Best-effort scheduling of (m, k)-firm real-time streams in multihop networks

In this paper, we address the problem of best-effort scheduling of (m,k)-firm real-time streams in multihop networks. The existing solutions for the problem ignore scalability considerations because the solutions maintain a separate queue for each stream and maintain per-stream state information. In this context, we propose a scheduling algorithm, Enhanced Distance Based Priority (EDBP), which is scalable (fixed scheduling cost) while offering performance close to that of the existing solutions. The proposed EDBP algorithm achieves this by allowing multiplexing of streams into a fixed number of queues and by using the notion of a look-ahead window. In the EDBP algorithm, at any point of time, the best packet for transmission is selected based on the state of the stream combined with the laxity of the packet. We have conducted extensive simulation studies to evaluate the effectiveness of the proposed EDBP algorithm by comparing it with existing algorithms for the problem. The simulation studies reveal that the dynamic failure performance of the EDBP algorithm is very close to that of the existing algorithms with a significant reduction in scheduling cost.

[1]  Walter Weiss,et al.  QoS with differentiated services , 1998, Bell Labs Technical Journal.

[2]  Chong Kwan Un,et al.  Performance Analysis of Reconstruction Algorithms for Packet Voice Communications , 1994, Comput. Networks ISDN Syst..

[3]  Hui Zhang,et al.  Service disciplines for guaranteed performance service in packet-switching networks , 1995, Proc. IEEE.

[4]  Henning Schulzrinne,et al.  Real-time communication in packet-switched networks , 1994, Proc. IEEE.

[5]  Dinesh C. Verma,et al.  A Scheme for Real-Time Channel Establishment in Wide-Area Networks , 1990, IEEE J. Sel. Areas Commun..

[6]  P. Ramanathan,et al.  DBP-M: a technique for meeting end-to-end (m, k)-firm guarantee requirement in point-to-point networks , 1997, Proceedings of 22nd Annual Conference on Local Computer Networks.

[7]  Parameswaran Ramanathan.  Graceful degradation in real-time control applications using (m, k)-firm guarantee , 1997, Proceedings of IEEE 27th International Symposium on Fault Tolerant Computing.

[8]  Donald F. Towsley,et al.  On per-session end-to-end delay distributions and the call admission problem for real-time applications with QOS requirements , 1993, SIGCOMM '93.

[9]  Kang G. Shin,et al.  Real-Time Communication in Multihop Networks , 1994, IEEE Trans. Parallel Distributed Syst..

[10]  Jim Kurose,et al.  On per-session end-to-end delay distributions and the call admission problem for real-time applications with QOS requirements , 1993, SIGCOMM 1993.

[11]  Scott Shenker,et al.  Two issues in reservation establishment , 1995, SIGCOMM '95.

[12]  Parameswaran Ramanathan,et al.  A Dynamic Priority Assignement Technique for Streams with (m, k)-Firm Deadlines , 1995, IEEE Trans. Computers.

[13]  Don Towsley,et al.  Optimal scheduling policies for a class of Queues with customer deadlines to the beginning of service , 1990, PERV.