University of Southern California

research

 

 

The following are some of the ongoing and recent research subjects (primarily in the area of wireless sensor networks) investigated by the Autonomous Networks Research Group at USC. Please click on the links below to read more about each:

 

 

Data-Centric Querying, Routing and Aggregation

One of the unique characteristics of sensor networks is their application specific nature and data-centric operation. This enables the possibility of in-network processing and aggregation to reduce the energy expenditure associated with data gathering.

[top]

 

 

Optimization for Data Gathering

This effort aims to formulate linear and non-linear optimization problems pertaining to data gathering in sensor networks in order to gain an understanding of fundamental limits and tradeoffs, to provide bounds that serve as benchmark for real protocols, and to develop implementable, decentralized optimal and near-optimal algorithms for data-gathering.

[top]

 

 

Localization and Tracking

The tracking of mobile targets and phenomena is a canonical problem in sensor networks. A related significant problem is that of localizing the sensor nodes themselves in case of random or ad-hoc deployment.

[top]

 

 

Critical Density Thresholds and Phase Transitions

Large scale ad-hoc wireless networks show phase transition phenomena, whereby there exist critical density thresholds below which a global network property such as connectivity is satisfied with negligible property and above which it is satisfied with high probability. Goel, Rai and Krishnamachari (see link below) have recently proved the conjecture that this holds for all monotone properties in random geometric graphs.

[top]

 

 

Routing in the Presence of Node and Link Unreliability

The low-power, inexpensive radios used for sensor networking are highly susceptible to poor quality, asymmetric, links. Further, they may be susceptible to hardware node failures. This line of research explores how these effects impact routing.

[top]

 

 

Medium Access

There is a crucial need to analyze and design medium access protocols suitable for sensor networks that are application-specific, low-energy, low-delay and fair. We have been exploring both randomized medium access schemes as well as scheduled access techniques.

    • Gang Lu, Bhaskar Krishnamachari and Cauligi Raghavendra, "Performance Evaluation of the IEEE 802.15.4 MAC for Low-Rate Low-Power Wireless Networks," to be presented at the Workshop on Energy-Efficient Wireless Communications and Networks (EWCN '04), held in conjunction with the IEEE International Performance Computing and Communications Conference (IPCCC), April 2004.
    • Gang Lu, Bhaskar Krishnamachari and Cauligi Raghavendra, "An Adaptive Energy-Efficient and Low-Latency MAC for Data Gathering in Sensor Networks," to appear in 4th International Workshop on Algorithms for Wireless, Mobile, Ad Hoc and Sensor Networks (WMAN 04), held in conjunction with the IEEE IPDPS Conference 18th International Parallel and Distributed Processing Symposium, April 2004.
    • Avinash Sridharan and Bhaskar Krishnamachari, "Max-Min Fair Collision-Free Scheduling for Wireless Sensor Networks," to be presented at the Workshop on Multihop Wireless Networks (MWN'04) to be held in conjunction with the IEEE International Performance Computing and Communications Conference (IPCCC), April 2003.
    • Marco Zuniga and Bhaskar Krishnamachari, "Optimal Transmission Radius for Flooding in Large Scale Sensor Networks," Workshop on Mobile and Wireless Networks, MWN 2003, held in conjunction with the 23rd IEEE International Conference on Distributed Computing Systems (ICDCS), Providence, Rhode Island, May 2003.

[top]

 

 

Robustness to Measurement Errors

We have developed Bayesian algorithms that exploit the redundancy of dense sensors to correct for measurement errors that may be likely in inexpensive devices.

[top]

 

 

Continuous Media Delivery and Mobility Issues in Ad-Hoc Wireless Networks

While wireless sensor networks are primarily concerned with low-data rate traffic, we have also explored data management and delivery issues in ad-hoc wireless networks where there is high bandwidth real-time traffic with demanding latency constraints and potentially variable topology due to mobile nodes.

[top]

 

 

 

 

 

 

Copyright Notices

Links to final or draft versions of papers are presented here to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or distributed for commercial purposes without the explicit permission of the copyright holder

The following applies to all papers listed above that have IEEE copyrights:
Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE

The following applies to all papers listed above that are in submission to IEEE conference/workshop proceeedings or journals:
This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.

The following applies to all papers listed above that have ACM copyrights:
ACM COPYRIGHT NOTICE. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications Dept., ACM, Inc., fax +1 (212) 869-0481, or permissions@acm.org.

The following applies to all papers listed above that have SPIE copyrights:
This was published in an SPIE publication/proceedings, and is made available as an electronic reprint (preprint) with permission of SPIE. Single print or electronic copies for personal use only are allowed. Systematic or multiple reproduction, or distribution to multiple locations through an electronic listserver or other electronic means, or duplication of any material in this paper for a fee or for commercial purposes is prohibited. By choosing to view or print this document, you agree to all the provisions of the copyright law protecting it.

 

 

University of Southern California - School of Engineering - Electrical Engineering Department - Computer Science Department