The performance of two-hop contention based bandwidth request (BR) mechanism for WiMAX relay networks is investigated under ITU-R path loss models. In conventional WiMAX systems, the mobile stations (MS) update their contention window irrespective of their transmission failures. Those systems update their contention window on collision and due to channel error or unavailability of bandwidth. Further, these failure models have been suggested for single hop networks. The failure model in two-hop systems becomes complex since it may include additional failure events such as improper detection of codes and channel error due to varying path loss. Interestingly, these failure events (collision, channel error, unavailability of bandwidth, and improper detection of codes) do not occur evenly for both hops of a link. Hence, to set the contention window effectively, unique failure models are developed by considering the characteristics of BR mechanism and hop at which the BR is performed. In the proposed system, the two-hop BR is carried out with all combinations of message and code bandwidth request schemes. Among them, the message-code BR mechanism performs better under suburban fixed and outdoor to indoor or pedestrian environment, and code-code BR scheme performs better for vehicular environment. 1. Introduction Broadband wireless technologies with worldwide interoperability for microwave access (WiMAX) networks are gaining tremendous attention due to the increasing consumer demands. WiMAX is envisioned to provide high-speed data rate to last mile and last inch customers. In recent years, mobile WiMAX has emerged to support high-speed data rate to customers at vehicular speed. The IEEE 802.16j task group has been formed to extend the scope of single hop WiMAX network (IEEE 802.16e) in terms of capacity (throughput) and coverage [1]. In WiMAX relay network, the stations of interest are base station (BS), relay station (RS), and mobile station (MS). Based on the number of hops between BS and MS, the WiMAX networks may be classified into two types, namely, single hop network and multihop network. Further, the architecture modes supported by the WiMAX standard are as follows: point-to-point (PP), point-to-multipoint (PMP), and mesh modes. In a single hop network, the MS communicate directly with the BS, and hence the network follows PP (between BSs) or PMP architecture [2, 3]. In multihop network, the MS may not be in a position to communicate directly with the BS and involve multiple hops to establish the connectivity. One or more RS are involved to establish
References
[1]
IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Broadband Wireless Access Systems, pp. C1-2004, May 2009.
[2]
W. H. Liao, K. P. Shih, C. Liu, A. K. Dubey, S. Arora, and S. P. Kedia, “An efficient scheduling algorithm for radio resource reuse in IEEE 802.16j multi-hop relay networks,” Computers and Electrical Engineering, vol. 37, no. 4, pp. 511–525, 2011.
[3]
F. M. Chang, I. P. Hsieh, and S. J. Kao, “An efficient uplink scheduling mechanism with enabling multi-device transmission and maximum latency fulfillment in IEEE 802. 16j networks,” in Proceedings of 6th International Conference on Computer Science & Education (ICCSE '11), pp. 1410–1415, August 2011.
[4]
M. Salem, A. Adinoyi, H. Yanikomeroglu, and Y. D. Kim, “Radio resource management in OFDMA-based cellular networks enhanced with fixed and nomadic relays,” in Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC '10), pp. 1–6, April 2010.
[5]
S. M. Kim, S. H. Kim, S. H. Yoon, and D. K. Sung, “A hybrid radio resource management scheme for uplink relay-based cellular networks,” in Proceedings of the IEEE 20th Personal, Indoor and Mobile Radio Communications Symposium (PIMRC '09), pp. 1873–1877, September 2009.
[6]
Z. Abichar, A. E. Kamal, and J. M. Chang, “Planning of relay station locations in IEEE 802.16 (WiMAX) networks,” in IEEE Wireless Communications and Networking Conference (WCNC '10), April 2010.
[7]
V. Genc, S. Murphy, and J. Murphy, “Performance analysis of transparent relays in 802.16j MMR networks,” in Proceedings of the 6th Intl. Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (Wiopt '08), pp. 273–281, April 2008.
[8]
F. Wang, A. Ghosh, C. Sankaran, P. J. Fleming, F. Hsieh, and S. J. Benes, “Mobile WiMAX systems: performance and evolution,” IEEE Communications Magazine, vol. 46, no. 10, pp. 41–49, 2008.
[9]
J. Zhang, G. Liu, F. Zhang, L. Tian, N. Sheng, and P. Zhang, “Advanced international communications,” IEEE Vehicular Technology Magazine, vol. 6, no. 2, pp. 92–100, 2011.
[10]
K. Bakowski and K. Wesolowski, “Change the channel,” IEEE Vehicular Technology Magazine, vol. 6, no. 2, pp. 82–91, 2011.
[11]
N. Lee, Y. Choi, S. Lee, and N. Kim, “A new CDMA-based bandwidth request method for IEEE 802.16 OFDMA/TDD systems,” IEEE Communications Letters, vol. 14, no. 2, pp. 124–126, 2010.
[12]
C. C. Chong, F. Watanabe, H. Inamura, K. Kitao, and T. Imai, “Performance comparison of the 3GPP/3GPP2 SCM and ITU-R IMT-advanced MIMO channel models,” in Proceedings of the IEEE 20th Personal, Indoor and Mobile Radio Communications Symposium (PIMRC '09), September 2009.
[13]
P. Begovic, N. Behlilovic, and E. Avdic, “A novel approach for evaluating applicability of existing empirical propagation models to coverage planning in 3.5 GHz WiMAX systems,” in Proceedings of 18th International Conference on Systems, Signals and Image Processing (IWSSIP '11), pp. 1–9, June 2011.
[14]
C. Ide, B. Dusza, and C. Wietfeld, “Mobile WiMAX performance measurements with focus on different QoS targets,” in Proceedings of 18th IEEE Workshop on Local & Metropolitan Area Networks (LANMAN '11), pp. 1–6, October 2011.
[15]
D. De Luca, F. Fiano, F. Mazzenga, C. Monti, S. Ridolfi, and F. Vallone, “Outdoor path loss models for IEEE 802.16 in suburban and campus-like environments,” in Proceedings of the IEEE International Conference on Communications (ICC '07), pp. 4902–4906, June 2007.
[16]
J. De Bruyne, W. Joseph, L. Verloock, and L. Martens, “Measurements and evaluation of the network performance of a fixed WiMAX system in a suburban environment,” in Proceedings of the IEEE International Symposium on Wireless Communication Systems (ISWCS '08), pp. 98–102, October 2008.
[17]
J. W. So, “Performance analysis of VoIP services in the IEEE 802.16e OFDMA system with inband signaling,” IEEE Transactions on Vehicular Technology, vol. 57, no. 3, pp. 1876–1886, 2008.
[18]
F. E. Ismael, S. K. Syed Yusof, and N. Fisal, “Bandwidth grant algorithm for delay reduction in IEEE 802.16j MMR WiMAX networks,” International Review on Computers and Software, vol. 5, no. 2, pp. 242–248, 2010.
[19]
B. Upase and M. Hunukumbure, “Dimensioning and cost analysis of multihop relay-enabled WiMAX networks,” Fujitsu Scientific and Technical Journal, vol. 44, no. 3, pp. 303–317, 2008.
[20]
K. C. Chu and T. C. Huang, “A novel bandwidth request mechanism for IEEE 802.16j networks,” Tamkang Journal of Science and Engineering, vol. 13, no. 1, pp. 71–78, 2010.
[21]
D. Niyato, E. Hossain, D. I. Kim, and Z. Han, “Relay-centric radio resource management and network planning in IEEE 802.16j mobile multihop relay networks,” IEEE Transactions on Wireless Communications, vol. 8, no. 12, pp. 6115–6125, 2009.
[22]
P. Mach and R. Bestak, “Analysis and performance evaluation of IEEE 802.16 enhanced with decentrally controlled relays,” in Proceedings of the 16th International Conference on Systems, Signals and Image Processing (IWSSIP '09), pp. 1–6, June 2009.
[23]
Z. Becvar and P. MacH, “Reduction of scanning reporting overhead in IEEE 802.16 networks with relays,” in Proceedings of the 9th International Conference on Networks (ICN '10), pp. 109–114, April 2010.
[24]
J. Zhang, S. Feng, W. Ye, and H. Zhuang, “Reducing signaling overhead and latency of 802.16j service flow management,” in Proceedings of the International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM '08), October 2008.
[25]
Y. T. Mai, C. C. Yang, J. Y. Chen, and K. Y. Chen, “A zone-based bandwidth allocation protocol in WiMAX multi-hop relay networks,” in Proceedings of the International Conference on Information Networking (ICOIN '11), pp. 257–261, January 2011.
[26]
E. Calvo, J. Vidal, and J. R. Fonollosa, “Optimal resource allocation in relay-assisted cellular networks with partial CSI,” IEEE Transactions on Signal Processing, vol. 57, no. 7, pp. 2809–2823, 2009.
[27]
Y. P. Fallah, F. Agharebparast, M. R. Minhas, H. M. Alnuweiri, and V. C. M. Leung, “Analytical modeling of contention-based bandwidth request mechanism in IEEE 802.16 wireless networks,” IEEE Transactions on Vehicular Technology, vol. 57, no. 5, pp. 3094–3107, 2008.
[28]
Q. Ni, L. Hu, A. Vinel, Y. Xiao, and M. Hadjinicolaou, “Performance analysis of contention based bandwidth request mechanisms in WiMAX networks,” IEEE Systems Journal, vol. 4, no. 4, pp. 477–486, 2010.
[29]
D. Chuck, K. Y. Chen, and J. M. Chang, “A comprehensive analysis of bandwidth request mechanisms in IEEE 802.16 networks,” IEEE Transactions on Vehicular Technology, vol. 59, no. 4, pp. 2046–2056, 2010.
[30]
R. Anbazhagan and N. Rangaswamy, “Contention resolution with EIED backoff for bandwidth request in IEEE 802.16 networks,” Elsevier International Journal of Electronics and Communications, vol. 67, no. 1, pp. 40–44, 2013.
[31]
International telecommunications Union—Recommendations (ITU-R), “Guidelines for evaluation of radio interface technologies for IMT-Advanced,” ITU-R Report M. 2135, Geneva, Switzerland, 2008.
