Active Projects

These are projects that I am actively working on, and that I foresee working on for some time before I am ready to call them either completed or dormant. Typically one or more funded students are working on each of these.

SDN Labs

The newly emerging paradigm called Software Defined Networking encompasses many areas of networking innovation, many of which are previously existing ones, but have come together under the SDN umbrella to provide new perspectives in light of the software and hardware technology capabilities of the day, as well as the economic and social realities. The concept of SDN is also closely related with network virtualization, and recent concepts such as NFV. While specific research areas within the SDN umbrella may mature or reduce in relevance, the broad field in the general SDN area will be of significant relevance in both academia and practice for the foreseeable future.

Recognizing the importance of SDN issues, over the last few years I have set up a lab to enable my research students to work in this area. Since new topics are slow to enter the curriculum, I have also attempted to design the lab to enable instructional use. By the kind cooperation of the Computer Science department, the lab is housed in the NetLabs area in EB2-East. It includes networking equipment donated by various industry partners, received from grants, and some computing equipment obtained from NetLabs. See the main SDN Labs website for more information.


ChoiceNet is the name of an architectural vision to support choice as the central aspect of the Internet architecture. This is funded by a large multi-university grant from NSF under the umbrella of its new program Future Internet Architecture (FIA) - this program has only funded 5 research projects, see the NSF FIA website for the others. Our project is called ChoiceNet - we postulate that fine-grain innovation in networking services can be encouraged by integrating a framework for accountable allocation of customer's expenditure, targeted measurement of performance, and selective re-composition of the service needed by the customer based on satisfaction of user expectation. We propose an initial set of architectural building blocks to achieve these goals, such that they could be integrated in not only the current Internet architecture, but a wide variety of other possible architectures, such as those being proposed by the FIA community. News of this grant was covered by National Public Radio (WUNC) in November, 2011, on the "All Things Considered" program, including quotes from Dr. Dutta and other PIs from NCSU and UNC-CH. See the Official ChoiceNet website for more information.


The Global Environment for Networking Innovation (GENI) is an initiative funded by NSF to provide a national resource to networking and computing researchers and educators. It is intended to be a virtual laboratory in which a wide variety of networking experiments can be performed, at national scale, by many research groups in parallel. As such, this testbed attempts to provide the capability to "slice", or virtualize, all resources in the entire GENI network. This is a tremendous challenge by itself, considering the national footprint of GENI. It is all the more complicated because the various resources in the GENI substrate are typically innovative and non-standard networking equipment in themselves - such as a sensor testbed in Oklahoma or a low-altitude radar network in Massachusets - and also under different ownership and management. These diverse resources as well as the available national bandwidth has to be "slivered", and then "stitched", to provide a seamless "slice" for a researcher - a network with national footprint made of real equipment but isolated from the networks of other GENI users.

To build this unprecedented facility, NSF funded BBN to set up the GENI Project Office (GPO), which in turn funded researcher groups to architect and develop parts of the whole. My Integrated Measurement Framework (IMF) project is one of these - the only one at NCSU so far that has been funded by GENI. Building GENI is an engineering exercise, but one that demands that experience and awareness in breadth of networking research inform it at every point, which is why GPO is funding various researchers and research groups to build GENI, rather than doing it all at BBN. GENI follows the processes and standards of deliverables that are more typical of production-grade engineering.

More information about the actual project can be found at the IMF project wiki at GENI. In this last year, we are designing the Measurement Plane messaging system for the instrumentation and measurement cluster of GENI. This is forming a critical piece of both GEMINI and GIMI - the two redundant Instrumentation and Measurement architectures being developed for GENI (I am part of the GIMI effort).


In Spring 2012, an effort I have been engaged in for several years has completed the final phase, and the Centennial Wireless Mesh Testbed (CentMesh) has been built and deployed for use by NCSU researchers and instructors. CentMesh is an outdoor, highly programmable, extensible, open testbed to support research and education on the design of wireless mesh networks, as well as IT systems and applications enabled by wireless mesh networks. It was conceived and designed by Dr. Mihail Sichitiu of the ECE department and myself, with foundational input and support from Dennis Kekas. The testbed was part of the vision included in the Secure Open Systems Initiative (SOSI) of which I am a PI, and subsequently, in 2009, we were awarded a Defense University Research Instrumentation Program (DURIP) funding from the Army Research Office to significantly increase the scope of this testbed. The NCSU Institute for Technology of the Next Generation (ITng) is in charge of the installation, operation and maintenance; Dr. Sichitiu and I continue to lead the research and teaching efforts.

Many emerging security and network research questions are in areas of network availability, reliability etc. Solutions are often proposed in research through routing, opportunistic MAC, adaptive power control, dynamic rate control and modulation, and other such research areas; these are all low down, or across traditional boundaries of, the networking stack. Commercially available wireless networking equipment do not allow experimentation at these detailed levels, and researchers are reduced to using commodity computing hardware and using them as wireless equipment.
We envisioned CentMesh, and subsequently architected and developed it, to provide a versatile wireless networking substrate that would be deeply programmable (to allow whatever research innovation it was called upon to support), but provide a flexible and modular interface (to allow a researcher to make specific changes in the programming relevant to the research without requiring to undertake a large software project). Further, it is architected to be extensible; the basis of ever more ambitious and powerful research enabling infrastructures to come, as researchers pursue evolving research directions, both guiding and contributing to the enhancement of CentMesh capabilities. CentMesh is thus a research project that provides usable facilities, not a development project that produces a static platform.

More information can be found at the CentMesh website. CentMesh was covered by The News and Observer - the daily paper of the Raleigh-Durham-Chapel Hill area. One brief clarification to the title of the archived news story (which attempts to capture the spirit of the story while staying within the brevity required of newspaper titles). CentMesh is a first in many ways, but it is obviously not the first outdoor Wi-Fi network. There are many commercial networks which do that, including the one that covers Raleigh downtown. There are also experimental outdoor WiFi testbeds. However, the combination of programmability, span, and complete researcher control of CentMesh is indeed unprecedented as far as we know.

Science of Security

Late in 2011, the National Security Agency awarded Drs. Laurie Williams and Michael Rappa of NCSU Computer Science to set up a "lablet" - one of three that together make up a complete "virtual lab" to focus on the science of security. The other two component lablets are at University of Illinois at Urbana-Champaign and Carnegie Mellon University. The development of information security over the years has stressed the development of tools and algorithms to solve security problems, on the engineering and application of security. Together, the lablets will attempt to articulate fundamental theoretical understanding of security as a science. Each lablet focuses on specific approaches - the NCSU lablet focuses on analytics. More information about the lablet is in the news release for the award, and on the websites of Drs. Williams and Rappa.

The lablet is pursuing various units of research aimed at security science topics, led by various researchers. I am engaged in two such units. The first is a project that addresses a specific collaborative approach for Sybil detection, suitable for sensor networks, that one of my students had previously worked upon. This project will investigate the limits of applicability of such an algorithm, and obtain detection probabilities under various conditions. The second project I am leading is on attempting a scientific description of network security mechanisms as control systems. This project will investigate specific network security systems by viewing them as feedback control systems, and attempting to determine general stability results or other characterization for them. Dr. Meeko Oishi from University of New Mexico is a co-PI on this project.

Areas for Upcoming Research

This is the section I use to describe research projects and problems I have been formulating and am ready to embark on, or apparently-promising ideas I get in the middle of the night, or anything inbetween. Thus they range from well-considered roadmaps to vague ramblings. If something strikes you as making no sense, that may be because it does not

under construction picture By definition, this section is perpetually under construction. Depending on when you came here, there might not be much here; hopefully there will be soon, check back.

Distributed Sensor

OpenFlow Related


Airborne Networking

Completed / Dormant Projects

This section lists projects that are not active at this time. In some cases, they are related to the work performed on a particular grant, which defined the scope of the work - so the project is considered "complete" even though my students may still be engaged in research on related topics. In other cases, the project is not attached to a particular grant, but may have been funded from various sources at various times, or unfunded in part; in that case, I consider it a "project" if it encompasses a distinct collection of highly related research.

Not all the research done by all my students is represented in here - not all thesis work is a "project" or part of one. That is why we have dissertations and publications - which after all are more important than my arbitrary organization here.

As with all research, these projects are dormant rather than ended - any of these areas could be topics for further research at a future time.


In 2005, NSF issued a call for "clean-slate future Internet design" proposals - the Future Internet Design (FIND) solicitation. Our SILO project was one of the few teams to get funded in the very first cycle of this program. I am grateful not only for the actual funding, but for having had the opportunit to be a participant in a completely new re-examination of planetary networking architecture. In the SILO project, we envisioned networking functionality to be provided in fine-grain services in the protocol stack (at end-nodes, and within the network), with separate control interfaces for cross-service tuning and optimization. At special FIND events held by NSF, we collaborated with other FIND teams to inform their research with ours, and vice versa.

More information is at the SILO project website. The project ended after two years, with several publications as well as a working prototype proving the concept of our paradigm, and an REU supplement. However, the concepts we developed in SILO continued to influence our Internet architectural work - we have applied them both in the GENI-IMF project and ChoiceNet.

Traffic Grooming

The quantum jump in transmission speed due to the use of fiber has not been matched by a similar improvement in processing speed at intermediate network processing elements (routers, switches), and as computational speeds go up, so does throughput. As a consequence, either the fiber has to be severely underutilized (not a preferable solution, and not viable in the long run), or many processing elements have to be deployed to conventionally route/switch at each intermediate (network interior) node. This latter solution can be prohibitively expensive. In addition, the processing equipment is all electronic, thus delay is incurred in electro-optic conversion every time the packets/cells contained in an optical signal must be routed. This will usually be necessary because the bandwidth of even a single wavelength is likely to be much larger than the typcial user channel bandwidth, thus many slower speed traffic streams will be multiplexed (probably TDM) over each wavelength channel. It becomes very attractive to allow some (hopefully the bulk) of the traffic to be switched optically, using wavelength routing, and resort to electro-optic conversion and electronic processing only when it cannot be avoided. This problem has been called traffic grooming in literature. In the general case, as well as in many quite restrictive cases of topology and traffic patterns, this problem is computationally intractable.

Over the years, I have worked with many students on various topics related to grooming. Some of it was archived at the Traffic Grooming website, but unfortunately that website has fallen out-of-date. Please see my 2007 and 2002 surveys on grooming, and also the book I co-edited in 2008.

Bridge SHM

This project was jointly conducted with Dr. Mihail Sichitiu of the ECE department and Dr. Sami Rizkalla of the CCEE department of NCSU. The goal of this project was to increase the lifetime of a battery-powered sensor network using a combination of scheduling and power aware routing for continuous monitoring sensor networks. The motivating application is structural health monitoring of building and bridges.

We developed algorithms to schedule sleep cycles of the sensors, to improve the lifetime of the network, to redistribute the energy of the network for maximum utilization, and to perform power-efficient routing. The final and highly relevant step for this project was the practical implementation of a signal pre-conditioning circuit featuring a programmable amplifier capable of variable range and resolution as well as temperature and non-linearity compensation. This was tested with actual bridge beams at the Constructed Facilities Laboratory at NCSU, with readings received remotely. The complete project is archived at the WALAN website.

Last updated: Aug 14, 2014