IMS Centralised Services

Table of Contents

1 Introduction

1.1 Thesis structure

1.2 Motivations behind IMS

1.2.1 Motivations from the operator’s perspective

1.2.2 Motivations from the user’s perspective

2 Overview of the IMS architecture

2.1 Drivers

2.2 IMS horizontal architecture

3 Evolution 2G/3G to IMS

3.1 2G/3G technology features

3.2 Towards IMS

3.3 Intelligent Network (IN) limitations

4 From circuit-switched to IMS-based voice services

4.1 Development path 2013 - 2018

4.1.1 Initial state

4.1.2 Intermediate state based on SCP and IM-SSF

4.1.2.1 Service delivery platform and the Service Broker

4.1.2.2 Service Broker benefits

4.1.2.3 Intermediate state setting

4.1.3 Target state 1 based on the SIP AS and rIM-SSF

4.1.4 Target state 2 based on the SIP AS and the I2 interface

4.2 Analysis criteria for IMS-based Voice services

4.2.1 LTE coverage

4.2.2 Handset capabilities

4.2.3 Service consistency

4.2.4 Roaming

4.2.5 Standardisation

4.3 SWOT analysis

4.3.1 Refarming and the Digital Dividend

4.3.2 Further considerations

5 Major mobile market characteristics

5.1.1 Consolidation trends

5.1.2 Regulation and competition

6 Conclusio

Objectives & Core Topics

This thesis examines the evolutionary transition from legacy circuit-switched (CS) voice services to modern IP Multimedia Subsystem (IMS) based architectures within a leading European telecommunications organization. The central research objective is to evaluate the technical and economic feasibility of implementing specific migration scenarios—an intermediate state versus two distinct target states—within the 2013-2018 timeframe, considering service consistency, market regulation, and competitive pressures.

• IMS architecture evolution and horizontal service integration.
• Technical transition pathways from 2G/3G networks to IMS-based voice services.
• Evaluation of service delivery platforms and Service Broker roles in network mediation.
• Strategic analysis using SWOT methodologies regarding technical constraints and economic profitability.
• Assessment of European mobile market characteristics, including consolidation trends and regulatory impacts.

Excerpt from the Thesis

Summary of Chapters

1 Introduction: Outlines the research scope, the transition timeline from CS to IMS, and the overall structure of the thesis.

2 Overview of the IMS architecture: Details the drivers for IMS adoption and the functional advantages of the horizontal architecture over traditional vertical models.

3 Evolution 2G/3G to IMS: Explores the technical progression from 2G/3G systems and identifies the specific limitations of existing Intelligent Networks (IN).

4 From circuit-switched to IMS-based voice services: Provides a comprehensive evaluation of migration pathways, service broker roles, analysis criteria, and a SWOT analysis for the deployment.

5 Major mobile market characteristics: Discusses the broader European market environment, focusing on industry consolidation and regulatory influences on operator strategies.

6 Conclusio: Synthesizes the findings, concluding that the intermediate migration solution is economically recommendable under specific timeframe and acceptance assumptions.

Keywords

IP Multimedia Subsystem (IMS), IMS centralised services, IMS evolution path 2013-2018, Circuit-switched, Packet-switched, Service Broker, IM-SSF, SWOT analysis, Fixed-mobile convergence, 3GPP, Network migration, Telecommunications, ARPU, Service consistency, VoIP.

Frequently Asked Questions

What is the primary focus of this thesis?

The thesis investigates the strategic migration of telecommunication voice services from legacy circuit-switched technologies to the IP Multimedia Subsystem (IMS) for a leading European operator between 2013 and 2018.

What are the key themes addressed in the work?

Key themes include IMS architecture design, service delivery platform optimization, the role of Service Brokers in network interworking, and the economic assessment of transitional network states.

What is the central research question?

The research primarily evaluates whether the deployment of an intermediate IMS migration state is technically and economically recommendable for the specific telecom organization under consideration.

Which methodology is employed for the analysis?

The author utilizes a technical evaluation of network layers followed by a SWOT analysis (Strengths, Weaknesses, Opportunities, and Threats) to assess the feasibility of the migration scenarios.

What topics are covered in the main body?

The main body covers the theoretical IMS framework, the technical transition from 2G/3G, specific intermediate and target network states, market characteristics, and regulatory impacts on operators.

How would you characterize this thesis with keywords?

The study is best characterized by terms such as IMS, Service Broker, network migration, fixed-mobile convergence, and telecommunications business strategy.

Why is the "Service Broker" considered a critical component?

The Service Broker acts as a vital mediation layer, allowing operators to leverage legacy network assets while transitioning to new IP-based services, thereby reducing CAPEX and enabling faster service creation.

What does the "Intermediate state" offer the operator?

The intermediate state enables IMS subscribers to access existing GSM/UMTS hosted services, providing a bridge that maintains service continuity while avoiding the immediate need for a full-scale, costly IMS infrastructure.

What role does the Austrian mobile market play in this analysis?

The analysis uses the specific regulatory and competitive environment of the Austrian market, including frequency band auctions and LTE deployment targets, to provide realistic assumptions for the financial model.

What is the final conclusion regarding the migration?

The author concludes that implementing the intermediate solution is beneficial if the net time for profit generation is between 30 and 36 months, given a reasonable customer acceptance rate.