scholarly journals QoS Priority-Based Mobile Personal Cell Deployment with Load Balancing for Interference Reduction between Users on Coexisting Public Safety and Railway LTE Networks

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2136
Author(s):  
Ishtiaq Ahmad ◽  
JinYoung Jang ◽  
KyungHi Chang

The Republic of Korea has played a leading role in the development of next-generation long-term evolution (LTE) public safety networks. The LTE-based public safety (PS-LTE) network, the LTE-based high-speed railway (LTE-R) network, and the LTE-based maritime (LTE-M) network use the same 700 MHz frequency band. That results in severe co-channel interference (CCI), so there is a dire need for practical research into resolving the CCI issue. Moreover, unplanned deployment of the mobile personal cell (mPC) generates serious user-association issues owing to its movement, which leads to severe co-channel interference in coexisting PS-LTE and LTE-R networks. Indeed, it is important to satisfy users’ quality of service (QoS) requirements during resource allocation in specific public safety situations. Therefore, we address the CCI issues through wise deployment of the mPC for user association and load balancing in overlapping PS-LTE and LTE-R networks. In this paper, we propose a QoS mPC deployment (QoS_mPCD) scheme for priority-based load balancing and interference reduction in coexisting PS-LTE and LTE-R networks. The proposed scheme efficiently manages the user-association and load-balancing problems, and allocates the best resources to high-priority users based on defined service priority levels. Moreover, we employ an enhanced inter-cell interference coordination (eICIC) scheme that further reduces the interference with the users offloaded onto an mPC. System-level simulations are performed to evaluate the proposed QoS_mPCD scheme by considering important performance matrices such as user equipment (UE) throughput, UE received interference, and UE outage probabilities.

Author(s):  
P.I. Tarasov

Research objective: studies of economic and transport infrastructure development in the Arctic and Northern Territories of Russia. Research methodology: analysis of transport infrastructure in the Republic of Sakha (Yakutia) and the types of railways used in Russia. Results: economic development of any region is proportional to the development of the road transport infrastructure and logistics. When a conventional railway is operated in the Arctic conditions, it is not always possible to maintain a cargo turnover that would ensure its efficient use, and transshipment from one mode of transport to another is very problematic. A new type of railway is proposed, i.e. a light railway. Conclusions: the proposed new type of transport offers all the main advantages of narrow gauge railroads (high speed of construction, efficiency, etc.) and helps to eliminate their main disadvantage, i.e. the need for transloading when moving from a narrow gauge to the conventional one with the width of 1520 mm, along with a significant reduction in capital costs.


Author(s):  
Xin Jian ◽  
Langyun Wu ◽  
Keping Yu ◽  
Moayad Aloqaily ◽  
Jalel Ben-Othman

2013 ◽  
Vol 639-640 ◽  
pp. 293-296 ◽  
Author(s):  
Ai Jun Chen ◽  
Guo Jing He

The major loss of the hurricane was damage and collapse of structures, In particular, wind power tower wich requires both the use of wind, wind on the structure plays a leading role in the tall slender flexible structure.In this paper, tests of remote sensing dynamic monitoring of tower structure with wind power are carried out, using measurement techniques of high-frequency and high-speed electromagnetic interference.


Author(s):  
Maniru Malami Umar ◽  
Amimu Mohammed ◽  
Abubakar Roko ◽  
Ahmed Yusuf Tambuwal ◽  
Abdulhakeem Abdulazeez

Call admission control (CAC) is one of the radio resource management techniques that regulates and provide resources for new or ongoing calls in the network. The existing CAC schemes wastes bandwidth due to its failure to check before degrading admitted real-time calls and it also increases the call dropping probability (CBP) and calling blocking probability (CBP) of real-time calls due to the delay incurred when bandwidth is degraded from them. This paper proposed an enhanced adaptive call admission control (EA-CAC) scheme with bandwidth reservation. The scheme employs a prior-check mechanism that ensured bandwidth to be degraded will be enough to admit the new call request. It further incorporates an adaptive degradation mechanism that degrades non-real time calls before degrading the RT calls. The performance of the EA-CAC scheme was evaluated against two existing schemes using Vienna LTE system level simulator. The EA-CAC scheme exhibits better performance compared to the two schemes in terms of throughput, CBP, and CDP of RT calls without sacrificing the performance of NRT calls.


2001 ◽  
Author(s):  
Luc G. Fréchette

Abstract This paper investigates the characteristics of viscous flow in the micron-scale clearances surrounding high-speed micro-rotors currently being developed for miniature energy conversion applications. Analysis and experimental results from 4 mm diameter microfabricated rotors operated above 1 million rpm are used to describe the viscous flow characteristics, and provide guidelines for system-level design. To first order, the flow is characterized as fully developed shear flow (Couette flow) across the small gaps, induced by the rotor motion. However, secondary flows are induced perpendicular to the direction of rotor motion when externally applied pressure gradients exist along the small gaps. The developing flow in the entrance region of the small gaps in this secondary flow direction impacts the shear flow profile, hence affecting the drag on the disk. The effect of other inertial forces, such as Coriolis and centrifugal forces, are investigated analytically and numerically and found to affect the shear flow profile on the fluid in the motor gap at high rotational speeds. Since viscous losses are prevelant in microsystems, appropriate modeling is necessary for system-level design.


Author(s):  
Richard Beblo ◽  
Darrel Robertson ◽  
James Joo ◽  
Brian Smyers ◽  
Gregory Reich

Reconfigurable structures such as morphing aircraft generally require an on board energy source to function. Frictional heating during the high speed deployment of a blunt nosed low speed reconnaissance air vehicle can provide a large amount of thermal energy during a short period of time. This thermal energy can be collected, transferred, and utilized to reconfigure the deployable aircraft. Direct utilization of thermal energy has the ability to significantly decrease or eliminate the losses associated with converting thermal energy to other forms, such as electric. The following work attempts to describe possible system designs and components that can be utilized to transfer the thermal energy harvested at the nose of the aircraft during deployment to internal components for direct thermal actuation of a reconfigurable wing structure. A model of a loop heat pipe is presented and used to predict the time dependant transfer of energy. Previously reported thermal profiles of the nose of the aircraft calculated based on trajectory and mechanical analysis of the actuation mechanism are reviewed and combined with the model of the thermal transport system providing a system level feasibility investigation and design tool. The efficiency, implementation, benefits, and limitations of the direct use thermal system are discussed and compared with currently utilized systems.


2019 ◽  
Vol 8 (2) ◽  
pp. 577-585
Author(s):  
Mohamed Njikam ◽  
Nanna S. ◽  
Shahrin S. ◽  
Mohd Fairuz Iskandar Othman

The African continent is ranked second most populated region and has a huge amount of natural resources to be locally transformed or outsourced overseas. The traditional telecommunications system has helped connect people and enabled them to manage their businesses and trading in Africa for a long-time; many African countries have embarked early in changing their network and technology systems during the first years of the information age. Over a few decades ago, the introduction of new telecommunication methods and techniques have influenced much of African countries’ growth via different perspectives. The situation has triggered an enormous interest in people. They analyzed the factors supporting such changes, which in the case of this paper is all about the advent and adoption of LTE/4G-LTE technologies including its service commercialization in Africa. This review article attempts to provide an overview of 4G-LTE networks technologies and the internet; it includes the current evolution of telecommunication networks within and even beyond the African continent, assisted by the 4G-LTE expansion. An extended view is provided throughout this article’s development with respect to what could be expected (or is missing) for the sake of this continent’s telecommunication infrastructure enhancement and a better QoS to Africa’s dwellers.


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