jblanes.bib

@article{SILVESTRE_IE_2011,
  author = {Silvestre, J. and Almeida, L. and Marau, R. and Pedreiras, P.},
  title = {On-line QoS Management for Multimedia Real-Time Transmission in Industrial Networks},
  journal = {IEEE Transactions on Industrial Electronics},
  year = {2011},
  volume = {58},
  number = {3},
  pages = {1061--1071},
  month = {March},
  doi = {10.1109/TIE.2010.2049711},
  issn = {0278-0046},
  isbn = {ISBN-OPTIONAL},
  keywords = {Ethernet, Real-Time communications, Industrial Networks, quality of service},
  note = {},
  key = {},
  abstract = {A growing number of industrial applications incorporate multimedia information processing. These multimedia applications are commonly distributed and subject to time constraints that must be met across networks without creating intolerable interference over typical control flows. However, multimedia traffic, in general, and video streaming, in particular, have specific characteristics that conflict with the operational framework of conventional real-time protocols. In particular, video compressors generate highly variable bit-rate streams that mismatch the constant-bit-rate channels typically provided by real-time protocols, severely reducing the efficiency of network utilization. This paper focuses on low-latency multimedia transmission over Ethernet with dynamic quality-of-service (QoS) management. We propose a multidimensional mechanism that controls, in an integrated way, both the compression parameters and the network bandwidth allocated to each stream. The goal is to provide the best possible QoS to each stream, recomputing the compression levels and network bandwidth whenever significant events, such as channel setup/teardown, or structural changes happen. This paper also presents novel QoS metrics based both on the image quality and network parameters. Several experiments with prerecorded video streams illustrate the advantages of the proposed approach and the convenience of the metrics}
}

@inproceedings{SILVESTRE_ETFA_2007,
  author = {Silvestre, J. and Almeida, L. and Marau, R. and Pedreiras, P.},
  title = {Dynamic QoS management for multimedia real-time transmission in industrial environments},
  booktitle = {12th IEEE Conference on Emerging Technologies and Factory Automation (ETFA'2007) Proceedings},
  year = {2007},
  editor = {},
  volume = {},
  series = {},
  pages = {1473--1480},
  address = {Patras, Greece},
  month = {September},
  organization = {},
  publisher = {},
  doi = {10.1109/EFTA.2007.4416963},
  issn = {},
  isbn = {978-1-4244-0826-9},
  keywords = {FTT-SE, Ethernet, JPEG quantification factor, MJPEG transmission, Bandwidth, Compressors, Condition monitoring, Environmental management, Ethernet, Interference constraints, Machine vision, Protocols, Time factors, Video compression},
  note = {},
  key = {},
  abstract = {The use of multimedia within industrial applications has become commonplace, targetting improved process monitoring and machine vision. In both cases, the multimedia information is commonly distributed and subject to time constraints that must be met across networks while avoiding untolerable interference over typical control flows. This can be achieved with Constant Bit-Rate (CBR) channels, typically supported by real-time protocols. However, the compressors used to reduce the amount of information to transfer generate Variable Bit-Rate (VBR) patterns. Adapting a VBR source to a CBR channel requires specific care in order to avoid wasting channel bandwidth or dropping video frames. This paper focuses on MJPEG transmission over Ethernet and proposes a bidimensional adaptation using the JPEG quantification factor q on the source side and frame acquisition/transmission period T on the source/network side respectively, using the FTT-SE protocol and its support for dynamic QoS management. The paper also shows several experiments with pre-recorded video streams that illustrate the advantages of the proposed approach}
}