Ims introduction

IMS High Level Presentation
Created by: Rogelio Gomez – May 2011 http://ar.linkedin.com/in/rogeliogomez

Definition of IMS…
• IP Multimedia Subsystem (IMS) is an architecture that enablesoperators to offer a new generation of advanced multimedia services
– Across both circuit and packet switched networking infrastructures

• IMS is a standard that defines an architecture that uses SIPfor call signaling between network elements
– Provides a layered approach with separated services, control, and transport planes

3GPP Experience
- 3GPP specified IMS as part of Rel 5 withimprovements in Rel 6 - 3GPP specified UMA as part of Rel 6 - 3GPP added support for I-WLAN in Rel 6 - 3GPP is enhancing IMS to support fixed broadband in Rel 7 - 3GPP adding Voice Call Continuity in Rel 7Many IMS based optimizations in Rel 7 IMS Based Multimedia services in Rel 7
Rel 5 Rel 6 Rel 7 Rel 8

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IMS – The simple View
KeyElements:
AS – Application Server
Application Application Application Server Server Server

MRFC - Multimedia Resource Function Controller MRFP - Multimedia Resource Function Processor MRF – MediaResource Function
HSS

S-CSCF

SIP
I-CSCF BGCF P-CSCF MGCF MRFC

CSCF- Call Session Control Function BGCF - Breakout Gateway Control Function MGCF - Media Gateway Control Function MGW - MediaGateway

CSCF

MRFP

MGW

RTP MRF

HSS - Home Subscription Server

Key IMS Concepts
• Multiple Plane Architecture – Makes use of separate planes: • Application, Transport and Session ControlCentralized Database – Single point for all users data HSS. With the use of Diameter protocol and HSS (Home Subscriber Server) to validate users The Subscribers Services are independent of the AccessMethod – Enables support for PSTN, 3G mobile, WiFi, GPON, etc.

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IMS Benefits
Convergent Applications Convergent Applications
•• •• •• •• Across Networks Across Networks Reduced...