iosr-JECE   Volume-6 ~ Issue-3

Abstract: In INDIA railways is one of the important means of transport. Driver of the train has to look out to get the status of the signal, if he fails to see the signal major mishaps could take place. There are different systems in use today including AWS (auxilliary warning system), ACD (automatic collision detection). AWS system is in use by western railway while ACD is used by Konkan railway.AWS system has a drawback of theft of trackside equipment while ACD system is based on GPS system where satellite is US owned. Proposed system focusses on automation of train controlling to avoid accidents. Designed system involves transfer of the status of signal directly to the engine which will control speed of the train as per the status of the signal. System has been designed to provide safe travelling especially during bad weather. System is based on wireless protocol 'Zigbee'. Low power consumption, low latency time of 30 ms and excellent security features as Zigbee uses 128-AES, use of DSSS modulation technique in Zigbee makes this system reliable and safe. System is operating within a range of 120m

Keywords - Zigbee, ACD, AWS, PIC Microcontroller,

[1] Zigbee Alliance, "White paper on Zigbee technology", June 2007
[2] Jin- Shyan lee, Yu-Wei su,Chung-chou shen , "Comparative study of Wireless Protocols- Bluetooth,Wi- Fi,UWB,Zigbee", 33rd
annual conference of IEEE Industrial Electronics Society(IECON)-Nov 5-8 2007,Taiwan
[3] Bhavneet Sidhu, Hardeep Singh, Amit Chhabra, "Emerging Wireless Standards- Wifi, Zigbee, WiMAX", World academy of
science, engineering and Technology Nov 25, 2007
[4] Patrick Kinny, "Zigbee Technology- Wireless control that simply works", Communication design conference, October 2,2003
[1] IRSSE- Indian Railway Services of Signal Engineers
[2] Indianrlys.wordpress.com
[3] KMRC- Kolkata Metro Rail Corporation
[1] Report of high level safety review committee, Feb 2012, under the chairmanship of Mr. Anil kakodkar

Abstract: FM signal propagation through the troposphere interacts with the terrain as obstacles and reflection planes. To understand the degree of interaction, signal strength measurements of the 93.1MHz frequency modulated Radio located at Federal University of Technology; Akure, Nigeria was carried out in the area surrounding the station. The paper reviews the various models for predicting transmission loss and employed the long rice irregular terrain model for its versatility for the study. The losses along the paths were determined and this was compared with the path loss predicted by the irregular terrain model and this was highly correlated. The result offers useful data for developing the contour map of the propagation loss which was developed for the station. It was concluded that with the irregular terrain model predictions can be used for accurate spectrum management in Nigeria.

Keywords: Signal Strength, Transmission Loss, Terrain, Spectrum Management

[1] A. F. Bruce, "RF Basis: Radio Propagation" 2008,www.connectos.com/spix/rd/gi/nme.
[2] George, A. G., Rice, P. L., Norton, K. A and Barsts, A. P., "Transmission loss Prediction for tropic communication circuits Tech. Note 101" U.S. Government Printing Office 1967 http://www.softwright.com/faq/engineering/prop_longley_rice.html

[3] Longley Rice
[4] Harry W, "Field Prediction in Irregular Terrain", 2002, http://www.fcc.gov/oet/fm/ptp/report.pdf

[5] D. John, and D. G Smith., "‟Telecommunication Engineering" London 1997. [6] T. S. Rappaport, "Wireless Communications Principles and Practice" Prentice Hall, Upper Saddle River, NJ. 1996

[7] J. S Seybold,., (2005) "Introduction to RF propagation", Wiley

[8] J. Klima and Mozucha Marian‟‟ Influence of Terrain on Multipath Propagation of FM‟‟, Signal journal of Electrical Engineering, VOL56 NO 5-6 pp. 113-120,2005

[9] R. Grosskopf, "‟Field Strength Prediction in the VHF and UHF Range Including Multipath‟‟, Propagation, Proc. 7th International Conference on Antennas and Propagation (ICAP 1991), York Conference Publication, 333, vol 2,pp. 965-967, London 1991.

[10] N. Blaunstern, et al. ,‟‟Characteristics Prediction in Urban and suburban Environment‟‟, IEEE Trans. Veh. Technol, Vol(47) pp 225-234,1998

Abstract: As the network size increases the probability of congestion occurrence at nodes increases. This is because of the event driven nature of ad hoc networks that leads to unpredictable network load. As a result congestion may occur at the nodes which receive more data than that can be forwarded and cause packet losses. In this paper we propose a hybrid scheme that attempts to avoid packet loss due to congestion as well as reduce end to end delay in delivering data packets by combining two protocols- Destination sequenced distance vector routing (DSDV), which is a table driven or proactive protocol and Improved Ad-hoc on demand vector routing (IAODV) which is an on-demand or reactive protocol that reduces packet loss due to congestion. The strategy adopted is use DSDV for path selection and if congestion occurs than switch over to IAODV. The routing performance of this model is then compared with IAODV and DSDV in terms of end to end delay, throughput and packet delivery fraction.

Keywords- DSDV, Hybrid protocol, AODV, IAODV, MANET

[1] E. Topalis S. Giannoulis, C. Antonopoulos and S. Koubias. Zrp versus DSR and TORA: A Compressive Survey on ZRP Performance. 10th IEEE Conference, ETFA 2005, Sept 2005.

[2] Kush, A., Gupta, P.; Hwang, C.J. A hybrid stable routing protocol for mobile ad hoc networks. Global Mobile Congress, 12-14 Oct. 2009

[3 ]Xiaoguang Niu Zhihua Tao, Gongyi Wu, Changcheng Huang,Li Cui ,Hybrid Cluster Routing: An Efficient Routing Protocol for Mobile Ad Hoc Networks. IEEE International Conference on Communications, 2006. ICC'06,Vol. 8, 3554-3559

[4] Wu Shaochuan Tan Xuezhi; Jia Shilou. AOHR: AODV and OLSR Hybrid Routing Protocol for Mobile Ad Hoc Networks, International Conference on Communications, Circuits and Systems Proceedings, June 2006 Vol. 3,1487-1491

[5] Venugopalan Ramasubramanian Zygmunt J. Haas Emin Gun Sirer SHARP: A Hybrid Adaptive Routing Protocol for Mobile Ad Hoc Networks.

6] Minseok Oh, A Hybrid Routing Protocol and Performance Evaluation in a Wireless Mesh Network, Journal of Advanced Information technology and convergence, vol.1, No.1, July 2011

[7] Yu-Doo Kim, Il-Young Moon, Sung-Joo Cho, A comparison of improved AODV routing protocol based on IEEE 802.11 and IEEE 802.15.4, Journal of Engineering Science and Technology Vol.4,No.2,2009.

[8] Harwinder Singh Sohal, Rajbir Singh Cheema, Ankit Arora, Improved NOVEL Routing Protocol for Load Balancing in Wireless Sensor Network, IJCST Vol. 2, Issue 3, September 2011.