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TelecomunicazioniDocente: Andrea Baiocchi

DIET - Stanza 107, 1° piano palazzina “P. Piga” Via Eudossiana 18

E-mail: [email protected]

University of Roma “Sapienza”

Corso di Laurea in Ingegneria Gestionale A.A. 2017/2018

DIET

Telecomunicazioni - a.a. 2017/2018 - Prof. Andrea Baiocchi

!2

Il piu’ e’ ancora da scoprire… Il più bello dei mari è quello che non navigammo. Il più bello dei nostri figli non è ancora cresciuto. I più belli dei nostri giorni non li abbiamo ancora vissuti. E quello che vorrei dirti di più bello non te l'ho ancora detto.

[Nazim Hikmet, Salonicco 1901 - Mosca 1963]


!3

I’d like to make a call…

GUI contacts security credentials mic, display (AV Codec)

…then I open an app on my laptop and select the contact of Lena…


!4

But I am running also other apps!Email WhatsApp Cloud storage (e.g., Dropbox) …

I need to multiplex the information flows to/from many apps into my single network interface.


!5

Now I am ready to send packets……but there is a network out there! And I’d like to share node and link capacity with others!

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Addressing Multiplexing Routing


!6

I know the route, now I have to hop…Encapsulate the packet in the link data unit and send across the link,…but it can fail!

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Error control (ARQ) Sequencing Flow control


!7

Wait a minute: the link is shared!I need rules to coordinate with other data unit sources and share the capacity of the channel

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Carrier sensing Defer Back-off

That’s me!


!8

Now the link is mine (for a while)I can finally transmit the bits that form the data frame that encloses the data unit that encapsulates the packet the embeds the transport segment…

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TX chain: DAC clock channel coding modulation shaping power RF


!9

I am on the air at last…… but there is a long way to go!

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