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Kommunikatsiooniteenuste arendus IRT0080

Kommunikatsiooniteenuste arendus IRT0080. Loeng 5 Avo Ots telekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst. avo.ots@ttu.ee. Teenusetase (SLA). Reaalajas ( Real-time ) Parim võimalik ( best effort ). Foon E-post alla-laadimine. Interaktiivne veeb. Lubatav viide. Voog

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Kommunikatsiooniteenuste arendus IRT0080

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  1. Kommunikatsiooniteenuste arendusIRT0080 Loeng 5Avo Otstelekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst.avo.ots@ttu.ee

  2. Teenusetase (SLA)

  3. Reaalajas (Real-time) Parim võimalik (best effort) Foon E-post alla-laadimine Interaktiivne veeb Lubatav viide Voog videoloeng Vestlus kõne Liiklusklassid viite järgi Põhiparameetrid Viide Ülekandekiirus Töökindlus

  4. Digitaalne sisu MOBIIL INTERNET I n t e r a k t I I v s u s S E A D M E D DIGI TV Kättesaadavus

  5. Edastuse kvaliteet (QoS)

  6. Kõneviite piirid • ITU G.114 soovitus One WayDelay (msec) Description 0–150 Acceptable for most user applications Acceptable provided that administrations are aware of the transmission time impact on the transmission quality of user applications 150–400 Unacceptable for general network planning purposes—however—It is recognized that in some exceptional cases this limit will be exceeded 400 +

  7. Ainult üks teenus: kõne Host on telefon Palju teenuseid Host tekitab mitu voogu Application telnet, ftp, email Layer Transport TCP, UDP Layer Network IP Layer (Data) Link 802.3, 802.11 Layer Telefoni vs datagrammi teenus Application Telephone Layer Telephone numbering, signaling, routing TelephoneNetwork (Data) Link TDMA Layer

  8. ports p1 p2 p1 p2 p3 p1 p2 A B C Liikluse (de)multipleksimine telnet HTTP ssh Application TCP Transport IP In TCP, a data stream is identified by a set of numbers: (Source Address, Destination Address, Source Port, Destination Port)

  9. Transpordiprotokolli funktsioonid • Multiplexing/demultiplexing for multiple applications. • Port abstraction • Connection establishment. • Logical end-to-end connection • Connection state to optimize performance • Error control. • Hide unreliability of the network layer from applications • Many types of errors: corruption, loss, duplication, reordering. • End-to-end flow control. • Avoid flooding the receiver

  10. Transmission Control Protocol (TCP) • Reliable bidirectional in-order byte stream • Socket: SOCK_STREAM • Connections established & torn down • Multiplexing/ demultiplexing • Ports at both ends • Error control • Users see correct, ordered byte sequences • End-end flow control 0 16 32 Source Port Dest. Port Sequence Number Acknowledgment Number HL/Flags Advertised Win. Checksum Urgent Pointer Options..

  11. TCP lisaomadused ja lipud • Sliding window protocol • Use sequence numbers • Bi-directional • Each host can be a receiver and a sender simultaneously • SYN: Synchronize • Used when setting up connection • FIN: Finish • Used when tearing down connection • ACK • Acknowledging received data

  12. Võrgujõudluse kasutus

  13. Ummistusest tekkinud viide

  14. Ummistuste haldamine

  15. vastuvõtja saatja Värin (jitter)ja sünkroniseerimine • Värin – saabumisaja erinevus • Sünkroniseerimine – tegevuste ajastamine

  16. vastuvõtja saatja Andmevoog (stream) • Paketid peavad jõudma kohale kindlal ajal kindlas järjestuses • Kui ei jõua, siis vastu ei võeta 9 8 7 6 5 4 2 1 3

  17. Len. SP (554) Payload type CRC DP (554) Seq. No Data Data RTP (Real Time Protocol) Timestamp Syncro Source

  18. Transmitter Receiver Leviedastus (Broadcast) • Eesmärgid • Otstarbekas ressursikasutus • Kõrge tunnetatav edastuse (ja kohaletoimetamise) kvalteet

  19. TV stuudio täna Kaamera juht- seade SDI vastu- võtja SDI saatja

  20. Digitaalne ülekanne ja seadmed Online Offline (salvestatud) Võrk Vastuvõtja Meediaseadmed Video serverid

  21. Kujutise mahud (pikselites) 160 352 720 800 1152 1280 1920 QSIF (19Kp) 120 SIF (82Kp) 240 601 (300Kp) 483 SVGA (500Kp) 600 A_TV (1Mp) 720 Workstation (1Mp) 900 HDTV (2Mp) 1080

  22. Halvem kvaliteet Halvem kvaliteet Pakkimise tegur Pakkimise tegur Parem kvaliteet Parem kvaliteet Keerukus Latentsus Kvaliteedi tagamine

  23. Edastuse juhtimine Kvanditud andmed Täis-kiiru-segaandmed Teisendus4:2:2 -> 8-bit 4:2:0 DCT Kvan-timine Entroopiakodee-rimine Puhver Pakitudandmed Info kadu Andme-hulkvähenes Poleinfo kadu Andme-hulksama Andme-hulkvähenes (info kadu) Andme-hulkvähenes (pole info kadu) Infomahu vähendamine (MPEG)

  24. Audio Programm 1 Video PTS/DTS Audio Programm 2 Video MUX PTS/DTS Transpordivoog Transport stream Audio Programm 3 Video PTS/DTS PAT PMT NIT Multipleks

  25. MPEG-2 • ISO/IEC 13818-1 Systems (transport and programs streams), PES, T-STD buffer model and the basic PSI tables: CAT, PAT, PMT and NIT. • ISO/IEC 13818-2 video coding. • ISO/IEC 13818-3 audio coding. • ISO/IEC 13818-4 MPEG test and conformance.

  26. MPEG-4

  27. MPEG-4 lahendusi • MPEG-4 on objektipõhine • Panoraamkujutised – ülisuure pakkimistihedusega – 1000:1

  28. Provider Provider Networks In-home Network In-home Network TV-Anytime Gateway PVR removable media Networks PVR NDR Gateway control/content control DVD service providerscontent providers storage

  29. Defined by the UHAPI Forum Simplifying software development for CE products Application portability over multiple HW/SW platforms Open Source implementation: UHAPI4Linux ISDB-BML content manager web-DVD Pictures discs Video editing EPG OCAP PVR Memory Card Internet Browsing MHP Picture Browsing MHEG Operating System and UNIVERSAL HOME API streaming A/V software streaming A/V software streaming A/V software streaming A/V software Architecture 3 … Architecture 1 Architecture 2 Architecture 4 Company C Company A Company B Company D Universal Home API • Application portability over multiple HW/SW platforms • Open Source implementation: UHAPI4Linux

  30. 4-8 Mbit 1.5-3.0 Mbit 8-12 Mbit IP tv (ülesanne) 100 Mbit FOC4 Mbit DSLDVB-C + IP CPE (Access-Switch) 100 Mbit TP 100 Mbit TP POTS ISDN VOIP Settop Box Scartkabel Telefon TV PC

  31. Lingid http://en.wikipedia.org/wiki/Transmission_Control_Protocol http://en.wikipedia.org/wiki/QoS http://en.wikipedia.org/wiki/H.264 http://en.wikipedia.org/wiki/Real-time_Transport_Protocol http://geocities.com/intro_to_multimedia/RTP/ http://www.cs.columbia.edu/~hgs/rtp/ http://en.wikipedia.org/wiki/MPEG-2

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