RTTI (Real-time Transfer of Tariff Information) — 3GPP Glossary

RTTI is a standardized mechanism for the real-time exchange of charging and tariff information between network operators and service providers. It enables accurate, immediate billing for services like premium SMS, content downloads, and data sessions, ensuring revenue assurance and customer transparency.

Description

Real-time Transfer of Tariff Information (RTTI) is a critical component within the 3GPP charging architecture, specifically defined for CAMEL (Customized Applications for Mobile networks Enhanced Logic) and other online charging systems. It operates as a protocol and data exchange framework that facilitates the immediate communication of tariff details—such as service costs, rating groups, and billing parameters—between network entities like the Service Control Point (SCP) or Online Charging System (OCS) and the network elements executing the service (e.g., MSC, SGSN, GGSN). This real-time capability is essential for services where the cost must be known and authorized before or during service delivery, preventing revenue leakage and enabling prepaid and convergent billing models.

The architecture of RTTI is integrated into the signaling and control plane. When a subscriber initiates a chargeable event (e.g., a voice call to a premium number or a mobile data session), the network element queries the charging system via standardized interfaces like CAP (CAMEL Application Part). The charging system responds with the applicable tariff information, which may include the price, currency, and validity period. This information is then used to authorize the service, apply the correct charging rate, and potentially notify the subscriber via mechanisms like Advice of Charge (AoC). The process ensures that the billing is synchronized with service usage, supporting complex tariff plans, promotions, and inter-operator settlements.

Key components involved in RTTI include the Charging Trigger Function (CTF), which detects chargeable events; the Online Charging System (OCS), which holds tariff data and performs rating; and the CAMEL service environment, which provides the intelligent network framework for real-time control. RTTI's role extends beyond simple billing; it is foundational for service differentiation, enabling operators to offer tailored, real-time charging for value-added services, roaming scenarios, and emerging data services, thereby enhancing customer experience and operational efficiency.

Purpose & Motivation

RTTI was created to address the limitations of traditional batch-based or post-event billing systems, which were inadequate for the dynamic, real-time services emerging in mobile networks. Prior to its standardization, charging for premium services or prepaid accounts often relied on delayed data exchanges, leading to inaccuracies, revenue loss, and poor customer experience due to unexpected charges. The growth of intelligent network services like CAMEL demanded a mechanism to authorize and tariff services in real-time, ensuring subscribers could be charged accurately at the moment of consumption.

The primary problem RTTI solves is the need for immediate tariff resolution and credit control. For prepaid subscribers, it enables real-time balance checks and deductions, preventing service usage beyond available credit. For postpaid and convergent billing, it allows for instant application of complex tariff rules, such as time-of-day rates or service-specific bundles. This capability is crucial for operator revenue assurance, as it minimizes the risk of unpaid usage and supports sophisticated business models for content providers and third-party services.

Historically, RTTI's development in 3GPP Release 8 and its continuation through subsequent releases was motivated by the evolution towards all-IP networks and the increasing variety of chargeable services, from SMS to mobile broadband. It provides a standardized, interoperable framework that replaces proprietary solutions, facilitating seamless roaming and multi-vendor network deployments. By ensuring real-time tariff transparency and control, RTTI underpins the commercial viability of modern mobile services.

Key Features

Real-time tariff information exchange during service delivery
Integration with CAMEL and Online Charging System (OCS) architectures
Support for prepaid and postpaid billing models
Enables Advice of Charge (AoC) for subscriber notification
Facilitates inter-operator charging and roaming settlements
Standardized across 3GPP specifications for interoperability

Evolution Across Releases

Rel-8 Initial

Introduced RTTI as a standardized mechanism within the CAMEL phase 4 and online charging framework. Defined initial protocols for real-time tariff data transfer between network elements like SCP and MSC/SSP, enabling immediate billing authorization for voice and basic data services.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-9

Enhanced RTTI to support EPS (Evolved Packet System) and PCC (Policy and Charging Control) integration. Extended capabilities for real-time charging of LTE data sessions, aligning with the Diameter-based Sy/Ro interfaces for online charging.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-10

Further refinements for multi-access and service data flow-based charging. Improved RTTI procedures for handling concurrent services and advanced tariff structures in heterogeneous networks.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-11

Strengthened RTTI for machine-type communication (MTC) and small data charging. Introduced optimizations for low-latency tariff exchanges to support IoT and emerging service models.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-12

Enhanced support for VoLTE and IMS-based services, ensuring RTTI works seamlessly with IMS charging architectures (e.g., via Rx interface). Added capabilities for real-time charging of multimedia sessions.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-13

Extended RTTI to accommodate network functions virtualization (NFV) and software-defined networking (SDN) environments. Updated protocols to support cloud-based charging systems and elastic scaling.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-14

Integrated RTTI with 5G preparation, focusing on service-based architecture (SBA) and network slicing. Began alignment with 5G charging frameworks for future compatibility.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-15

Formally adapted RTTI principles for 5G systems, supporting the 5G core network and converged charging system (CCS). Enabled real-time tariff transfer for 5G network slices and edge computing services.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-16

Enhanced RTTI for industrial IoT and ultra-reliable low-latency communication (URLLC) scenarios. Improved mechanisms for real-time charging of critical services with stringent QoS requirements.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-17

Further evolved RTTI to support integrated access and backhaul (IAB) and non-terrestrial networks (NTN). Extended tariff information exchange for novel deployment scenarios and expanded coverage.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-18

Continued enhancements for AI/ML-driven charging and dynamic policy enforcement. Optimized RTTI for real-time analytics and personalized tariff offerings in advanced 5G-Advanced networks.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Rel-19

Ongoing updates to ensure RTTI compatibility with 6G research and next-generation service paradigms. Focused on scalability and security for future network evolution.

TS 32.260 TS 32.280 TS 43.064 TS 44.060 TS 45.001 TS 45.002 TS 45.003 TS 51.021

Defining Specifications

Specification	Title
TS 32.260	3GPP TR 32.260
TS 32.280	3GPP TR 32.280
TS 43.064	3GPP TR 43.064
TS 44.060	3GPP TR 44.060
TS 45.001	3GPP TR 45.001
TS 45.002	3GPP TR 45.002
TS 45.003	3GPP TR 45.003
TS 51.021	3GPP TR 51.021