scholarly journals Connectivity Analysis of Millimeter-Wave Device-to-Device Networks with Blockage

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Haejoon Jung ◽  
In-Ho Lee

We consider device-to-device (D2D) communications in millimeter-wave (mm Wave) for the future fifth generation (5G) cellular networks. While the mm Wave systems can support multiple D2D pairs simultaneously through beamforming with highly directional antenna arrays, the mm Wave channel is significantly more susceptible to blockage compared to microwave; mm Wave channel studies indicate that if line-of-sight (LoS) paths are blocked, reliable mm Wave communications may not be achieved for high data-rate applications. Therefore, assuming that an outage occurs in the absence of the LoS path between two wireless devices by obstructions, we focus on connectivity of the mm Wave D2D networks. We consider two types of D2D communications: direct and indirect schemes. The connectivity performances of the two schemes are investigated in terms of (i) the probability to achieve a fully connected network PFC and (ii) the average number of reliably connected devices γ. Through analysis and simulation, we show that, as the network size increases, PFC and γ decrease. Also, PFC and γ decrease, when the blockage parameter increases. Moreover, simulation results indicate that the hybrid direct and indirect scheme can improve both PFC and γ up to about 35% compared to the nonhybrid scheme.

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1608
Author(s):  
Ed Kamya Kiyemba Edris ◽  
Mahdi Aiash ◽  
Jonathan Loo

Device-to-Device (D2D) communications will be used as an underlay technology in the Fifth Generation mobile network (5G), which will make network services of multiple Service Providers (SP) available anywhere. The end users will be allowed to access and share services using their User Equipments (UEs), and thus they will require seamless and secured connectivity. At the same time, Mobile Network Operators (MNOs) will use the UE to offload traffic and push contents closer to users relying on D2D communications network. This raises security concerns at different levels of the system architecture and highlights the need for robust authentication and authorization mechanisms to provide secure services access and sharing between D2D users. Therefore, this paper proposes a D2D level security solution that comprises two security protocols, namely, the D2D Service security (DDSec) and the D2D Attributes and Capability security (DDACap) protocols, to provide security for access, caching and sharing data in network-assisted and non-network-assisted D2D communications scenarios. The proposed solution applies Identity-based Encryption (IBE), Elliptic Curve Integrated Encryption Scheme (ECIES) and access control mechanisms for authentication and authorization procedures. We formally verified the proposed protocols using ProVerif and applied pi calculus. We also conducted a security analysis of the proposed protocols.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5485
Author(s):  
Abel Rodriguez Medel ◽  
Jose Marcos C. Brito

Mobile networks have a great challenge by serving the expected billions of Internet of Things (IoT) devices in the upcoming years. Due to the limited simultaneous access in the mobile networks, the devices should compete between each other for resource allocation during a Random-Access procedure. This contention provokes a non-depreciable delay during the device’s registration because of the great number of collisions experienced. To overcome such a problem, a framework called Random-Access Accelerator (RAA) is proposed in this work, in order to speed up network access in massive Machine Type Communication (mMTC). RAA exploits Device-To-Device (D2D) communications, where devices with already assigned resources act like relays for the rest of devices trying to gain access in the network. The simulation results show an acceleration in the registration procedure of 99%, and a freed space of the allocated spectrum until 74% in comparison with the conventional Random-Access procedure. Besides, it preserves the same device’s energy consumption compared with legacy networks by using a custom version of Bluetooth as a wireless technology for D2D communications. The proposed framework can be taken into account for the standardization of mMTC in Fifth-Generation-New Radio (5G NR).


2018 ◽  
Vol 3 (1) ◽  
pp. 35 ◽  
Author(s):  
Cihat Şeker ◽  
Turgut Ozturk ◽  
Muhammet Tahir Güneşer

In this proposed paper, a single band microstrip patch antenna for fifth generation (5G) wireless application was presented. 28, 38, 60 and 73 GHz frequency bands have been allocated for 5G mobile communications by International Telecommunications Union (ITU). In this paper, we proposed an antenna, which is suitable for the millimeter wave frequency. The single band antenna consists of new slot loaded on the radiating patch with the 50 ohms microstrip line feeding used. This single band antenna was simulated on a FR4 dielectric substrate have relative permittivity 4.4, loss tangent 0.02, and height 1.6 mm. The antenna was simulated by Electromagnetic simulation, computer software technology High Frequency Structural Simulator. And simulated result on return loss, VSWR, radiation pattern and 3D gain was presented. The parameters of the results well coherent and proved the literature for millimeter wave 5G wireless application at 38 GHz.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2143
Author(s):  
Chunzhi Hou ◽  
Zhensen Wu ◽  
Jiaji Wu ◽  
Yunhua Cao ◽  
Leke Lin ◽  
...  

Deterministic channel models, such as the three-dimensional (3D) ray launching method, can yield wireless channel parameters. In the non-line-of-sight (NLOS) propagation, the outdoor 3D ray launching method that considers diffraction effects is more accurate than the one that does not. While considering the diffraction effect, obtaining the diffraction point is challenging. This paper proposed a method for determining diffracted rays using the receiving sphere method in 3D ray launching. The diffraction point is determined using the shortest distance method between two straight lines, and the signal loss from the transmitting to receiving antennas is obtained. Furthermore, experiments on a millimeter wave in a microcell scenario were performed. The test results of the wireless channel parameters were compared with theoretical calculations. The results obtained via the 3D ray launching method that only considers the specular reflection and direct rays agree with the experimental results in the line-of-sight (LOS); furthermore, they generate larger errors compared with the experimental results in the NLOS. The results obtained via the 3D ray launching method that considers the direct ray, reflected rays, and diffracted rays agree with the experimental results both in the LOS and NLOS. Therefore, the 3D ray launching method that considers the diffraction effect can improve the prediction accuracy of the millimeter wave channel parameters in a microcell.


Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 64 ◽  
Author(s):  
Fidel Rodríguez-Corbo ◽  
Leyre Azpilicueta ◽  
Mikel Celaya-Echarri ◽  
Peio López-Iturri ◽  
Imanol Picallo ◽  
...  

With the growing demand of vehicle-mounted sensors over the last years, the amount of critical data communications has increased significantly. Developing applications such as autonomous vehicles, drones or real-time high-definition entertainment requires high data-rates in the order of multiple Gbps. In the next generation of vehicle-to-everything (V2X) networks, a wider bandwidth will be needed, as well as more precise localization capabilities and lower transmission latencies than current vehicular communication systems due to safety application requirements; 5G millimeter wave (mmWave) technology is envisioned to be the key factor in the development of this next generation of vehicular communications. However, the implementation of mmWave links arises with difficulties due to blocking effects between mmWave transceivers, as well as different channel impairments for these high frequency bands. In this work, the mmWave channel propagation characterization for V2X communications has been performed by means of a deterministic in-house 3D ray launching simulation technique. A complex heterogeneous urban scenario has been modeled to analyze the different propagation phenomena of multiple mmWave V2X links. Results for large and small-scale propagation effects are obtained for line-of-sight (LOS) and non-LOS (NLOS) trajectories, enabling inter-data vehicular comparison. These analyzed results and the proposed methodology can aid in an adequate design and implementation of next generation vehicular networks.


Sign in / Sign up

Export Citation Format

Share Document