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MobiMedia 2006
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Workshops and Special Sessions
Third generation (3G) mobile communication
standards are currently ''on the air'' and, by this, a plethora of multimedia services can be provided to mobile
users with a fair quality. Cellular phones and handsets are now becoming more and more similar to small ''portable
multimedia centers'', so that people often watch TV or surf on Internet walking on foot, traveling by car, bus, train, etc.
Authors: L. Vandendorpe and X. Jaspar
The turbo codes have been first published in 1993. The turbo idea has originally been applied for the purpose of decoding. The encoder is made of the concatenation of two simple codes, separated by an interleaver. At the decoder side, two soft input/soft output modules each take care of one of the constituent codes, and exchange soft information (properly (de)interleaved) in an iterative fashion. Basically this concept of iteratively exchanging soft information can be applied to other functions separated by an interleaver in a communication chain. This observation has lead to the so-called turbo principle. In the present contribution the purpose is to show that this idea can also be applied to the iterative recovery of information which has first been compressed and then encoded, that is to say for the purpose of iterative source/channel decoding. It turns out that the receiver can be optimized to minimize for instance the image error probability. This leads to the computation of marginals; a nice tool enabling to identify how neighbor modules of the receiver should exchange soft information is the sum-product algorithm operating on factor graphs. Thanks to this framework optimized yet of affordable complexity receivers can be designed. Simulations results will be reported, showing the potential of the concept of turbo source/channel decoding.
A Multi-Agent Middleware Architecture for 4G Wireless Networks
Applications and services envisaged for the upcoming 4G system are various and very challenging in terms of Quality of Service (QoS) requirements. To tailor applications and services to any segment (Wi-Fi, Wi-max, UMTS, etc.) of the future wireless heterogeneous system is unconceivable, thereby an attractive solution is to design a Middleware architecture on top of these heterogeneous segments to the aim of a seamless and dynamic adaptation of the end-to-end QoS.
The multi-agent based middleware we propose is able to inter-work with heterogeneous underlying network segments, to provide end-to-end resources, and to automatically trigger changes in the application's characteristics following dynamic variations in the available (wired and wireless) resources. User preferences and profile are also taken into account when negotiating/re-negotiating QoS.
Performance assessment of our multi-agent middleware platform has been carried out on a real testbed.
For further information, please contact directly the organizer:
Mobile multimedia services is a hotter topic than ever before. Network operators offer multimedia services over mobile networks but it is still limited to particular devices on specific networks. The delivery of multimedia content to every mobile handset on every mobile network, anytime and anywhere is still a major challenge. Mobile media can be delivered via a multitude of different networks with very different characteristics like cellular networks (WCDMA, HSDPA, 3G MBMS), broadcast networks (DVB-H, DMB) or other networks standards like WLAN or Wimax. Mobile terminals like mobile phones, mobile TVs or handheld computers have different capabilities and characteristics. Consequently, seamless interworking between these terminals and networks is becoming more important in order to make uniform media delivery possible. New mobile multimedia services for large user groups like MobileTV, interactive TV, video on demand, TV chatting and multimedia telephony are arising. Each service has its own
characteristics and demands for mobile media delivery. As always for mobile services spectrum efficiency is a pre-requisite for large scale deployment.
Important dates:
Symposium Co-chairs: Stefan Håkansson - Ericsson, Sweden (M-Pipe) Publicity chair: James le Blanc - Lulea University of Technology, Sweden
International Program Committee (approval pending):
Today Broadband Wireless access (mobile/nomadic) is emerging to offer outstanding opportunities. In this new world of communicating devices, the evolution towards ubiquitous networking is promising new paradigm with the aim of providing communication capability all the time, everywhere, transparently and invisibly to the user, using devices embedded in the surrounding physical environment. The implementation of such a paradigm requires innovation in wireless network technologies and devices, development of infrastructures, enablers supporting enhanced features for ubiquitous capability.
Submission Dates:
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 Last update: 09/12/2006 
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