5G K-SimNet: Network Simulator for Evaluating End-to-end Performance of 5G Cellular Systems

2018 ◽  
Author(s):  
S. Choi ◽  
S. Kang ◽  
S. Bahk ◽  
J. Song ◽  
Ted T. Kwon
Keyword(s):  
Cellular Systems ◽  
Network Simulator ◽  
End To End

5G K-SimNet: Network Simulator for Evaluating End-to-End Performance of 5G Cellular Systems

2019 ◽  
Vol 44 (3) ◽  
pp. 609-617
Author(s):  
Siyoung Choi ◽  
Junghwan Song ◽  
Junseok Kim ◽  
Seongjoon Kang ◽  
Ted Taekyoung Kwon ◽  
...  
Keyword(s):  
Cellular Systems ◽  
Network Simulator ◽  
End To End

scholarly journals SIMULATION AND PERFORMANCE ANALYSIS EVALUATION FOR MULTIPATH EXTENSION OF AODV TO IMPROVE END TO END DELAY, ROUTE ERROR SENT, ROUTING LOAD AND PACKET DROP RATIO

2015 ◽  
pp. 89-94
Author(s):  
MANJHARI JAIN ◽  
AKHILESH WAOO ◽  
P. S. Patheja
Keyword(s):  
Routing Protocol ◽  
Routing Algorithm ◽  
Discrete Event ◽  
Simulation Software ◽  
Link Failure ◽  
Network Simulator ◽  
Optimal Paths ◽  
End To End Delay ◽  
End To End ◽  
Packet Drop

This paper describes improvement in standard routing protocol AODV for mobile ad-hoc networks. Our mechanism setups multiple optimal paths based on bandwidth and delay. It allows to store multiple optimal paths based on Bandwidth and delay. At time of link failure, it will switch to next available path. To set up multiple paths, we have used the information that we get in the RREQ packet and also send RREP packet to more than one path. It reduces overhead of local route discovery at the time of link failure and because of this End to End Delay and Drop Ratio decreases. The main feature of our mechanism is that it is simple, efficient. We evaluate through simulations the performance of the AODV routing protocol including our scheme and we compare it with HLSMPRA (hot link split multi-path routing algorithm) Algorithm. Indeed, our scheme reduces routing load, End to End Delay, route error sent, and Packet drop ratio. The simulations have been performed using network simulator OPNET-14.0. The network simulator OPNET is discrete event simulation software for network simulations which means it simulates events such as sending, receiving, forwarding and dropping packets.

scholarly journals End-to-End Performance Evaluation of Selected TCP Variants across a Hybrid Wireless Network

10.28945/3022 ◽  
2006 ◽  
Author(s):  
Ayodeji Oluwatope ◽  
Biodun Obabire ◽  
G. Adesola Aderounmu ◽  
Matthew Adigun
Keyword(s):  
Wireless Network ◽  
Communication Networks ◽  
Network Simulator ◽  
Lossy Networks ◽  
Packet Losses ◽  
Computer Communication ◽  
Tcp Protocol ◽  
Hybrid Wireless Network ◽  
Tcp Westwood ◽  
End To End

Reliable transport protocols such as TCP are tuned to perform well in traditional networks where packet losses occur mostly because of congestion. TCP is intended for use as a highly reliable end-to-end transport protocol for transporting applications such as World-Wide Web (WWW) between hosts in packet-switched computer communication networks. TCP was originally designed for wired links where the error rate is really low and actually assumed that packet losses are due to congestion in the network. However, the increasing popularity of wireless networks indicates that wireless links will play more important role in future internetworks but TCP performance in such networks suffers from significant throughput degradation and very high interactive delays. TCP responds to all losses by invoking congestion control and avoidance algorithms, resulting in degraded end-to-end performance in wireless and lossy systems. Thus, in a bid to show and determine the possibility of adapting TCP protocol for optimal performance on the wireless link, this paper reviews and models the behaviors of TCP variants with a view to evaluate the end-to-end performance analysis of TCP versions: TCP Reno, TCP SACK and TCP Westwood (TCPW), which are designed to improve the performance of TCP in lossy networks. A wireless network model was developed using NS-2 network simulator which and the model was simulated. The results were analyzed in MATLAB 6.5 using throughput as a metric for comparison. The overall results indicate that TCP Westwood (TCPW) demonstrates better performance indices over other versions in a hybrid wireless network environment.

Fault-Tolerance Evaluation of VANET Under Different Data Dissemination Models

2017 ◽  
Vol 1 (1) ◽  
pp. 54-68
Author(s):  
Awadh Moqbel Gaamel ◽  
Barakat Pravin Maratha ◽  
Tarek Rahil Sheltami ◽  
Elhadi M. Shakshuki
Keyword(s):  
Fault Tolerance ◽  
Packet Loss ◽  
Ad Hoc ◽  
Data Dissemination ◽  
Ieee 802.11P ◽  
Network Simulator ◽  
Static Source ◽  
End To End Delay ◽  
Dynamic Source ◽  
End To End

Mobile Ad hoc Networks (MANETs) is a collection of wireless mobile nodes, which form temporary networks over infrastructure-less environments. Over the last few years, Vehicular Ad hoc Network (VANET) technology has been considered as an active research area. VANET is a sub class of MANET with some unique characteristics such as fast vehicle speed, frequent topology changes and restricted mobility on roads. The communication between vehicles provides a new avenue for different types of applications such as safety, traffic management, entertainment, etc. These applications are categorized based on how data is transmitted from source to destination. The performance of such applications does not only depend on routing protocols, but also on the data dissemination mechanism. Data dissemination in VANETs is a significant factor, which can be accomplished using four different models: Dynamic Source Dynamic Destination (DSDD), Dynamic Source Static Destination (DSSD), Static Source Dynamic Destination (SSDD), and Static Source Static Destination (SSSD). Each one of these models is suitable for specific types of applications. In this paper, the authors study and evaluate the fault-tolerance of VANET under different data dissemination techniques in terms of throughput, average End-to-End delay, and percentage of packet loss. the authors used NCTUns 6.0 network simulator and IEEE 802.11p wireless communication standard. Their findings show that DSDV is more fault-tolerant than both DSR and AODV in terms of packet loss percentage for all dissemination techniques. However, AODV shows better performance in average End-to-End delay and throughput under DSDD and SSDD techniques.

Label-free, mass-sensitive single-molecule imaging using interferometric scattering microscopy

2020 ◽  
Author(s):  
Nikolas Hundt
Keyword(s):  
Single Molecule ◽  
Cellular Systems ◽  
Single Molecule Imaging ◽  
Label Free ◽  
Measurement Sensitivity ◽  
Mass Distributions ◽  
Quantitative Measurements ◽  
Contrast Mechanism ◽  
Cellular Components ◽  
Scattering Signal

Abstract Single-molecule imaging has mostly been restricted to the use of fluorescence labelling as a contrast mechanism due to its superior ability to visualise molecules of interest on top of an overwhelming background of other molecules. Recently, interferometric scattering (iSCAT) microscopy has demonstrated the detection and imaging of single biomolecules based on light scattering without the need for fluorescent labels. Significant improvements in measurement sensitivity combined with a dependence of scattering signal on object size have led to the development of mass photometry, a technique that measures the mass of individual molecules and thereby determines mass distributions of biomolecule samples in solution. The experimental simplicity of mass photometry makes it a powerful tool to analyse biomolecular equilibria quantitatively with low sample consumption within minutes. When used for label-free imaging of reconstituted or cellular systems, the strict size-dependence of the iSCAT signal enables quantitative measurements of processes at size scales reaching from single-molecule observations during complex assembly up to mesoscopic dynamics of cellular components and extracellular protrusions. In this review, I would like to introduce the principles of this emerging imaging technology and discuss examples that show how mass-sensitive iSCAT can be used as a strong complement to other routine techniques in biochemistry.

Surgical management of extracranial carotid artery aneurysms

VASA ◽  
2016 ◽  
Vol 45 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Jan Paweł Skóra ◽  
Jacek Kurcz ◽  
Krzysztof Korta ◽  
Przemysław Szyber ◽  
Tadeusz Andrzej Dorobisz ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Surgical Management ◽  
Minor Stroke ◽  
Stroke Rate ◽  
Extracranial Carotid Artery ◽  
Long Term Follow Up ◽  
End To End ◽  
Dacron Patch ◽  
Major Stroke

Abstract. Background: We present the methods and results of the surgical management of extracranial carotid artery aneurysms (ECCA). Postoperative complications including early and late neurological events were analysed. Correlation between reconstruction techniques and morphology of ECCA was assessed in this retrospective study. Patients and methods: In total, 32 reconstructions of ECCA were performed in 31 symptomatic patients with a mean age of 59.2 (range 33 - 84) years. The causes of ECCA were divided among atherosclerosis (n = 25; 78.1 %), previous carotid endarterectomy with Dacron patch (n = 4; 12.5 %), iatrogenic injury (n = 2; 6.3 %) and infection (n = 1; 3.1 %). In 23 cases, intervention consisted of carotid bypass. Aneurysmectomy with end-to-end suture was performed in 4 cases. Aneurysmal resection with patching was done in 2 cases and aneurysmorrhaphy without patching in another 2 cases. In 1 case, ligature of the internal carotid artery (ICA) was required. Results: Technical success defined as the preservation of ICA patency was achieved in 31 cases (96.9 %). There was one perioperative death due to major stroke (3.1 %). Two cases of minor stroke occurred in the 30-day observation period (6.3 %). Three patients had a transient hypoglossal nerve palsy that subsided spontaneously (9.4 %). At a mean long-term follow-up of 68 months, there were no major or minor ipsilateral strokes or surgery-related deaths reported. In all 30 surviving patients (96.9 %), long-term clinical outcomes were free from ipsilateral neurological symptoms. Conclusions: Open surgery is a relatively safe method in the therapy of ECCA. Surgical repair of ECCAs can be associated with an acceptable major stroke rate and moderate minor stroke rate. Complication-free long-term outcomes can be achieved in as many as 96.9 % of patients. Aneurysmectomy with end-to-end anastomosis or bypass surgery can be implemented during open repair of ECCA.

Reliability of the Mangled Extremity Severity Score in the Management of Peripheral Vascular Injuries in Children: A Retrospective Review

2020 ◽  
Author(s):  
Ahmed Mousa ◽  
Ossama M. Zakaria ◽  
Mai A. Elkalla ◽  
Lotfy A. Abdelsattar ◽  
Hamad Al-Game'a
Keyword(s):  
Severity Score ◽  
Vein Graft ◽  
Bypass Surgery ◽  
Age Groups ◽  
Vascular Injuries ◽  
Peripheral Vascular ◽  
Group Iii ◽  
Mangled Extremity ◽  
Group I ◽  
End To End

AbstractThis study was aimed to evaluate different management modalities for peripheral vascular trauma in children, with the aid of the Mangled Extremity Severity Score (MESS). A single-center retrospective analysis took place between 2010 and 2017 at University Hospitals, having emergencies and critical care centers. Different types of vascular repair were adopted by skillful vascular experts and highly trained pediatric surgeons. Patients were divided into three different age groups. Group I included those children between 5 and 10 years; group II involved pediatrics between 11 and 15 years; while children between 16 and 21 years participated in group III. We recruited 183 children with peripheral vascular injuries. They were 87% males and 13% females, with the mean age of 14.72 ± 04. Arteriorrhaphy was performed in 32%; end-to-end anastomosis and natural vein graft were adopted in 40.5 and 49%, respectively. On the other hand, 10.5% underwent bypass surgery. The age groups I and II are highly susceptible to penetrating trauma (p = 0.001), while patients with an extreme age (i.e., group III) are more susceptible to blunt injury (p = 0.001). The MESS has a significant correlation to both age groups I and II (p = 0.001). Vein patch angioplasty and end-to-end primary repair should be adopted as the main treatment options for the repair of extremity vascular injuries in children. Moreover, other treatment modalities, such as repair with autologous vein graft/bypass surgery, may be adopted whenever possible. They are cost-effective, reliable, and simple techniques with fewer postoperative complication, especially in poor/limited resources.

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