Search

Your search keyword '"Babaei, Alireza"' showing total 332 results
Start Over Author "Babaei, Alireza" Publication Year Range Last 50 years
332 results on '"Babaei, Alireza"'

2. On the Impact of LTE-U on Wi-Fi Performance

Author

Babaei, Alireza, Andreoli-Fang, Jennifer, and Hamzeh, Belal

Subjects
Computer Science - Networking and Internet Architecture
Abstract

With the exponential growth in mobile data traffic taking place currently and projected into the future, mobile operators need cost effective ways to manage the load of their networks. Traditionally, this has been achieved by offloading mobile traffic onto Wi-Fi networks due to their low cost and ubiquitous deployment. Recently, LTE operating in the unlicensed spectrum has drawn significant interests from mobile operators due to the availability of the unlicensed spectrum. However, the deployment of LTE networks in the unlicensed band poses significant challenges to the performance of current and future Wi-Fi networks. We discuss the LTE and Wi-Fi coexistence challenges and present analysis on performance degradation of the Wi-Fi networks at the presence of LTE., Comment: 2014 IEEE 25th Annual International Symposium on Personal, Indoor, and Mobile Radio Communication (PIMRC)

Published
2022
Full Text
View/download PDF

19. Optimal Trajectory-Planning of UAVs via B-Splines and Disjunctive Programming

Author

Babaei, Alireza and Karimi, Amirhossein

Subjects
Mathematics - Optimization and Control
Abstract

This paper investigates an efficient algorithm for trajectory planning problem of autonomous unmanned aerial vehicles which fly over three-dimensional terrains. The proposed algorithm combines convex optimization with disjunctive programming and receding horizon concept, which has many advantages, such as a high computational speed. Disjunctive programming is applied in order to relax the non-convex constraints of the problem. Moreover, the B-spline curves are employed to represent the trajectories which should be generated in the optimization process.

Published
2018

22. Wi-Fi Coexistence with Duty Cycled LTE-U

Author

Pang, Yimin, Babaei, Alireza, Andreoli-Fang, Jennifer, and Hamzeh, Belal

Subjects
Computer Science - Information Theory
Abstract

Coexistence of Wi-Fi and LTE-Unlicensed (LTE-U) technologies has drawn significant concern in industry. In this paper, we investigate the Wi-Fi performance in the presence of duty cycle based LTE-U transmission on the same channel. More specifically, one LTE-U cell and one Wi-Fi basic service set (BSS) coexist by allowing LTE-U devices transmit their signals only in predetermined duty cycles. Wi-Fi stations, on the other hand, simply contend the shared channel using the distributed coordination function (DCF) protocol without cooperation with the LTE-U system or prior knowledge about the duty cycle period or duty cycle of LTE-U transmission. We define the fairness of the above scheme as the difference between Wi-Fi performance loss ratio (considering a defined reference performance) and the LTE-U duty cycle (or function of LTE-U duty cycle). Depending on the interference to noise ratio (INR) being above or below -62dbm, we classify the LTE-U interference as strong or weak and establish mathematical models accordingly. The average throughput and average service time of Wi-Fi are both formulated as functions of Wi-Fi and LTE-U system parameters using probability theory. Lastly, we use the Monte Carlo analysis to demonstrate the fairness of Wi-Fi and LTE-U air time sharing.

Published
2016

23. Iran supports a great share of biodiversity and floristic endemism for Fritillaria spp. (Liliaceae): A review

Author

Kiani, Mahmoud, Mohammadi, Shirin, Babaei, Alireza, Sefidkon, Fatemeh, Naghavi, Mohamad Reza, Ranjbar, Mojtaba, Razavi, Seyed Ali, Saeidi, Keramatollah, Jafari, Hadi, Asgari, Davoud, and Potter, Daniel

Subjects
Biological Sciences, Evolutionary Biology, Conservation, Ecosystem, Endemic, Middle East, Phylogenetic, Taxonomy
Abstract

Iran supports a great share of exotic and/or endemic plant genera and species. The genus Fritillaria (Liliaceae) is a precious part of this botanical richness with 19 species, of which 10 are endemic to the country. However, signs are mounting that the country is truly at a crossroads when it comes to preservation of this national wealth. In this regard, an effective conservation strategy should thoroughly consider the classification of Fritillaria, as conservation practices are compromised by knowledge gaps in systematics and taxonomy. As published studies on Fritillaria in Iran have been sporadic and limited in scope, the aim of this review is to provide information necessary to help bridge these information gaps. Our objective is to facilitate increased understanding of the geographic, taxonomic, cytogenetic and phylogenetic status of Iranian Fritillaria, which is vital to meeting the goal of sustainable conservation of the genus in Iran and neighboring areas.

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results