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@PHDTHESIS{Mertz:64341,
      author       = {Mertz, Frank},
      othercontributors = {Vary, Peter},
      title        = {{E}fficient audio communication over heterogeneous packet
                      networks with wireless access},
      address      = {Aachen},
      publisher    = {Publikationsserver der RWTH Aachen University},
      reportid     = {RWTH-CONV-125664},
      pages        = {XIV, 238 S. : graph. Darst.},
      year         = {2010},
      note         = {Prüfungsjahr: 2010. - Publikationsjahr: 2011; Aachen,
                      Techn. Hochsch., Diss., 2010},
      abstract     = {Communication networks are transforming towards all-IP
                      networks with different fixed-line and wireless access
                      technologies (e.g., DSL, UMTS, WLAN). One of the biggest
                      challenges in such heterogeneous packet networks for the
                      realization of real-time services (e.g., Voice over IP,
                      music, and video streaming) is dealing with transmission
                      impairments which include variable packet transmission
                      delays and packet losses. Current systems utilize different
                      techniques to combat these impairments, such as a Jitter
                      Buffer to compensate the variance in transmission delay and
                      reduce jitter based losses, Forward Error Correction (FEC)
                      to recover lost frames, and Packet Loss Concealment (PLC) to
                      estimate unrecoverable frame losses. An issue which has not
                      yet been sufficiently addressed is how to choose the best
                      suitable methods and parameterize them optimally for a given
                      scenario of application and transmission channel. This
                      dissertation develops a new methodology to analyze and
                      determine the most suitable FEC method for a given
                      transmission scenario. This approach aims at the best
                      possible transmission quality by considering both signal
                      quality and end-to-end delay. The main results include: a
                      new channel model for packet losses which is based on the
                      Gilbert-Elliott model and can be adapted for different
                      packet sizes and transmission intervals; analytical
                      determination of residual frame loss probabilities after
                      erasure correction for different FEC methods based upon the
                      new channel model; fair comparison of methods with different
                      packet sizes and transmission intervals given the
                      adaptability of the new channel model; derivation of optimal
                      system parameters by applying the newly developed
                      methodologies to real-life scenarios of speech and music
                      transmission in UMTS, WLAN, and heterogeneous packet
                      networks. Furthermore, new PLC techniques for state-of-art
                      speech codecs are developed, which are particularly suitable
                      for wireless transmission channels. In particular, the
                      estimation of lost codec parameters is improved by
                      transmission of low-rate side information in following
                      packets. By utilizing steganographic methods, this side
                      information can be transmitted as hidden bit stream in the
                      encoded bits of the following frame, thereby requiring no
                      additional data rate.},
      keywords     = {Internettelefonie (SWD) / Streaming <Kommunikationstechnik>
                      (SWD) / Vorwärtsfehlerkorrektur (SWD) / Fehlerverdeckung
                      (SWD)},
      cin          = {613310},
      ddc          = {620},
      cid          = {$I:(DE-82)613310_20140620$},
      typ          = {PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:hbz:82-opus-35908},
      url          = {https://publications.rwth-aachen.de/record/64341},
}