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Access Networks

foto : http://www.ctuf.za.org/26telcodirections.htm. Access Networks. lectures 200 8 /0 9 part : 1 Tele communications network. Ing. Ľudmila Maceková , PhD. ludmila.macekova @ tuke.sk Vysoko školská 4, 119A. Access Network (AN)

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Access Networks

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  1. foto: http://www.ctuf.za.org/26telcodirections.htm Access Networks lectures 2008/09 part: 1 Telecommunications network Ing. Ľudmila Maceková, PhD.ludmila.macekova@tuke.skVysokoškolská 4, 119A

  2. Access Network (AN) = the part of communications network, which connects (joins?) users – subscribers, customers to their immediate provider (in PSTN: to the first/ local telecomm. exchange) - so called the “first mile”

  3. AN - The Plan of Lectures • Telecommunications Networks = TN • Access Networks = AN • xDSL Technologies • (ISDN Networks) Telecommnications Networks: - Introduction - abbreviations and some basic terms (their list will be updated step by step) - the term and evolution of TN - structure (architecture) of TN - types (sorts) of TN

  4. Telecommunications - Introduction • telecommunications = interchange (relaying) of information (remote) • the main tasks of telecommunications from the point of view of customers (end-users) • evolution = enhancing of Quality of Services(QoS / p.17) – ... sequential transformation from partially analogous to completely digital networks • the requirements to system from the side of operator ... • history...(fire-light signaling, ..., cipher signalling, electric signals - telephone and telegraph = telecommunications, ...)

  5. Some basic terms in area of AN: • 4-Wire Transport(switching) • duplex • …etc. - see ‘TN_basic_terms.doc’ • a good terminology source - see [4]

  6. Term and evolution of TN • Networkvs. system • TN = ... (nowadays also PC networks) • VoiceTNs = • Evolution ... , digitizing

  7. The sorts of TNs(TN classification)and their differentiation aspects Tab.1

  8. a)...Structure (architecture) of TN – Layer model of TN 7. 6. 5. 4. 3. 2. 1. Intelligent network T M N Signalling network Transmission (transport) network Switching network Access network End devices network Fig. 1

  9. 1.= end devices (=terminals)+ transmission networkconnectingthem to interface (end point of AN)- in the PSTN, it deals with subscribers TN Architecture - continue • 2. . . ........ - subscriber (connecting) net • 3.... - exchanges and interconnection between them, different types of exchanges [1]/p.38-fig.2.12 , terms: switched network, switching, PSTN = Public Switched Telephone Network • 4.(tr.n.)(transport network) ... – transmission systems utilizing (SDH!) a transport media (optical! andothers) • several levels (national transmission n., regional tr.n. ....) • Backbone n.,Core Network = tr.n. + switch.n. • (connections of any-to-any devices on the network)

  10. TN Architecture – continue 2: TMN t.n. SDH, PDH, ATM Tr.n. t.n. t.n. WAN e.n e.n. LAN AN C MD TD TD TD TD TD TD TD TU-terminal device (end d.), K-concentrator, MD–muldex,LAN-local area network, e.n.- end node (terminal n.), t.n.-transitnode, TMN-telecom.management network, SDH-synchr.dig.hierarchy,PDH-plesiochron.dig.hierarchy,ATM-asynchr.transport mode,WAN- wide area network Fig.1The basic parts of both access and transport networks

  11. TN Architecture – continue 3: 5. Signalling network – logical independent, packet oriented net -sig.system CCITT/ITU No.7 6. Intelligent network– IN -(virtual)– the all-network services; they are appended to existing technology; distributed intelligence 7. TMN = Telecomm. Management Network - monitoring and control systems – controling of whole network; under condition of the following the interface and protocols standards

  12. Continue: segmentation (classification) of TNs: b) The transport media - wire vs. wireless (radio waves) Classification of wire media: -according to material: metallic (copper) optical (light conducting) -according to construction.:symetrical vs. assymetrical (…) -further survey: - wire -metallic outdoor (conductiong)media – telephone copper line above earth surface - telephone lines with broadening band -very high voltage power lines - cables - symetrical pairs – LFcopper lines (with load coils – Pupin Coils; pupinization) (additional inductance was required to balance the cable capacitance andto voice signal spectrum flatten; but – disadvantage: HP suppressing →loid coils must be removed /or switched befor DSL - technology installing) -without load coils (unloaded lines) -HF cables - Coaxial cables (asymmetrical lines) – microcoax. - small coax - Waveguides

  13. Transmission lines – continue: Opticalfibres: single-mode fibre (for long distances) - multimode fibres – with stepped index - with graded index s Wireless (radiofrequency) telecomm. media: - microwave lines - tropospheric - stratospheric (HAPS – High Altitude Platform systems) – in developing – comunications airships and small unmanned airplains flowing in the about 17-25 km above earth -satellite

  14. c)user access to network: public or private (closed) networks, branch netw. d) transport an switch equipment (time-, freq.-,apce-, code-division; analogous- digitalor hybrid networks e) Classification accordig to type of terminal equipments: Specialty networks – telephone, telegraph, teleprint, PC – networks, radio broadcasting or TV networks Integrated – based only on digital principles (IDN, ISDN), NISDN, BISDN – the aim: services , economical aim - profit (!)... f) according to creation of connection: fixed network, commuted, unidirect or bidirect network

  15. g) according to transmission type: 2-Wire or 4-Wire • h) according to process of switching: circuit switching or message switching, packet switching, …, virtual channels and virtual network • topology: (see next –Fig.3: spider net, star net, lattice (trellis, grid?) net., combined (mixed) net, tree net, ring -, and line (tandem) net • j)according to evolution (progress) of digitization: digital islands and overlaping nets

  16. Fig.3Some net topology examples

  17. Applications and requirements: access to information sources ... TB parameters: data speed, etc. (Requirements from the side of user: ...) -Quality of Services (QoS)- ... ITU-T G.1000 and - 1010 Tab.2 Basic quality criteria for transport of voice and video information

  18. Tab.3Zákl.kvalitatívne ukazovateľe pre prenos dát [3]

  19. Požiadavky na TS zo strany zriaďovateľov a poskytovateľov služieb: ... • * Pozn: Iný pohľad na štruktúru TS: • Zariadenia sieťových uzlov • -Chrbtová sieť • -Prístupová sieť Ešte niektoré ďalšie druhy sietí v súlade s PC technológiami: TS [3] /13: WAN –rozsiahla.. MAN- metropolitná – súčasť PrS LAN- miestna – v objekte účastníka TS PAN- Personal Area Network- v rámci miestnosti –BlueTooth a IR prenos

  20. References [1] V.Kapoun: Přístupové a transportní síte. VUT v Brně, 1999. [2] Vaculík: Prístupové siete. ŽU v Žiline, 2000. [3] J. Vodrážka: Přenosové systémy v přístupové síti. ČVUT, 2003. [4] L. Harte: Introduction to Digital Subscriber Line (DSL). Technologies, Operation and systems, Althos, 2005.

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