Supporting Remote Sensing and Control over IP Networks
This is the subject matter of my Ph.D. dissertation. We aim to solve the
communication problems associated with remotely controlling robotic sensors and
collecting the feedback such as video, audio etc. I designed an
overlay network based framework to improve the QoS for real-time
teleoperated robotic tasks through the Internet. A
similar mechanism is also developed for wireless (MANET) environments.
Improve QoS of Teleoperation Systems over Overlay Networks
For Internet based real-time teleoperation systems, random time delay can cause
instability in the closed loop control system and hence hinder task
accomplishment. Event based control systems have been proposed to overcome the
instability caused by the random time delay. High latency at the transport
layer can still impede effective and reliable execution of tasks with high
dexterity requirements. Network QoS based dynamic resource allocation has been
proposed to increase the efficiency and reliability of task execution. However,
these approaches only try to mitigate or overcome the effects of random time
delay and do not address the cause of latency issues in the communication
This research addresses the efficiency and reliability requirements for
supermedia enhanced teleoperated systems by reducing the end-to-end
transmission latency through the use of overlay networks. The proposed system (Supermedia
TRansport over Overlay Networks, STRON) reduces the transmission
latency by using multiple, disjoint paths in overlay networks. The proposed
system facilitates reliable and efficient task completion for tasks with high
Simulation of the system under NS2 shows
the system works better than traditional approaches.
NS2 plugins of the supermedia application.
Features include: (1) the OPSM module of STRON; (2) a modified TFRC agent that
supports payloads; (3) a modified link module that can change the link capacity
according to traces, etc.
Experimental validation of the proposed teleoperated system using the
PlanetLab (the overlay relay agent)
Network is provided for the task of teleoperating a mobile manipulator system.
This is a joint work with RA Lab under
the direction of Dr. Mutka and
Publications: Networking 2005 (poster,
and a longer technical report version Technical
Report MSU-CSE-05-01), ICRA 2005
(slides), and IROS
A poster presented to the CSE department.
Another poster presented to the CSE department,
which was awarded the best posters prize.
Improved Transport Service for Remote Sensing and Control over Wireless
In remote sensing and control applications, such as bilateral teleoperated
systems, the signal transmissions between an operator and the slave
manipulators have different QoS requirements in comparison to traditional
network traffic. The challenge for supporting teleoperated systems over
wireless networks is more difficult in comparison to wired networks. The media
streams involved in teleoperated systems differentiate themselves from other
media types in that they require both reliable and smooth delivery. Reliable
delivery requires that the transport service have TCP style semantics. By being
smooth, the transport service should be able to deliver the control and sensing
data with both the average latency and the standard deviation of the latency
bounded and reduced. We conducted numerous teleoperated experiments using our
system. Our teleoperation experiments and simulations show that traditional
transport services have great difficulty meeting the latency requirements of
delivering sensing and control data over wireless networks. This research
project proposes an improved Transport service for Remote Sensing and Control
. The service reduces the end-to-end latency and the standard deviation of the
latency (jitter) for real-time reliable media in mobile ad hoc networks by
using forward error correction encoding and multiple network paths.
Part of the research is published in MASS 2005
Modeling and Design of Mobile Surveillance Networks
Networked surveillance systems provide an extended perception and distributed
reasoning capability in monitored environments through the use of multiple
networked sensors. The challenge for such large scale networked systems is to
design an efficient modeling and analysis tool and devise stable control
algorithms for accomplishing the surveillance task. Current feature (point)
based visual servo and tracking techniques generally employed do not provide an
optimal solution for the surveillance task. This research project presents a
mutational analysis approach for shapes, and shape based control to model and
design mechanisms for such active surveillance systems. The techniques of image
based Hausdorff tracking and cooperative Hausdorff tracking are studied. Our
experimental results demonstrate the efficacy of the proposed approach for
tracking targets over a large area.
This is collaborated with Amit Goradia
and Dr. Ning Xi, et al.
Part of the research is published in IROS 2005
(slides), AIM 2005
and FLAIRS 2006.
Available Bandwidth Measurement through One Way Delay Trend Detection
Available bandwidth (AB) defined as a minimum spare capacity of links
constituting a network path is an important QoS characteristic of the path. We
propose to improve a whole range of AB measurement tools that send sequences of
measurement packets (called trains) across the network path. If transmission
times of packets in the train, called One Way Delays (OWD), show an increasing
trend as packet sequence number in the train increases, then AB is believed to
be lower than the rate at which the train was sent. In contrast, an absence of
a trend indicates that AB is higher than the rate of the train. We propose an
algorithm for efficient OWD trend detection and compare it to widely used OWD
trend detection tests.
Collaborated with Alexander L Chobanyan under the direction of Dr. Mutka.
Part of the research is published in GLOBECOM 2005.
cpuload: a tool to push the CPU load to a certain
extent to facilitate the measurement test. A wrapper
to run pathload on PlanetLab nodes. tgen: a UDP
traffic generator that generates traffic between two end hosts according to a
A Topology-Aware Routing Protocol for Hierarchical Wireless Sensor Networks
We proposed a Topology-Aware (TPAW) routing protocol for hierarchical wireless
sensor networks (WSNs), where each cluster head is capable of determining its
nearest base station (BS) and reporting timely to this very BS. A dynamic route
recovery method is proposed in the protocol to handle route failures. The
recovery is on demand as the AODV protocol does. However, in order to save
routing overheads, the TPAW takes advantage of the topology information
obtained from a probing procedure to "direct" the recovery, where the probing
is periodically initiated by the BS's to refresh the topology information. In
contrast to the DSDV protocol where each node broadcasts into the network for
route updating, the updating in TPAW is centralized by the few number of BS's.
As a result, the TPAW protocol is a hybrid of a centralized DSDV and AODV
protocol. As an effort to alleviate the frequency of probing and hence reduce
the network traffic, a robust majority vote method is proposed in TPAW protocol
to locally update the topology.
On going research collaborated with Huahui
Wang and Dr. Tongtong Li.
The work is published in EIT 2006.
QoS Aware Wireless Bandwidth Aggregation for 3G Cellular
Some mobile devices are beginning to support both cellular and IEEE 802.11 based
network interfaces. Although rates are increasing, current cellular networks
provide relatively low bandwidth that do not meet the QoS requirements of many
high-demanding multimedia applications. In this research, we propose an
integrated network architecture that utilizes both wireless interfaces to
provide better QoS support by QoS Aware Wireless Bandwidth Aggregation (QAWBA).
Via QAWBA, mobile nodes form a mobile ad hoc network (MANET) using their IEEE
802.11 interfaces to share their cellular link capacity. Some mobile nodes act
as proxies to contribute their idle cellular links to support a QoS request
that may exceed the available bandwidth of any individual mobile node. A K-path
proxy discovery algorithm is proposed for fast and efficient proxy discovery.
Simulation results show that QAWBA can significantly improve network
utilization and the admission rate of QoS requests.
This is a joint research with Danyu Zhu under the direction of Dr.
Mutka. The work is published in Qshine
2004 and GLOBECOM 2005.
We also designed a MAC layer retransmission rate based mechanism to determine
the optimal number of peers in a bandwidth sharing system. The work is
published in MASS 2006.
Solving Minimal Dominating Set Problem
CSE830 (Design and Theory of Algorithms) term project. Minimal dominating set is
one of the major NP-Complete problems. I developed a brute force algorithm with
a lot of heuristic optimizations. Here is the C Code.
Security of Windows LM Authentication
CSE891 (Selected Topics on Computer Security) term project. I discussed security
issues related with the Windows authentication protocols. Here are the
Motion Prediction in Mobile Communication Systems from a
Historical and Geographical Perspective
CSE812 (Advanced Operating Systems) term project, collaborated with
Hong Chen and Xiaomei Liu.
We proposed an algorithm to predict the motion of mobile communication hosts
based on neural network algorithms. Here are the report
Exploring Dynamic Branch Prediction Methods
This is the term project of CSE820 (Computer Architecture), working together
with Ming Wu and Junwei Zhou.
It is a literature survey of current (when I was taking the class) technologies
of predicting branches in modern processors. The report is
Network Measurement and Analysis Platform
This is my major
master degree work under the direction of Prof. Chuanshan Gao in
the Computer Science and Engineering Department of Fudan University. My
colleagues were Suo Cong,
Gansha Wu, Liangxiu Han, Chunbo Chu, Yan Liu, Feng Rao, Jun Yang, Zhige
The Internet has historically been insufficiently measured compared with its
fast development. With the rapid, tremendous, and ceaseless growth of the
network, this issue is becoming even worse. The global infrastructure of the
Internet makes it a very complex and gigantic system to analyze diagnostically.
However, the insights into the network performance are very critical to the
operation, maintenance, design and research of the network. It is well known
now that the systemic measurements of elaborate defined performance metrics
would facilitate network operations and engineering. Each measurement effort
provides a new window on the infrastructure for network operation, design and
research. But without well-considered, strategically deployed, and
collaboratively maintained measurement tools/infrastructure, these windows
cannot offer any useful insight.
The FUNAP (Fudan University Network Analysis Platform) project focuses mainly on
researching the methodologies applied in measuring the network performance,
analyzing and simulating the behavior of the network. The results from FUNAP
can be used not only in network operation and problem diagnosis but also in
researching the evolution of next generation network. I worked in this group
from Sept. 1999 to Jun. 2002.
Here are some related projects of our peers:
The Internet Performance Measurement and Analysis Project,
Towards a systemic understanding of the Internet organism: a framework for the
creation of a network analysis Infrastructure, 1998, http://moat.nlanr.net/NAI;
An Infrastructure for Internet Performance Measurements, June 1999,
Bell Labs Internet Traffic Research: http://cm.bell-labs.com/cm/ms/departments/sia/InternetTraffic/
CAIDA, a famous project on Traffic Engineering: http://www.computer.org/internet/v5n1/caida.htm,
In Chaos, Solitons and Fractals. In
Small and Micro Computer System, Chinese. In
PDCS 2001. In the Third International
Asia-Pacific Web Conference (the Presentation).
My master thesis (in Chinese) in Fudan
University. Proposal of this paper (MS PowerPoint)
Web-Based Document Management System
A joint project of GE China Lighting Technical Center and Fudan University.
Published in Computer Applications and Software,
Co-translated "Understanding Data Communications & Networks, Second
Edition", Shay, W. A., Machine Industry Publishing House. Mar., 2000
Co-translated "Distributed System Design", Jie Wu, Machine Industry Publishing
House. Feb., 2001.
Second Prize in the 5th English Lecture Contest of Fudan University Graduate
School, May, 2000. You can find the lecture script
and the slides. I used to be the Board Master of
the Foreign Language Board of Fudan BBS, here are introduction
to the board and the slides.
An introduction to Tool Command Language(MS PowerPoint)
and TCP/IP(MS PowerPoint) presented in
Kingnet Security, Inc. where I worked for a part time position in