08 1 Telephone Networks

Communication
Systems
8th lecture

Chair of Communication Systems
Department of Applied Sciences
University of Freiburg
2006
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Communication Systems
Administrative stuff
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Lecture on 13.06 might be called off. Please check the webpage before the lecture.

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06.06, 08.06, 15.06 are holidays, no lecture, no practical.

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Next practical course is on 22.06, in RZ basement -101.

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Communication Systems
Last lectures
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We started with rather modern communication technologies and introduced the Internet Protocol as a global orientated packet switching network technology
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IP can be run over very different physical media and intermediate protocols

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And IP is used for more and more networked services

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Very popular traditional service is telephony mostly 1:1 voice communication –

With the upcoming “Voice-over-IP” we could observe a merge of both networks

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Communication Systems
Upcoming lectures
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To get an idea how traditional and modern wireless telephony networks work, we give an introduction to ISDN,
GSM and UMTS
First traditional telephony networks its history and their concepts in general
Digitization of voice - PCM
Then introduction to ISDN – a completely digitalized communication infrastructure
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call setup and global routing in telephony networks

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Communication Systems plan for this lecture
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History of telephony networks and wireless information networks

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Line switching

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DTMF – dual tone multi frequency

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Telephony protocol

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Standards in telecommunication

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Digital telephony networks – PCM

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ISDN – Integrated Services Digital Network

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D channel

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DSS1 layer 3 protocol

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Communication Systems
History of telephony networks
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Traditional analogous telephony networks
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1848: State Telegraphy System in Prussia (Siemens)

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1851: First trans-sea cable between Dover and Calais

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1858: Transatlantic line-based telegraphy between Europe and America

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1866: Durable transatlantic cable