Next Generation Telecom Network Optimization

Transcription

1 Ph.D. Thesis titled Next Generation Telecom Network Optimization Submitted in partial fulfilment for award of the degree of Doctor of Philosophy (Electronics and Telecommunication Engineering) By Munir Bashir Sayyad (Reg. No. : ) Research Guide Dr. S. L. Nalbalwar Department of Electronics and Telecommunication Engineering Dr. Babasaheb Ambedkar Technological University Lonere , Dist. Raighad [M.S.] (August 2013)

2 In the loving memory of My Late father Abbu, and dedicated to My Mother Ammi, Wife Faimida, Sweet Daughter Alfiya and Loving Son Arslaan. i

3 Contents Contents List of Figures List of Tables Acknoledgement Declaration of Candidate Acronyms Abstract II VIII X XI XIII XIV XVII 1. Introduction NGTN architecture Transport functions Transport functions activities Control functions Service functions Motivation for NGTN Optimization To achieve High bandwidth with access agnostic philosophy To achieve Bandwidth Optimization and QoS enablement Audio, Video Quality Improvements Problem Statement Aim Importance of Next Generation Telecom Networks Importance of Optimization in Telecom Networks Importance of the Problem Statement & NGTN Capabilities Objectives Research Methodology Fundamental Characteristics of NGTN Contributions towards the Thesis First Contribution: Proposed Network Architecture for NGTN Second Contribution: Proposed Method for Network Behaviour optimization Third Contribution: Application Destination Path Based Routing Optimization Fourth ContributionTo provide Signalling Bandwidth Optimization: Fifth Contribution: Using Network Intelligence for Bandwidth Optimization Sixth Contribution: Video Traffic Optimization (Delay Elimination) Seventh Contribution: Proposed Lawful Interception Monitoring System for NGTN Novelty of the Idea End-to-End Quality of Service Network Management Security Management Generalized mobility Disaster and relief communications capabilities Organization of Thesis 21 ii

4 2. Literature Review History of Next Generation Telecom Technology Standardization Historical Background for NGN from Literature Background History of ITU-T s Work on Next Generation Network At Present 2005 to 2013: NGN Global Standards Initiative (NGN-GSI) Evolution of Telecom Networks to Next Generation Telecom Networks GPP Work History on NGN IP Multimedia Subsystem Global Status of NGN from Literature Survey Literature review related to Next Generation Services Literature review related to Next Generation Network Optimization Conclusion Next Generation Telecom Networks Legacy and present day telecom networks Public Switched Telephone Network (PSTN) Speech Coding for PSTN Mobile Networks Wireless Cellular Networks GSM GPRS CDMA Cellular Networks UMTS Architecture G Technology Basic Theory, principle and Importance: Next Generation Telecom Network Basic Theory of NGN? ITU-T definition of NGN (Feb 2004) NGTN principles Importance of NGTN Present Day Network Realities Evolution towards Next Generation Telecom Networks Functional Network Nodes in LTE (4G) for NGTN E-UTRAN: LTE Access Network E-UTRAN Functions EPC: LTE Core Network MME S-GW P-GW HSS PCRF Functional Network Elements of the Converged Core (IMS) Session Border Controller (SBC Interconnect border control function Transport Gateway (TrGW) Proxy- CSCF (P-CSCF) 71 iii

5 3.5.5 Emergency-CSCF (E-CSCF) Location Retrieval Function (LRF) Interrogating-CSCF Serving-CSCF (S-CSCF Interworking nodes (with other IP networks and other Legacy networks) Breakout Gateway Control Function (BGCF) Media Gateway Control Function (MGCF) Media Gateway (MGW) Signalling Gateway (SGW) Application Nodes MMTel/TAS Group Calling Service (GCS) Media Resource Function Media Resource Function Controller (MRFC) Media Resource Function Processor (MRFP) Subscriber Data Repository Servers Home Subscriber Server (HSS) Service Delivery Platform (SDP) IP Short Message Gateway (IP SMGW) Notification Server Cloud Address Book (CAB) Social Networking Gateway (SNGW) Rich Communication Suite Enhanced (RCSe) Restful API Charging Servers Off Line Charging Server (OFCS) On-Line Charging Server (OCS) Support Elements Load Balancer Domain Name Server ENUM Server DRA NTP Number Portability Database (NPDB) IMS generic architecture Service or application plane The control plane User / Transport plane IMS framework IMS Logical Architecture IMS Application Services MMTel Service Communication hold Communication Barring Communication waiting (CW) 111 iv

6 CRBT Services Announcement Service Advertise Service Message and call tagging Notification Services Cloud Services Messaging Services IPSM (IP shot message) Gateway Social Networking Conclusion Optimization of the Next Generation Telecom network Proposed Network Elements for Next Generation Telecom Network Architecture Session Control Network Nodes Media Gateway Control Function (MGCF) Interworking nodes (with other IP networks and other Legacy networks) Application Nodes Subscriber Data Repository Servers Service Delivery Platform (SDP) Charging Servers Support Network Elements Advantages of the Proposed Architecture of NGTN Analysis of Different Methods of Congestion Control in SS 7 Network Introduction to Packet Switched network and SS7 Signaling mechanism Signaling Network Nodes Introduction to Congestion Control MTP Routing and Congestion Control MTP Congestion Control SCCP Routing and Congestion Control Conclusion on SS7 Congestion Control A Novel Method for bandwidth optimization on retransmitted in SIP Introduction to SIP (Session Initiation Protocol) Mathematical Modelling Bandwidth Optimization result discussion and conclusion Improvement and optimization of QoS of a Multiple Server Queue Introduction to Server queuing Models Single Server Queue Multi Server Queue Discussion on LITTLE s Law Use of LITTLE s Law for MSMA Discussion on Results and Conclusion Results Resolving Network Security Issues in IP-PBX in Converged Architecture Introduction to IP PBX (Internet Protocol Private Branch Exchange) 151 v

7 4.6.2 IP PBX Overview IP-PBX System Architecture Network Security Issues Prevention of Security Violation Result Discussion Proposed Method for Network Behaviour optimization Application Destination Path Based Routing Optimization for NGTN Using Network Intelligence for Bandwidth Optimization Experimental setup and Conclusion Video Traffic Optimization (Delay Elimination) Conclusion Lawful Interception Monitoring Optimization using Distributed Architecture Next Generation Telecom Network Complexity for LI Proposed Distributed Architecture for Lawful Interception What happens during LI of SIP to H323 call? Call Flow Steps of Proposed LI Conclusion Core Network System Optimization Results Objective: - Open Source OS optimization is focused on the following activities Technical Discussion and Implementation Initial Environment HSS (Home Subscriber Server) HSS Architecture Desired Performance Metrics HSS Tuning and Optimization Error Detection and Correction (EDAC) units Power Management System Management Interrupts (SMI) SOFTWARE TUNING HSS Core Build Design & OS Tuning HSS Post Iteration PCSCF (IMS) PCSCF Architecture Desired Performance Metrics PCSCF Performance Tuning (ITERATION 1) Power Management Error Detection and Correction (EDAC) units System Management Interrupts (SMI) Observations Software Tuning PCSCF Core Build Design & OS Tuning PCSCF Post Iteration 1 Tuning and Performance Optimization 188 vi

8 6.4.3 Objective Experimental set up preparation Overall IMS Optimization Test Results Conclusion Conclusion Objectives achieved Future Scope 193 Bibliography 195 Published Papers 203 vii

9 List of Figures Figure 1.1: NGTN Decomposition Layer... 2 Figure 1.2: NGTN Transport Layer... 4 Figure 1.3: NGTN control layer... 4 Figure 1.4: NGTN Proposed Architecture Figure 1.5: Thesis Organization Figure 3.1 : GSM system architecture Figure 3.2 : UMTS architecture Figure 3.3 : Evolution towards NGTN Figure 3.4 : NGTN uses Figure 3.5 : Migration towards NGTN Figure 3.6 : Overall LTE Architecture Figure 3.7: Overall E-UTRAN Architecture Figure 3.8: SBC Interfaces Figure 3.9: Interfaces of the P-CSCF Figure 3.10: E-CSCF Interfaces Figure 3.11: I-CSCF interfaces Figure 3.12: S-CSCF interfaces Figure 3.13: BGCF interfaces Figure 3.14: Media Gateway Interfaces Figure 3.15: Media Gateway Architecture Figure 3.16: MMTel/TAS Interfaces Figure 3.17: GCS Interfaces Figure 3.18: MRF Interfaces Figure 3.19: HSS Interfaces Figure 3.20 : Architecture of the IP SMGW Figure 3.21: IP SMGW interfaces Figure 3.22: Architecture of Notification Server Figure 3.23: NS interfaces Figure 3.24: CAB Interfaces Figure 3.25: SNGW Architecture Figure 3.26: SNGW Interfaces Figure 3.27: RCSe Architecture Figure 3.28: RCSe Interfaces Figure 3.29: DNS Hierarchy Figure 3.30: DNS Procedure Figure 3.31: ENUM Mapping Figure 3.32: ENUM call flow Figure 3.33: DRA Routing Interfaces Figure 3.34: NTP Logical architecture Figure 3.35: IMS architecture Figure 3.36: IMS framework Figure 3.37: IMS logical architecture viii

10 Figure 3.38: IMS Services Figure 3.39: Service Flow Diagram Figure 4.1 : NGTN Proposed Architecture Figure 4.2 : Single Level Hierarchy Figure 4.3: Two Level Hierarchies Figure 4.4 : Failed STP condition Figure 4.5 : Registration process Figure 4.6 : Proxy server example Figure 4.7 : Request redirection Figure 4.8 : SIP Session setup Figure 4.9 : Message length versus message flow Figure 4.10 : Components of a Basic Queuing Process Figure 4.11 : Single Server Queue Figure 4.12 : Little s Law Representation Figure 4.13 : Practical set up of Interfacing IP-PBX with MSC through SBC Figure 4.14 : SIP call flow for a call originated from IP- PBX and terminating on cell phone Figure 4.15 : A part of SIP invite message (611) Figure 4.16 : IP-PBX server as a separate network element for managing IP-PBXs Figure 4.17 : Traffic Characteristics per AS Path Figure 4.18 : Use of Network intelligence for Bandwidth optimization Figure 4.19 : Video traffic optimization setup Figure 5.1 : NGN layered structure Figure 5.2 : Distributed architecture diagram Figure 5.3 : SIP to H323 call Setup Figure 5.4 : Call flow for LI during SIP to H323 call Figure 6.1 : IMS Test Setup Figure 6.2: HSS Schematic Figure 6.3 : PCSCF Schematic Figure 6.4 : Experimental setup flow for kickstart ix

11 List of Tables Table 3.1 : Tandem Coding Performance of Some PSTN Narrowband Codecs Table 3.2 Tandem Coding Performance of Some PSTN Narrowband Codecs Table 3.3 : Characteristics of Wideband Speech Coding Standards for PSTN Table 3.4 : 3G Characteristics Table 4.1 : Session Control Functions Table 4.2 :Media Gateway Functions Table 4.3 : Interworking Nodes Table 4.4 : Application Nodes Table 4.5 : SDR Servers Table 4.6 : SDP Servers Table 4.7 : Support Network Elements Table 4.8 : Mapping table at MSC end Table 4.9 : Video Call packet analysis Table 6.1 : Hardware tuning HSS Table 6.2 : Tuning and Performance Data Table 6.3: Hardware tuning - PCSCF Table 6.4 : Tuning and performance optimization PCSCF x

12 Acknowledgements The endless thanks goes to Lord Almighty for all the blessings he has showered upon me. During the period of my research I have been blessed with some extraordinary people who have spun a web of support around me. Words can never be enough in expressing how grateful I am to those incredible people in my life who made this thesis possible. I am deeply indebted to my research supervisor, Professor Dr. Sanjay Nalbalwar for presenting me such an interesting thesis topic. Each meeting with him added invaluable aspects to the implementation and broadened my perspective. He has guided me with his suggestions, lightened up the way in my darkest times and encouraged me a lot in the academic life. From him I have learned to think critically, to select problems, to solve them and to present their solutions. I would like to thank him for furthering my education in many subjects like probability theory, Computer network, Telecom networks and Multirate Signal Processing. His drive for scientific excellence encouraged me to go for research in the latest research area of my interest. Sometime we are just (or incredibly) lucky!!! To get such wonderful, inspiring and motivating Guide. It was a great pleasure for me to have a chance of working with him. I consider it a great honour to have been part of Rancore lab, and I salute the efforts of my Mentor Mr. P.K. Bhatnagar for his contributions towards furthering the cause of Indian innovations in Telecommunication world. He has always been an inspiration and source of motivation for me to continue striving for research and keep learning. I would like to thank Mr. K. T. Subramanian for His invaluable support and guidance. Subramanian Sir has given me confidence and encouraged me xi

13 to continue the research work. My deep gratitude towards Prof. G. R Sreenivasan for his support and encouragement. I would also like to thank Mr. Kuppu Sridhar for His valuable suggestions and all the technical discussions. I would like to convey my gratitude to Prof. Dr. S.B. Deaosarkar for His precious inputs and suggestions. It is with sincere gratitude that I wish to thank Dr. Milind Pandey, Dr. J.W.Bakal, Dr.Sandeep Inamdar, for being particularly supportive during times of need. I take this opportunity to dedicate this work to my parents who have made me what I am, wife and children who have given consistent support throughout my research, and my guide who have shown faith in my work and enthusiasm. I will be failing in my duty if I don t acknowledge some of my friends who had helped me to continue my research work. I would like to thank Mr. Aayush Bhatnagar for giving insight of many telecom protocols in IMS. I would like to mention my sincere thanks to Mr. Atul Agrawal and Mr. Amrish Bansal for their Support and co-operation. I would like to mention my special thanks to Mr. Anup Patil for his invaluable inputs, critique and long discussions on the research topic. His quality of deep diving in to the subject has motivated me a lot. My sincere thanks to Prof. Shankar Nawale for his support and encouragement during the research. There are so many known or unknown individuals, who have helped me directly or indirectly in this period. It is impossible to name each and every one. My sincere thanks to all of them. Munir Bashir Sayyad xii

14 Declaration by the Candidate I hereby declare that the work being submitted in this thesis titled Next Generation Telecom Network Optimization in partial fulfilment for the requirements for the award of degree of Doctor of Philosophy and submitted in the Department of Electronics & Telecommunication Engineering, Dr. Babasaheb Ambedkar Technological University, Lonere-Raigad, is an authentic record of my own work carried out during the period from 4 th July 2009 to 20 th July 2013 under supervision of Prof. Dr. Sanjay L. Nalbalwar (Head of the Department of Electronics & Telecommunication Engineering, DBATU, Lonere). The matter presented in this thesis has not been submitted for award of any other degree of this or any other University /Institute. Munir Bashir Sayyad Name of the Candidate: Munir Bashir Sayyad Registration No.: This is to certify that the above declaration made by the candidate is correct to the best of my/our knowledge and belief. Dr. S.L Nalbalwar (Supervisor) xiii

15 Acronyms AKA AS BG Authentication and Key Agreement Application Server Border Gateway BGCF Breakout Gateway Control Function CDR CS Charging Data Record Circuit Switched CSCF Call Session Control Function CSR Cell Site Router DHCP Dynamic Host Configuration Protocol DNS DRA Domain Name System Diameter Routing Agent ENUM E.164 Number Mapping GMLC Gateway Mobile Location Centre HSS IBCF Home Subscriber Server Interconnection Border Control Function I-CSCF Interrogating-CSCF IETF IMS IMSI IN IP Internet Engineering Task Force IP Multimedia Core Network Subsystem International Mobile Subscriber Identifier Intelligent Network Internet Protocol IPv4 Internet Protocol version 4 IPv6 Internet Protocol version 6 IP-SM-GW IP Short Message Gateway ISDN ISIM Integrated Services Digital Network IMS SIM xiv

16 ISUP ISDN User Part IWF Interworking Function MGCF Media Gateway Control Function MME Mobility Management Entity MRFC Multimedia Resource Function Controller MRFP Multimedia Resource Function Processor NAI Network Access Identifier NAPT Network Address Port Translation NAT Network Address Translation NA(P)T-PT Network Address (Port-Multiplexing) Translation-Protocol Translation NPDB Number Portability Database NTP OCS Network Terminal Point Online Charging System OFCS Offline Charging System OIP OIR Originating Identification Presentation Originating Identification Restriction P-CSCF Proxy-CSCF PCC Policy and Charging Control PCEF Policy and Charging Enforcement Function PCRF Policy and Charging Rules Function PDN PDP Packet Data Network Packet Data Protocol e.g., IP PLMN Public Land Mobile Network PSI Public Service Identity PSTN Public Switched Telephone Network PSAP Public Safety Answering Point QoS RFC Quality of Service Request for Comments xv

17 SAEGW SAE Gateway SCS Service Capability Server S-CSCF Serving-CSCF SDP SLF SSF Session Description Protocol Subscription Locator Function Service Switching Function SS7 Signalling System 7 SIM SIP Subscriber Identity Module Session Initiation Protocol S-GW Signalling Gateway THIG Topology Hiding Inter-network Gateway TIP TIR Terminating Identification Presentation Terminating Identification Restriction TrGW Transition Gateway xvi

18 Abstract The emergence of convergence created a need to articulate altogether different telecommunication architecture. Application Convergence, Services Convergence and Network Convergence are to be considered while preparing the converged network architecture. The Legacy network architecture does not support multiple services and functions which are becoming necessary today (Voice, Video and Data etc.). At the same time internet architecture is evolving to provide some blended converged services but do not comply with telephony service architecture and regulations. The telecommunication technologies evolution was planned by many standardization bodies across the world like 3GPP, 3GPP2, ETSI, ARIB etc. Each one of them has proposed different ways and means to get high throughput at the user end with various methods. Also the methods vary on the basis of services provided at user end. But the concept of convergence and planning of providing all services like voice, video and data at user end gives rise to various possibilities and many technical challenges as well. The presented research work focuses on the problems of converged architecture of Next Generation Telecommunication Network. This work focuses on End to End Network optimization in particular. As the Next Generation Telecommunication Network will be completely heterogeneous in nature and a different approach is required for its optimization. The research work also incorporates the access agnostic IP Multimedia Subsystem in NGTN. The use of IMS also creates multiple possibilities to optimise the network. This becomes a special case of NGTN optimisation as well. The test setup of open source IMS was created to realise various scenarios. Novel method of Lawful Interception Monitoring is proposed to provide adequate security and comply the NGTN with regulatory procedures. Attempt is made to optimise end to end Next Generation Telecommunication Network by taking 360 degree view of the network. RF optimization, Backhaul optimization, Core Network and System Optimization methods are generalised. Use of network intelligence is done as much as possible to make adaptive optimization reality in heterogeneous network environment. While thinking of next generation xvii

19 telecommunication network special consideration is given to keep legacy network functioning intact. Bandwidth Consumption aware and call status aware type of optimization methods are introduced in the Network for Self-healing of the network. Traffic segregation at system end and deep packet classification at network end are the concepts introduced for network optimization. Network Optimization performance matrix is prepared along with the predefined KPI s and drills down work flow analysis structure is proposed for effective manageability of the NGTN. Thus the thesis is concluded and dedicated for end to End Optimization of NGTN. xviii

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