PAST RESEARCH PROJECTS
Co-PI: Patrick Schaumont
This project will develop a novel tool, named Sunshine, to effectively support joint evaluation and design of sensor network (sensornet) hardware and software. A critical roadblock to the success of sensornets is the prohibitively slow and energy-wise impractical software implementations of many important applications. On the other hand, specialized hardware implementation can outperform, energy-wise as well as performance-wise, equivalent software implementations by orders of magnitude. Hence, the joint software-and-hardware design of sensornet applications is a very appealing, yet unexplored, approach. The objective of this project is to develop an effective tool, named Sunshine, to support such codesign. This project may fundamentally transform the relationship between the hardware and software communities of sensornet research. These communities can use Sunshine to efficiently exchange mutual requirements and spread the latest technology advances in each other's fields. Such evolutionary change will greatly improve the state-of-the-art in sensornet technology. Novel hardware architecture and platforms that are unexplored in current designs can be created and tested through Sunshine's cross-domain design environment.
Duration: 8/2009 - 7/2010
Co-PI: Michael Hsiao, Luiz Da Silva
The objective of this project is to bring a revolutionary change to the design process of routing systems by building a highly flexible architecture for the automatic assembling and testing of a great variety of routing designs. Instead of focusing on a particular suite of routing protocols as existing research efforts, this architecuture, called Orchestra, introduces evolutionary design into the routing area. It accepts various designs of routing components and automatically assemble them into workable routing protocols. Based on the performance of the assembled protocols, Orchestra switches and tunes designs of routing components to eventually identify the best design for a network setting.
Co-PI: Thomas Hou
The current rich collection of wireless routing designs brings significant compatibility issues between different design choices. A combination of arbitrary designs of routing components with a routing metric may result in catastrophe on a network's normal operation, such as routing loops, inconsistent routing decisions, suboptimal paths and routing instability. Previous works for modeling routing metric designs focused on several IP routing protocols deployed for the Internet. There remains a serious lack of understanding of the compatibility issue for wireless networks. The objective of this project is to address this challenging issue by systematically studying the fundamental compatibility space of routing metrics for different wireless routing designs. The proposed project will move the traditional simple linear wireless routing metric design into the new era of non-linear design and provide in-depth analysis of potential incompatibility issues. The routing theory developed in this proposed project is a major step in the understanding of interoperability and compatibility between wireless routing protocols. In addition, the theory of compatible routing designs also brings insights for developing flexible wireless routing architecture so that designs that potentially may put too many restrictions on the development of routing metrics can be avoided. The proposed research will foster the integration of research and education by expanding the existing curriculum with the new results from this project. The outreach component of the project includes disseminate research results and pedagogical materials via education and industry outreach programs.
Co-PI: Michael Buehrer, Jung-min Park
The objective of this research is to develop a localization system capable of localizing an adversary that is actively trying to disguise its location in a wireless network by distorting its signal features. The approach is a proactive, cross-layer localization design that incorporates attack traceback, cross-layer traffic manipulation, and physical layer position estimation. The attack traceback aspect focuses on narrowing down an adversary’s location to the coverage area of a couple of access points. The traffic manipulation aspect will develop trapping techniques to force or lure the adversary to exhibit their true location-related signal features. Leverage these true location-related signal features, the physical layer position estimation aspect will develop proactive and robust localization techniques to accurately position the adversary.
The proposed project establishes accountability in wireless networks and serves as an invaluable tool for attack deterrent. It is the first to address many technical challenges in localization and traceback. This project can also enhance the security of systems where location information is used to restrict access to critical resources. Furthermore, the proposed research results can be used to improve the accuracy of localization systems in harsh communication environments that severely distort the characteristics of emitted signals from legitimate users.
Co-PI: Amy Bell
Modern data networks are complex distributed systems that promise to provide military and civilian users with network connectivity at any location and any time. However, without a robust and secure communication framework, the full potential of communication technology will not be fully realized. This is because the communication environments of data networks can vary dramatically due to changes in node mobility, radio interference, traffic pattern, and energy constraint. In addition, data networks are increasingly becoming the target of malicious attacks. A communication system that lacks robustness and security may crash miserably in these demanding operating environments. Hence, to fully realize the potential of data networks, the ASC team is building an autonomous and secure communication system that dynamically evolves the architecture design of a network according to its environment so that the survivability, availability, manageability, capacity, integrity, and confidentiality of the communication system can stay at its optimal level.
The ASC team seeks to completely change the current ad hoc and manual ways of network engineering and bring the entire network design field into the new era of automatic system design and adaptation. This evolutionary change will greatly accelerate the advances of communication technologies.
- Runtime Tuning of Contention Parameters
In a contention based wireless network (e.g. IEEE 802.11), the amount of bandwidth that a node can get depends on the activities of its neighboring nodes. By assigning different contention parameters (e.g. contention-window size, inter-frame space etc) to different nodes (or flows), service differentiation and high channel utilization can be achieved. I have been analyzing the relationship between these tunable parameters and the resultant bandwidth allocation and have designed a distributed algorithm to dynamically adjust these parameters to achieve the desired fair bandwidth allocation to best effort flows and QoS guarantees to realtime flows while maintaining high channel utilization in a dynamic environment.
- Bandwidth Prediction in Multi-Priority Wireless Networks
Predicting the achievable bandwidth of a new flow and its impact on existing flows are both crucial for bandwidth-aware services, such as load balancing, admission control, routing, etc. In a multi-priority contention-based wireless network (e.g. IEEE 802.11e), such prediction must be based on the contention behavior of flows, which is related to the priorities and traffic types of the flows. I have been analyzing the relationship between the contention behavior of flows and their bandwidth allocations and have designed a novel channel model that can be used to accurately predict the achievable bandwidth and network impact of a new flow.
- Interference Aware Protocol
In a wireless network, interference may happen among nodes that do not know each other directly, since they may be outside each others communication range but inside each others interference range. When performing QoS routing or admission control in such a network, the effect of interference must be considered. I have been studying the effect of interference on QoS routing and admission control in ad hoc networks and have designed interference aware protocols to support QoS in such networks.
- Channel State Adaptation of TCP
In a wireless LAN, the channel state experienced by a flow often varies dramatically due to fading. Instead of using scheduling algorithms to exploit this characteristic, which has been extensively studied by other researchers, my research focused on the possibilities of adapting TCP according to the channel state to achieve the same goal of the channel-state-dependent scheduling algorithms.
- Communication Resource Discovery
Currently many mobile devices are equipped with multiple communication interfaces. (e.g. a laptop may be able to communicate through infrared, IEEE 802.11, Bluetooth, and wired network.) Several protocols have been proposed to exploit the multi-interface ability of mobile devices to improve the QoS. However, as a mobile device roams around, it has to periodically wake up each interface to check the availability of communication resources in its environment. This is very expensive in terms of energy consumption. We proposed to build a map of available communication resources. The mobile device can first download this map into its memory and then decide which interfaces to wake up based on its location in the map.