No abstract

The nano terahertz networks represent one of the promising areas in the field of wireless telecommunications. Technological advances in miniaturization of antennas and terahertz communications have paved the way for new network applications such as the body network, the programmable material and multi-core processors. Some of these applications require the concentration of a very large number of tiny nodes in a limited space. In this ultra-dense context and in the absence of centralized access control units, we propose to implement a distributed strategy of spatial and temporal traffic regulation to guard against the risks of congestion, interference and energy over-consumption. In this paper, we propose a protocol for optimizing radio links that both reduces the flow of redundant traffic over the network, smooths the volume of communications exchanged over time, and preserves the lifetime of the nodes.

New applications in the field of radio networks require a high concentration of micro-machines (micro-robots, sensors/actuators) in a small space. Those devices are characterized by a high volatility and limited computing, storage and energy capabilities. Traditional routing approaches in ad hoc networks are unusable due to a significant amount of additional control traffic and a lack of robustness regarding the instability of the nodes. In this paper, we present an original, efficient and intuitive distributed routing protocol in ultra-dense terahertz networks, called Multipoint-to-Multipoint Routing Protocol (M2MRP), which is an emanation of electrostatic physics. A complexity analysis is performed to compare the M2MRP protocol with classical methods. Our study shows that the proposed protocol takes advantage of the nodes density to define a robust routing policy with a moderate additional traffic control. In addition, routing paths are adapted gradually and continuously according to the nodes location (mobility), availability (failures), congestion and energy level. Simulations show that the M2MRP routing protocol significantly outperforms the well-known routing protocols for dense networks both in terms of the number of exchanged messages and of success rate, making this routing protocol the most suitable for systems such as swarm micro-robots, programmable matter and ultra-dense sensor networks.

The recent progress in nanotechnologies is giving birth to a novel topology of wireless networks characterized by a high local density and an intensive node instability such as in WBAN and swarm micro-robots systems. In this paper, we show that classical and dedicated ad hoc nanonetwork routing solutions are inefficient in this case and present a low reliability level and add a supplementary delay and control traffic. Majority of these solutions are based on point to point relaying mode, which is not adapted to the instability context. The multirelay to multirelay approaches allow countering the problem of nanonodes uncertainty by using the high number of inter-node connections. However, these approaches perform badly when the nanonetwork deployment presents distortions and concave sides. We propose a new routing protocol called Multirelay to Multirelay Routing Protocol (M2MRPv2), which provides a natural way to manage the residual energy levels on the nanonodes. M2MRPv2 is, to the best of our knowledge, the only approach that proposes a proactive multirelay to multirelay routing mode where the residual energy level of the nanonodes and reliability of the routing paths are taken into account. We study the performances of multirelay to multirelay protocols according to different multi-source to multi-sink communication scenarios. The obtained results show that M2MRPv2 protocol outperforms by far the Sustainable Longevity Routing (SLR) protocol (the reference protocol for Terahertz nanonetworks) in terms of transmission reliability and energy management. This outperformance is accentuated when the Terahertz nanonetwork deployment presents many concavities.