Dynamic PL&T using Two Reference Nodes Equipped with Steered Directional Antenna for Significant PL&T Accuracy

Dynamic Position Location and Tracking (PL&T) is proposed deploying the integrated approach of zone finding and triangulation using two friendly nodes equipped with Steered Directional Antenna (DA) in Mobile Ad hoc Networks (MANET). This approach allows the system to use only two references instead of a typical 3 references for a straight triangulation. Moreover, the performance of the proposed algorithm with references using directional antennas shows significant improvement over triangulation using references with Omnidirectional antennas as the beam power is concentrated. However, dynamic switching of reference nodes is frequently required as the target moves outside the predicted zone. This paper presents a better tracking accuracy in using proposed dynamic PL&T as compared to other PL&T techniques. The multipath fading is also addressed with the use of KV transform coding technique which uses forward error correction and sample interleaving achieves greater than 90% tracking accuracy with BERs of 10-6 or better. DOI: 10.4018/jitn.2012100103 International Journal of Interdisciplinary Telecommunications and Networking, 4(4), 40-53, October-December 2012 41 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. to achieve 3D PL&T, however the references have to be above the ground (at least one node) at least 100 ft. Usually, the nodes can be placed in Unmanned Aerial Vehicles (UAV) and used as references. Extensive work has been done in Future Warrior Soldier program by Boeing Corporation using Raytheon Micro-lights and more recently Joint Tactical Radios (JTRS). Also, using Internet Protocol (IP) based triangulation for 2D and 3D PL&T tracking using embedded Real Time Predictive Trajectory Polynomial demonstrated tracking accuracies of less than a meter (Lacovara & Vaman, 2005). However, severe multi-path handling in indoor environment is still a serious issue. One of the critical issues in PL&T tracking based on triangulation is the cumulative error in the PL&T as nodes are continuously tracked at different locations, even though the tracking accuracy at each location is 1 meter. Thus, there is a need for re-initialization of each node after repeated tracking at different locations. This can only be achieved by sending the node to a known location for recalibration. Also, the reference nodes can also move and as they move, their locations can become inaccurate. Thus, there is a need to make them targets with other accurate references to allow them to achieve accurate positions using the PL&T triangulation. Therefore, in triangulation based tracking, there is a need to switch each node as target and as reference which requires dynamic reference module above the PL&T triangulation. The complexity increases and therefore, power consumption in each node increases. The use of triangulation for PL&T is becoming increasingly important as many countries have capabilities to destroy the satellite, thereby denying Global Positioning Satellite (GPS) based tracking. Also, GPS is not very accurate near the buildings and inside the buildings. The triangulation for PL&T allows MANET to maintain strict friendly nodes for multi-hop connectivity. It is possible to design a system where ToD and ToA are encrypted and used only in strict friendly nodes. However, the issue of multi-path interference needs to be addressed without which one cannot design PL&T system based on triangulation. REVIEW OF LITERATURE The forward movement based prediction considers zone prediction within a constrained forward movement of a target node (Lu, Fletcher, Ian, Pietro, & Zhang, 2008). It uses single reference node, limited random movement and does not consider sharp turns or obstacles which can be addressed by the optimal zone forming that considers any random movement. In addition, the received signal strength based prediction has better tracking accuracy over the triangulation method as long as multi-path fading is small and longer averaging availability (Malhotra, Krasniewski, Yang, Bagchi, & Chappell, 2005). The signal is spread in the lack of zone and errors are accumulated in the computation of both the distance and the angle and has limited non-random trajectory. This can be resolved by Zone finding and adaptive beam forming. On the other hand, multi hop based prediction deploy the position locations of nodes estimation using multiple levels of reference nodes which increases the cumulative errors in multi hop measurements and has no beam adaptation used (Siuli et al. 2005). Thus, significantly reduces accuracy of tracking. This is over-come by zone forming with dynamic switching of reference nodes and dynamic ranging which provides improved accuracy in the location tracking. Furthermore, directional lines intersection based prediction localization of nodes use point of intersection of highly directional beams for low speed mobile anchor nodes (Zhang & Yu, 2010). This has higher overhead in scanning and does not address random trajectory. This can be addressed by zone forming and adaptive beam forming which reduces the scanning overhead in the random trajectory. 12 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the product's webpage: www.igi-global.com/article/dynamic-using-two-referencenodes/75161?camid=4v1 This title is available in InfoSci-Journals, InfoSci-Journal Disciplines Communications and Social Science. Recommend this product to your librarian: www.igi-global.com/e-resources/libraryrecommendation/?id=2