Enhanced Uplink Scheduling for Continuous Connectivity in High Speed Packet Access Systems

Saied M. Abd El-Atty, Konstantinos Lizos

Department of Computer Science and Information, College of Arts & Science, Salman Bin Abdulaziz University, Wadi Addawasir, KSA.
Head of IT Department, Embassy of Greece Nobels Gate 45, Oslo, Norway.

DOI: 10.4236/ijcns.2012.58055                

Abstract

The efficiency of high speed packet access (HSPA) systems is mainly based on channel quality information (CQI) reports transmitted by user equipment (UE) to Node B. In this paper, we propose an improved CQI prediction scheme based on a finite state Markov chain (FSMC) model for wireless channel, in order to reduce CQI signaling overhead in the HSPA system. Then, we introduce an enhanced uplink packet scheduling (EUPS) scheme to provide quality of services (QoS) guaranteed for continuous packet connectivity in the enhanced uplink (EUL). EUPS serves the active UEs not only according to buffer status but also according to reported state of the wireless channel of each UE. The performance of the proposed scheme in terms of average packet delay, average packet drop and average cell throughput is compared to the classical scheduler of 3GPP standards. The simulation results show the effectiveness of the proposed scheme.

Keywords

EUL; Scheduling; CQI; FSMC; HSPA

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	“HSPA Brings the World,” http://www.ericsson.com
[2]	H. Holma and A. Toskala, “HSDPA/HSUPA for UMTS High Speed Radio Access for Mobile Communications,” John Wiley & Sons Ltd., Hoboken, 2006. doi:10.1002/0470032634
[3]	3GPP TS 25.319 V7.2.0, “Enhanced Uplink; Overall Description; Stage 2 (Release 7),” 2007.
[4]	C. Rosa, J. O. Carnero, T. B. S?rensen, J. Wigard and P. E. Mogensen, “Combined Time and Code Division Scheduling for Enhanced Uplink Packet Access in WCDMA,” IEEE Proceedings of the 60th Vheicular Technology Conference, Los Angeles, 26-29 September 2004, pp. 851-855.
[5]	D. C. Dimitrova, J. L. van den Berg, G. J. Heijenk and R. Litjens, “Flow Level Performance Comparison of Packet Scheduling Schemes for UMTS EUL,” Proceedings of 6th International Conference on Wired/Wireless Internet Communications, Tampere, 28-30 May 2008, pp. 27-40.
[6]	Y. J. Kang, J. Kim, D. K. Sung and S. Lee, “Hybrid Scheduling Algorithm for Guaranteeing QoS of Real-Time Traffic in High Speed Uplink Packet Access (HSUPA),” IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, Athens, 3-7 September 2007, pp. 1-5.
[7]	3GPP TR 25.858 V5.0.0, “High Speed Downlink Packet Access: Physical Layer Aspects (Release 5),” 2002.
[8]	N. Fukui, “Study of Channel Quality Feedback in UMTS HSDPA,” 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 7-10 September 2003, pp. 336-340.
[9]	Q. Q. Zhang and S. A. Kassam, “Finite-State Markov Model for Rayleigh Fading Channels,” IEEE Transactions on Communication, Vol. 47, No. 11, 1999, pp. 1688-1692. doi:10.1109/26.803503
[10]	3GPP TR 25.896 V6.0.0, “Feasibility Study for Enhanced Uplink for UTRA FDD,” 2004.
[11]	ETSI, “Universal Mobile Telecommunications System (UMTS); Selection Procedures for the Choice of Radio Transmission Technologies of the UMTS,” TR 101 112, V3.2.0, 1998.