SIP dans le réseau mobile : SIP et IMS

Mastering Voice over LTE (VoLTE) and 5G: A Deep Dive

Understanding the Evolution of Mobile Voice Services

The voice service has historically been a cornerstone of mobile networks. Early mobile networks primarily focused on delivering voice communication. However, the evolution of mobile technology has shifted the landscape, with data services now playing a dominant role. The advent of 4G and 5G networks, designed as "full data" networks, initially didn't natively support voice. This course explores how voice is now seamlessly integrated into these advanced mobile networks.

VoLTE: Voice over LTE Explained

VoLTE (Voice over LTE) is the technology that enables high-quality voice calls over 4G networks. It achieves this by implementing the SIP (Session Initiation Protocol) protocol within the 4G network infrastructure. Crucially, VoLTE relies on the IMS (IP Multimedia Subsystem) platform.

This course provides a detailed understanding of the signaling flows between the various components of the IMS and the 4G core network (EPC - Evolved Packet Core) that facilitate voice service delivery to a 4G subscriber. We will cover key aspects including:

• 4G Architecture: Understanding the role of the RAN (Radio Access Network) and EPC, including entities, dedicated bearers, QCI (Quality of Service), attachment procedures, and more.
• IMS Fundamentals: A comprehensive overview of the IMS architecture and its key entities.
• SIP in IMS: In-depth exploration of SIP signaling, including:
  • SIP REGISTER: Authentication within the EPC and the registration process.
  • SIP INVITE: Detailed analysis of the INVITE request, including the implications of supported:100rel and supported:precondition.
  • Preconditions: Understanding and implementing preconditions to define QoS for VoLTE calls. We'll delve into attributes like a=cur, a=des, and a=conf.
  • Dedicated Bearers: Analysis of UPDATE requests and 200 OK responses.
  • SIP Messages for VoLTE: A comprehensive look at the SIP messages used in VoLTE.
  • Call Flow: Detailed call flow scenarios involving P-CSCF, S-CSCF, I-CSCF, HSS, and PCRF.
• Diameter Signaling: A thorough examination of Diameter protocol and its role in SIP registration and call management.
• Voice Call Continuity (VCC): Introduction to VCC, including key entities, call scenarios, and signaling mechanisms.

Advanced Topics: Diameter and SIP Procedures

This section delves deeper into the intricacies of Diameter and SIP procedures:

• SIP Registration: Detailed explanation of the SIP registration process, from registration generation to communication between S-CSCF and HSS.
• Diameter and SIP Call Flow: Comprehensive call flow diagrams for incoming, outgoing, and transfer calls, with detailed message analysis.

5G Architecture: A New Era for Voice

This course also provides an introduction to 5G network architectures:

• 5G SBA (Service-Based Architecture)
• 5G NSA (Non-Standalone) & Greenfield Architectures
• Mandatory Codecs in 5G
• SIP in 5G: How SIP is adapted for use in 5G networks.

Target Audience: This course is designed for professionals seeking a comprehensive understanding of VoLTE, IMS, SIP, Diameter, and the evolving landscape of mobile voice technology, particularly in the context of 4G and 5G networks. It provides a deep dive into the technical details, equipping participants with the knowledge to engage with industry experts and contribute to the advancement of mobile communication.