Abstract of doctoral thesis - Vassilios Chimaras

Development of a secure and encrypted Long Range and Low Power wireless communication network (voice and data), based on noise-tolerant modulation techniques, for the deployment of Sensor networks for commercial and military purposes 

The safe and immediate transmission of information and commands in urban and sensitive geopolitical areas, either under normal circumstances or in a time of crisis, presupposes the uninterrupted operation of a secure communication network. We aim to design and build a digital communication network for short and medium distances for commercial or military purposes.

Such can be a broadcast system, where the transmission from one station is received from all other stations in the network. Every station will be able to transmit speech (voice) with low bit rate coding and short data (e.g. small text messages, location data - sensors), which can be stored in a secure database on the Internet (cloud- IoT). The scope of the system ranges from short distances in urban areas and areas with obstacles (e.g. forest), to medium distances in open fields or over water.

The proposed system will have high jamming resistance and great difficulty in locating it from Electronic Support Measures (ESMs), which is a consequence of the usage of a broad-spectrum configuration (Chirp Spread Spectrum) or very narrow bandwidth transmission. In addition, it will support encryption for the transmission of voice and data packets.

The crucial development of a network consisted of base stations and transceivers is proposed. All data will be transmitted among broadcast systems and a decision-making sector will be able to decide and issue helpful instructions and orders for all the parties involved.