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Journal of Information Science and Engineering, Vol. 23 No. 5, pp. 1407-1419 (September 2007)

Design of a Reliable Real-Time Scheduling Policy for Dual-Channel Networks*

Junghoon Lee, Mikyung Kang, Gyung-Leen Park and Sung Y. Shin+
Department of Computer Science and Statistics
Cheju National University
Jeju Do, 690-756 Korea
E-mail: {jhlee; mkkang; glpark}
+School of Computer Science and Engineering
South Dakota State University
South Dakota, SD 57007, U.S.A.

This paper designs and analyzes the performance of a communication scheduler that cooperates with each other over the dual-channel wireless network, aiming at enhancing reliability and timeliness of time-sensitive applications on embedded devices. The proposed scheme consists of (1) evenly partitioning the stream set into two identical ones, (2) applying EDF (Earliest Deadline First) policy on the respective set after an acceptance test, and (3) maximizing the number of switchable pairs. Based on this schedule and channel estimation, the coordinator schedules each node according to 3-level selection steps made up of normal schedule, channel switch, and slot reallocation. Simulation results show that the proposed scheme improves the deadline meet ratio by up to 28 %, compared with the global EDF policy, when packet error rate reaches 0.4. The slot reallocation can enhance the real-time performance by 11% when the deadline of each application gets larger up to 5 times of execution time.

Keywords: 3-level scheduling, embedded operating system, time-sensitive application, dual wireless channel, channel error handling

Full Text () Retrieve PDF document (200709_07.pdf)

Received November 15, 2006; accepted February 15, 2007.
Communicated by Sung Shin and Tei-Wei Kuo.
*This research was supported by the MIC, Korea, under the ITRC support program supervised by the IITA (IITA-2006-C1090-0603-0040).