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VDSL

VDSL. Access Networks lectures 2008/09 Ľ . Macekov á – KEMT – FEI –TU -KE. 30 MHz. Data down. Data up. Data down. Data up. up to 1,5 km. variable freq.bands. up to 52 Mbps split Upstream and Downstream. Fig.1 – VDSL architecture – max. downstream onl y to 300 m ([6],.

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VDSL

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  1. VDSL Access Networks lectures 2008/09 Ľ.Maceková – KEMT – FEI –TU -KE

  2. 30 MHz Data down Data up Data down Data up up to 1,5 km variable freq.bands up to 52 Mbps split Upstream and Downstream Fig.1 – VDSL architecture – max. downstream only to 300 m ([6],

  3. Tab. 1Data speeds and reach by ETSI (Europe); for wiresΦ 0,4 mm

  4. Fig.2General reference VDSL model (by ITU-T) [1]

  5. Fig.3Functional reference model VTU-x by ITU -T [1]

  6. Fig.4 … by ITU [1]

  7. Asymmetrical traffic VDSL upstream ISDN or POTS VDSL down stream frequency Symmetrical traffic VDSL upstream ISDN or POTS VDSL down stream frequency Fig.5 Symmetrical and asymmetrical VDSL services

  8. telephone spectrum frequency Fig.6 DMT – VDSLspectrum (in combination with analog telephone) [7] Fig.7VDSL downstream (DS) and upstream (US) subbands alocation – generally [1] - see next slide...

  9. Fig.8 The different frequency plans for VDSL by ITU [1] (Opt = Optional(yes/no, DS/US)

  10. Tab. 2An example of VDSL mask in downstreams DS1,DS2 described in standard ITU-T G.993.1

  11. STM – synchronous transport mode Fig. 9 VDSL transport modes possibilities [2]

  12. Fig.10DSL network [6,8]

  13. VDSL2 • - ITU-T G.933.2 (2006) • enhanced VDSL version – the goal: do not lose customers in competitive with “cable” VoIP, Internet, digital TV and VoD-HD providers • freq, band up to 30 MHz • symmetric up- and down- streamseach of 100 Mbps (aggregatedata speed 200 Mbps) • reach to 2,5 km ( US0 band - to 276kHz, EC, TEQs) • several profiles • Zipper DMT (DMT based duplex – subcarrier bands, each 4 or 8kHz wide – from 2048 to 4096 bands – see next fig.) – allocation of subcarriers and data speed adaptation accordingly to immediate requirements of applications on the both sides of line • trellis encoding • STM and PTM supporting • interoperability with ADSL devices, there are also several profiles (8) for different applications – see tab. 3 and fig.12 in the next slides

  14. Fig. 11VDSL2 spectrum utilization and comparison with ADSL2 and ADSL2+ Tab. 3 VDSL2 profiles

  15. Fig.12 VDSL2 profiles in comparison with ADSL and ADSL2+

  16. Tab. 4 VDSL2 profiles[Wikipedia]

  17. Fig. 1ones more comparison ADSL and VDSL: data speeds and reach (4500 f = 1,47 km, 18 000 feet=5,5 km)

  18. other xDSL systems

  19. FDSL – fiber DSL (but also other relevances) Using fiber to span long distance; hybrid technology (optical / copper lines) Fig.15 [5]

  20. PDSL - it was described already [5]

  21. BDSL – Broadcast DSL Subscriber lines Fig.16Architecture of BDSL technology[4] - standard submitted to Committee T1E1.4, - it is dedicated for distribution of more TV (up to several tens) channels, which share transport medium (twisted pairs) with analog teleph. line (point-to-multipoint technology) Analog. signals are digitized, and together with digital TV channels are compressed. There are used 3 subcarriers – 40 kHz, 80 kHz and 1,2 MHz..., DSLAM; ATM technology

  22. References [1] ITU-T G.993.1 Recommendation, 2004 [2] W. J. Goralski: ADSL and DSL Technologies. Sec. Edition.Osborne Mc.Graw-Hill, 2002. [3] ITU-T G.933.2 Recommendation, 2006. [4] Vaculík: Prístupové siete. ŽU v Žiline, 2000. [5] J.Dúha, P. Podhradský, P. Trúchly: Technológie v prístupových sieťach a procesy ich integrácie do NGN. (Projekt: NGN- multimédiá, multimed.ICT technológie,... .) Bratislava, 2007. [6] L. Harte: Introduction to Digital Subscriber Line (DSL): Technologies, Operation and Systems. ALTHOS, 2005. [7] K.Blunár, Z.Diviš: Telekomunikačné siete, časť IV..- skriptum ŽU v Žiline, 2000. K.Blunár, Z.Diviš: Telekomunikačné siete, časť IV..- skriptum ŽU v Žiline, 2000 [8]http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/gsol_dsl/dsl_arch/gdslarch.htm#1002608 [9]http://findarticles.com/p/articles/mi_m0NUH/is_10_37/ai_107759816/pg_1?tag=artBody;col1

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