| |
Overview
Efficient data access for mobile and pervasive computing is a field of
increasing importance for a wide range of mobile businesses and
applications. It will be a key technology as ubiquitous wireless
connectivity becomes a reality. We are one of the first few pioneers who
started research in this area. We have been studying several fundamental
issues in data and resource management of mobile computing systems,
including: indexing and caching for reducing power consumption and
increasing data access efficiency, data allocation for multiple wireless
communication channels, cache invalidation and replacement policy for
wireless data dissemination, and performance modeling and evaluation for
wireless data access.
Many of the techniques we developed have been well received in the field
and inspired a number of follow-up works. The signature schemes we developed
for wireless information filtering [DAPD'96,
WINET'99] have become a classical energy efficient indexing technique
for wireless data broadcast services. We also analyzed the problems of
wireless channel allocation for data dissemination via on-demand and
broadcast channels and developed a dynamic channel allocation algorithm to
optimize the system performance [ICDCS'98,
MONET'99]. By integrating various related techniques proposed in our
studies, we developed a hierarchical wireless data dissemination system
which has brought a lot of insights to to the research of data dissemination
systems [MobiCom'99].
We also developed indexing techniques to support energy-efficient queries
specified based on multiple attributes [ICDE'00,
MONET'01] and mobile caching techniques for on-demand data broadcast
systems [CIKM'00,
ICPP'01,
TKDE'04]. Moreover, We have recently developed a novel parameterized
index, called the exponential index, which allows the system
administrators to use two tuning knobs (i.e., index base and chunk
size), to optimize the access latency with the tuning time bounded by a
given limit, and vice versa [MobiSys'04,
TKDE].
These research results could be used in wireless data services such as MSN
Direct and StarBand and may have practical impact on on-going work in
standard bodies (e.g., the Broadcast and Multicast Service for CDMA2000
Wireless IP network, being developed by the Third Generation Partnership
Project 2 (http://www.3gpp2.org/).
While many of of our previous work focused on system issues, we have
recently paying attention to various application requirements such as
timeliness and security. We have developed a novel on-demand
broadcast scheduling algorithm by taking into consideration the urgency
of requests and the number of outstanding requests [TPDS].
In this study, theoretical bound of request drop rate when the request
arrival rate rises towards infinity is derived. We have also investigated
the tradeoff between performance and confidentiality of
signature-based air indexes in terms of their relationships to false drop
and false guess probabilities of the signatures [CIKM'05].
This is the first time the issue of confidentiality loss in air indexing has
been identified and discussed in the literature. Additionally, an efficient
key management scheme, KTR, has been developed to for access control
of broadcast data [Mobiquitous'05].
KTR allows multiple broadcast programs share a single key tree such that the
users subscribing these programs need to hold only a small number of keys.
In this scheme, rekey cost is minimized by identifying the minimum set of
keys that must be changed to ensure broadcast security. This is also the
first time a key management scheme being proposed for wireless data
broadcast.
Current Members
Collaborators
 | Dik Lun Lee |
 | Peng Liu |
 | Xueyan Tang |
 | Jianliang Xu |
Publication
-
C.K. Lee, W.-C. Lee, and
S. Madria, Pervasive Data Access in Wireless and Mobile Computing
Environments, Wireless Communication and Mobile
Computing Journal, to appear.
-
J. Xu, W.-C. Lee, X. Tang,
Q. Gao, and S. Li, An Error-Resilient and Tunable Distributed Indexing
Scheme for Wireless Data Broadcast, IEEE
Transactions on Knowledge and Data Engineering (TKDE), to
appear. [pdf]
-
J. Xu, X. Tang, and W.-C.
Lee, On Scheduling Time-Critical On-Demand Broadcast,
IEEE Transaction on Distributed and Parallel
Systems,
Volume 17, Issue 1, Jan. 2006, pp. 3-14.
[pdf]
-
Q. Tan,
W.-C. Lee, B. Zheng, P. Liu, and D.L. Lee, Balancing Performance and
Confidentiality in Air Index, ACM Fourteenth
Conference on Information and Knowledge Management (CIKM'05),
Breman, Germany, October 2005, to appear. [pdf]
-
J. Xu, W.-C. Lee, and X.
Tang, Exponential Index: A Parameterized Distributed
Indexing Scheme for Data on Air, the Second
International Conference on Mobile Systems, Applications, and Services
(Mobisys'04), Boston, MA, June 6-9, 2004, pp. 153-164. [pdf]
-
J. Xu, W.-C. Lee, and J.
Liu, Scheduling Web Requests in Broadcast Environments,
the thirteenth International World Wide Web
Conference (WWW'04), New York, NY, May 17-22, 2004, pp.
280-281. (Poster)
-
J. Xu, Q. Hu, W.-C. Lee,
and D.L. Lee, Performance Evaluation of an Optimal Cache Replacement
Policy for Wireless Data Dissemination under Cache Consistency,
IEEE Transaction on Knowledge and Data Engineering (TKDE),
Volume 16, No. 1, January, 2004, pp. 125-139. [pdf]
J. Lee, W.-C. Lee, C.-P.
Liu, A.-T. Wang, and C. Chang, Monte Carlo Methods on Customer Retrial
Calls in Communication Networks, Chung Yuan
Journal, Vol. 31, No. 3, September, 2003, pp. 151-159.
J. Xu, W.-C. Lee, D.L.
Lee, and Q. Hu, Data Broadcast, Handbook of
Wireless Networks and Mobile Computing, edited by I.
Stojmenovic, John Wiley & Sons, 2002, ISBN 0-471-41902-8, pp. 243-265.
W.-C. Lee and D.L. Lee,
Models and Infrastructures for Pervasive Computing,
NSF Workshop on Context-Aware Mobile Database
Management (CAMM), Providence, Rhode Island, January 24-25,
2002. [pdf]
J. Xu, Q. Hu, W.-C. Lee,
and D.L. Lee, An Optimal Cache Replacement Policy for Wireless Data
Dissemination under Strong Cache Consistency,
International Conference on Parallel Processing (ICPP'01),
Valencia, Spain, September 3-7, 2001, pp. 267-274. [pdf]
Q. Hu, W.-C. Lee, and D.L.
Lee, Indexing Techniques for Power Management in Multi-Attribute Data
Broadcast, ACM Mobile Networks and Applications
Journal (MONET): Special Issue on Management of Mobility in Distributed
Systems, Volume 6, No. 2, March 2001, pp. 185-197. [pdf]
Q. Hu, W.-C. Lee, and D.L.
Lee, A Hybrid Index Techniques for Power Efficient Data Broadcast,
Distributed and Parallel Databases,
Volume 9, No. 2, March 2001, pp. 151-177. [pdf]
Q. Hu,
W.-C. Lee, and D.L. Lee, Power Conserving and Access Efficient
Indexes for Wireless Computing, Information
Organization and Databases, edited by K. Tanaka, S.
Ghandeharizadeh, and Y. Kambayashi, Kluwer Academic Publishers, Boston,
MA, 2000, pp. 249-264.
J. Xu, Q.
Hu, W.-C. Lee, and D.L. Lee, SAIU: An Efficient Cache Replacement
Policy for Wireless On-demand Broadcasts, the
Ninth ACM International Conference on Information and Knowledge Management
(CIKM’00), McLean, VA, Nov. 6-11, 2000, pp. 46-53. [pdf]
Q. Hu,
W.-C. Lee, and D.L. Lee, Power Conservative Multi-Attribute Queries
on Data Broadcast, IEEE International Conference
on Data Engineering (ICDE'00), San Diego. Feb. 2000, pp.
157-166. [pdf]
W.-C. Lee, J. Lee and K.
Huff, On Simulation Modeling of Information Dissemination Systems in
Mobile environments, ACM/IEEE International
Conference on Mobile Data Access (MDA’99), Hong Kong, Dec.
1999, pp. 45-57. [pdf]
Q. Hu,
W.-C. Lee, and D.L. Lee, Indexing Techniques for Wireless Data
Broadcast Under Data Clustering and Scheduling,
ACM International Conference on Information and Knowledge Management
(CIKM'99), Kansas City, Missouri, Nov. 1999, pp. 351-358. [pdf]
Q. Hu, D.L.
Lee, and W.-C. Lee, Performance Evaluation of a Wireless
Hierarchical Data Dissemination System, ACM/IEEE
International Conference on Mobile Computing and Networking (Mobicom'99),
Seattle, Washington, August 1999, pp. 163-173. [pdf]
W.-C. Lee,
Q. Hu, and D.L. Lee, A Study of Channel Allocation Methods for Data
Dissemination in Mobile Computing Environments,
ACM Mobile Networks and Applications Journal (MONET): Special Issue on
Resource Management in Wireless Network, Volume 4, No. 2, 1999,
pp. 117-129. [pdf]
W.-C. Lee and D.L. Lee,
Signature Caching Techniques for Information Filtering in Mobile
Environments, ACM Wireless Networks Journal (WINET),
Volume 5, No. 1, January 1999, pp. 57-67. [pdf]
Q. Hu,
W.-C. Lee, and D.L. Lee, Dynamic Data Delivery in Wireless
Communication Environments, International
Workshop on Mobile Data Access, Singapore, Nov. 1998, pp.
218-229.
D.L. Lee,
Q. Hu, and W.-C. Lee, Indexing Techniques for Data Broadcast on
Wireless Channel, the Fifth International
Conference of Foundations of Data Organization (FODO'98), Kobe,
Japan, Nov. 1998, pp. 175-182. [pdf]
Q. Hu, D.L.
Lee, and W.-C. Lee, Optimal Channel Allocation for Data
Dissemination in Mobile Computing Environments,
IEEE Conference on Distributed Computing Systems (ICDCS'98),
Amsterdam, Netherlands, May 1998, pp. 480-487. [pdf]
Q. Hu,
W.-C. Lee, and D.L. Lee, A Comparison of Index Methods for Data
Broadcast on the Air, International Conference on
Information Networking (ICOIN'98), Tokyo, Japan, Jan. 1998, pp.
656-659.
W.-C. Lee,
Q. Hu, and D.L. Lee, Channel Allocation Methods for Data
Dissemination in Mobile Environments, the Sixth
Symposium on High Performance Distributed Computing (HPDC'97),
Portland, Oregon, August 5-8, 1997, pp. 274-281. [pdf]
W.-C. Lee,
and D.L. Lee, Using Signature Techniques for Information Filtering
in Wireless and Mobile Environments, Distributed
and Parallel Databases: Special Issue on Database and Mobile Computing,
Vol. 4, No. 3, July 1996, pp. 205-227. (Also appears as a chapter in the
book, Databases and Mobile Computing,
edited by D. Barbara, R. Jain and N. Krishnakumar, Kluwer Academic
Publishers, 1996, ISBN: 0792397495. ) [pdf]
W.-C. Lee,
and D.L. Lee, On Signature Caching of Wireless Broadcast and
Filtering Services, the Second International
Mobile Computing Conference, Hsinchu, Taiwan, March 25-27,
1996, pp.15-24.
W.-C. Lee, and D.L. Lee, Information Filtering in Wireless and
Mobile Environments, IEEE International Phoenix
Conference on Computers and Communications (IPCCC'96), Phoenix,
Arizona, March 27-29, 1996, pp. 508-514. [pdf]
|
|
|