Channel Propagation Characteristics on the Performance of 4G Cellular Systems from High Altitude Platforms (HAPs)

In this paper, we investigated the effect of different channel propagation characteristics on the performance of 4G systems from high altitude platforms (HAPs). The use of High-Altitude Platforms for communication purpose in the past focused mostly on the assumption that the platform is quasi stationary. The technical limitation of the assumption was that of ensuring stability in the positioning of the platform in space. The use of antenna steering and other approaches were proposed as a solution to the said problem. In this paper, we proposed a channel model which account for the motion of the platform. This was done by investigating the effect of Doppler shift on the carrier frequency as the signals propagate between the transmitter and receiver while the High-Altitude Platform is in motion. The basic free space model was used and subjected to the frequency variation caused by the continuous random shift due to the motion of the HAPs. The trajectory path greatly affects the system performance. A trajectory of 30km, 100km and 500km radii were simulated. An acute elevation angle was used in the simulation. The proposed model was also compared to two other channel models to illustrate its performance. The results show that the proposed model behave similar to the existing models except at base station ID 35 and 45 where the highest deviation of 20dBm was observed. Other stations that deviated were less than 2dBm.

Wireless Communication for Flying Cars

Current ground-based transportation systems are subjected to various challenges, including the high cost of infrastructure development, limited land space, and a growing urban population. Therefore, the automotive and aviation industries are collaborating to develop flying cars, also known as electric, vertical, takeoff, and landing aircrafts (eVTOLs). These eVTOLs will allow for rapid and reliable urban and suburban transportation. Safe operation of eVTOLs will require well-developed wireless communication networks; however, existing communication technologies need enhancement in order to provide services to flying cars. We describe several potential innovations that make communication between eVTOLs and the ground feasible. These innovations include three-dimensional cellular networks on-ground, tethered balloons, high-altitude platforms, and satellites.

Design and Evaluation of Large-Scale IoT-Enabled Healthcare Architecture

Employment of the Internet of Things (IoT) technology in the healthcare field can contribute to recruiting heterogeneous medical devices and creating smart cooperation between them. This cooperation leads to an increase in the efficiency of the entire medical system, thus accelerating the diagnosis and curing of patients, in general, and rescuing critical cases in particular. In this paper, a large-scale IoT-enabled healthcare architecture is proposed. To achieve a wide range of communication between healthcare devices, not only are Internet coverage tools utilized but also satellites and high-altitude platforms (HAPs). In addition, the clustering idea is applied in the proposed architecture to facilitate its management. Moreover, healthcare data are prioritized into several levels of importance. Finally, NS3 is used to measure the performance of the proposed IoT-enabled healthcare architecture. The performance metrics are delay, energy consumption, packet loss, coverage tool usage, throughput, percentage of served users, and percentage of each exchanged data type. The simulation results demonstrate that the proposed IoT-enabled healthcare architecture outperforms the traditional healthcare architecture.

Wireless Communication for Flying Cars

The existing ground-based transportation systems suffer from various challenges, mainly the high cost of infrastructure development, limited land space, and the growing urban population. Therefore, the automotive and aviation industries are collaborating to develop flying cars, also knows as electric vertical takeoff and landing aircrafts (eVTOLs). These eVTOLs will enable reliable and rapid urban and suburban transportation. Safe operation of eVTOLs will require well-developed wireless communication networks. However, existing communication technologies need advancement to provide services to flying cars. We report various potential solutions that are feasible for communication among the eVTOLs and with the ground. These possibilities include on-ground three-dimensional cellular networks, tethered balloons, high altitude platforms, and satellites.