Mobile Agents For Personalized
Information Retrieval: When are they a
good idea?
Ravi Jain and
Farooq Anjum
An SAIC Company
Telcordia Contact:
Farooq Anjum
[email protected]
Telcordia Technologies Proprietary – Internal Use Only
This document contains proprietary information that shall be distributed, routed or made available only
within Telcordia Technologies, except with written permission of Telcordia Technologies.
Plan
 Contributions
 Mobile Agents
 Performance Model
 Performance Evaluation
 Summary
 Future Work
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Contributions
 A preliminary analytical model for comparing performance
benefits of using mobile agents over client server computing
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Client Server vs Mobile Agent
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Mobile Agents
 Mobile Agent
– Self contained piece of software that can migrate and execute
on different machines in a dynamic networked environment
 Justifications for using Mobile Agents
– Performance benefits




reduction in network bandwidth consumption
reduced latency
reduced computation
increased fault tolerance
– Software Engineering
 conceptualize solutions better
 improve code modularity and reusability
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Performance Model
 A stationary user with a wireless last hop
 Information gathering
 Desire to consider the latency
– with client server paradigm
– with mobile agents
 N servers to be searched for information
 packets lost over wireless link with prob p
 size of client query message is unity
 size of agent is then M
 parameter R to model information filtering by agents
 At each site information found with probability pi and time to
process query denoted ti
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
System model for wireless information
retrieval
Can characterize the average information latency under the
two paradigms
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Model Evaluation Scenarios
 ALL
– all N predetermined server sites are searched
 SURE DECREASING
– servers searched in decreasing order of success probability
 SURE RANDOM
– servers searched in random order
 MAYBE-LARGE
– information need not exist on servers searched
– pi <1
 MAYBE-SMALL
– information need not exist on servers searched
– pi <0.1
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Visiting all servers without agent filtering
Agents advantageous for
•small agent size without filtering
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Visiting all servers with agent filtering
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Visiting servers in sequential order
With sequential search and no filtering
advantage of mobile agents is lost
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Visiting servers in sequential order with
filtering
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Visiting servers in random order
If sites to be searched in random order then MA
to be preferred
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Maybe Large Scenario
A scenario that is not favorable to MA
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Maybe Small Scenario
A scenario that is favorable to MA
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Summary
 Developed a simple analytical model to quantify
performance benefits of using mobile agent technology over
client server techniques
 Evaluated the model for different scenarios
– Expected latency being the metric
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Future Work
 Multiple Mobile Users
 A detailed study
– Queuing theoretic approach
 Considering agent activation/inactivation
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000
Any questions
Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Farooq Anjum
WCNC 2000 Sept 23-28 2000