C06-Broadcast_Systems - Mobile Communications Chapter 6...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Prof. Dr.-Ing. Jochen Schiller, MC SS02 6.1 Mobile Communications Chapter 6: Broadcast Systems Unidirectional distribution systems DAB architecture DVB Container High-speed Internet
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Prof. Dr.-Ing. Jochen Schiller, MC SS02 6.2 Unidirectional distribution systems Asymmetric communication environments bandwidth limitations of the transmission medium depends on applications, type of information examples z wireless networks with base station and mobile terminals z client-server environments (diskless terminal) z cable TV with set-top box z information services (pager, SMS) Special case: unidirectional distribution systems high bandwidth from server to client (downstream), but no bandwidth vice versa (upstream) problems of unidirectional broadcast systems z a sender can optimize transmitted information only for one group of users/terminals z functions needed to individualize personal requirements/applications
Image of page 2
Prof. Dr.-Ing. Jochen Schiller, MC SS02 6.3 Unidirectional distribution service provider service user sender receiver receiver receiver . . . unidirectional distribution medium A A A A A A A B B B B optimized for expected access pattern of all users individual access pattern of one user
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Prof. Dr.-Ing. Jochen Schiller, MC SS02 6.4 Sender cyclic repetition of data blocks different patterns possible (optimization possible only if the content is known) Receiver use of caching z cost-based strategy: what are the costs for a user (waiting time) if a data block has been requested but is currently not cached z application and cache have to know content of data blocks and access patterns of user to optimize Structuring transmissions - broadcast disks A B C A B C flat disk A A B C A A skewed disk A B A C A B multi-disk
Image of page 4
Prof. Dr.-Ing. Jochen Schiller, MC SS02 6.5 DAB: Digital Audio Broadcasting Media access COFDM (Coded Orthogonal Frequency Division Multiplex) SFN (Single Frequency Network) 192 to 1536 subcarriers within a 1.5 MHz frequency band Frequencies first phase: one out of 32 frequency blocks for terrestrial TV channels 5 to 12 (174 - 230 MHz, 5A - 12D) second phase: one out of 9 frequency blocks in the L-band (1452- 1467.5 MHz, LA - LI) Sending power: 6.1 kW (VHF, Ø 120 km) or 4 kW (L-band, Ø 30 km) Date-rates: 2.304 Mbit/s (net 1.2 to 1.536 Mbit/s) Modulation: Differential 4-phase modulation (D-QPSK) Audio channels per frequency block: typ. 6, max. 192 kbit/s Digital services: 0.6 - 16 kbit/s (PAD), 24 kbit/s (NPAD)
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Prof. Dr.-Ing. Jochen Schiller,
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '08
  • wu
  • Bit rate, Digital television, High-definition television, Multiplexing, Digital Video Broadcasting, Jochen Schiller

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern