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This work presents two-rank (Wi-Fi and LTE) analytical model, from which we can evaluate the goodput of vehicular wireless network depending on the number of vehicles N in the access point (AP) coverage area. To evaluate the suitability of the model used, experimental data are compared with the theoretically calculated data. The results obtained allow us to evaluate the performance of each individual...
Smart optimisation of radio resource distribution techniques is crucial in improving the overall performance of Next-Generation Networks (NGNs). Since higher data rates, lower latency and increased fairness for users are the main goals, an efficient scheduling algorithm has to be used. In this paper an evaluation of the performance of an indoor network is realised using the Realistic Indoor Environment...
This paper introduces a new innovation for the analytical model to improve the throughput performance and energy efficiency for ideal channel conditions by the integration which challenges both fountain code and Markov chain modeling. In this context, the energy consumption is a critical resource that can be saved by minimizing the number of transmissions to be performed in the network. Channel contention...
Opportunistic communications through wireless ad-hoc mesh networks have been thoroughly studied in the context of military infrastructureless deployments, sensor networks and even human-centered pervasive networking. However, due to the lack of a model that accurately computes the probability distribution of the delay, we usually content ourselves with the mean values. Such an approach can limit both...
Extending LTE to unlicensed bands (LTE-U) is gaining increasing interest recently. However, its success faces great challenges due to the inherent lack of compatibility between LTE and Wi-Fi. In this paper, we address the problem of harmonious coexistence and efficient spectrum sharing for LTE-U and Wi-Fi. We develop an analysis framework for the Carrier Sensing Adaptive Transmission (CSAT) mechanism,...
Memory price will continue dropping in the next few years according to Gartner. Such trend renders it affordable for in-memory key-value stores (IMKVs) to maintain redundant memory-resident copies of each key-value pair to provision enhanced reliability and high availability services. Though contemporary IMKVs have reached unprecedented performance, delivering single-digit microsecond-scale latency...
In March 2016, a new protocol called licensed-assisted access (LAA) has been embodied in Release 13 (Rel-13) for Long-Term Evolution (LTE) to operate on unlicensed spectrum and interwork with Wi-Fi. The relevant standards clarify the channel access procedures and contention window (CW) adjustment procedures for LAA. In a long period of time, the coexistence performance of LAA with other technologies,...
This work aims at understanding and evaluating the impact of using different path loss models in the optimization trade-off of small cell (SC) networks. In LTE-A, the more realistic propagation models are the more efficient the radio and network optimization becomes. In this work we compare four urban path loss models: the urban/vehicular and pedestrian test environment from the ITU-R M. 1255 Report...
It will cause the loss of information in the distributed satellite networks, if the network node is failure. For this problem, a method for distributed satellite networks based on standby nodes is presented in this paper. Firstly, it can establish a main path and confirm main nodes according to max-throughput principle in this method. Secondly, it can establish standby nodes set for the main path...
A structured overlay running as the base of a DHT or ALM occasionally receives a large number of messages collectively. Those cases are opportunities for an overlay to bundle multiple different messages into a single message and achieve extraordinarily effective message deliveries. Such message bundling reduces the number packet transmissions on an underlay network such as an IP network. This paper...
Harmonious coexistence between LTE with Licensed-Assisted Access (LTE-LAA) and WIFI is a research issue due to deploying LTE to unlicensed spectrum 5GHz. Listen-before-talk (LBT) scheme works as a requisite in unlicensed spectrum to ensure the fairness among different radio access technologies (RATs). To reduce the collision caused by relatively fixed contention window (CW) of LBT scheme and ensure...
In this paper we present a novel dynamic spectrum sensing and access model in cognitive radio networks. This model allows secondary user (SU) to sequentially sense two times if necessary due to the false alarm, and choose different accessing manner according to the sensing result. In practice, sensing results often affect the data transmission in cognitive radio systems. Therefore, a hybrid interweave/underlay...
The principle of attacking methods against the MAC layer of underwater acoustic network is first introduced briefly. Underwater acoustic channel characteristics are modeled corresponding Propagation Delay, Received Power and Background Noise by using OPNET pipeline stage. MAC Layer and Network Layer modules of network node are implemented. The results of a single node attack and two nodes distributed...
Probabilistic reasoning applied to dynamic spectrum sharing systems enables them to characterize situational uncertainties and determine acceptable spectrum access behaviors. Spectrum sharing systems may use sensing data to reduce situational uncertainty and improve spectrum sharing potential. Probabilistic reasoning approaches enable risk-constrained spectrum access, a concept in which spectrum sharing...
In this paper, we investigate the effect of scale-free structure of a network topology on performance of CCN (Content-Centric Networking). Specifically, we generate multiple scale-free and non-scale-free network topologies by two synthetic network generation models (i.e., scale-free tree and generalized BA model). We compare the average delivery delay and throughput of CCN with scale-free and non-scale-free...
In this paper, we propose a modeling approach for a Content-Centric Networking (CCN) network by considering the dynamics of its transport layer protocol. Transport layer protocols for CCN have mainly been investigated through simulation experiments because CCN itself is a complicated network architecture compared with IP, and the complex interaction between CCN caching and the behavior of a transport...
East and West Africa are currently the regions with the fastest economic development growth in Africa. In this article, East and West African major ports efficiency over time are measured and analyzed using the Data Envelopment Analysis (DEA) Window Analysis. A comparison of port efficiency between East and West African ports is then made based on the results found. The Container throughput, the total...
Optical wireless communication (OWC) or visible light communication (VLC) has recently experienced a significant growth in interest. Due to the vast bandwidth available in the unlicensed light spectrum, the ascent of LED-based lighting, inherent security and EM benefits, OWC can be regarded as an attractive alternative to commonly available RF-based communication, specifically Wi-Fi. With its importance...
In this paper, to estimate the Wi-Fi throughput between smart TV and AP (Access Point), the novel methodology is realized by modeling of Wi-Fi 802.11n communication considered real system characteristics. Also, analysis of throughput performance of digital TV by noise effect using the simulation methodology is presented. This result shows very good agreement between measurement and the proposed methodology.
In multi-tier cloud service systems, performance evaluation relies on numerous experiments in order to collect key metrics such as resources usage. The approach may result in highly time-consuming in practice. In this paper, we propose an automated framework for performance tracking, data management and analysis to minimize human intervention in multi-tier cloud service systems. The framework support...
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