WINET: Wireless Networking Research Group, IIT

Some Selected Projects Conducted by WINET Group at IIT:

USA NSF CPS:Medium: The Study of and Methodology Development for Loosely Coupled Networked Control Systems with Disturbances funded by NSF CPS to Sept, 2013 (Estimated). Xiangyang Li, Principal Investigator; Co-PIs: ShangPing Ren, Paul Anderson, and Fouad Teymour
The objective of this research is to understand the loosely coupled networked control systems and to address the scientific and technological challenges that arise in their development and operation. The approach is to (1) develop a mathematical abstraction of the CPS, and an online actuation decision model that takes into account temporal and spatial dependencies among actions; (2) develop algorithms and policies to effectively manage the system and optimize its performance with respect to applications' QoS requirements; and (3) develop an agent-based event-driven framework to facilitate engineers easily monitor, (re)configure and control the system to achieve optimized results. The developed methodologies, algorithms, protocols and frameworks will be evaluated on testbeds and by our collaborating institution.
The project provides fundamental understanding of loosely coupled networked control systems and a set of strategies in managing such systems. The components developed under this project enables the use of wireless-sensor-actuator networks for control systems found in a variety of disciplines and benefits waterway systems, air/ground transportation systems, power grid transmission systems, and the sort.
The impact of this project is broadened through collaborations with our collaborating institution. This project provides a set of strategies and tools to help them meet the new standards. The inter-disciplinary labs and curriculum development at both undergraduate and graduate level with an emphasis on CPS interdisciplinary applications, theoretical foundations, and CPS implementations prepare our students as future workforce in the area of CPS applications.
NeTS-NECO: Some Fundamental Problems for Performance Study of Opportunistic Spectrum Utilization, funded by NSF CCR 0832120, to December 31, 2011 (Estimated). Xiangyang Li, Principal Investigator.
Imagine what happens as more devices go wireless -- not just laptops, or cell phones and BlackBerrys, but sensor networks that monitor everything (from temperature in buildings to moisture in cornfields), radio frequency ID (RFID) tags that track merchandise at the local Wal-Mart, devices that monitor nursing-home patients. All these gadgets have to share a finite -- and increasingly crowded -- amount of radio spectrum. As a consequence, today new wireless technologies are struggling for bandwidth. Dynamic sharing of spectrum can provide a system some flexibility. Our society will gain substantial benefits, both in the short run and in the long run, from introduction of SOP sharing. This work will greatly improve the network performance, and have broad impact on the efficient usage of scarce spectrum resource in networks and furthermore, our society. This project is expected to improve the overall wireless spectral efficiency; enable wireless devices or systems to make full use of spectral resources in an autonomous and distributed manner; stimulate new applications to take full advantage of cognitive radios for better QoS; and provide an excellent vehicle for educating students with hands-on experience.
This work will develop, design, and implement efficient wireless network protocols for better spectrum utilization and study some fundamental performance bounds for networks with opportunistic spectrum utilization. This work will study the Nash Equilibrium points of the spectrum sensing game and spectrum access game when secondary users are selfish. This work will design stable distributed link scheduling and routing methods to maximize throughput, and derive some necessary and/or sufficient conditions on attainable flows. This work will also develop tractable and insightful metrics and models for wireless networks using SOPs; obtain upper and lower performance bounds for these metrics for a given set of models; define the negotiation between application and network for picking the operating point.
More readings in the topic of spectrum sharing and cognitive radio: Cognitive Networking, and local backup.
SOME PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
1. Xiang-Yang Li, Ashraf Nusairat, Yanwei Wu, Yong Qi, JiZhong Zhao, Xiaowen Chu, and YunHao Liu. "Joint Throughput Optimization for Wireless Mesh Networks," IEEE Transaction on Mobile Computing (TMC), 2009.
2. Xiang-Yang Li, Yu Wang, Haiming Chen, Xiaowen Chu, Yanwei Wu, Yong Qi,. "Reliable and Energy Efficient Routing for Static Wireless Ad Hoc Networks with Unreliable Links," IEEE Transactions on Parallel and Distributed Systems (TPDS), 2009, p. 1408.
3. Yan-Li Cai, Wei Lou, Ming-Lu Li, and Xiang-Yang Li. "Energy-efficient Target-Oriented Scheduling in Directional Sensor Networks," IEEE Transaction on Computers, 2009.
GreenObs: A Long-Term Kilo-Scale Wireless Sensor Network System in the Vast Forest, for forest monitoring (collaboration with YunHao Liu from HKUST, JiZhong Zhao from Xi'An JiaoTong, Ming Gu from Tsinghua, GuoMo Zhou from Zhejiang Forestry Univ, GuoJun Dai from HangZhou DianZi, HuaDong Ma from Beijing University of Posts and Telecommunications).
The missions of GreenOrbs are two fold:
(1) On one hand, GreenOrbs realizes all-year ecological surveillance in the forest, collecting various sensory data including temperature, humidity, illumination, and carbon dioxide titer. The collected information is utilized to support various significant applications, such as forest surveillance, forestry observation and research, fire risk evaluation, and succor in the wild.
(2) On the other hand, GreenOrbs pioneers the effort in the sensor network community to build a practical system. Through the real-world experience in GreenOrbs, we expect to explore the potential design space and scientific solutions, especially addressing the research and engineering challenges for a wireless sensor network system that is deployed in the virgin forest, involves 1000+ sensor nodes, and needs to operate for over one year.
Check this for online data retrieving.
OceanSense, Sensor Network for Sea Monitoring (collaboration with YunHao Liu from HKUST).
OceanSense aims to build an integrated sensor network system for environment surveillance on the sea. The focus of this work is to acquire and analyze information about environment factors such as temperature, light illuminance, sea depth, etc. Current methods are mostly labour-intensive and the data collection lacks both the density and consistency of samplings. By deploying a wireless sensor network, we are able to achieve continuous surveillance on the sea environment.
We are deploying the working system in Tsingtao, China. We use TelosB motes and TinyOS as our development basis. Current system consists of 20 sensor nodes deployed in the field, reporting sensing data continuously to the base station. The complete system is designed to scale to hundreds of sensors covering the sea area off Taipingjiao, Tsingtao.
A short demo about our deployment.

Selected Finished Projects by WINET Group at IIT:

Prefix-Free Vertex Coloring for Channel Assignment in OVSF-CDMA Wireless Ad Hoc Networks, supported by NSF CCF 0311174, August 1, 2003-July 31, 2006. PI: Peng-Jun Wan; Co-PI: Xiang-Yang Li.
Orthogonal variable spreading factor (OVSF) code provides a means of support of variable rate data service at low hardware cost in CDMA wireless systems. In an OVSF-CDMA wireless ad hoc network, a code assignment has to be conflict-free, i.e., two nodes can be assigned the same codeword or two non-orthogonal codewords if and only if neither of them is within the transmission range of the other and no other node is located in the intersection of their transmission ranges. In this proposal, we propose to study various optimization problems on conflict-free channel assignments in OVSF-CDMA wireless ad hoc networks. The proposed studies include conflict-free channel assignment for maximum throughput, for maximum bottleneck rate, and for both at the same time, and transmission scheduling for minimum schedule duration when all nodes have specified transmission rate. All these optimization problems are expected to be NP-hard even when all nodes have the uniform transmission radii. We will prove the NP-hardness of these problems and develop provably good polynomial-time approximation algorithms. These studies are both theoretical challenging and practical important for the deployment of OVSF-CDMA wireless ad hoc networks. Furthermore, since wireless ad hoc networks support applications related to disaster relief, public event coordination, and military and law enforcement operations, increasing their throughput and communication bottleneck has vast societal impact.
SOME PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
1. Li, X.-Y., and Wang, Y.. "Simple approximation algorithms and ptass for various problems in wireless ad hoc networks," Journal of Parallel and Distributed Computing, 2006.
2. Li, X.-Y., Song, W.-Z., and Wang, W.. "A unified energy efficient topology for unicast and broadcast," ACM MobiCom, 2005.
3. Li, X.-Y., Tang, S.-J., and Ophir, F.. "Multicast capacity for large scale wireless ad hoc networks," ACM Mobicom, 2007.
4. Wang, W., Wang, Y., Li, X.-Y., Song, W.-Z., and Frieder, O.. "Efficient interference aware tdma link scheduling for static wireless mesh networks," ACM Mobicom, 2006.
5. Wang, Y., Wang, W., and Li, X.-Y.. "Efficient distributed low-cost weighted backbone formation for wireless ad hoc networks," ACM MobiHoc, 2005.
6. X.Y. Li, P.-J. Wan. "Theoretically Good Distributed CDMA/OVSF Code Assignment for Wireless Ad Hoc Networks," COCOON 2005, 2005.