Rajesh Krishnan

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We describe PRioritized EPidemic (PREP) for routing in opportunistic networks. PREP prioritizes bundles based on costs to destination, source, and expiry time. Costs are derived from per-link "average availability" information that is disseminated in an epidemic manner. PREP maintains a gradient of replication density that decreases with increasing distance(More)
Self-organization of wireless sensor networks, which involves network decomposition into connected clusters, is a challenging task because of the limited bandwidth and energy resources available in these networks. In this paper, we make contributions towards improving the efficiency of self-organization in wireless sensor networks. We first present a novel(More)
Wireless and satellite networks often have non-negligible packet corruption rates that can significantly degrade TCP performance. This is due to TCP’s assumption that every packet loss is an indication of network congestion (causing TCP to reduce the transmission rate). This problem has received much attention in the literature. In this paper, we take a(More)
DARPA’s Disruption-Tolerant Networking (DTN) program is developing technologies that enable access to information when stable end-to-end paths do not exist and network infrastructure access cannot be assured. DTN technology makes use of persistence within network nodes, along with the opportunistic use of mobility, to overcome disruptions to connectivity.(More)
In this paper we survey issues and challenges in enhancing the survivability of mobile wireless networks, with particular emphasis on military requirements*. Research focus on three key aspects can significantly enhance network survivability: (i) establishing and maintaining survivable topologies that strive to keep the network connected even under attack,(More)
Large scale clustered continuous media (CM) servers deployed in applications like video-on-demand have high availability requirements. In the event of server failure, streams from the failed servers must be reassigned to healthy servers with minimum service disruption. Such servers may also suffer from periods of transient overload resulting from a high(More)
Experts have long recognized that theoretically it was possible to perform traffic analysis on encrypted packet streams by analyzing the timing of packet arrivals (or transmissions). We report on experiments to realize this possiblity using basic signal processing techniques taken from acoustics to perform traffic analysis on encrypted transmissions over(More)
We consider the concept of <i>opportunistic spectrum access (OSA)</i> -- whereby radios identify unused portions of licensed spectrum, and utilize that spectrum without adverse impact on the primary licensees. OSA allows both dramatically higher spectrum utilization and near-zero deployment time, with an obvious and significant impact on both civilian and(More)
This paper introduces a binary neural network-based prediction algorithm incorporating both spatial and temporal characteristics into the prediction process. The algorithm is used to predict short-term traffic flow by combining information from multiple traffic sensors (spatial lag) and time series prediction (temporal lag). It extends previously developed(More)