OPNET Technologies © 2008 OPNET
Technologies, Inc. |
University: Heriot-Watt University Research Project: Higher Layer Synchronization in Ultra Wideband Networks Researcher: Margaret Anyaegbu |
Background
| Model Description | Publications
|
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.
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.
OPNET Technologies, Inc. is a leading provider of solutions
for managing networks and applications. OPNET's best-in-class
solutions address application
troubleshooting, application
monitoring, network
monitoring, network
configuration management, capacity
management, and network
simulation. OPNET’s solutions have been
operationally proven in thousands of customer environments worldwide, including
corporate and government enterprises, government and defense
agencies, network service providers, and network equipment manufacturers. For
more information about OPNET and its
products, visit www.opnet.com.