Abstract-TeraSim: An ns-3 extension to simulate Terahertz-band communication networks

Zahed Hossain, Qing Xia Josep Miquel Jornet,



https://www.sciencedirect.com/science/article/pii/S1878778918300772

In the quest of higher wireless data-rates, Terahertz (THz)-band (0.1-10 THz) communication is envisioned as a key wireless technology of the next decade. In parallel to the development of THz transceivers and antennas, simulation tools are needed to expedite the development of communication and networking protocols tailored to this novel networking paradigm, at a fraction of the cost. The few simulation platforms developed to date for THz communication networks do not capture the peculiarities of the THz channel or the capabilities of THz devices. In this paper, TeraSim, i.e., an open source network simulation platform for THz communication networks is presented. TeraSim is built as an extension for ns-3, which is one of the most widely used teaching and education network simulation software. The simulator has been developed considering two major types of application scenarios, namely, nanoscale communication networks (average transmission range usually below one meter) and macroscale communication networks (distances larger than one meter). The simulator consists of a common channel module, separate physical and link layers for each scenario, and two assisting modules, namely, THz antenna module and energy harvesting module, originally designed for the macroscale and nanoscale scenario, respectively. The structure, relations and content of each module are presented in detail. Extensive simulation and test results are provided to validate the functionalities of the implemented modules. TeraSim is expected to enable the networking community to test THz networking protocols without having to delve into the channel and physical layers.

Abstract-Pulse-Based Distance Accumulation Localization Algorithm for Wireless Nanosensor Networks

Lina Zhou,  Guangjie Han,   Li Liu,

Diagram of network structure where nodes are divided into corner nodes, border nodes, and center nodes, and the distance between two adjacent nodes is estimated based on the value of the received pulse

http://ieeexplore.ieee.org/document/7994597/

Wireless nanosensor networks (WNSNs) consist of nano-sized communication devices, which are equipped with nano-transceivers, nano-antennas, and other functional modules. A nanosensor is an integrated device that ranges from 10 to 100 μm2 in size. Due to the limited communication capabilities of WNSNs, existing localization algorithms and protocols for wireless sensor networks (WSNs) are no longer applicable to WNSNs. This paper proposes a pulse-based distance accumulation (PBDA) localization algorithm for WNSNs that can be utilized to estimate the distance between nodes with known positions and nodes with unknown positions. The algorithm adopts femtosecond-long pulse for terahertz band communication based on ON-OFF keying (OOK) modulation. A clustering algorithm is first employed to reduce the energy consumption and time delay, then the nano-device analyzes the value of the received pulse based on the OOK modulation and estimates the distance between nodes. MATLAB simulations are implemented to verify the performance of PBDA by comparing it against the flooding-based hop-counting algorithm and cluster based hop-counting algorithm in terms of estimated distance accuracy, energy consumption, and time delay. The trilateral positioning method is also utilized to compare the localization error of PBDA with that of distance vector (DV)-hop. The results show that PBDA is able to support WNSNs with very high density in ranging and locating.

Abstract-Stochastic geometry analysis of interference and coverage in Terahertz networks

Xin-Wei Yao, Chao-Chao Wang, Wan-Liang Wang,  Chong Han,

http://www.sciencedirect.com/science/article/pii/S1878778917300261


Terahertz (THz) band communication has been envisioned as a key wireless technology for providing unprecedented high data rates. However, due to the severe path loss, the transmission distance in THz band is very limited. Therefore, the beamforming techniques are explored to enlarge the communication range in THz networks, particularly employed at Access Points (APs). Interference is a critical factor affecting the performance of THz networks. In this paper, the interference and the coverage probability are investigated for the THz band communications with beamforming APs. First, based on the Line-of-Sight (LoS) and Non-Line-of-Sight (NLoS) ray propagation models of THz signals, the interferences from neighboring users and beamforming APs are modeled in closed forms based on stochastic geometry methods. Then, the Signal-to-Interference-plus-Noise-Ratio (SINR) and the coverage probabilities are further derived based on the THz channel and interference model. Extensive simulations are carried out to evaluate the interference and coverage for the THz band communications with beamforming APs, for the different system parameters, which include SINR threshold, density of APs, transmission frequency, gain of beamforming AP, density of users and radius of interference area. Learning from the simulation results, high density of APs with a small beam-width and the transmission at THz frequencies with low absorption efficient, such as 0.67 THz, are recommended to mitigate the interference and achieve a better coverage performance.