Abstract

The number of mobile agents and total execution time are two factors used to represent the system overhead that must be considered as part of mobile agent planning (MAP) for distributed information retrieval. In addition to these two factors, the time constraints at the nodes of an information repository must also be taken into account when attempting to improve the quality of information retrieval. In previous studies, MAP approaches could not consider dynamic network conditions, e.g., variable network bandwidth and disconnection, such as are found in peer-to-peer (P2P) computing. For better performance, mobile agents that are more sensitive to network conditions must be used. In this paper, we propose a new MAP approach that we have named Timed Mobile Agent Planning (Tmap). The proposed approach minimizes the number of mobile agents and total execution time while keeping the turnaround time to a minimum, even if some nodes have a time constraint. It also considers dynamic network conditions to reflect the dynamic network condition more accurately. Moreover, we incorporate a security and fault-tolerance mechanism into the planning approach to better adapt it to real network environments.

Keywords: Mobile agents; Distributed information retrieval; Internet and mobile computing; Distributed computing; P2P computing

Article Outline

1. Introduction

2. Related works

2.1. Mobile agents and mobile agent planning

2.2. Security and fault-tolerance issues

3. System model

3.1. Structure of a mobile agent system

3.2. Planning model

4. The Tmap problem

4.1. Tmap problem

4.2. Formal Tmap problem

5. Proposed planning algorithms

5.1. Static planning

5.1.1. Preprocessing: construction of the shortest latency network

5.1.2. Planning algorithms

5.2. Dynamic planning

5.3. Security and fault-tolerance mechanism

6. Simulation

6.1. Simulation environment

6.2. Simulation results

7. Conclusions

References