, immersive media with multiple viewpoints, and efficient multicast delivery where different objects can be delivered over different bearers.

In terms of network integration, OTI is used by 5G Media Streaming (5GMS) and 5G Multicast/Broadcast Service (5MBS) functions to make delivery decisions. For example, the 5GMS Application Function can use OTI to determine which objects should be delivered via unicast versus multicast, or to prioritize objects based on user preferences. The 5GMS Application Server can use OTI to cache objects and serve them efficiently. Security considerations include object integrity protection, access control, and privacy of object metadata. Overall, OTI in Rel-19 provides a standardized foundation for object-based media delivery in 5G-Advanced networks, enabling more flexible, efficient, and personalized media experiences.

Purpose & Motivation

OTI exists to address the limitations of stream-based media delivery in 5G networks. Traditional media delivery treats content as a continuous stream, which makes it difficult to selectively process, cache, or personalize individual media components. As media becomes more complex — with multiple audio tracks, subtitles, immersive components, and personalized overlays — there is a need for a more granular approach that treats media as a collection of discrete objects. OTI provides the metadata framework that makes this object-based approach possible.

The motivation for OTI in 3GPP Release 19 comes from several converging trends. First, the growth of immersive and personalized media requires flexible composition of media components at the receiver. Second, the expansion of multicast/broadcast services in 5G requires efficient delivery of shared content while allowing personalization. Third, edge computing and caching require media to be addressable and cacheable at the object level. Fourth, network slicing and QoS differentiation require delivery decisions to be made per object rather than per stream. OTI addresses all these needs by providing a standardized way to describe objects and their delivery requirements.

Historically, previous approaches to media delivery relied on container formats such as MP4 and DASH, which provide some object-like structures (e.g., segments and tracks) but lack a unified, network-aware metadata framework. OTI extends these approaches by integrating delivery parameters, dependency relationships, and network constraints into a single information model. This allows network functions to make informed decisions about object delivery without deep packet inspection or application-specific logic. By standardizing OTI, 3GPP enables interoperability between content providers, network operators, and device vendors, and lays the groundwork for more intelligent, efficient, and personalized media delivery in 5G-Advanced and beyond.