wimax

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Multimedia Streaming in WiMAX Networks

This project studies multimedia services in the emerging WiMAX networks. We look into efficient multimedia broadcast framework over mobile WiMAX networks utilizing the MBS and sleep mode features, in particular, broadcasting multiple scalable video streams to mobile receivers. We study problems like maximizing the quality of video at mobile receivers, minimizing energy consumption at mobile receivers and other related problems. Although some of the currently deployed WiMAX networks are mostly used to provide wireless Internet access to subscribers, the WiMAX standard supports various network services. One of these services is the Multicast and Broadcast Service (MBS), which can be used to deliver multimedia traffic to large-scale user communities. It is expected that more WiMAX deployments will offer mobile multimedia services in the near future.

Although considerable amount of work has been done to make these deployments a reality, several research problems remain to be addressed in order to optimize the quality of the offered multimedia services. Our research is concerned with addressing two important problems in multimedia streaming over WiMAX networks: 1) maximizing the video quality and 2) minimizing energy consumption for mobile receivers. We consider broadcasting multiple scalable video streams to mobile receivers. Because of their flexibility, scalable video streams can efficiently support heterogeneous receivers, adapt to network conditions, and utilize the available wireless bandwidth. The problem of selecting the best set of substreams (or layers) from the scalable video streams in order to maximize the quality for mobile receivers is an NP-Complete problem. We propose approximation algorithms that produce near-optimal solutions and run in real time and analytically show that the approximation factor is close to one.

In addition, since many subscribers of the WiMAX multimedia services are expected to be mobile users with energy-constrained devices, such as smart phones, minimizing the energy consumption of these devices becomes an important problem in order to extend the viewing time. To address this problem, we extend our algorithms to reduce the energy consumption of mobile receivers by selecting the best substreams to be transmitted in bursts. This enables mobile receivers to turn off their wireless interfaces for longer periods of time in order to save energy. We construct the burst transmission schedules that reduce the energy consumption without sacrificing the video quality or introducing any buffer overflow or underflow instances. We rigorously evaluate the proposed algorithms using simulation and mathematical analysis.


Contents

People


Publications

  • S. Sharangi, R. Krishnamurti and M. Hefeeda, Energy-efficient Multicasting of Scalable Video Streams over WiMAX Networks, IEEE Transactions on Multimedia, 15 pages, Accepted August 2010.
  • S. Sharangi, R. Krishnamurti and M. Hefeeda, Streaming Scalable Video Over WiMAX Networks, In Proc. of IEEE International Workshop on Quality of Service (IWQoS'10), 9 pages, Beijing, China, June 2010. (Acceptance: 25%)


Discussion and Ideas


Updates from Industry

Multimedia:


References and Links

  • XOHMTM mobile 4G service WiMAX deployment by Sprint [1] (First pay-per-use WiMAX service offered in Baltimore, 2 to 4 megabits per second)
  • S. Ahson and M. Ilyas, The WiMAX Handbook, CRC Press, 2008. Three volumes. V1: Technologies, Performance Analysis, and QoS. V2: Standards and Security. V3:Applications, eCopy of V3 through SFU Library.