voice over lte report
TRANSCRIPT
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
A PROJECT REPORT ON
VOICE OVER LONG TERM EVOLUTION Vo-LTE
SUBMITTED TO
ANSAL UNIVERSITY, SECTOR-55, GURGAON
IN THE PARTIAL FULFILLMENT FOR THE COMPLETION OF
INTERNSHIP PROJECT, (ECE 4th year)
BY
ANIRUDH YADAV
UNDER THE GUIDANCE OF
Mr. TANUJ DUHAN
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
1
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CERTIFICATE
This is to certify that the project report entitled
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Submitted by ANIRUDH YADAV
is a bonafide work carried out by him under the supervision of Mr. Tanuj Duhan and it is
approved for the partial fulfillment of the requirement for the completion of Final Project, (ECE
department-4th year).This project report has not been earlier submitted to any other Institute or
University for any degree or diploma.
Place: GurgaonDate :
Mr. Sudarshan GuptaProject Manager
Head of EP-Core & Cloud (COS)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
2
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
ACKNOWLEDGEMENT
I would like to extend our acknowledgement to certain people who have been very helpful and
without whom this project would not have been a success. I express my profound gratitude to my
Project Guide Mr. Tanuj Duhan (General Manager) in particular for his inspiring guidance due to
which my difficulties, questions and frustrations were shaped into the development of this
project. I am very thankful to him for his very much support. I would like to thank Mr. Susheel
Narayan (General Manager) who helped me complete my report by giving me the knowledge of
Benefits & Future scope of my project. I would also like to thank the Project Manager Mr.
Sudarshan S. Gupta (Head of Engagement Practices (EP)-COS) & Mrs. Deepti Dang (Floor
Warden) for providing with a good working environment which helped me in successful
completion of my project.
BY
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
3
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
ANIRUDH YADAV
ABSTRACT
3GPP Long Term Evolution networks are now a commercial reality. As cellular network operators continue to plan LTE coverage and capacity expansion, the need to migrate traditional voice calling services to LTE becomes ever more pressing. The emergence of GSMA IR.92 – IMS Profile for Voice and SMS – as the de facto voice-over-LTE standard has cleared the way for global adoption of a single LTE voice solution. IR.92’s forward-looking foundation on IMS/SIP ensures its longevity, but it also introduces functional, performance, and quality challenges. Comprehensive testing and verification of Vo-LTE-enabled mobile devices is crucial to ensuring consumer adoption and commercial success of voice services on LTE.
With LTE networks now a growing commercial reality, migrating traditional voice services to LTE becomes ever more pressing. GSMA IR.92 – IMS Profile for Voice and SMS – clears the way for a global solution but also introduces functional, performance, and quality challenges. This project explores these challenges and the role testing of VoLTE-enabled mobile devices will play in ensuring commercial success.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
4
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
LIST OF FIGURES
Figure No. Title Page No.
1.1 3GPP logo 14
1.2 Table of all the 3gpp Releases using various technologies & their UL/DL speeds
15
1.3 3GPP2 logo 16
2.1 Table of key figures & data of mobile subscriptions, essentials & growth during 2013-15 & 2020 forecast
19
2.2 Flowchart of ERICSSON’s working ways 28
2.3 ERICSSON’s organization structure 29
2.4 ERICSSON’s hierarchical departmental structure 30
2.5 Table showing Inputs & Outputs of all Sub-processes regarding Sales Process of Ericsson
40
2.6 Sales Process steps flow diagram 40
2.7 Connected Me slide 42
2.8 Connected Print slides 43
2.9 Picture of a Connected Print Paper 43
2.10 Connected Paper slides 44
2.11 Connected Paper Examples slide 44
2.12 An App displaying the parameters of The Smart Ball 45
2.13 The Radio Dot 46
2.14 Slides & pictures displaying the uses, compactness, advantages of Radio Dot
47
3.1 Vo-LTE Drivers 51
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
5
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.1 Vo-LTE E2E Architecture 54
4.2 EPS Terminology Flowchart 55
4.3 Architecture of EPS system 56
4.4 WCDMA vs. LTE/SAE architecture 57
4.5 Control Plane & User Plane EPS diagram 59
4.6 EPS Attach Procedure 60
4.7 EPS attach procedure summary 63
4.8 EPS bearer service architecture 63
4.9 EPS vs. GPRS architecture 64
5.1 Vo-LTE E2E Architecture 66
5.2 IMS architecture 68
5.3 High level IMS session establishment flow 72
6.1 Vo-LTE Architecture 74
6.2 Ericsson E2E conversational Vo-LTE architecture 74
6.3 High level steps of Vo-LTE call flow 75
6.4 Registration of Vo-LTE 76
6.5 Vo-LTE charging system 77
6.6 Vo-LTE charging with CS-co-existence architecture 77
6.7 CS Fall-back 78
6.8 Vo-LTE Roaming Phasing 79
6.9 Maintenance of Vo-LTE 80
7.1 Benefits of Vo-LTE 82
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
6
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CONTENTS
CERTIFICATE II
ACKNOWLEDGEMENT III
ABSTRACT IV
LIST OF FIGURES V
ORGANIZATION OF PROJECT REPORT X
CHAPTER TITLE PAGE NO.
1. TECHNOLOGY EVOLUTION 11
1.1 GENERAL INTRODUCTION 12
1.2 HISTORY 12
1.2.1 FIRST GENERATION (1G) 12
1.2.2
1.2.3
SECOND GENERATION (2G)
THIRD GENERATION (3G)
12
13
1.2.4 THIRD GENERATION PARTNERSHIP PROJECT (3GPP)
14
1.2.5 3GPP2 16
2. NETWORK SOCIETY 17
2.1 ERICSSON MOBILITY REPORT 18
2.2 WORLDWIDE REGIONS OF ERICSSON 19
2.3 ERICSSON WORKING 28
2.4 ORGANISATION ARCHITECTURE 29
2.5 DEPARTMENTAL ARCHITECTURE 30
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
7
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
2.6 SALES PROCESS 35
2.7 VISIT TO ERICSSON EXPERIENCE CENTRE 41
2.8 NETWORKED SOCIETY SUMMARY 48
3. SAMPLE PROJECT-VOICE OVER LTE (Vo-LTE)
49
3.1 INTRODUCTION 50
3.2 WHY Vo-LTE? & ITS MOTIVATION 50
3.3 DRIVERS/REQUIREMENTS FOR Vo-LTE 51
3.3.1 SUBSCRIBER REQUIREMENTS 51
3.3.2 CARRIER REQUIREMENTS 52
3.4 SUMMARY 52
4. EVOLVED PACKET SYSTEM (EPS) 53
4.1 Vo-LTE E2E ARCHITECTURE 54
4.2 EPS TERMINOLOGY CLARIFICATION 55
4.3 EPS ARCHITECTURE 56
4.3.1 USER EQUIPMENT (UE) 56
4.3.2 EVOLVED-NODE B (e-nodeB) 57
4.3.3 MOBILE MANAGEMENT ENTITY (MME) 58
4.3.4 HOME SUBSCRIBER SERVER (HSS) 58
4.3.5 SERVING GATEWAY (S-GW) 58
4.3.6 PACKET DATA NETWORK GATEWAY (PGW) 59
4.3.7 EPS CONTROL & USER PLANE 59
4.4 EPS ATTACH PROCEDURE 60
4.4.1 ATTACH REQUEST 60
4.4.2 AUTHENTICATION INFO
REQUEST/RESPONSE
61
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
8
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.4.3 UPDATE LOCATION REQUEST 61
4.4.4 UPDATE LOCATION ANSWER 61
4.4.5 CREATE SESSION REQUEST 61
4.4.6 CREATE SESSION RESPONSE 62
4.4.7 ATTACH ACCEPT 62
4.4.8 ATTACH COMPLETE 62
4.4.9 MODIFY BEARER REQUEST 63
4.4.10 QUICK SUMMARY 63
4.5 EPS BEARER ARCHITECTURE 63
4.6 HISTORICAL CONTEXT 64
5. IP MULTIMEDIA SUBSYSTEM (IMS) 65
5.1 Vo-LTE E2E ARCHITECTURE 66
5.2 WHAT IS IMS ? 67
5.3 HISTORY OF IMS 67
5.4 STRUCTURE OF IMS 67
5.5 IMS ARCHITECTURE 68
5.5.1 DATABASE ELEMENTS 69
5.5.2 IMS CONTROL ELEMENTS 69
5.5.3 CONTROL PLANE INTERWORKING ELEMENTS
71
5.6 IMS SESSION ESTABLISHMENT FLOW 72
6. Vo-LTE OVERALL ARCHITECTURES 73
6.1 Vo-LTE ARCHITECTURE 74
6.2 Vo-LTE CALL-FLOW-HIGH LEVEL STEPS 75
6.3 Vo-LTE REGISTRATION 76
6.4 Vo-LTE CHARGING SYSTEM 77
6.5 CIRCUIT SWITCHED FALL-BACK 78
6.6 ROAMING IN Vo-LTE 79
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
9
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
6.7 Vo-LTE MANAGEMENT 80
7. BENEFITS & FUTURE SCOPE OF Vo-LTE 81
7.1 BENEFITS OF Vo-LTE 82
7.2 FUTURE SCOPE OF Vo-LTE 83
8. REFERENCES 84
9. APPENDIX 85
ORGANISATION OF PROJECT REPORT
The report consists of nine chapters. Each chapter serves the purpose of describing the
various aspects of the project such as basic information of the system, its design and
implementation.
1. First chapter is ‘TECHNOLOGY EVOLUTION’. It gives the general introduction about
the project. It includes the aspects like how the technology evolved from 1G to 3G &
3GPP releases.
2. Second chapter includes the Network Society. ‘NETWORK SOCIETY’ includes the
mobility report, working style, departmental architecture & sales process of Ericsson. It
also includes ‘Visit to the Experience center’ & Ericssons’ various technological
products. The purpose of this chapter is to introduce the company to the reader.
3. Third chapter is my sample project i.e. ‘VOICE OVER LTE (Vo-LTE)’. This mentions
the reason & motivation for Vo-LTE, Why Vo-LTE? & it’s drivers & requirements.
4. Chapter fourth is ‘EVOLVED PACKET SYSTEM (EPS)’. It includes the detailed
explanation of all its nodes & their functions, call flow steps & the historical context.
5. Chapter fifth is ‘IP MULTIMEDIA SUBSYSTEM (IMS)’. It includes the structure,
architecture & detailed explanation of all entities of IMS & session establishment flow.
6. Chapter sixth is ‘Vo-LTE OVERALL ARCHITECTURES’. It includes an overall
architecture, CSFB, charging & Roaming in Vo-LTE & maintenance of Vo-LTE.
7. Chapter seventh is ‘BENEFITS & FUTURE SCOPE’ of Vo-LTE. It includes the
advancements in Vo-LTE, LTE advanced & the upcoming technology of 5G.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
10
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
8. Chapter eighth is ‘REFERENCES’. It includes a list of all books, white papers & data
sheets used in my project. All websites referred to are also listed.
9. Chapter ninth is ‘APPENDIX’. It includes all the acronyms & short forms used in the
report.
CHAPTER 1 TECHNOLOGY EVOLUTION
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
11
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
1.1 GENERAL INTRODUCTION
This project, which is titled as ‘VOICE OVER LONG TERM EVOLUTION (Vo-LTE)’ is a part of my work for the completion of mini project, embedded system design (ECE-1021). The basic idea behind this project is to transmit voice over wireless fidelity (Wi-Fi). The focus is on the system from a Mobile Broadband (MBB) service point of view. At this particular day the involvement of technology in the industries is tremendous. Every day new products & services are coming to the market. This project will be much easier for a person to communicate through it. With the help of this project wireless communication will become simple at relatively low cost.
1.2 HISTORY
The following historical overview is based on conventional & informal terms in the mobile industry, telecom, media & press.
1.2.1 FIRST GENERATION (1G)
It includes
1. NMT (Nordic Mobile Telephony)
2. AMPS (Advanced Mobile Phone Service) &
3. TACS (Total Access Communication System)
These systems all have in common that the user traffic, which is voice, is transmitted with analogue FDMA (Frequency Division Multiple Access) radio techniques.
NMT was developed during the seventies & launched in 1981.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
12
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
1.2.2 SECOND GENERATION (2G) It includes systems like
1. GSM (Global System for Mobile communication)
2. D-AMPS (Dual-Mode AMPS)
3. PDC (Personnel Digital Communications)
4. IS-95
The new thing with these systems was that they supported both voice & data traffic with digital TDMA (Time Division Multiple Access) or CDMA (Code Division Multiple Access) circuit switched radio techniques.
Voice, SMS, CS data can be transmitted with a speed of 9.6kbit/s (50 kbit/s HSCSD)
GSM standardization started in 1982 & it was launched in 1991.
Enhancements of 2G, like the introduction of packet data GPRS (General Packet Radio Service), is often referred to as 2.5G. PS data transfer can be done with a speed of 50 kbit/s.
Further enhancements like EDGE (Enhanced Data Rates for GSM & TDMA Evolution), is referred to as 2.75G. PS data can be transmitted with a speed of 500 kbit/s.
1.2.3 THIRD GENERATION (3G) The IMT-2000, a guideline for every Third Generation (3G) standard is a
standard on which the ITU (International Telecommunication Union) started to work on, in 1986.
The radio frequency bands 1885-2025 & 2110-2200 MHz, were identified as the common worldwide spectrum for 3G systems by the World Administrative Radio Conference (WARC), in 1992.
For the FDD & TDD (Frequency & Time Division Duplex) mode of UMTS (Universal Mobile Telecommunication System), following multiple access methods were chosen
1. WCDMA (Wideband Code division Multiple Access)2. TD-CDMA (Time Division Code division Multiple Access)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
13
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
by the European Telecommunication Standards Institute (ETSI) in January 1998. 3G was commercially launched in 2001 in Japan & 2003 in Europe.
1.2.4 3rd GENERATION PARTNERSHIP PROJECT (3GPP)
Fig 1.1 3GPP Logo
3GPP is a standardization body that defines mobile networks. It is a collaboration agreement that brings together a number of telecommunications standard bodies, e.g. ARIB, CCSA, ETSI, TTA & TTC was established in December 1998.
The original scope of 3GPP was to produce globally applicable technical specifications & technical reports for a 3G mobile system based on evolved GSM core networks & the radio access technologies that they support (i.e., Universal Terrestrial Radio Access
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
14
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
(UTRA) both FDD & TDD modes). The scope was subsequently amended to include the maintenance & development of the GSM technical specifications & technical reports including evolved radio access technologies (e.g., General Packet Radio Service (GPRS) & EDGE).
RELE
ASE
TECHNOLOGI
ES
UL/D
L SPEED (BIT
RATES)
1. Release 99 WCDMA - supports both
Circuit Switched (CS) &
Packet Switched (PS) traffic.
2Mbps
2. Release 5 (2002) HSDPA - High Speed
Downlink Packet Access.
DL – 14Mbps
3. Release 6 (2004) HSUPA - High Speed Uplink
Packet Access.
UL - 5.76Mbps
4. Release 7 HSPA+ - accomplished using
MIMO (Multiple input
Multiple output) antenna
solutions & Higher Order
DL – 42 Mbps
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
15
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Modulation (HOM).
5. Release 8 (2006-07) Evolved UT Radio Access
Network (E-UTRAN), 3G
Long Term Evolution (LTE),
Evolved Packet System
(EPS) & Core (EPC) – Core
Network (CN)
E-UTRAN+EPC=EPS
LTE/SAE
-
6. Release 10 IMT Advanced – 4G, LTE
Advanced will fulfill
requirements of Release 10.
1 Gbit/s
Fig 1.2 3gpp Releases using various technologies & their UL/DL speeds
1.2.5 3GPP2
Fig 1.3 3GPP2 Logo
A parallel Partnership Project was also established which, quite similar to its sister project 3GPP, also standardizes International Telecommunication Union’s (ITU) International Mobile Telecommunications IMT-2000 based networks.
It focuses on the evolution of cdmaOne with cdma2000 & EV-DO (HRPD).
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
16
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
It is divided into four Technical Specification Groups (TSGs).
1. TSG-A for Access Network Interfaces2. TSG-C for cdma20003. TSG-S Services & Systems Aspects4. TSG-X Core Networks
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
17
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 2NETWORK SOCIETY
2.1 ERICSSON MOBILITY REPORT
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
18
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
19
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.1 Figures & data comparison mobile subscriptions, essentials & traffic growth during 2013-2015 & 2020 forecast.
2.2 REGIONS OF ERICSSON WORLDWIDE
1. RNAM – Region North America2. RLAM – Region Latin America3. RWCE - Region Western & Central Europe4. RMED – Region Mediterranean5. RECA – Region Northern Europe & Central Asia6. RSSA – Region Sub Saharan Africa7. RMEA – Region Middle East8. RNEA – Region North East Asia9. RASO – Region South East Asia & Oceania
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
20
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
10. RINA – Region India
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
21
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
22
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
23
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
24
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
25
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
26
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
27
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
28
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
2.3 ERICSSON WORKING
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
29
END USER (EU)
CUSTOMER E.g. - Airtel, Idea, Vodafone etc.
EQUIPMENTS E.g. - (BTS, uWs, Core/Switches, Routers, IN, OSS)
TECHNOLOGY SUPPLIER
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.2 Flowchart showing ERICSSONs’ working ways & style in telecom industry
2.4 ORGANIZATION ARCHITECTURE
Fig
2.3 ERICSSON’s
organization structure
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
30
CUSTOMER UNIT (CU) E.g. - Bharti
TECHNICAL SOLUTIONS
SERVICES (DESIGN IMPLEMENTATION)
MANAGED SERVICES
COMMERCIAL PROJECT SERVICES
ENGAGEMENT PRACTICES (EP)
COMMERCIAL
HR & FACILITIES
MARKETING & STRATEGY
OPERATIONS
BHARTI NORTH WEST VODAFONE
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
India is divided into four Telecom regions
1. BHARTI2. NORTH3. WEST4. VODAFONE
& ERICSSON has its five departments
1. Engagement Practices (EP)2. Commercial3. Human Resource (HR) & Facilities4. Marketing & Strategy5. Operations
spread across all four regions parallel to each other.
2.5 DEPARTMENTAL ARCHITECTURE
Fig 2.4 ERICSSON’s hierarchical departmental structure
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
31
Managing Director (MD)
Engagement Practices (EP)
Head
Mobile Broadband (MBB) Core &
Cloud (CCL)Fixed
Broadband (FBB)
Other Business Services (OBS)
OSS BSS
TV & Media
Emerging Technology
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
1. Mobile Broadband (MBB) The mission of the EP is to maximize ERICSSON’s position in this market utilizing technical strengths & thought leadership, in stalled base & services position in the prevailing market environment. The MBB practice drives business in the mobile data access market which:
Enable operators to address new market segments with the latest radio technologies
Optimize operators total cost of ownership through high performance radio equipment
Modernize operators installed base of both radio & site equipment to ensure a higher grade of operational performance
In order to achieve this mission the EP is organized into 3 separate groups:
1. Radio Access Network2. Product Related Services3. New Business Development & Software Sales
An important focus area for the MBB practice is to support operators’s success in the Indian market with their MBB offering on 3G.
The focus of MBB practice moving forward is to secure the success of MBB in India across all mobile technology segments & to provide thought leadership so as to position ERICSSON as the market leader.
2. Emerging Technology Innovation & Partnership (ETIP)ETIP is created to address the needs of an evolving technology & industry landscape. This unit will focus on forward looking domains & work on ensuring ERICSSON’s leadership & contribution in some of the key innovation forums.
ETIP comprises of units driving1. Cloud Initiatives2. Network Society & Technology Consulting (NSTC)3. Standardization4. Factory Support5. Partnership6. Regulatory7. TEC&E2E solutions
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
32
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
With a structure that goes across the various practice organizations, ETIP is chartered to drive innovation, partnership, regulatory & standardization activities that will have market impact beyond immediate business horizon.
3. Core & Cloud (Communication Services)The practice partners with operators broadly with
A. Measures of efficiency &B. Measures of identifying new revenue streams.
While the practice has been driving efficiency & TCO measures through best in market mobile switch & user data solutions, this track is now moving towards network function virtualization & having Telco applications in Cloud. At the same time the practice helps operators build new communication services with
A. Evolved communication solutions such as Vo-LTE, Rich communication Suite, Enterprise communication etc.,
B. Machine to machine enablers such as device connection platform, connected car application etc. &
C. Web communication services such as Web-RTC & network exposure.
With a wide & interesting portfolio spanning traditional services/efficiency measures & New advanced services/Revenue measures, COS practice is responsible to shape & drive communication services needs of consumers & hence operators business in the most effective manner.
4. IP & Transport (Fixed Broadband (BB) & Convergence)Engagement Practice IP & Transport (EP-IPT) is responsible for bringing to market Solutions in the areas of Fixed Broadband access, Converged transport, Packet core, Network transformation, IP convergence, Data offload, Caching, Data Monetization.
With mobility operators they will leverage the ERICSSON reference building solutions, viz., Mobile Backhaul and Metro Transport, together with creating customized business cases & TCO propositions. They will offer end-to-end packet core & service aware charging & control solutions to mobile operators t fulfill their needs of DPI, policy control & data monetization. For LTE operators, the offering will consist of evolved packet core including MME, P/S-GW & HSS, in addition to SACC.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
33
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
In the domain of IPv4 to IPv6, they will work to proactively, & in a consultative manner, develop the best strategies & plans to upgrade their networks. They will offer end-to-end Wi-fi solution to operators including all the scenarios like mobile offload, fixed broadband access, Voucher based access under different architectures.
Their solutions will be built around the ERICSSON packet core, IP & Microwave Product portfolio of products & services & where relevant, 3PP.
To do the Business Unit & Product Area Packet Core, IP & Microwave, they will endeavour to deliver the best practices that can be replicated across the other Regions.
EP IPT Solutions:
EIN Mobile Packet Core Evolved Packet Core Service Aware Charging & Control Broadband & Fixed Line Introduction Ericsson Network Integrated Wi-fi
5. Managed Service PracticeMission is to understand customer’s needs & deliver excellent services by creating outstanding business value through high quality, cost efficiency & time accuracy.
RINA EP Managed Service is responsible for managing the services business & defining the services in the region. EP MS comprises of Managed Services, customer support, learning services & wireline network rollout, Design & optimization. The team has e2e responsibility of securing profitable business opportunities which result in thick margins & improved customer perception. It encompasses full responsibility to drive sales in order to secure a critical mass of business revenue for continued operation of these strategic business areas.Managed services focus on network operations. The service offering provides e2e services both for wireless & wireline (including fiber) & covering rollout, Design & optimization, Customer support & operations as an e2e service.Main Principles of the Engagement Practice are to:
Develop a strategic way of thinking & evolve solutions to meet customer requirements in Telecom, IT, Industries & Society
Deliver the Optimal Network solution to customer, leveraging shared network model.
Apply a consultative sales approach & solution value selling
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
34
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Assure high level of quality when developing solution documentation & presenting our value propositions to customers
Gain efficiency for the customer & Ericsson by re-applying best practices & lessons learned globally
The main goal of the practice is to lead business transformation services like managed services including outsourcing, customers support, & under a Comprehensive MS relationship (Network rollout, integration & professional services) which help operators to sharpen focus on core business.
The midterm objective is to have a strong value proposition for ECMS (Experience Centric Managed Services), e2e Wireline & Fiber Managed Services & Rollout, Network sharing (small cell as a service), IT MS, Energy Management (including Passive MS) & I&S MS.
6. OSS/BSS (OBS-Other business services)The Engagement Practice OSS BSS is responsible for driving RINA sales growth
for OSS BSS product portfolio & related CSI.
The focus is on strengthening Ericsson’s RINA customers with diverse portfolio & CSI of BSS (Prepaid charging, MBC, SDS, Converged billing) & OSS (EMS/NMS, Service Assurance & fulfillment, Network inventory). This would cater to the end to end operations & business support solutions; & offerings to Telecom & Non Telecom companies in RINA leveraging both Ericsson & Telcordia portfolio.
The objective is to ensure this mindset change in Region India through EP OSS BSS. The objective of EP would be:
Protect & harvest on the IN charging business New solution offerings beyond prepaid like data charging, converged billing etc. Extend the BSS solutions to non-Telco service providers Protect & Expand on the run-rate EMS business Leverage Telcordia to Extend the OSS offering to include service management,
network inventory services
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
35
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
The EP OSS BSS practice will work establishing itself as a business partner for both Telco & non-Telco verticals through innovative OSS & BSS solutions to value creation Business transformation.
7. TV & Media (TVM) The practice addresses the market generated from the creation, management, delivery & consumption of digital media on any device, anytime, anywhere. The practice addresses the customers’ needs in creating, delivering & managing digital media throughout the content chain, over any network, any platform, any platform & any device.
Typical Engagement
Converged TV & Integrated Content & Management Platform Hybrid Satellite & IP solutions IPTV & CDN engagements VOD Broadcast Platforms Web & Mobile TV solutions Play-out & Teleport SDP MSP Cloud offering for Enterprises & government sector
2.6 SALES PROCESS
INPUT SUB-PROCESS OUTPUT
Growth Plan, Event, Business Development, Lead Generation
Generate Lead
A registered Lead is defined and qualified.
Qualified Lead
Qualified Lead
Opportunity from Growth plan
New identified Sales Opportunity
Nurture Lead
The qualified lead is nurtured according to the set activity plan. When the customer demand is defined the Lead is ready for SDP0 decision. Lead passed SDP0 is converted to opportunity and ACR is assigned for further processing
SDP0 with Go or No go decision
Lead passed SDP0 is converted to Opportunity
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
36
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
in opportunity phase.
Qualified Lead Qualify Opportunity
To proactively identify and qualify new sales opportunities to be pursued and to determine an accurate process Track for opportunity management.
All opportunities are to be qualified or disqualified before process Track is chosen is concluded.
RFQ from customer towards a valid Frame Contract is defined as Recurrent Sales and processed in Frame Contract Execution/Recurrent Sales process flow.
For Full Track Opportunities before SDP1 is taken to pursue for proposal. In case SDP1 is rejected the opportunity is marked as Not pursued. The opportunity must be reviewed and updated to enable re-take of SDP1.
Qualified opportunity
SDP1 signed or rejected for Full Track Contract Opportunity
Qualified Opportunity
Create Proposal
Core Three together with support resources create an as strong proposal as possible to be submitted to customer. An assignment specification for strategy and planning of contract execution is issued. The customer proposal is designed upon scope of customer solution, work and responsibility matrix, updated
Customer Proposal for Small Value Track Contract sent to customer
Recommendations for improvements on T&C's and conclusions
Proposal for Fast/Full track Contract is ready for approval
SDP2 signed off or rejected
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
37
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
sales strategy and trade compliance confirmation. The risk analysis, GAP analysis, commercial analysis and AD09 pre-assessment are performed.
Perform the contract evaluation analysis on the Proposal terms & conditions for Full Tracks.
Sales Decision Base for SDP2 is prepared for Full and Fast Track Sales Opportunities.
The completed proposal for Small Value Track Sales Opportunities is signed and submitted to customer. The Proposal is archived according to Global instruction.
SDP2 decision is performed for Opportunities determined in Fast or Full Track sales flow. The signed Proposal is submitted to customer. The Proposal is archived according to global instruction.
The opportunity is set to Not pursue if the SDP2 decision is rejected and the sales opportunity will not be pursued. If the intention is to update the Proposal to pursue the opportunity it is required to remake SDP2 decision.
Signed Proposal sent to customer
Archived Proposal
Small Value Track Proposal accepted by customer
Close Deal
Seek approval for Early Start
Early Start is approved and handed over for execution
Small Value Track Firm Contract
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
38
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fast Track Proposal accepted by customer
Full Track proposal accepted by customer
if applicable.
Formally accepted proposal is received from customer. For Fast and Small Value track the accepted proposal and received Purchase Order are treated as a contract and archived according to global instructions.
Additional activities for Fast track to reach an acceptable deal for both parties if the proposal is not accepted as such:
Final scoping, terms and conditions including update of risk analysis, update of OPCM, creation of final BoQ and AD09 assessment is done. Negotiate with customer to reach an acceptable deal for both parties. The contract is completed with all terms and conditions and performs a contract review before the contract is ready to be signed by Ericsson and customer.
Additional activities for Full track:
Negotiate with customer to get acceptance for the submitted proposal to reach an acceptable deal for both parties.
Complete risk analysis, commercial analyses, BoQ and AD09 assessment. Finalize scoping and terms
acknowledged and archived
Fast Track Firm/Frame Contract signed and archived
Firm/Frame Contract ready for sign
Recommendations for improvements on T&C's and conclusions
Sales Decision Base for SDP3
SDP3 signed or rejected
Contract signed
Contract ID
Contract archived
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
39
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
and conditions.
Perform the contract evaluation analysis on the Proposal terms & conditions for Full Tracks.
Complete the contract with all terms and conditions and perform a contract review to ensure completeness.
SDP3 for Full Track Contract Flow
SDP3 decision is performed. The contract is signed by authorized signatories at Customer and Ericsson. The Contract is archived according to Global instruction.
The opportunity is set as Not pursued if the SDP3 is rejected. The draft Contract is also closed accordingly.
Review and change of the draft Contract and supporting documents are required to retake SDP3.
Deal and Contract
handed over to
execution parties
Execute Contract
Monitor contract execution. Monitor and review contract financial performance and risk exposure and assess any need for mitigation activities, corrective actions or provisions on loss.
Maintain Sales Prediction.
All contract obligations fulfilled and contract ready for SDP4
SDP4 signed off/rejected
Contract terminated
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
40
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Maintain product lifecycle changes which have impact on contract BoQ and price list.
Manage escalations from delivery process.
In case of change requests from customer or Ericsson, perform an impact analysis of the request to conclude if contract amendment is required.
For Frame Contract Deals if Recurrent Sales Opportunities exist, maintain the activities on the Frame Contract scope
Secure final payment collection from customer.
Prepare for Sales Decision Base for SDP4 when all contract obligations are fulfilled (Fast or Full track Contract) or request for contract termination is received.
Perform SDP4 decision.
Release appropriate guarantees and bonds from the customer when contract is completed.
Close contract in all tools.
Rejected SDP4 decision means that the contract/deal is not yet ready for completion.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
41
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.5 Table showing Inputs & Outputs of all Sub-processes regarding Sales Process of Ericsson
Lead Qualified Lead Opportunity
Fig 2.6 Sales Process steps flow diagram
2.7 VISIT TO THE EXPERIENCE CENTRE OF ERICSSON
All the interns including me, working under Engagement Practices Department, were taken to a visit to the Experience Center of ERICSSON on 13th July, 2015.
We all were really mesmerized, amazed, & impressed by the technology & devices displayed there at the studio. We also saw many videos showing the upcoming technologies by 2020.
We saw how & in which ways would the technology would greatly affect & totally change our lifestyles in the coming 5 years. We all got to learn a lot from the Experience Center. Thanks to Mr. Tanuj Duhan Sir, Mrs. Deepti Daang ma’am & Mr. Sudarshan Sir for arranging this visit. Some of the Electronic devices displayed were:
1) Connected Twittering Tree
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
42
Generate Lead
Nurture Lead
Qualify Opportunity
Create Proposal
Close deal
Execute Deal
SDP0 SDP1
SDP2SDP3SDP4
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Our “Twittering Tree” senses changes in the electromagnetic field around it as people pass, and sends Tweets that reflect its mood directly to its Twitter account, Connected Tree. This tree also reacts to people´s presence and movements by playing music, speaking and turning on and off lights.
The tree´s responses aren´t random – they are based on the activity around it. When someone moves away from it the tree will express its “loneliness” with a particular tune and a tweet. When several visitors are competing for its attention, it will comment on how busy it is. A special response is generated when someone touches the tree and an SMS is sent to the passerby´s mobile phone.
So how does it work and what is the technology behind it?
When someone walks by or approaches the Twittering Tree, its sensor transmits information about that movement and the changes it causes in its electromagnetic field to a processor in a nearby laptop, which then activates a number of responses.
The tree is connected to a device that turns the tree into an electromagnetic field sensor, enabling it to detect motion.The data is processed by an analysis engine, which forwards the tree’s reactions to Twitter and SMS.A local visuals engine produces lights and sounds.
2) Connected Me It was basically a pair of transmitter & receiver, which uses our body current as a medium of data transfer. You all might be shocked to hear the fact that:
OUR BODY CAN TRANSFER DATA AT A SPEED OF 10Mbps WITH NO HARM DONE TO IT.
So basically, the device uses Capacitive Coupling concept for data transfer. There were 2 boxes kept on which metallic sheets were mounted. A mobile phone playing music was connected to the transmitter & a speaker was connected to the receiver side. When we touch both the boxes with both of our hands & complete the circuit we hear the song being transmitted through our body on the speaker connected to the receiver side. We
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
43
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
also saw a photo clicked on a mobile phone being transferred within seconds through our body and being displayed on the TV connected to the receiver side.
Fig 2.7 Connected Me slide
3) Connected Print Connected Paper makes it easy for the individual to access information about anything with print on it by touching it. By touching the Connected Paper, the user is identified and will have access to specific information via their digital device.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
44
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.8 Connected Print slides
Fig 2.9 Picture of a Connected Print Paper
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
45
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.10 Connected Paper slides
4) Connected Label This technology was the same as we all have in our smartphones in the form of barcode scanner camera. But, instead the camera was used for any kind of labels, be they posters or books & novels or advertisements in newspapers etc. The smart device every information about the label onto which the camera is being focused on.So, the next time you decide to watch any movie in multiplex without knowing its storyline or watched its trailer, just focus your camera toward the movie’s poster and get to know everything about it. Might happen that the movie might be not worth watching at the cinema, you can save your 300 bucks using this upcoming technology.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
46
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.11 Connected Paper Examples slide5) Smart Table
We also saw the smart table connected to the internet, having a large touch screen just like a smart phone. The software installed in it was Windows 7 including multitasking. Just like a vertical TV, it was a touch screen horizontal smart table on which you can search every bit of information & order your favourite coffee from Café Coffee Day, while listening to music or even playing piano on it.
6) Adidas miCoach Smart Ball A coach inside a football .
Football is the most popular sport in the world, a sport that brings people together both on and off the field. Imagine how much more interesting the sport would be if players were constantly improving?
Scott Tomlinson, an Englishman from Newcastle, has been developing a new type of football coach. The Adidas miCoach Smart Ball is a football and coach in one. A sensor integrated into the ball sends real-time data to an app on a mobile device using Bluetooth, allowing the player to track speed, spin, strike and flight path of the ball.
Now what happens on the training field can be shared and discussed off the field in digital detail. The ball and app can be used as a training partner and coach, give you personal challenges or share and compare progress with friends to improve your football skills.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
47
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.12 An App displaying the parameters of The Smart Ball
7) Radio Dot The Ericsson Radio Dot System delivers seamless app coverage to the operator’s consumer and business customers in the broadest range of in-building deployment scenarios, including the underserved, high growth, medium-to-large building and venue category. Indoor environments pose special challenges for service providers. Current indoor solutions present complexity, scalability and service continuity limitations that can restrict the user experience. Distributed Antenna System (DAS) are built mainly for voice coverage in very large buildings and venues and are expensive to upgrade to meet the growing capacity demands of mobile data. At the other end of the spectrum, most residential and small business or venue requirements are addressed by the outside-in effect of the outdoor macro or micro. As building size increases along with the numbers of highly mobile users, a new solution needs to provide coverage scalability, interference and handover capabilities.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
48
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig. 2.13 The Radio Dot
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
49
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 2.14 Slides displaying the uses, compactness & advantages of Radio
Dot
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
50
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
2.8 NETWORKED SOCIETY SUMMARY
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
51
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
52
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 3 Sample Project-VOICE OVER LTE (VoLTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
53
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
3.1 INTRODUCTION
Terminal industry is driven by new high end type of devices such as smartphones and tablets. These types of devices drive the demand for high performance mobile broadband network, both regarding capacity and coverage. In order to meet these demands, operators are investing in more efficient radio technologies such as LTE. However, as voice is still major source of revenue and high quality voice service must therefore be preserved also when moving into a mobile broadband centric future. The industry has aligned around GSMA Voice over LTE (VoLTE) as the standard for the telephony in LTE.
With VoLTE, the 3GPP MMTel standard has become the industry’s preferred solution for voice and SMS services over LTE. VoLTE is also supporting delivery of conversational video services over LTE. VoLTE leverages traditional telecom characteristics, such as high quality and global reach, while at the same time offers an optimal evolution path towards full multimedia services. Recently “wifi calling” has generated a lot of interest in industry and is supported by Mobile Telephony Evolution by means of EPC integrated Wi-Fi as an access extension to the VoLTE service. VoLTE ecosystem is building up fast due to the traction in the market. Ericsson has a great position to support operators around the world with our strong end-to-end VoLTE solution portfolio including the LTE Radio, Evolved Packet Core, Mobile Softswitch Solution, User Data Management, IMS portfolio, as well as our extensive delivery capabilities of complex end-to-end projects.
3.2 WHY Vo-LTE? & ITS MOTIVATIONS
The motivation for the deployment of 3GPP Long-term Evolution (LTE) mobile broadband technology is simple: All things considered, LTE delivers to carriers the lowest cost-per-transported bit. That said, the adage that “voice pays the bills” still applies: Though in decline, carriers continue to derive the bulk of their revenues from voice and integrated messaging services.
In the context of LTE, this presents a dilemma. A fundamental aspect of legacy technologies such as GSM, UMTS, and cdma2000 is that they possess integrated services1: voice, voice supplementary services (e.g., call forwarding), short messaging, etc. In contrast, LTE makes no such provisions: it is subscriber service-agnostic. Further, LTE is a pure packet technology, with no inherent conception of a circuit-switched (CS) bearer, on which legacy voice services depend.
Because of the realities of the cellular revenue model, and because cellular subscribers expect service continuity, the question arises: How can we best deliver voice and other legacy services via LTE? As with any engineering exercise, this requires articulation of the
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
54
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
requirements.
3.3 DRIVERS/REQUIREMENTS FOR Vo-LTE
Fig. 3.1 Drivers for Vo-LTE
The requirements for voice over LTE (Vo-LTE) solutions fall into one – or both – of two categories: The requirements of cellular subscribers, and the requirements of cellular carriers. The most important of these requirements are as follows:
1. Subscriber Requirements2. Carrier Requirements
3.3.1 SUBSCRIBER REQUIREMENTS
Telephony – Subscribers, first and foremost, expect replication of legacy cellular telephony services. The expectation of support for voice and messaging services is intuitive. But supplementary services – and the management thereof – are also required. While this might seem like a trivial requirement, the implementation of supplementary services in the context of Vo-LTE isn’t necessarily obvious. Further, subscribers – not to mention regulators – have clear expectations on the availability and performance of emergency calling services. Additionally, video telephony is fast becoming a basic expectation for subscribers.
Quality – Subscribers also require call quality that is not noticeably different from that of existing telephony services. This presents a technical challenge in that LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
55
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
is a purely packet-switched (PS) system, and the maintenance of quality-of-service (QoS) in PS systems is notoriously challenging – especially over the parts of the channel outside the cellular carrier’s purview.
Ubiquity – Subscribers expectations in terms of service ubiquity go only one way over time – up. This means that both local and wide-area mobility must be supported transparently by any Vo-LTE solution. In technical terms, this means seamless inter-RAT (IRAT) operations as well as domestic and international roaming.
Battery – In order to be viable, a Vo-LTE solution cannot result in significantly higher battery consumption than is experienced with legacy voice services.
3.3.2 CARRIER REQUIREMENTS
Cost – For cellular carriers, a minimized total cost of ownership is the fundamental requirement. But costs can be manifested in a multitude of ways. For example:
Efficiency – The more efficient a technology is, the more traffic can be handled per node and per megahertz of transmission capacity. This is particularly important over the air interface, since radio spectrum is one of a carrier’s most precious assets: Spectrum procurement is challenging due to the limited amount of spectrum available and regulation by the various government agencies which control it.
Complexity – Reduced network complexity was a fundamental principle employed during the design of LTE. As complexity increases, the required hardware and the software development effort – particularly with terminal devices – increases. Therefore an excessively complex voice solution is not desirable.
Reusability – Solutions that permit the reuse of existing infrastructure – or are designed to have a long lifespan – are desirable.
It is with these requirements that the various options are evaluated to deliver Vo-LTE.
3.4 SUMMARY
3GPP Long Term Evolution networks are now a commercial reality. As cellular network operators continue to plan LTE coverage and capacity expansion, the need to migrate traditional voice calling services to LTE becomes ever more pressing. The emergence of GSMA IR.92 – IMS Profile for Voice and SMS – as the de facto voice-over-LTE standard
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
56
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
has cleared the way for global adoption of a single LTE voice solution. IR.92’s forward-looking foundation on IMS/SIP ensures its longevity, but it also introduces functional, performance, and quality challenges. Comprehensive testing and verification of Vo-LTE-enabled mobile devices is crucial to ensuring consumer adoption and commercial success of voice services on LTE.
CHAPTER 4EPS - EVOLVED PACKET SYSTEM
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
57
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.1 Vo-LTE E2E ARCHITECTURE
Fig 4.1 E2E Vo-LTE architecture
Firstly, we would be studying about the E-UTRAN & the EPC part of the E2E Vo-LTE architecture.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
58
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.2 EVOLVED PACKET SYSTEM (EPS)
Terminology Clarification:
Fig 4.2 Terminology
Flowchart
EPS architecture goes like this-
User (UE, e-node B) Radio Network EPC Destination IP Network (Eg.- E-UTRAN) (Eg.-IMS)
4.3 EPS ARCHITECTURE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
59
3GPP Release 8
LTE (Long Term Evolution)
SAE (System Architecture
Evolution)
E-UTRAN (Evolved UMTS terrestrial Radio access network)
EPC (Evolved
Packet Core)E-UTRAN + EPC = EPS
Core side
Radio side
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 4.3 Architecture of EPS system
4.3.1 USER EQUIPMENT (UE)
Definition: UE refers to the device controlled by the user of the wireless network. Eg.- Cell phone, Tablet, USB dongle etc.
Aside from just being your phone, an LTE ‘UE’ must support the 3GPP procedures & call flows required of such a device.
Specifications drawn for distinction between a UE & a SIM, & further for a SIM distinction can be drawn between a UICC (Hardware) & USIM (Software/Application).
International Mobile Equipment Identifier (IMEI) number is a unique identifier for a physical device. It is used to identify & track the host device.
International Mobile Subscriber Identifier (IMSI) number is a unique identifier for a SIM card. It is used to identify & track the SIM card.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
60
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.3.2 EVOLVED-nodeB (e-nodeB)
Formal name for LTE cell tower. Provides radio access to UE’s (through Uu interface). Tunnels control traffic from the UE towards the network (S1-MME interface). Tunnels data between the UE & the input network of service that the user is trying to
access (S1-U interface). Talks to other e-nodeBs & forwards traffic to them when UEs move through the
network (X2 interface). Cell towers couldn’t talk directly to each other, but instead through the common
Radio Network Controller (RNC) or Base Station Controller (BSC).
Fig 4.4 WCDMA vs. LTE/SAE architecture
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
61
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.3.3 MOBILITY MANAGEMENT ENTITY (MME)
Keeps track of user’s state whether it is ON or OFF (timeout when session has gone/maintaining the session).
MME communicates with & asks Home Subscriber Server (HSS) for security keys & encrypted data to authenticate & authorize the user & the encrypted traffic. It asks the queries Eg.- Which services the user wants to access ? The response is in the form of networks allowed to reach, bandwidth, data rate etc.
Primary responsibilities can be divided into ‘EMM’ or ‘Evolved Mobility Management’ & ‘ESM’ or ‘Evolved Session Management’.
EMM is used to know at which location the subscriber is present & its state in the network. It is usually for circuit switched networks.
ESM is used for creating an actual data session. Usually for GMM/GPRS, 3G data architectures.
A user can be registered with or located on only one MME at a time.
4.3.4 HOME SUBSCRIBER SERVER (HSS)
Acts as a database information that can be queried by MMEs to determine permitted services.
Holds the primary security key information for all the SIM cards in a mobile network. Keeps a bird-eye view of which users are located where in the network. HSS knows
which MME & in which network a SIM is registered on & can inform the old MME. Similar to the Home Location Register (HLR).
4.3.5 SERVING GATEWAY (S-GW)
One or more S-GWs will serve a given group of e-nodeBs for user-plane data. A single UE can be served by only one S-GW at one time. MME talks & tell S-GW what P-GW to talk to. S-GW anchors the user & PDN-GW anchors the PDN. Subscriber is served by single S-GW. He can reach different P-GW to reach different
PDN as dictated by the MME. Handles user IP Packets between P-GW & e-nodeB. S-GW & P-GW are basically IP
Routers used for packet forwarding. Protocol used between MME & S-GW is the GPRS tunneling protocol.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
62
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.3.6 PACKET DATA NETWORK GATEWAY (PDN/P-GW)
Also known as ‘PCEF’ or Policy Control Enforcement Function, it controls the amount of QoS dictating its services. It acts as a dictator.
P-GW has a billing server which knows that which UE has how much balance & data sharing over the internet during a busy hour or not.
Provides access to PDN. PDN-GW would be an IP-GW reaching that PDN. If the UE has multiple data sessions to multiple PDNs, the UE can be connected to
multiple P-GWs. The UE will still be served by only one S-GW, however. Functionally, the P-GW is an IP router with support for a few mobile-specific
tunneling & signaling protocols. Protocols used are GTP & diameter between S-GW & P-GW.
4.3.7 EPS CONTROL PLANE & USER PLANE
Fig 4.5 Control Plane & User Plane EPS diagram
UE & e-nodeB, both have User Plane (Uu interface) & Control Plane (Radio interface).
The interface between S-GW & P-GW in the local network is S5, but in Roaming scenario the interface would be of S8.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
63
UE e-nodeB
MME
S-GW
HSS
P-GW PDN
Control plane
User plane
S1-MME
S1-US5/S8
Uu
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
4.4 EPS ATTACH PROCEDURE
Fig 4.6 EPS Attach Procedure
4.4.1 ATTACH REQUEST
1) UE sends attach request to e-nodeB.2) UE has an International Mobile Subscriber Identifier (IMSI) number on its SIM card
including supported capabilities Eg.- Particular Bandwidth & services, data rates etc. It sends all of them in the form of request to the e-nodeB.
3) It also sends IMTI (Temperate Identifier) number to the MME. Reason is because encryption has not been set up at this point.
4) E-nodeB determines which MME to send the request to. It connects to the particular MME using Round Robin or it queries the DNS server to get an MME to serve the
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
64
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
subscriber of multiple names dynamically what MMEs are available to him for attach procedure.
5) It also indicates whether or not, it wants to request a specific data service or is this the default attach?
6) In the default attach procedure, the network decides what external PDN, data network to connect to, based on policy information. In case of a specific service, it sends a flag.
4.4.2 AUTHENTICATION INFO REQUEST/RESPONSE
1) MME queries the HSS for subscriber info for Key information.2) There is a pre-shared Key concept. UE or rather a SIM card has a K Key. HSS also
has a K Key. Both the K Keys are checked against each other.3) MME asks the e-nodeB what specific thing it wants to ask. UE declares specific IP to
connect to.4) Authentication successful.
4.4.3 UPDATE LOCATION REQUEST
1) Subscriber is now located in a particular MME. HSS declares the specific authentic MME for the UE.
2) In case of old MME, it cancels it & updates the location register.
4.4.4 UPDATE LOCATION ANSWER
1) HSS forwards the UE’s subscription services, QoS networks & information to the MME.
2) Eg. – This particular subscriber has access to this particular data network with this particular QoS settings & so on.
3) Here the protocol used is Diameter.
4.4.5 CREATE SESSION REQUEST
1) MME figures out what P-GW can serve that external network & what S-GW can serve what e-nodeB to which subscriber is connecting on. It will actually use DNS (concept of GW selection).
2) MME asks four queriesa) What PDN-GW can serve this PDN to which subscriber is trying to reach?b) What is the IP address of that PDN-GW?
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
65
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
c) What S-GW can serve this e-nodeB i.e. the tracking area/radio network in which the subscriber is present right now?
d) What is the IP address of that S-GW?
3) MME requests the S-GW & this request indicates the IP address of P-GW selected for the session. This request gets transported from S-GW to P-GW, which the MME has sent.
4) Request will also include S-GW IP & selected Tunnel Endpoint ID (TEID) for this requested bearer.
5) Tunneling points/legs of data sessions get built. Out of them two are between e-nodeB & S-GW & between S-GW & P-GW. They work on the GTP protocol.
4.4.6 CREATE SESSION RESPONSE
1) P-GW takes the requested APN & QoS settings as input. It selects the QoS for the EPS bearer & sends it in a response. Here the P-GW is the dictator.
2) The response includes TEID for the S5 bearer. It will also include an IP address (IPv4/IPv6) for the UE & other information such as which DNS servers to use.
3) PCRF (Policy Control Rules Function) decides quantity of data rate & QoS settings accordingly Eg.-whether a busy hour or not.
4) OCS (Online charging server) keeps a check on the balance of the UE.5) MME gets the ‘CREATE SESSION RESPONSE’ from the P-GW through S-GW.
4.4.7 ATTACH ACCEPT
1) MME gets the ‘CREATE SESSION RESPONSE’ from the P-GW. MME can reject the response but can’t change the QoS settings for the bearer.
2) MME sends the user’s IP information in ‘ATTACH ACCEPT’ message to the UE via e-nodeB. It also includes the IP address & TEID of S-GW for the e-nodeB.
3) E-nodeB forwards the ‘ATTACH ACCEPT’ as part of an RRC radio message to the UE & will also include the radio bearer identifier to the UE.
4.4.8 ATTACH COMPLETE
1) UE acknowledges the RRC message from e-nodeB creating the radio bearer.2) UE sends the ‘ATTACH COMPLETE’ message to acknowledge & accept the
‘ATTACH ACCEPT’ message. This is forwarded to the MME.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
66
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
3) In the ‘ATTACH COMPLETE’ being sent to the MME, e-nodeB also sends ‘Initial Context Setup Response’, including the TEID & IP address to be used for setting up the S1-U bearer with S-GW.
4) Now the interfaces between the UE & e-nodeB & between S-GW & P-GW have been built.
4.4.9 MODIFY BEARER REQUEST
1) MME sends the ‘MODIFY BEARER REQUEST’ message to the S-GW. This includes the IP & TEID information for the e-nodeB.
2) Acknowledgement of this message by the S-GW completes the S1-U bearer (interface between e-nodeB & S-GW) & with it the EPS bearer.
3) The UE is able to exchange data with the PDN via the P-GW.
4.4.10 QUICK SUMMARY
Fig 4.7 EPS attach procedure summary
1) UE asks to connect 2) MME & HSS authenticate/authorize UE 3) MME asks P-GW/S-GW to set up data session 4) MME forwards the session details to UE 5) Final acknowledgements & bearer setup
4.5 EPS BEARER ARCHITECTURE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
67
UE e-nodeB
MME
S-GW
HSS
P-GW PDN
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 4.8 EPS bearer service architecture4.6 HISTORICAL CONTEXT
Evolved Packet System
GPRS architectureFig 4.9 EPS vs. GPRS architecture
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
68
UE e-nodeB
MME
S-GW
HSS
P-GW PDN
UuS1-MME
S1-U
S5
Mobile Station
(MS)
nodeB RNC SGSN
HLR
GGSN PDN
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 5IMS-IP MULTIMEDIA SUBSYSTEM
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
69
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
5.1 Vo-LTE E2E ARCHITECTURE
Fig 5.1 E2E Vo-LTE architecture
Now, we will be studying about the 3 layers of IMS i.e. the IMS connectivity, control & the service layers & about their respective nodes & entities.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
70
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
5.2 WHAT IS IMS?
IMS stands for IP Multimedia Subsystem. It is a cornerstone for providing converged multimedia services across multiple accesses. It is an architectural framework for delivering IP multimedia to mobile users. The IMS standard defines a generic access agnostic architecture to offer converged
multimedia services. To ease the integration with the Internet, IMS uses IETF (i.e. Internet) protocols such as
Session Initiation Protocol (SIP). IMS is access agnostic & as such is independent of the access technology used.
5.3 HISTORY OF IMS
It was originally designed by the wireless standards body 3 rd Generation Partnership Project (3GPP), & is a part of the vision for evolving mobile networks beyond GSM. Its original formulation represented an approach to delivering Internet services over GPRS. This vision was later updated by 3GPP, 3GPP2 & TISPAN by acquiring support of networks other than GPRS, such as Wireless LAN, CDMA2000 & fixed line making IMS access independent.
5.4 STRUCTURE OF IMS
It consists of common core, enablers, support systems & interworking functions enabling operators & service providers to leverage on installed legacy networks, thus reducing cost, while proving key end-user benefits like reliability & security.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
71
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Ericsson IMS is based on layered architecture, which separates functionality into three layers - an application layer, a control layer & a connectivity layer. The layered architecture allows each layer to evolve independently as market & technology demands change. For example, it supports the migration to new transmission technologies by making the upper layers independent of the transmission technology in the connectivity layer.
IMS is not intended to standardize applications itself but to aid the access of multimedia & voice applications across wireless & wireline terminals. This is done by having a horizontal control layer which isolates the access network from the service layer. Services need not have their own control functions, as the control layer is a common horizontal layer.
5.5 IMS ARCHITECTURE
Definition: IMS is an architecture designed to support the control layer for packet based services, which uses the bearer services of the access network to support the media associated with the service.The IMS nodes can be split into 3 groups of elements:
Database elements (HSS, SLF) IMS control elements (P-CSCF, I-CSCF & S-CSCF) Control plane interworking elements (MGCF, BGCF & SGW)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
72
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 5.2 IMS architecture
Advantage: One key advantage of this architecture is that the home network provides the services & service features. This means that the user’s configurations are always the same & are always provided by the home network operator. The user is not restricted to the capabilities of the visited IMS network as is seen in the current wireless network (i.e. if an MSC doesn’t support a feature that you have subscribed to, you will not be able to use that feature). However the user is still limited by the visited access network capabilities.
5.5.1 DATABASE ELEMENTS
1. HOME SUBSCRIBER SERVER (HSS)
The main database element is the HSS. This element is the evolution of the HLR element. The HSS contains the feature
of the HLR (subscriber data & authentication data) & other functions such as Location Register, IMS service profile processing & IMS subscription & authentication data.
The HSS will be accessed by the I-CSCF, the S-CSCF & external platforms.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
73
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
The HSS uses the diameter protocol with the diameter multimedia application extension.
2. SUBSCRIPTION LOCATOR FUNCTION (SLF)
This database is accessed by the I-CSCF & the S-CSCF in order to obtain which HSS stores the user data when more than one HSS is present in the network.
The query will contain the identification of the user & the response will contain the HSS that stores the data for the specific user.
5.5.2 IMS CONTROL ELEMENTS
The three IMS control elements are nodes that act on the control (SIP) signaling flows. These nodes provide Call Session Control Functions (CSCF) & each separate node (Serving, Proxy & Interrogating) has a different role & function.
1. SERVING CALL SESSION CONTROL FUNCTION (S-CSCF)
The S-CSCF is the node that performs the session management within the IMS network for the UE. The S-CSCF operates in a stateful manner.
The S-CSCF also ensures end-to-end reachability for users & services by interacting with other CSCFs, SIP servers & Application servers.
The S-CSCF also authenticates the user. The S-CSCF is the main control point for services. The S-CSCF enforces the rule
set for services based on the general policy of the operator & the user’s subscription parameters. The S-CSCF may reject a service according to these factors.
The S-CSCF decides on the handling of service requests from the user based on the user’s profile (provided by the HSS during registration). Where the services of an application server are required to complete the requested service, the S-CSCF will forward the request to the appropriate application server either based on the user’s profile or on the operator’s local policy.
The S-CSCF is always located in home network. There can be several S-CSCFs in the network. They can be added as required based on the capabilities of the nodes or the capacity requirements of the network & if required they can be assigned dedicated functions.
The management of S-CSCF in the IMS network is dynamic & the I-CSCF can allocate the S-CSCF for a user at registration time.
The S-CSCF may be chosen based on the services requested or the capabilities of the mobile.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
74
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
2. PROXY CALL SESSION CONTROL FUNCTION (P-CSCF)
The P-CSCF is the entry point towards the IMS network from any access network.
The assignment of a P-CSCF to a user is determined by the access network configuration. In the case of LTE the allocation takes place at PDP context activation, where the UE may use a DHCP query to obtain the list of P-CSCFs or the UE is provided the IP address of the P-CSCF by the GGSN in the PDP activation message. The P-CSCF is located in the same PLMN as the GGSN.
Signaling : The P-CSCF is a stateful SIP proxy & all signaling between the user & the IMS system is routed through the P-CSCF. The P-CSCF will also enforce the routing of signaling messages through the user’s home network.
SIP Registration : The P-CSCF is responsible for sending the 1st SIP message (SIP registration query) towards the corresponding I-CSCF, based on the domain name in the registration request. After successful completion of the registration procedure, the P-CSCF maintains the knowledge of the ‘SIP server’ (the serving S-CSCF located in the home network) associated to the user, & will forward all requests from the user towards it.
Security : The P-CSCF is responsible for establishing a security association with the user, which it maintains for the lifetime of the ‘connection’. Once the security association is established, it is responsible for receiving & validating all session requests.
Policy Decision Function (PDF): The P-CSCF also includes the Policy Decision Function (PDF) which authorizes the use of bearer & QoS resources within the access network for IMS services.
3. INTERROGATING CALL SESSION CONTROL FUNCTION (I-CSCF)
The I-CSCF is the first point of contact within the home network from a visited network or external network.
Its main job is to query the HSS & find the location of The S-CSCF. The I-CSCF may act as a hiding entity into a home network’s IMS.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
75
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
5.5.3 CONTROL PLANE INTERWORKING ELEMENTS
1. MEDIA GATEWAY CONTROL FUNCTION (MGCF)
The MGCF is a gateway that enables communication between IMS & CS users. All incoming call control signaling from CS users is destined to the MGCF that performs protocol conversion between the ISDN user part (ISUP), or the Bearer Independent Call Control (BICC), & SIP Protocols & forwards the session to IMS. In similar fashion all IMS originated sessions towards CS users traverses through MGCF. MGCF also controls media channels in the associated user plane entity, the IMS Media Gateway CIMS-MGW.
2. BREAKOUT GATEWAY CONTROL FUNCTION (BGCF)
The BGCF is responsible for choosing where a breakout to the CS domain occurs. The outcome of a selection process can be either a breakout in the same network in which the BGCF is located or another network. If the breakout happens in same network, then the BGCF selects a Media Gateway Control Function (MGCF) to handle a session further. If the breakout takes place in another network, then the BGCF forwards a session to another BGCF in a selected network.
3. SIGNALLING GATEWAY (SGW)
An SGW is used to interconnect different signaling networks such as SCTP/IP based & SS7 signaling networks. The SGW performs signaling conversion (both ways) at the transport level between the SS7 based transport of signaling & the IP based transport of signaling (i.e. between Sigtran SCTP/IP & SS7 MTP). The SGW doesn’t interpret application layer (Eg.-BICC, ISUP) messages. The SGW is often included in the MGC.
5.6 IMS SESSION ESTABLISHMENT FLOW
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
76
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig 5.3 High level IMS session establishment flow
When user A (Eric) wants to have a session with user B (Pat), UE A generates a SIP INVITE request & sends it to the P-CSCF. The S-CSCF processes the request, executes service control, which may include interactions with application servers (ASs) & eventually determines an entry point of the home operator of user B based on user B’s address & forwards the request to the I-CSCF of operator B. The I-CSCF contacts the HSS to find the S-CSCF that is serving user B. The request is passed to the S-CSCF. The S-CSCF takes charge of processing the terminating session, which may include interactions with application servers (ASs) & eventually delivers the request to the P-CSCF. After further processing (Eg.- conversion & privacy checking), the P-CSCF delivers the SIP INVITE request to UE B. UE B generates a response , 183 session progress , which traverses back to UE A following the route that was created on the way from UE A (i.e. UE B P-CSCF S-CSCF I-CSCF S-CSCF P-CSCF UE A). After a few more round trips, both sets of UE complete session establishment & are able to start the actual application (Eg.- a voice conversation). During session establishment an operator may control the usage of bearers intended for media traffic.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
77
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 6 Vo-LTE ARCHITECTURES
6.1 Vo-LTE ARCHITECTURE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
78
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig. 6.1 Vo-LTE Architecture
S1-Ue-Uu
S1-MME S11 ISC
Mb
eNB
MMTelAS
A
Mw
P-CSCF /IMS AGw
PCRF
RxGx
HSS
Sh
Cx
S6a
S&PGW
Signaling Bearer (Default) , QCI=5
Dedicated Voice Bearer , QCI=1
I-/S-CSCF
SGI
Gm
Ut
SIP (SDP)XCAP
Voice(RTP)RTCP
MME
Bearer and APN ManagementQoS HandlingP-CSCF Discovery
QoS and Bearer Handling in LTE– Intra LTE HO– DRX in order to maximize battery liftime– RoHC– Scheduling– Admission Control– Bearer Continuity
Supplementary service management using Ut with XCAP procedures
Media Handling– AMR-NB and WB– RTCP– Jitter Buffer management
MobilityCS Interworking
Policy Control
IMS feature– Registration and Authentication– MMTel Supplementary Services
Fig. 6.2 Ericsson E2E conversational Vo-LTE architecture
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
79
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
To be able to provide a full conversational voice service over LTE, a number of functions are required to be supported by the different domains.
IMS level provides the basic communication functionality, including supplementary service support. For Vo-LTE, the authentication mechanism has also been mandated to secure the possibility for roaming in the future.
The Evolved Packet Core system also provides additional functionality for IMS APN management, Voice indication to UE, QoS handling, and P-CSCF discovery. Note that a separate APN is required for IMS, and it is highly recommended to use a special APN also for self-management traffic (XCAP). EPC also provide additional functionality for e.g., SRVCC, Access Domain Selection, and CSFB.
6.2 Vo-LTE CALL FLOW – HIGH LEVEL STEPS
Fig 6.3 High level steps of Vo-LTE call flow
1. Detect available network.Check that compatible frequency band exist
2. Attach to the LTE network. Check that network is voice capable.
3. Setup IMS APN and find P-CSCF Make sure IMS APN can be established.
4. Register in IMSRegister and authenticate in IMS
5. Place a call / receive a call Call establishment can be made.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
80
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
6.3 Vo-LTE REGISTRATION
Fig. 6.4 Registration of Vo-LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
81
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
6.4 Vo-LTE CHARGING SYSTEM
Fig 6.5 Vo-LTE charging system
CDF (Charging Data) and CGF (Charging Gateway) functions are realized in the product Multi Mediation (MM): Can be co-located on same hardware optimizing the hardware needs for a mediation solution
OCS (Online Charging System) is realized in the product Mobile Broadband Charging (MBC): MTAS Ro support
All charging information provided by MMTel nodes. Charging system supports Rf & Ro mechanisms. Online charging for VoLTE subscribers shall only be done by IMS. Offline charging for VoLTE subscribers shall primarily be done by IMS however certain
CS co-existence use cases may result in charging information from CS core as well e.g. mid call services in an Mg deployment.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
82
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
Fig. 6.6 Vo-LTE Charging with CS co-existence architecture
There are number of reasons why CS coexistence may be needed for an operator including for example:
Reuse of existing CS roaming agreements
CS Emergency call handling already in place
Lack of LTE radio coverage in some areas
6.5 CIRCUIT SWITCHED FALL-BACK (CSFB)
Fig. 6.7 CS fall back
CSFB is a standardized solution utilizing existing MSC-network to provide services to LTE-capable devices before homogenous LTE-coverage is built. CSFB allows a UE to be reachable and fall-back to CS voice service when connected to LTE. The UE moves to 2G/3G access to establish a call. Network pages UE over LTE to indicate an incoming call on CS. CSFB can also be used to handle roaming as well as early emergency call solution. CSFB has impact on UE, CS core, LTE RAN and EPC.
In CSFB, upon a voice call origination attempt or when receiving a page for CS voice (via SGs interface), the UE is moved to WCDMA/GSM and the voice is sent over one of these access networks. The page response is sent over the new RAT on the Iu or A interface. The UE will return to LTE after call completion if LTE is preferred and coverage exists.
The CSFB function is only possible to realize in areas where E-UTRAN coverage is overlapped with GSM and WCDMA coverage. The MME can be configured to make sure that during ongoing Vo-LTE call, CS Fallback will not be allowed. This that ongoing voice call will not be interrupted due to incoming CSFB paging. Support for CSFB with packet handover is introduced in 15A. CSFB will allow retaining current roaming relationships
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
83
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
between operators, since CS voice is still used. CSFB can also be used to handle early emergency call solution.
6.6 ROAMING IN Vo-LTE
Ericsson proposes phasing approach for the stable architecture based on the VoLTE Introduction status. Figure shows the first step of possible VoLTE roaming phasing. In this revision, the introduced VoLTE network supports CS roaming and CSFB use cases.
In the CS roaming case, VoLTE user is roaming and attaches to VPMN in “CS-Mode”. In case that the roaming agreement exists however no Camel agreement exists, all originating services will be executed in the VPMN MSC which means that an originating dual service engine deployment exists. Users terminating service engine is in IMS (HPMN). As the user is not registered in IMS, T-ADS (SCC-AS) will direct the call to the CS domain using the MSRN (Mobile Station Roaming Number). In case that Camel agreement exists. User A’s (ICS user) call routed to the H-PLMN IMS for execution of originating IMS services using ICS Mg/Camel.
In case that the 2G/3G and LTE data only radio coverage is available when VoLTE user is roaming, the user does a combined EPS/IMSI attach (TS.23.221) to VPMN. Profile is downloaded from HSS (UDA) to MME with default APN (internet). As no PS voice available, CSFB procedures are initiated in the VPMN.
CS Core
Fallbackfor voice
2G/3G RAN
LTE RANEvolved
Packet Core
CSFB
VPMN
CS voice/ICS
HPMN
IMS(HPMN)
CS Core(GMSC/MGCF)
CS Core2G/3G RAN
VPMNCS voice/ICS
HPMN
IMS(HPMN)
CS Core(GMSC/MGCF)
Pre-VoLTE roaming - CS roaming
Pre-VoLTE roaming – Data roaming with CSFB
Fig. 6.8 Vo-LTE Roaming Phasing
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
84
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
6.7 Vo-LTE MANAGEMENT
All Ericsson products constituting the Vo-LTE end-to-end solution support Performance management (PM), Fault management (PM) and Configuration management (CM) based
on IMS release together with OSS-RC. The end-to-end CM guideline and the end-to-end trouble shooting guideline are provided in a part of Vo-LTE end-to-end CAL Store.
ENIQ Events
Data sources (events)3G GPEH4G CELL TRACECS CDRSGSN-MME EBM
SGSNSGSNSGSN- MME
EPGEPGEPG
RNCRNCRAN
SGSNSGSNMSS
4G
ENIQ Statistics
RNCRNCRAN
2G
SGSNSGSNIMS
CS Core PS Core
LTE Events Stats (Counters)
Data sources (Stats)Counter files
PS Core IMS
OSS-RC
RNCRNCRAN
3G
Counter files
Counter filesCounter and event files
Counter filesevent files
Counter files
Counter and event files
Counter files
Event StreamEvent files Event files Counter files
EMM Topology
EMM: Filtering and mediation of charging data
OSS-RC: Initiation and mediation of PM data
Topology
Fig. 6.9 Maintenance of Vo-LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
85
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 7
BENEFITS & FUTURE SCOPE OF Vo-LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
86
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
7.1 BENEFITS OF Vo-LTE
With VoLTE, operators can make use of the wider capabilities of IP-based networks to deliver high-capacity mobile-broadband services and launch interoperable communication services. VoLTE is a foundation for a modern user experience including services like HD voice, video calling, HD conferencing, IP messaging and contact management (as specified in GSMA’s Rich Communication Services program [2]), as well as new innovative services – all available anywhere, on any device.
With IMS/MMTel as the base for VoLTE, operators can evolve their voice services and add video calling – described in the GSMA specification for IMS conversational video [3]. VoLTE can leverage the world’s largest mobile user community (the Mobile Subscriber Integrated Services Digital Network - MSISDN), as well as traditional telecommunication principles such as guaranteed end-to-end QoS, support for emergency and regulatory services, global interoperability and mobility, interconnect and international roaming.
Fig 7.1 Benefits of Vo-LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
87
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
7.2 FUTURE SCOPE OF Vo-LTE
The telecomm technology has evolved from 2G(Kbps), 3G, 4G(100Mbps) & 5G is yet to
come in the up-coming years. We are moving towards voice centric services towards data
centric services. Using 2G & 3G technology users can access to both voice (circuit switched)
& data (packet switched) services. But in 4G only data services (packet switched) are
available as all the voice services can be easily accesses through 2G & 3G. So what about the
voice? Hence IMS was introduced which is used in the Vo-LTE technology.
A debate regarding the introduction of IMS technology happened between ONE VOICE
& VoLGA(Voice over LTE generic access). VoLGA introduced the concept of LGA system
that could be used between user end & MSC. Unluckily its idea of implementation died.
Ultimately ONE VOICE introduced the IMS system, which was standardized by GSMA &
given a name as IR 92 (Vo-LTE).
The IMS system can offer :
Voice
Enriched comms
High Definition (HD) videos
Enterprise services
Multimedia services
All the new cab services & applications like OLA, Uber etc. use the IMS system as their
operating service platform. Meru cab service has declined in these years. So, this is an
example of services over 4G LTE. Like these applications, many more apps & services can
be discovered & they can use the huge bandwidth provided by the upcoming technologies
like 5G & so on.
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
88
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 8
REFERENCES
8.1 BOOKS
LTE SAE System Overview (Global Services) - ERICSSON
8.2 WEBSITES
www.ericsson.com www.slideshare.net www.youtube.com www.altanaitelecom.files.wordpress.com www.3gpp.org www.3gpp.org www.techonline.com www.radcom.com www.anritsu.com www.ipv6.com www.commons.wikimedia.org www.catis-blog.com www.tech.queryhome.com www.techhive.com
8.3 DATA SHEETS & WHITE PAPERS
Anritsu Vo-LTE an_0214_v1 http://internal.ericsson.com/book-pages MTE with Vo-LTE
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
89
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
CHAPTER 9
APPENDIX
AMPS: Advanced Mobile Phone System
APN: Access Point Name
ARIB: Association of Radio Industries and Businesses
BICC: Bearer-Independent Call Control
CDMA: Code Division Multiple Access
DHCP: Dynamic Host Configuration Protocol
EMS/NMS: Element/Network Management System
ETSI: European Telecommunications Standards Institute
EV-DO (HRPD) : Evolution- Data Optimized (High Rate Packet Data)
GSM: Global Sytem for Mobile Communication
GSMA: Groupe Speciale Mobile Association
GPRS: General Packet Radio Service
GGSN: Gateway GPRS Support Node
HSPA: High Speed Packet Access
H-PLMN: Home Public Land Mobile Network
HSDPA: High Speed Downlink Packet Access
HPMN: Home Public Mobile Network
IMT: International Mobile Telecommunications
IS 95: Interim Standard 95
IRAT: Inter radio access technology
IETF: Internet Engineering Task Force
ISUP: Integrated Services Digital Network User Part
ISDN: Integrated Services Digital Network
MMTel: Multi Media Telephony
MSISDN: Mobile Station International Subscriber Directory Number
MSP: Mobility Services Platform
MTP: Media Transfer Protocol
PDN: Packet Data Network
PDP: Packet Data Protocol
QoS: Quality of Service
SMS: Short Message Service
SDP: Session Description Protocol
SCTP: Stream Control Transmission Protocol
SRVCC: Single Radio Voice Call Continuity
SGSN: Serving GPRS Support Node
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
90
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
TTA: Telecommunications Technology Association
TEC: Telecommunications Engineering Centre
TISPAN: Telecommunications and Internet converged Services and Protocols for Advanced Networking
T-ADS: Terminating Access Domain Selection
UICC: Universal Integrated Circuit Card
USIM: Universal Subscriber Identity Module
VOD: Video on Demand
Web RTC: Web Real time communications
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
91
VOICE OVER LONG TERM EVOLUTION (Vo-LTE)
SCHOOL OF ENGINEERING & TECHNOLOGY, ANSAL UNIVERSITY, GURGAON
92