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1 Kommunikatsiooniteenuste arendus IRT0080 Loeng 11/2008 Avo Ots telekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst. avo.ots@ttu.ee
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2 Many Radios...Limited Spectrum Near Field Communication 60GHz UWB Bluetooth WiMAX Wi-Fi A,B,G,N 3G TV- DVB GPS FM
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3 Use Cases Many applications including … –Delivering multiple HD streams to several receivers –Displaying stored digital contents from media servers to display devices –Browsing contents in distributed devices through big screen TVs Home PC STB (Cable TV access) DTV Wireless AP (Internet gateway ) Digital camera Camcorder PMP DVD player Projector Home theater (AV receiver) 3
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4 Multicast – Content server multicasts multimedia streams to many authenticated users. – Regardless of how many users receive the streams, a single WLAN channel is expected to be used. – Content server can be STB, PC, AP, or even any portable devices. PMP Laptop PCAP STB (Cable TV access ) Home PC PMP Laptop PC PMP 4
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5 One TS contains audio, video, data TS Header (4 bytes) has an adaptation field control. This is used among other things to identify the presence of PCR (Program Clock Reference) following the header.
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6 Codec Bit rate (Mbps) Loss period (# of IP packets) Acceptable average PER (Packet Loss w/zero retries) MPEG-2 (HDTV) 15.024<= 1.17 E-06 1727<= 1.16 E-06 18.129<= 1.17 E-06 MPEG-4 (HDTV) 814<= 1.28 E-06 1017<= 1.24 E-06 1220<= 1.22 E-06 6 Max duration of an error event <= 16 ms; 1 error event per 4 hours Max video/audio delay < 200/50 ms; max jitter < 50 ms Parameters* * From TR-126 www.dslforum.org
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7 Multi-Radio Concurrent Usages WiMAX Coverage Wi-Fi Coverage Bluetooth Coverage in home / office on the road Seamless Handover Wireless Gateway
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8 Wi-Fi / WiMAX /Bluetooth Wi-Fi (802.11g)WiMAX (802.16e) Bluetooth Range100m1000m3m Bandwidth20MHz10MHz1MHz Media AccessCSMAOFDMATDMA Peek Data Rate54Mbps64Mbps (2x2)3Mbps QoS SupportLowHighMedium SpectrumUnlicensedLicensed / Unlicensed Unlicensed TX Power20dBm24dBm0dBm Wireless technologies have different sweet spots of operation in terms of coverage, QoS, power, throughput, etc.
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9 Inter-Radio Interference GPS UWB BT CDMA 1800 GSM 800 Wi-Fi WiMax UWBBT CDMA180 0 GSM 800Wi-FiWiMax Isolation Requirements Severe Moderate Cautious No-problem >55db 40-55db 25-40db <25db Motivation Interferer Victim
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10 Link http://www.compression.ru/video/quality_measure/ind ex_en.html
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