Silvija Kokalj-Filipovic

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We analyze the benefits of an automatic repeat- request (ARQ) scheme employed in doped belief-propagation decoding for increasing the throughput of fountain encoded data transmissions. The proposed doping mechanism selects doping symbols randomly from the set of input symbols contributing to degree-two output symbols. Here an output symbol is the encoded(More)
This paper studies decentralized, Fountain and network-coding based strategies for facilitating data collection in circular wireless sensor networks, which rely on the stochastic diversity of data storage. The goal is to allow for a reduced delay collection by a data collector who accesses the network at a random position and random time. Data dissemination(More)
In this paper we apply a Bayesian non-parametric model to segmenting time series of observed wireless node transmission activity in order to learn routing patterns in an unknown ad-hoc network, as well as its topology. This emulates cognition of a spectrum sensing radio network capable of geolocating transmitting nodes of another network and detecting(More)
We propose a compression/transmission scheme that allows the quality of the reconstructed signal to gracefully degrade as the channel quality drops, as well as steadily improve with the channel improvement. The main idea is to partition the channel and/or network resources into m units (e.g., sub-bands, packets) and compress the source independently m times(More)
This paper studies decentralized strategies for facilitating data collection in circular wireless sensor networks, which rely on the stochastic diversity of data storage. The goal is to allow for a reduced delay collection by a mobile data collector (MDC) who accesses the network at a random position and random time. We consider a two-phase data collection:(More)
We propose a method for estimating channel parameters from RSSI measurements and the lost packet count, which can work in the presence of losses due to both interference and signal attenuation below the noise floor. This is especially important in the wireless networks, such as vehicular, where propagation model changes with the density of nodes. The method(More)
We describe three in-field data collection efforts yielding a large database of RSSI values vs. time or distance from vehicles communicating with each other via DSRC. We show several data processing schemes we have devised to develop Vehicle-to-Vehicle (V2V) propagation models from such data. The database is limited in several important ways, not least, the(More)
For wireless sensor networks with many location- unaware nodes, we investigate a protocol, dubbed BeSpoken, that steers data transmissions along a straight path called a spoke. The protocol directs data transmissions by randomly selecting relays to retransmit data packets from crescent-shaped areas along the spoke axis. The resulting random walk of the(More)
We describe three in-field data collection efforts yielding a large database of RSSI values vs. time or distance from vehicles communicating with each other via DSRC. We show several data processing schemes we have devised to develop opportunistic Vehicle-to-Vehicle (V2V) propagation models from such data. The database is limited in several important ways,(More)