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Efficient Multimedia Transmission over Wireless Sensor Networks

Shahbazi, Moloud | 2010

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 40808 (19)
  4. University: Sharif University of Technology
  5. Department: Computer Engineering
  6. Advisor(s): Movaghar Rahimabadi, Ali
  7. Abstract:
  8. One of the basic characteristics of Wireless Sensor Networks is their resource limitations. As a result, it is essential to try to decrease costs in such networks. These limitations are more critical in transmitting multimedia data with larger data units. In addition, when transmitting real-time multimedia data, delay is an important factor to consider. According to these limitations, Wireless Multimedia Sensor Networks are congestion prone. In this thesis, a transport layer protocol has been proposed. This protocol consists of three three steps in handling congestion. First, it detects congestion according to the queue length in the node. If the lsength is greater than a minimum threshold, in the second step, it sends a congestion packet toward source node in backward channel. Finally, when the source receives the congestion packet, it regulates the Video Source Coding rate according to the congestion value which is the length of congested queue. The NS2 simulation results show a significant performance in the directed diffusion algorithm while using this protocol. Also, we add a cache management in this protocol to record transmitting frames in intermediate nodes according to their valid time expiration. This adds the ability to reply fast to retransmission requests. As a result the general performance improves. This protocol has been simulated in NS2 simulator as a filter above directed diffusion. The video trace traffic was generated using Evalvid tool. The results have been compared with the directed diffusion algorithm and show an improvement in valid frame received, delay and energy.
  9. Keywords:
  10. Wireless Sensor Network ; Congestion Control ; Memory Management ; Multimedia Traffic

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