On the effects of adaptive forward error correction mechanism in direct broadcast satellite networks

In wireless networks where channel conditions vary over time, forward error correction (FEC), if properly employed, may be an eflective mechanism to sustain throughput. In this paper we present an adaptive FEC mechanism, developed as part of an Adaptive Resource Allocation and Management (ARAM) algorithm, for use in Direct Broadcast Satellite (DBS) networks. The algorithm performs admission control and dynamically adjusts traJfic source rate and FEC rate to sati& quality of services (QoS) requirements. To analyze its performance, we have simulated the adaptive algorithm with varying traficjlows and channel conditions. The traffic model includes a variable bit rate (VBR) source model that represents MPEG traflc jluctuations while the DBS channel model is based on A WGN. As measures of performance, the simulator quantifies throughput and dropped frames due to congestion during transmission as well as QoS variations due to channel (FEC) and source (MPEG compression) rate changes. To show the advantage of the adaptive FEC mechanism, we present the performance results when the fied FEC rates are employed. The results indicate significant throughput and/or quality gains are possible when the FEChource pairs adjusted properly.

[1]  J. Doob.  Stochastic processes , 1953 .

[2]  Olivier Verscheure,et al.  Perceptual quality measure using a spatiotemporal model of the human visual system , 1996, Electronic Imaging.

[3]  Michele Zorzi,et al.  Performance of FEC and ARQ error control in bursty channels under delay constraints , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[4]  Fouad A. Tobagi,et al.  On the performance of networks carrying multimedia traffic , 1995, High-Speed Networking for Multimedia Applications.

[5]  Raymond L. Pickholtz,et al.  Management of heterogeneous traffic loading in DBS networks , 1999, Defense, Security, and Sensing.

[6]  J. O. Noah.  A rational approach to testing MPEG-2 , 1997 .

[7]  David Haccoun,et al.  High-rate punctured convolutional codes for Viterbi and sequential decoding , 1989, IEEE Trans. Commun..

[8]  Martin Vetterli,et al.  Joint source/channel coding of statistically multiplexed real-time services on packet networks , 1993, TNET.

[9]  Amy R. Reibman,et al.  Constraints on variable bit-rate video for ATM networks , 1992, IEEE Trans. Circuits Syst. Video Technol..

[10]  Iain E. G. Richardson,et al.  Digital Video Communications , 1997 .

[11]  Ernst W. Biersack,et al.  Performance Avaluation of Forward Error Correction in an ATM Environment , 1993, IEEE J. Sel. Areas Commun..

[12]  Stephen A. Thomas,et al.  IPng and the TCP/IP Protocols: Implementing the Next Generation Internet , 1996 .

[13]  Branimir R. Vojcic,et al.  Adaptive Resource Allocation and Rate Control for Heterogeneous Traffic on DBS Links , 1999 .