Packet size optimization for wireless nanosensor networks in the Terahertz band

Wireless Nanosensor Networks (WNSNs), i.e., networks of miniaturized devices with unprecedented sensing capabilities, are at the basis of transformative applications in the biomedical, environmental and industrial fields. Recent developments in plasmonic nano-antennas point to the Terahertz (THz) band (0.1-10 THz) as the frequency range of communication among nanosensors. While this potentially enables extremely high data rates in WNSNs, the very high path-loss at such frequencies and the limited power of energy-harvesting nano-devices limit the achievable throughput. In this paper, the link throughput maximization problem in WNSNs is addressed by taking into account the device and communication interdependencies in WNSNs. The optimal data packet size which maximizes the link efficiency is derived by capturing the device, channel, physical and link layer peculiarities of WNSNs. The energy harvesting limits and the successful packet transmission time are defined as the optimization problem constraints, and the optimal solution is derived by using a bisection method. Numerical results are provided to analyze the impact of the packet size for different error control strategies. The results show that the optimal packet size quickly decreases with the transmission distance, approaching several hundreds bits for distances beyond a few millimeters.