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Series of lectures “Telecommunication networks” Lecture#9 Concluding session, part I Instructor: Prof. Nikolay Sokolov, e-mail: [email protected] The Bonch-Bruevich Saint-Petersburg State University of Telecommunications Main definition Telecommunication. “Any transmission, emission or reception of signs, signal, writing, images and sounds or intelligence of any nature by wire, radio, visual or other electromagnetic systems“. International Telecommunication Conference, Atlantic City, 1947. Black box Input Output Instructions Reports A(t) D(t) Black box B(t) Controlled subsystem Management C(t) To carry To take Controlling subsystem Communication effectiveness Communication effectiveness 2 people at whiteboard 2 people on phone 2 people on mail Videotape Audiotape Paper Form of communication Telecommunication system Customer Premises Network Access Network Core Network Service Nodes Responsibility of the Telecom Operator This model is proposed by ITU-T for the GII (Global Information Infrastructure). On the other hand, this model is useful for any telecommunication network. Definitions of term “Network” ITU-T, E.164 (2005): Internationally interconnected physical nodes and operational systems operated and maintained by one or more ROAs (Recognized Operating Agency) to provide public telecommunications services. Private networks are not included in this definition. ITU-T, G.998.1 (2005): All equipment and facilities, including loop plant, located on the carrier side of the network interface. ITU-T, G.805 (2000): All of the entities (such as equipment, plant, facilities) which together provide communication services. ITU-T, Y.101 (2000): A set of nodes and links that provide connections between two or more defined points to facilitate telecommunication between them . International Telecommunication Union ITU is the leading United Nations agency for information and communication technologies. As the global focal point for governments and the private sector, ITU's role in helping the world communicate spans 3 core sectors: Radiocommunication, Telecommunication Standardization and Telecommunication Development. ITU also organizes TELECOM events and was the lead organizing agency of the World Summit on the Information Society. ITU is based in Geneva, Switzerland, and its membership includes 191 Member States and more than 700 Sector Members and Associates. ETSI ETSI was created by CEPT (European Conference of Postal and Telecommunications Administrations) in 1988. Based in Sophia Antipolis (France), ETSI is officially responsible for standardization of Information and Communication Technologies (ICT) within Europe. ETSI has 696 members from 62 countries/provinces inside and outside Europe, including manufacturers, network operators, administrations, service providers, research bodies and users — in fact, all the key players in the ICT arena. Maslow's Hierarchy of Needs (1) Abraham Maslow developed the Hierarchy of Needs model in 1940-50s USA, and the Hierarchy of Needs theory remains valid today for understanding human motivation, management training, and personal development. Telephone conversations Maslow's Hierarchy of Needs (2) Telephone communications system "Telephone communications system" term is usually refers to base principles of telephone network’s construction, operation and development. These principles usually include the following positions: •purpose of the system; •supported services; •network structure; •quality of service ratings; •numbering plan; •maintenance; •equipment requirements; •main directions of system development. Revenue distribution Other services International and long-distance communications Mobile communications Internet (access) Local telephone communications Transit of traffic Market evolution Per 100 people Source: ITU 80 70 60 50 Mobile contracts Internet users Fixed telephone lines Mobile broadband access contracts Fixed broadband access subscribers 40 30 20 10 Year 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Distribution of the amount of calls during the day Amount of calls Time of day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 In the PSTN, required bandwidth is identical for any connection. Traffic on a Monday morning Equipment evolution Single-wire line (voice channel) xDSL Two-wire line (voice channel) FTTx . . . BWA Time XX century Switchers Manual exchange XXI century Step-by-step exchange Crossbar exchange Digital exchange NGN Time XX century XXI century Broadband channel Access Networks Distribution box Phone jack Terminal Access network (1) Main distribution frame Distribution cabinet Multipair cable 20% 80% Distribution box Phone jack Terminal a) model of the old subscriber line 20% Main distribution frame Remote module Fiber optic cable conversion “о/е” and “е/о” 80% b) model of the modern subscriber line Terminal Distribution box Terminal Distribution box Access network (2) Distribution cabinet ADSL (up to 8 Mbit/s) or ADSL2+ (up to 24 Mbit/s) Main distribution frame Remote module Fiber To The Remote (FTTR) e.g. VDSL2 (up to 100 Mbit/s) LR Terminal Fiber To The Premises (FTTP) LP BP>100 Mbit/s Optical fiber Spectral range First data transmission systems for the mainframe Data Link Mainframe Mainframe a) Connection between two mainframes Terminal Subscriber Line Terminal Subscriber Line Mainframe Terminal Subscriber Line b) Connections for terminals Traffic growth Internet (RFC 3935 ) The Internet: A large, heterogeneous collection of interconnected systems that can be used for communication of many different types between any interested parties connected to it. The term includes both the "core Internet" (ISP networks) and "edge Internet" (corporate and private networks, often connected via firewalls, NAT – network address translation – boxes, application layer gateways and similar devices). The Internet is a truly global network, reaching into just about every country in the world. The IETF community wants the Internet to succeed because we believe that the existence of the Internet, and its influence on economics, communication, and education, will help us to build a better human society. Example of the Internet network structure AS1 AS2 AS3 AS5 AS4 AS – Internet autonomous system Interconnection of two local networks R R R R LAN LAN R R R R R R – router, LAN – Local Area Network Forecast of the access demands Households, % 100 80 Sources: Alcatel Telecommunications Review, 2nd Quarter 2003, Telektronikk, Volume 100, No. 4, 2004. 100 Mb/s 60 24 Mb/s 40 6 Mb/s 1.5 Mb/s 20 Year 1995 2000 2005 2010 2015 2020 2025 Internet in our life Research company “Yougov” carried out survey among broadband Internet users in Great Britain. The main goal was to define goods and services that citizens will be eager to sacrifice during economic depression. Approximately 3% of the respondents were ready to save money by limiting expenses on Internet access. About 30% of respondents (near 5 million) were ready to cut down expenses related to newspapers & magazines, alcohol, cigarettes but will use Internet. On the other hand, only 60% of respondents were going to use services from their Provider. Remainder will find Provider with inexpensive services. Cellular topology with seven different frequency ranges D R F6 F7 F5 F1 F4 F6 F2 F3 F7 F5 F1 F4 F2 F3 Handover and roaming Network 1 Network 2 BS12 T BS11 BS13 BS21 ... MSC1 MSC2 Interworking functions CO1 PSTN Main elements of the network Intra-network interfaces Air interface Mobile terminal Switching subsystem Radio subsystem Internetwork interface Other network(s) Interfaces MSC – mobile switching center MS – mobile station F BTS – base station BSC – base station controller EIR – equipment identification register EIR E MSC A Abis BSC Um C MSC B D HLR BTS MS-SIM MS SIM – subscriber identity module HLR – home location register SIM VLR – visited location register VLR G VLR Typical structure of the radio and television broadcasting networks Main Center Main path Main path Main path Regional Center Standby path Regional Center Served area Local Centers Regional Center Classification of the television broadcasting systems Television broadcasting On-air broadcasting Cable television Satellite television Combined system Standard quality television One-way broadcasting Analogue channels High definition television Interactive television Digital channels Cycles in the telephone communication development Milestones of telephony development Emergence of the telephone communications Time 80s of the XIX century Automation of the telephone communications network Utilization of the program control 20s of the XX century 60s of the XX century Transition towards packet transmission and switching technologies Beginning of the XXI century The main goal is the real demands of each customer! The Death of Distance *) Falling costs 100 Transatlantic telephone call 80 Ocean freight Satellite charge 60 Air transport 40 20 Year 0 1920 1930 1940 1950 1960 1970 1980 1990 Source: World Development Report 1995, World Bank *) F. Cairncross. The Death of Distance. – Harvard Business School Publishing, 1997. Integration, convergence, and consolidation (1) Integration is aggregation or interpenetration. In some cases, integration is considered as creation of the relationships. Convergence is a process by which unrelated organisms independently acquire similar characteristics while evolving in separate ecosystems. In telecommunications (according to ITU-T Q.1761), coordinated evolution of formerly discrete networks towards uniformity in support of services and applications. It means convergence is approximately the same as integration. Consolidations is a reasonable combination of the integration and convergence. Integration, convergence, and consolidation (2) Typical example of integration is ISDN (Integrated service digital network). One network supports the services that were previously provided by number of the existing networks. Typical example of convergence is the functions of the fixed and mobile networks. Mobile networks support the Internet access. Fixed networks provide the SMS transfer. Typical example of consolidations is utilization of the common cable lines for the transmission of the different information (voice, data, video). Integration, convergence, and consolidation (3) ITU, Recommendation Q.1702, Converged services: The integration of Internet, multimedia, e-mail, presence, instant messaging, m-commerce, etc., services with voice service. Sometimes term “convergence” is used instead of word “integration”. Term “integration” was attractive during elaboration of the ISDN concept. Market of the ISDN mostly was not successful. For this reason, number of experts use term “convergence”. Global Information Infrastructure (1) A collection of networks, end user equipment, information, and human resources which can be used to access valuable information, communicate with each other, work, learn, receive entertainment from it, at any time and from any place, with affordable cost on a global scale. Source: ITU-T, Recommendations Y.101 and Y.110 Global Information Infrastructure (2) Driving forces: 1. Two predominant factors distinguish a situation for the Global Information Infrastructure (GII) which is likely to be radically different from previous information infrastructures. These two factors are: -the convergence of technologies in use within telecommunications, computers, consumer electronics and the move of content provision industries towards digital technology; - new business opportunities, created by the unbundling of services made possible or necessary by deregulation, and other commercial and/or open market pressures. 2. Digitalization (All forms of information, including voice, data or video/image, are simply reduced to streams of digital bits for transfer over a bit-way (or digital network). This represents a possible decoupling between networks and their payloads). Global Information Infrastructure (3) Driving forces: 3. Value chain models and business opportunities. The following properties of an added-value chain are relevant to ITU-T standardization work: a) Every link and item in an added-value chain, from content to user or user to user, potentially represents a possible business opportunity. b) Every link in the chain establishes sufficient demarcation points to facilitate potential separate ownership and operation to be realized within the context of the entire chain. c) a) and b) are sources of requirements for the definition of standards-based functions and/or interfaces. This model can be used to represent a competitive telecommunications and information provision environment, involving the interconnection of networks in parallel or in series, as well as systems which enhance or modify information content. Global Information Infrastructure (4) Definition of the NGN http://www.itu.int/ITU-T/studygroups/com13/ngn2004/working_definition.html A Next Generation Network (NGN) is a packet-based network able to provide services including Telecommunication Services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. Next generation network model CU2 CU1 CU3 CU4 TS1 TS2 PS5 PS7 PS2 PS1 PC1 PS3 PS4 PS6 PS8 PS9 Local Network 2 Local Network 1 Long-distance network CU – control unit, PS – packet switch, TS – telephone set, PC – personal computer PC2 Integration of the existing telecommunications networks NGN Telephone networks Data transmission networks Broadcasting networks Process of the forming of the NGN Forming of the NGN “Saturation” stage Active development stage Initial stage Time T0 TI T2 T3 Points of the technology change under transition to the NGN TS TS Local network with channels switching A B Local network with channels switching Long-distance IP network TS TS G C E IP-TS Local IP network D Local IP network International International network IP network with channels switching F IP-TS Network structure. Some definitions Network structure Term is used to describe the method of how data on a network is organized and viewed. Network architecture Also referred to as the network model, the network architecture is the overall structure of how a network is laid out. The network architecture is commonly drawn out as a diagram for a visual representation of the overall network. A well designed network architecture helps prevent network bottlenecks and various other issues. Some authors use term “topology” instead of the word “architecture” because term “architecture” is widely applied in the publications concerning telecommunication protocols. Examples for the graph with six nodes a2 a2 a3 a3 a1 a1 a4 a4 a6 a6 a5 b) Tree a) Star a2 a2 a3 a1 a1 a5 c) Ring a3 a4 a4 a6 a5 a6 a5 d) Full mesh Oriented, unoriented and mixed graphs a2 a1 c23 a4 a6 l23 a2 a3 a2 a3 a4 a) Oriented graph a6 a5 b) Unoriented graph a1 l l a3 a2 l a5 c) Mixed graph Example of finding the Steiner point l 3 a3 a4 a6 a5 r23 Two variants of the ring network construction a2 a2 a3 a3 a1 a1 a4 a4 a6 a5 a) First structure of transport network a6 a5 b) Second structure of transport network Example of the several rings creation 7 2 5 11 ∞ ∞ 9 4 12 1 6 8 10 3 0 Transformation of the optimization problem (1) Ring I Ring I TS TF Ring II Ring III Subscript “s” – start, subscript “f” – future Ring II Transformation of the optimization problem (2) p7 << p5 a2 a2 a5 TX a1 a3 ed et el a3 D a1 g ed e p6 → 1 a4 a7 a6 a4 P7 → 0 Rational decision Capital expenditures Upper bound Designed value Actual data Time TX Cost-performance compromise If π is very small (e.g. 0.1%) cost of the network will be high. For this reason, cost of service will be supernormal. The number of the users will be small. If π is very high (e.g. 50%) cost of the network will be relatively small. On the other hand, quality of service will be poor. For this reason, the number of the users will be small as well. It is obvious there is cost-performance compromise. Therefore we have to define optimum value of the π. This task is the main one among problems of the network planning. Improvement of the network characteristics Network planning Performance measurement Network tuning Performance analysis Concluding session, part I Questions? Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]