Simulation Studies on Effects of Dual Polarized Directional Antenna on the Performance of Mobile Ad-hoc Networks
Rinki Sharma
Faculty of Engineering and Technology, Department of Computer Science and EngineeringFET, CSE
Theme
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Abstract
| In the purview of efficient communication in MANETs for enhanced data rates and reliable routing of information, this thesis deals with dual polarised directional antenna based communication. This thesis proposes a dual polarised directional communication based cross-layer solution to mitigate the problems of interference, exposed nodes, directional exposed nodes, and deafness, and to achieve efficient routing of information. At the physical layer of network protocol stack, this thesis proposes the use of dual polarised directional antenna for the mitigation of interference. Use of dual polarised directional communication at the physical layer calls for appropriate modifications in the functionality of MAC and network layers. At the MAC layer, the DPDA-MAC protocol proposed in this thesis achieves mitigation of the problems of exposed nodes, directional exposed nodes and deafness, by using dual polarised directional antenna at physical layer. At network layer, the DPDA-MRP protocol presented in this thesis facilitates the discovery of multiple routes between the source and destination nodes to route information in accordance with the desired dual polarised directional communication. To achieve efficient dual polarised directional communication and routing of information, it is essential to maintain well populated Neighbour Table (NT) and Routing Table (RT). This thesis proposes a novel Corruption Detection Pulse (CDP) based technique to handle corruption of broadcast packets such as Link ID and RREQ arising due to hidden node problem. Since the nodes participating in the formation of MANETs have limited battery energy, the protocols proposed in this thesis are featured with a provision for dynamic power control to achieve energy efficient communication. Nodes maintain Received Signal Strength Indicator (RSSI) information in the NT, which along with the information of node location is used in the formulation of decision logic of dynamic power control. Through numerous simulation studies, this thesis demonstrates the benefits of dual polarised directional communication to enhance the performance of MANET. The design principles, benefits and conceptual constraints of proposed DPDA-MAC protocol are analysed with SPDA-MAC and CSMA/CA, while those for DPDA-MRP are analysed with SPDA-MRP and DSR through performance metrics of throughput, Packet Delivery Ratio (PDR) and per hop delay. The thesis also analyses the impact of variations of channel capacity, node density, rate of packet transmission and mobility of nodes on the performance of the proposed and conventional protocols invoked in MANETs. Conclusion: The main contributions of this thesis can be categorised among three layers of the network protocol stack. These are the physical layer, MAC layer and network layer. The concept of dual 268 polarised directional antenna is applied at the physical layer. In order support dual polarised directional communication it is required to modify the protocols at MAC layer and network layer. The proposed DPDA-MAC protocol is designed to allow access to the medium to support dual polarised directional communication. The DPDA-MRP is a multipath routing protocol which routes information directionally, on available polarisation. The proposed CDP based method to handle corruption of broadcast packet allows formation of well populated NT and RT to support functionality of DPDA-MAC and DPDA-MRP. The conclusive observations, inferences, implicit and explicit novelties of research findings of this thesis are enlisted in this section. These are categorised according to the physical, MAC and network layers. |