Mobile Computing and Databases Systems
Mobile and wirless networks introduce many
new sub-problems in distributed computing and information systems
that are not present in
traditional computer networks, distributed databases and computing systems.
We study the effects of this new environment in the
design and development of mobile wireless networks and database systems.
An example of a mobile information and computing system is
the military inventory management that provides
total asset visibility through accurate tracking and recording
tens of thousands of items that are highly mobile over large distance
in rapidly changing environment such as the battlefield.
An effective solution to this problem is to make
each item in the inventory an active entity with
Radio Frequency Identification (RFID)
package tags that may communication with many other tagged items and
mobile support computers via terrestrial and satellites wireless
The inventory control system must interface seamlessly with
existing large military management information systems
used for command and control operations during joint field/force operations.
We have studied the problem through
characterization of wireless networks and distributed mobile system,
concept study and development,
model design and analysis,
simulation of behavior, and
evaluations of results.
We first examine
features and properties of the
the physical distributed mobile environment
in which the Army is required to track and record tens of thousands
of mobile items.
Then we survey and analyze new concepts that should be adopted
in designing various novel techniques in different areas of the system.
These new concepts are studied by building analytical and simulation model.
The behavior of the new concepts represented by the models
are then simulated using computer simulation software.
We evaluated the different alternative concepts and techniques
by comparing the results of these simulations under different set of
operating conditions or workload.
There must also be appropriate repositories and information caches
to maintain most of the voluminous data from many sources
in the radio computer network.
We are also re-examining efficient support for transactions
in mobile logistics databases involving mobile units.
Client server cache strategies must be modified to account
for mobility and changes in network attributes of both clients and servers
since communication speed and reliability will be adversely affected.
New methods for maintaining consistency and recoverability
of data may be required.
Study on the Design of Large-Scale Mobile Recording and Tracking Systems"
by Alvin Lim and Kui Mok, 31th Hawaii International Conference on System
Sciences, Hawaii, Jan 1998.
Media Access Control for Highly Mobile Information Servers: Simulation
and Performance Evaluation" by Alvin Lim, Kui
Mok, ACM Mobile Computing and Communication Review, Vol 1, No. 2,
Evaluation of Wireless Media Access Control for Mobile Computing Applications"
by Kui W. Mok and Alvin Lim, Computer Networking Workshop, Asian
Computing Science Conference, Singapore, December 1996.
Naval Facilities Engineering Service Center, PI on A Study on the
Characteristics and Requirements of Very Large and Mobile Distributed Systems
and Distributed Databases, July 95 - Mar 96, (entirely for CAU), with Calton
Pu of Oregon Graduate Institute and Nazir Warsi of Clark Atlanta University.
Science Foundation (NSF) CAREER Award. PI on Operating System Support
and Programming Environment for Evolutionary Parallel and Distributed Applications,
May 95 -- April 98.
Co-PI of award from the Army Research Laboratory
(95-98) and Army research Office (92-95) for
the Army Center of Excellence in Information Sciences, July 1992 -- June
1998, with Nazir Warsi (PI), et. al.