OPNET Simulation of Fast Handover WLAN Protocols for Voice over WLAN (VoWLAN)

Sophisticated and robust security algorithms, demanded in today widely deployed IEEE 802.11 WLAN Technology, have introduced a challenging topic for time-sensitive voice application during roaming from one Access Point (AP) to another. A lot of research has been performed to minimize the latency involved in handover from one AP to another without compromising the security. These research efforts were aimed to reduce the latency of handoff process which can be categorized to three important phases: scanning and detecting the best time to start for handover, selecting the best available AP to handover to and the secure execution of handover to the new AP.

In this project, I plan to review the handover schemes and protocols that have been developed to improve the handover performance and explore the possibility of developing a new fast secure handover protocol. The IEEE 802.11r, which is an extension to IEEE 802.11 to support the fast roaming, will be the base of my study. I also plan to simulate the protocol performance using OPNET.

References:
[1] IEEE 802.11r, Wireless LAN Medium Access Control and Physical Layer Specification: Amendment for Fast BSS Transition, IEEE Standard 2008.
[2] H. Ahmed and H. Hassanein, "A performance study of roaming in wireless local area networks based on IEEE 802.11r," in Proc. IEEE 24th Biennial Symposium on Communications, Kingston, ON, June 2008, pp. 253-257.
[3] T. Clancy "Secure handover in enterprise WLANs: capwap, hokey, and IEEE 802.11R," IEEE Journal, Wireless Communications, vol. 15, no. 5, pp. 80-85, Oct. 2008.
[4] T. Manodham, L. Loyola, G. Atoche, M. Hayasaka, and T. Miki, "A novel handover scheme for reducing latency in WLANs, in Proc. 62nd IEEE Vehicular Technology Conference, vol. 2, Sept. 2005, pp. 1141-1144.
[5] J. Raiyn, "A novel handover scheme based on adaptive agent for reducing real-time communication latency in automation environment," in Proc. 10th International IEEE Conference on Computer Modeling and Simulation, Apr. 2008, pp. 555-561.
[6] OPNET Modeler version 14.5 with wireless module, WLAN MAC process modelD: http//www.opnet.com.
[7] P. Goransson and R. Greenlaw, "Roaming securely in 802.11," in Secure Roaming in 802.11 Networks, Elsevier, 2007, pp.195-218.

Efficient Protocols for Interactive Applications in Internet

Presentation slides and final report (PDF files).

TCP and UDP protocols are most widely used transport protocols in the Internet. Even though most Internet applications rely on TCP or UDP transmission, they are not designed for the interactive applications that require real-time operations. Several approaches proposed new transport protocols for the interactive applications [1]-[3]. In this project, I plan to investigate efficient transport protocols for the interactive applications and evaluate TCP and UDP performance in terms of time delays and data losses.

References:
[1] R. Wirz, "Efficient transport protocol for networked haptics applications," Proceedings of the 6th International Conference on Haptics: Perception, Devices and Scenarios, Madrid, Spain, June 2008, vol. 5024, pp. 3-12.
[2] L. Ping, "Transport layer protocol reconfiguration for network-based robot control system," Proceedings of IEEE International Conference on Networking, Sensing and Control, Tucson, AZ, Mar. 2005, pp. 1049-1053.
[3] Y. Uchimura, "Bilateral robot system on the real-time network structure," IEEE Transactions on Industrial Electronics, vol. 51, no.5, pp. 940-946, Oct. 2004.
[4] J. Postel, RFC 793: Transmission Control Protocol, DARPA Internet Program Protocol Specification, 1981.
[5] J. Postel, RFC 768: User Datagram Protocol, 1980.

Implementation of an IEEE 802.15.4 and ZigBee Protocol using the OPNET simulator

Presentation slides and final report (PDF files).

The IEEE 802.15.4 standard and ZigBee protocol define a low-cost, ultra-low power consumption, reliable and secure wireless network with a low data rates up to 250 kbps. They are used in Advanced Metering Infrastructure (AMI), Home Automation, and Industrial Plant Monitoring (IPM). The physical layer employs three unlicensed RF bands of 868, 915, and 2400 MHz. The range of radio transmission of the ZigBee devices are from 30 to 200 meters. In some cases, remote access or longer range is required to operate the network effectively. In this project, I plan to implement the ZigBee protocol and use a gateway to communicate to a remote device via Internet using TCP/IP protocol to demonstrate the effectiveness of the approach.

References:
[1] E. D. Pinedo-Frausto, and J. A. Garcia-Macias, "An experimental analysis of ZigBee networks," Proc. LCN, 33rd IEEE Conference, Montreal, Que. Oct. 2008, pp. 723 - 729.
[2] X. Li, K. Fang, J. Gu, and L. Zhang, "An improved ZigBee routing strategy for monitoring system," Proc. ICINIS, First International Workshop, Wuhan, Nov. 2008, pp. 255 - 258.
[3] W.-K. Park, C.-S. Choi, J. Han, and I. Han, "Design and implementation of ZigBee based URC applicable to legacy home appliances," Proc. ISCE, IEEE International Symposium, Irving, TX. June 2007, pp. 1 - 6.
[4] N.-C. Liang, P.-C. Chen, T. Sun, G. Yang, L.-J. Chen, and M. Gerla, "Impact of node heterogeneity in ZigBee mesh network routing," Proc. SMC, IEEE International Conference, Taipei, Oct. 2006, vol. 1, pp. 187 - 191.
[5] Y.-Wen Bai, and C.-H. Hung, "Remote power On/Off control and current measurement for home electric outlets based on a low-power embedded board and ZigBee communication," Proc. ISCE, IEEE International Symposium, Vilamoura, Apr. 2008, pp. 1 - 4.
[6] S. Ahn, J. Cho, and S. An, "Slotted beacon scheduling using ZigBee cskip mechanism," Proc. SENSORCOMM , Second International Conference, Cap Esterel, Aug. 2008, pp. 103 - 108.
[7] I.-K. Hwang, and J.-W. Baek, "Wireless access monitoring and control system based on digital door lock," IEEE J. Consumer Electronics, vol. 53, no. 4, pp. 1724 - 1730, Nov. 2007.
[8] C.-H. Liu, and C.-C. Fan, "ZigBee - research into integrated real-time located systems," Proc. APSCC, IEEE, Yilan, Taiwan, Dec. 2008, pp. 942 - 947.
[9] J. Y. Jung, and J. W. Lee, "ZigBee device access control and reliable data transmission in ZigBee based health monitoring system," Proc. ICACT , 10th International Conference, Gangwon-Do, Feb. 2008, vol. 1, pp. 795 - 797.
[10] P. Suarez, C.-G. Renmarker, A. Dunkels, and T. Voigt, "Increasing ZigBee network lifetime with X-MAC", Proc. REALWSN, Glasgow, Scotland, 2008, pp. 26 - 30.
[11] M. Kohvakka, M. Kuorilehto, M. Hnnikinen, and T. D. Hmlinen, "Performance analysis of IEEE 802.15.4 and ZigBee for large-scale wireless sensor network applications," Proc. PE-WASUN, Terromolinos, Spain, 2006, pp. 48 - 57.
[12] Y.-C. Tseng, and M.-S. Pan, "Quick convergecast in ZigBee/IEEE 802.15.4 tree-based wireless sensor networks," Proc. MOBIWAC, Terromolinos, Spain, 2006, pp. 60 - 66.
[13] M.-S. Pan, and Y.-C. Tseng, "The orphan problem in ZigBee-based wireless sensor networks," Proc. MSWiM, Chania, Crete Island, Greece, 2007, pp. 95 - 98.
[14] H. Labiod, H. Afifi, and C. De Santis, Wi-Fi, Bluetooth, ZigBee and WiMAX. London: Springer, 2007, pp. 109 - 122, 210 - 212.
[15] Wikipedia, ZigBee. Available: http://en.wikipedia.org/wiki/ZigBee
[16] ZigBee Alliance. Available: http://www.zigbee.org
[17] Jennic, Jennic's ZigBee e-learning Course. Available: http://www.jennic.com/elearning/zigbee/index.htm