ii I am very happy and thankful to the staff of AIT-TC department, Ms Premma Rao, Mr. Rajesh Dehury and Mr.Jarook, for providing me the necessary things and equipment on happening hours and non-happening hours, throughout my research period. I thank all my friends from the department of TC & ICT, as well as people of AIT, for providing the love and support for the completion of my research.Last, but not the least, I would like to thank my parents and brother, for their constant encouragement, love and support, every single day.Best regards, V.Sandeep Reddy.iii ABSTRACT As we are moving towards smart homes and smart cities, the need for wireless sensors are increasing continuously. Most of the sensors are powered with batteries, which have limited amount of power. So, in a wireless sensor network, the main motive is to minimize the energy consumption and increase the lifetime of the network. Communication between the sensors and from sensors to sink is an energy consuming process. Here comes, the LEACH protocol, with the concept of clustering, that makes the network energy efficient and gives longer lifetime to the network. This LEACH protocol has many drawbacks. One among them is the uneven distribution of CHs in the network, in several rounds. This leads to higher consumption of energy by sensor nodes, which in turn reduces the stability period and also the overall lifetime of the network. This problem is solved to majority extent in this research by concept of dividing the sensor field into sub-regions and choosing cluster head from each sub-region. This modification reduces the uneven distribution of CHs to maximum extent. Modified protocol is simulated in MATLAB and its results show that, the stability period as well as overall lifetime is improved than existing basic LEACH protocol.iv

Wireless signals play major a role not only in establishing communication between the node to node but also for providing information about the other end of the destination node. Wireless signals especially used in radar engineering are used to detect the target eliminating the use of large number sensors. RF wireless signals which are generated from the networking (WiFi routers) devices can be used for remotely detecting the object. And nowadays networking devices installed in the household and the companies are the part of modern communication and by using these devices for the above said would greatly reduce the use of sensors for object sensing. A person away from his home can detect the changes during his absence with the routers that are installed in his home. This study aims at studying different techniques that are used for object detection using wireless signals at different scenarios.

Virtual private networks (VPN) provide a remote secure connection for clients toexchange information with company networks. Dynamic Multipoint Virtual PrivateNetwork “DMVPN” is a solution for the dynamic creation of virtual Private IP tunnelsbetween multiple sites automatically, quickly, and with the least configuration.Dynamic Multipoint VPN (DMVPN) used in this research with some supportingprotocols to allow the changing of Internet Protocol (IP) addresses of remote locations.It proves to be a very scalable VPN technique with minimal configurations androbustness. The lesser delay between two branches of an organization by establishingdirectly protected tunnels called Shortcut Tunnels. These Shortcut Tunnels aredynamically created when traffic flows on demand and are protected by IPsec.DMVPN network is implemented with security protocols for Internet key managementand exchange to Ensure Data confidentiality, integrity, and authenticity using theGNS3 Network simulator. The testing and verification analysis of data packets is doneusing both PING-tool and Wire- shark to ensure the encryption of data packets duringdata exchange between different sites.

Wireless signals play major a role not only in establishing communication between the node to node but also for providing information about the other end of the destination node. Wireless signals especially used in radar engineering are used to detect the target eliminating the use of large number sensors. RF wireless signals which are generated from the networking (WiFi routers) devices can be used for remotely detecting the object. And nowadays networking devices installed in the household and the companies are the part of modern communication and by using these devices for the above said would greatly reduce the use of sensors for object sensing. A person away from his home can detect the changes during his absence with the routers that are installed in his home. This study aims at studying different techniques that are used for object detection using wireless signals at different scenarios.

my master's course and thesis. It is also a great pleasure for me to thank my co-advisor, Dr. Poompat Saengudomlert for providing hardware and timely guidance in the methodological development of the thesis. I also take this space to extend my sincere gratitude to my committee member, Dr. Attaphongse Taparugssanagorn for his comments on improving the thesis.Secondly, I take this opportunity to convey many thanks to Ms. Premma Rao and Mr. Rajesh Kumar Dehury for their timely act on providing hardware and lab infrastructure in the Telecommunication Engineering department for doing experimentation. In addition, a grateful thanks are extended to the Asian Institute of Technology, Thailand for providing AIT fellowship to support my masters.Finally, I remember Dr. L. Pratap Reddy, Professor, JNT University Hyderabad, India because of whom my focus towards open research is improved from while I being in my undergraduate. -Praveenii ABSTRACT This thesis presents an approach of integrating single board computers as an access point and as a short-range object localization system. This is achieved by using open hardware and implementing IEEE 802.11 a/g/p based transceiving on low-cost Adlam Pluto Software Defined Radio (SDR), which operates in the S-band frequency range with Frame Error Rate (FER) controlled calibration. Experiments are conducted to investigate the effect of FER on the Received Signal Strength Indicator (RSSI) of IEEE 802.11 a/g/p transceiving, there by drawing the connection between the RSSI and the FER. Object localization is done based on the referenced RSSI and the real-time RSSI with FER based controlled calibration of RSSI. About 80% of accuracy can be expected from the implemented object localization system.