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University: Heriot-Watt University
Professor: Dr. Cheng-Xiang Wang
Department:
School of Engineering & Physical Sciences

   

Research Project: Higher Layer Synchronization in Ultra Wideband Networks

Researcher: Margaret Anyaegbu
Supervised by:
Dr. Cheng-Xiang Wang (Heriot-Watt University)

 

Background | Model Description | Publications |


BACKGROUND

Real-time video streaming over UWB links is an important application e.g. for wireless home entertainment systems.  The generic network model for this application scenario consists of a video server streaming packets to multiple end devices (e.g. multiple loudspeakers) over Ethernet and UWB links, as illustrated below.

 

 

 

For such applications, there are two key QoS requirements. The first requirement relates to minimizing the effects of the jitter which occurs when consecutive packets experience different delays as they traverse the UWB links. A jitter buffer is typically used to satisfy this requirement but depending on the amount of delay experienced by packets, a larger, more expensive buffer might be required.  The second requirement is for synchronized playback for the entire system when multimedia applications are streamed to multiple devices, in order to prevent distortion and guarantee a satisfactory Quality of Experience for the end user. Higher layer clock synchronization (i.e. synchronizing the clocks at the server and end devices) is the only way to achieve the second requirement, and it can also relax the requirements of the jitter buffer.

 

The goal of this project, which is under development in OPNET environment, is to evaluate the performance of some synchronization algorithms in a UWB network. In order to achieve this, we are developing a simplified UWB OPNET model.

 

MODEL DESCRIPTION

The figures below illustrate the UWB node model and the UWB MAC process model being developed as part of our research:

 

 

 

The MAC process model is a simplified version of the ECMA-368 UWB standard. For the moment, we focus only on the parts of the standard that are relevant to our research. The model assumes that the network is operating in an active quiescent state at the start of every simulation, i.e. a beacon group has been formed, operating channels have been assigned, hard DRP reservations have been negotiated, and the devices are ready to start transmitting and receiving over these reservations.


PUBLICATIONS

[1]        M. U. Anyaegbu, A. Weir, and C-X. Wang, “Higher layer synchronization in an ECMA-368 Ultra Wideband network,” ICUWB 2010 IEEE International Conf. on Ultra-Wideband, vol. 2, pp. 1 - 4, Sept. 2010.

 

 

 

 

 

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This page was last modified on 13 October 2011.