Robust and Adaptive Protocol Design for Multimedia Wireless Networks
A Stanford Networking Research Center Project
The main theme of our proposed work is to design a robust and
adaptive protocol suite to insure reliable and high-quality
end-to-end performance in wireless multimedia networks. We propose a
three-fold approach to achieve this goal: distributed cross-layer
adaptive protocols, network diversity, and network scheduling. Our
previous work has shown that the variability and volatility of
wireless networks can be exploited by adapting to the wireless link,
network, and application dynamics. Such adaptation is typically only
feasible if it can be done in a distributed manner. We have also
shown transmission scheduling to be a powerful mechanism to insure a
given performance level and optimize network resource utilization
given underlying network dynamics. However, wireless networks
inherently maintain some uncertainty that cannot be adapted to or
scheduled around. We propose to conquer this uncertainty by
developing diversity techniques for each layer of the protocol
stack. Network diversity is a new and innovative research thrust for
network design. Diversity in wireless links - using multiple antennas
to reduce the random variations due to multipath fading - has been
exploited for several decades, yet the basic concept of diversity has
not typically been used in other layers of the network protocol
stack. We propose to develop network diversity techniques that
include access diversity, path diversity, content location diversity,
application diversity, and resource diversity. These diversity
techniques will provide robustness to random variations at each layer
of the network protocol stack, and will also be integrated with
adaptive techniques at each layer. Diversity also provides enhanced
network security and reliability in addition to robustness. We will
also continue work on adaptive cross-layer protocol design to jointly
adapt and optimize the behavior of individual protocol layers to each
other. Specifically, we will explore link adaptation, dynamic
allocation and management of network resources, and application
adaptation. Our work in this area will mainly focus on distributed
adaptive techniques. We will also study the integration of network
diversity with adaptive protocol design. Our prior work has shown
that scheduling provides robust and efficient performance in wireless
networks. Scheduling insures sufficient resources will be available
in the network to meet the performance requirements (e.g. rate and
delay) of a given application. It can also be used to minimize the
energy requirements in the network. We plan to extend these results
to develop and analyze new and innovative scheduling techniques that
maximize efficiency and robustness in multimedia wireless
networks. Our proposed work will have a high impact on wireless
network design. It is now well-recognized that cross-layer design is
critically needed to insure continuity, robustness, and good
end-to-end performance in multimedia wireless networks. Yet, this is
a highly complex design problem that requires multiple levels of
expertise across the network protocol stack. We believe the depth and
breadth of our research team makes us uniquely positioned to develop
and analyze strategies for cross-layer design techniques. In
addition, our ideas for scheduling and diversity in network design
are new, innovative, and have the potential for significant impact on
network design and performance. Our team's collaboration over the
last two years has yielded important concrete research results and,
perhaps more importantly, substantial cross-fertilization across
disciplines resulting in broad new ideas for network design. The next
phase of the project will place even more emphasis on this
cross-fertilization and on the exploration of the resulting
innovations.
This project is a continuation of the SNRC project
"A Multilayer Approach to Mobile Networking" (2000-2002).
Last modified on November 7, 2003.
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