Networking together hundreds or thousands of cheap microsensor nodes allows users to accurately monitor a remote environment by intelligently combining the data from the individual nodes. These networks require robust wireless communication protocols that are energy efficient and provide low latency. We develop and analyze low-energy adaptive clustering hierarchy (LEACH), a protocol architecture for microsensor networks that combines the ideas of energy-efficient cluster-based routing and media access together with application-specific data aggregation to achieve good performance in terms of system lifetime, latency, and application-perceived quality. LEACH includes a new, distributed cluster formation technique that enables self-organization of large numbers of nodes, algorithms for adapting clusters and rotating cluster head positions to evenly distribute the energy load among all the nodes, and techniques to enable distributed signal processing to save communication resources. Our results show that LEACH can improve system lifetime by an order of magnitude compared with general-purpose multihop approaches.

/pdf/an-application-specific-protocol-architecture-for-wireless-1s7y9fiv40.pdf

An application-specific protocol architecture for wireless microsensor networks

Statistics for Spatial Data.

Advances in processor, memory and radio technology will enable small and cheap nodes capable of sensing, communication and computation. Networks of such nodes can coordinate to perform distributed sensing of environmental phenomena. In this paper, we explore the directed diffusion paradigm for such coordination. Directed diffusion is datacentric in that all communication is for named data. All nodes in a directed diffusion-based network are application-aware. This enables diffusion to achieve energy savings by selecting empirically good paths and by caching and processing data in-network. We explore and evaluate the use of directed diffusion for a simple remote-surveillance sensor network.

/pdf/directed-diffusion-a-scalable-and-robust-communication-4tsx5vxsas.pdf

Directed diffusion: a scalable and robust communication paradigm for sensor networks

Mobile ad hoc routing protocols allow nodes with wireless adaptors to communicate with one another without any pre-existing network infrastructure. Existing ad hoc routing protocols, while robust to rapidly changing network topology, assume the presence of a connected path from source to destination. Given power limitations, the advent of short-range wireless networks, and the wide physical conditions over which ad hoc networks must be deployed, in some scenarios it is likely that this assumption is invalid. In this work, we develop techniques to deliver messages in the case where there is never a connected path from source to destination or when a network partition exists at the time a message is originated. To this end, we introduce Epidemic Routing, where random pair-wise exchanges of messages among mobile hosts ensure eventual message delivery. The goals of Epidemic Routing are to: i) maximize message delivery rate, ii) minimize message latency, and iii) minimize the total resources consumed in message delivery. Through an implementation in the Monarch simulator, we show that Epidemic Routing achieves eventual delivery of 100% of messages with reasonable aggregate resource consumption in a number of interesting scenarios.

/pdf/epidemic-routing-for-partially-connected-ad-hoc-networks-s5rslcaiip.pdf

Epidemic routing for partially-connected ad hoc networks

http://www.csun.edu/~andrzej/COMP529-S05/papers/Mesh%20Networks%20Survey.pdf

Wireless mesh networks: a survey

Mobile web page load time depends on three key factors: (1) the complexity of the Webpage, (2) the underlying network conditions, and (3) the processing capability of the device. While there are several works focusing on the Web complexity and the network, there is a little work in understanding the hardware bottlenecks in the page load process. In this poster, we analyze the effect of hardware bottlenecks of Web pages. We also analyze the effect of GPU offloading, a commonly used solution to speed up Web page loads.

https://dl.acm.org/doi/pdf/10.1145/3123878.3131980

Demystifying Hardware Bottlenecks in Mobile Web Quality of Experience

This manual gives an introduction to writing parallel discrete event simulation programs for the Georgia Tech Time Warp (GTW) system (version 3.1). Time Warp is a synchronization mechanism for parallel discrete event simulation programs. GTW is a Time Warp simulation kernel implemented on distributed network of uniprocessor and shared memory multiprocessor machines. Use of this program shall be restricted to internal research purposes only, and it may not be redistributed in any form without authorization from the Georgia Tech Research Corporation. Derivative works must carry this Copyright notice. This program is provided as is and Georgia Tech Research Corporation disclaims all warranties with regard to this program. In no event shall Georgia Tech Research Corporation be liable for any damages arising out of or in connection with the use or performance of this program.

/pdf/georgia-tech-time-warp-gtw-version-3-1-programmer-s-manual-4h8t3nrz19.pdf

Georgia Tech Time Warp (GTW Version 3.1) Programmer's Manual for Distributed Network of Workstations

We address the problem of localizing an (unauthorized) transmitter using a distributed set of sensors. Our focus is on developing techniques that perform the transmitter localization in an efficient manner, wherein the efficiency is defined in terms of the number of sensors used to localize. Localization of unauthorized transmitters is an important problem which arises in many important applications, e.g., in patrolling of shared spectrum systems for any unauthorized users. Localization of transmitters is generally done based on observations from a deployed set of sensors with limited resources, thus it is imperative to design techniques that minimize the sensors' energy resources. In this paper, we design greedy approximation algorithms for the optimization problem of selecting a given number of sensors in order to maximize an appropriately defined objective function of localization accuracy. The obvious greedy algorithm delivers a constant-factor approximation only for the special case of two hypotheses (potential locations). For the general case of multiple hypotheses, we design a greedy algorithm based on an appropriate auxiliary objective function--and show that it delivers a provably approximate solution for the general case. We develop techniques to significantly reduce the time complexity of the designed algorithms by incorporating certain observations and reasonable assumptions. We evaluate our techniques over multiple simulation platforms, including an indoor as well as an outdoor testbed, and demonstrate the effectiveness of our designed techniques--our techniques easily outperform prior and other approaches by up to 50-60% in large-scale simulations and up to 16% in small-scale testbeds.

Selection of Sensors for Efficient Transmitter Localization

The Science DMZ (SDMZ) is a special purpose network architecture proposed by ESnet (Energy Sciences Network) to facilitate distributed science experimentation on terabyte- (or petabyte-) scale data, exchanged over ultra-high bandwidth WAN links. Critical security challenges faced by these networks include: (i) network monitoring at high bandwidths, (ii) reconciling site-specific policies with project-level policies for conflict-free policy enforcement, (iii) dealing with geographically-distributed datasets with varying levels of sensitivity, and (iv) dynamically enforcing appropriate security rules. To address these challenges, we develop a fine-grained dataflow-based security enforcement system, called CoordiNetZ (CNZ), that provides coordinated situational awareness, i.e., the use of context-aware tagging for policy enforcement using the dynamic contextual information derived from hosts and network elements. We also developed tag and IP-based security microservices that incur minimal overheads in enforcing security to data flows exchanged across geographically-distributed SDMZ sites. We evaluate our prototype implementation across two geographically distributed SDMZ sites with SDN-based case studies, and present performance measurements that respectively highlight the utility of our framework and demonstrate efficient implementation of security policies across distributed SDMZ networks.

https://dl.acm.org/doi/pdf/10.1145/3359789.3359843

Coordinated dataflow protection for ultra-high bandwidth science networks

We study and propose a novel algorithm for detecting Wormhole Attacks in wireless ad hoc and sensor networks. The algorithm uses only local connectivity information and utilizes disk packing argument to detect such attacks. The success of the detection algorithm depends on the density of nodes in the network. Preliminary simulation results indicate that for uniformly distributed UDG networks, wormholes can be detected with very high probabilities for average degrees as low as 8.

Samir R. Das

Papers

Demystifying Hardware Bottlenecks in Mobile Web Quality of Experience

Georgia Tech Time Warp (GTW Version 3.1) Programmer's Manual for Distributed Network of Workstations

Selection of Sensors for Efficient Transmitter Localization

Coordinated dataflow protection for ultra-high bandwidth science networks

Detecting wormhole attacks in wireless networks