Mihnea, Amalya

Channel assignment in multi-radio networks is a topic of great importance because
the use of multiple channels and multiple radios reduces interference and increases the
network throughput. The goal of our research is to design algorithms that maximize the
use of available resources while providing robustness to primary users that could reclaim
one or more channels. Our algorithms could be used in ad hoc networks, mesh networks,
and sensor networks where nodes are equipped with multiple radios. We design
algorithms for channel assignment which provide robustness to primary users without
assuming an accurate primary user behavior model. We also compute bounds for capacity
in grid networks and discuss how the capacity of a network changes when multiple
channels are available. Since preserving energy is very important in wireless networks,
we focus on algorithms that do not require powerful resources and which use a reduced
number of messages.

The use of permutations in data compression is an aspect that is worthy of further exploration. The work that has been done in video compression based on permutations was primarily oriented towards lossless algorithms. The study of previous algorithms has led to a new algorithm that could be either lossless or lossy, for which the amount of compression and the quality of the output can be controlled. The lossless version of our algorithm performs close to lossy versions of H.264 and it improves on them for the majority of the videos that we analyzed. Our algorithm could be used in situations where there is a need for lossless compression and the video sequences are part of a single scene, e.g., medical videos, where loss of information could be risky or expensive. Some results on permutations, which may be of independent interest, arose in developing this algorithm. We report on these as well.