Telecom Pub Date : 2021-12-10 DOI: 10.3390/telecom2040031

I. Keramidi, I. Moscholios, P. Sarigiannidis

{"title":"Call Blocking Probabilities under a Probabilistic Bandwidth Reservation Policy in Mobile Hotspots","authors":"I. Keramidi, I. Moscholios, P. Sarigiannidis","doi":"10.3390/telecom2040031","DOIUrl":"https://doi.org/10.3390/telecom2040031","url":null,"abstract":"In this paper we study a mobility-aware call admission control algorithm in a mobile hotspot. To this end, a vehicle is considered which has an access point with a fixed capacity. The vehicle alternates between stop and moving phases. When the vehicle is in the stop phase, it services new and handover calls by prioritizing them via a probabilistic bandwidth reservation (BR) policy. Based on this policy, new handover calls may enter the reservation space with a predefined probability. When the vehicle is in the moving phase, it services new calls only. In that phase, two different policies are considered: (a) the classical complete sharing (CS) policy, where new calls are accepted in the system whenever there exists available bandwidth, and (b) the probabilistic BR policy. Depending on the selected policy in the moving phase, we propose the probabilistic BR loss model (if the CS policy is selected) and the generalized probabilistic BR loss model (if the probabilistic BR policy is selected). In both stop and moving phases, where the call arrival process is Poisson, calls require a single bandwidth unit in order to be accepted in the system, while the service time is exponentially distributed. To analytically determine call blocking probabilities and the system’s utilization, we propose efficient iterative algorithms based on two-dimensional Markov chains. The accuracy of the proposed algorithms is verified via simulation.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115386463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

A Novel System-Theoretic Matrix-Based Approach to Analysing Safety and Security of Cyber-Physical Systems 一种新的基于系统理论矩阵的网络物理系统安全分析方法

Telecom Pub Date : 2021-12-09 DOI: 10.3390/telecom2040030

L. Liew, Giedre Sabaliauskaite, N. Kandasamy, Choong-Yew William Wong

引用次数: 0

A Survey on Traffic Prediction Techniques Using Artificial Intelligence for Communication Networks 基于人工智能的通信网流量预测技术综述

Telecom Pub Date : 2021-12-03 DOI: 10.3390/telecom2040029

Aaron Chen, Jeffrey Law, Michal Aibin

引用次数: 11

A Survey from Real-Time to Near Real-Time Applications in Fog Computing Environments 雾计算环境中从实时到近实时应用综述

Telecom Pub Date : 2021-12-03 DOI: 10.3390/telecom2040028

Eliza Gomes, F. Costa, Carlos Roberto de Rolt, P. Plentz, M. Dantas

引用次数: 11

Intelligent Interference Management in UAV-Based HetNets 基于无人机的HetNets智能干扰管理

Telecom Pub Date : 2021-11-24 DOI: 10.3390/telecom2040027

Simran Singh, Abhaykumar Kumbhar, Ismail Güvenç, M. Sichitiu

{"title":"Intelligent Interference Management in UAV-Based HetNets","authors":"Simran Singh, Abhaykumar Kumbhar, Ismail Güvenç, M. Sichitiu","doi":"10.3390/telecom2040027","DOIUrl":"https://doi.org/10.3390/telecom2040027","url":null,"abstract":"Unmanned aerial vehicles (UAVs) can play a key role in meeting certain demands of cellular networks. UAVs can be used not only as user equipment (UE) in cellular networks but also as mobile base stations (BSs) wherein they can either augment conventional BSs by adapting their position to serve the changing traffic and connectivity demands or temporarily replace BSs that are damaged due to natural disasters. The flexibility of UAVs allows them to provide coverage to UEs in hot-spots, at cell-edges, in coverage holes, or regions with scarce cellular infrastructure. In this work, we study how UAV locations and other cellular parameters may be optimized in such scenarios to maximize the spectral efficiency (SE) of the network. We compare the performance of machine learning (ML) techniques with conventional optimization approaches. We found that, on an average, a double deep Q learning approach can achieve 93.46% of the optimal median SE and 95.83% of the optimal mean SE. A simple greedy approach, which tunes the parameters of each BS and UAV independently, performed very well in all the cases that we tested. These computationally efficient approaches can be utilized to enhance the network performance in existing cellular networks.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117187084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Multi-Tier Cellular Handover with Multi-Access Edge Computing and Deep Learning 基于多访问边缘计算和深度学习的多层蜂窝切换

Telecom Pub Date : 2021-11-15 DOI: 10.3390/telecom2040026

Percy Kapadia, Boon-Chong Seet

引用次数: 2

A Survey on the Implementation and Management of Secure Virtual Private Networks (VPNs) and Virtual LANs (VLANs) in Static and Mobile Scenarios 静态和移动场景下安全vpn和vlan的实现与管理研究综述

Telecom Pub Date : 2021-11-05 DOI: 10.3390/telecom2040025

Antonio Francesco Gentile, P. Fazio, Giuseppe Miceli

{"title":"A Survey on the Implementation and Management of Secure Virtual Private Networks (VPNs) and Virtual LANs (VLANs) in Static and Mobile Scenarios","authors":"Antonio Francesco Gentile, P. Fazio, Giuseppe Miceli","doi":"10.3390/telecom2040025","DOIUrl":"https://doi.org/10.3390/telecom2040025","url":null,"abstract":"Nowadays, the demand for connection between the remote offices of a company, or between research locations, and constantly increasing work mobility (partly due to the current pandemic emergency) have grown hand in hand with the quality and speed of broadband connections. The logical consequence of this scenario is the increasingly widespread use of Virtual Private Network (VPN) connections. They allow one to securely connect the two ends of a connection via a dedicated network, typically using the Internet and reducing the costs of Content Delivery Network (CDN) lines (dedicated connections). At the same time, Virtual Local Area Networks (VLANs) are able to decrease the impact of some scalability issues of large networks. Given the background above, this paper is focused on overviewing and surveying the main progresses related to VPNs and VLANs in wireless networks, by collecting the most important contributions in this area and describing how they can be implemented. We state that security issues in VLANs can be effectively mitigated through the combination of good network-management practices, effective network design and the application of advanced security products. However, obviously, the implementation of VPNs and VLANs poses specific issues regarding information and network security; thus some good solutions are also surveyed.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116796989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Channel Modeling for In-body Optical Wireless Communications 体内光无线通信的信道建模

Telecom Pub Date : 2021-11-03 DOI: 10.20944/preprints202111.0114.v1

Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, N. Chatzidiamantis, G. Karagiannidis

{"title":"Channel Modeling for In-body Optical Wireless Communications","authors":"Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, N. Chatzidiamantis, G. Karagiannidis","doi":"10.20944/preprints202111.0114.v1","DOIUrl":"https://doi.org/10.20944/preprints202111.0114.v1","url":null,"abstract":"Next generation in-to-out-of body biomedical applications have adopted optical wireless communications (OWCs). However, by delving into the published literature, a gap is recognised in modeling the in-to-out-of channel, since most published contributions neglect the particularities of different type of tissues. Towards this direction, in this paper we present a novel pathloss and scattering models for in-to-out-of OWC links. Specifically, we derive extract analytical expressions that accurately describe the absorption of the five main tissues’ constituents, namely fat, water, melanin, oxygenated and de-oxygenated blood. Moreover, we formulate a model for the calculation of the absorption coefficient of any generic biological tissue. Next, by incorporating the impact of scattering in the aforementioned model we formulate the complete pathloss model. The developed theoretical framework is verified by means of comparisons between the estimated pathloss and experimental measurements from independent research works. Finally, we illustrate the accuracy of the theoretical framework in estimating the optical properties of any generic tissue based on its constitution. The extracted channel model is capable of boosting the design of optimized communication protocols for a plethora of biomedical applications.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128506513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Wideband Mixed Signal Separation Based on Photonic Signal Processing 基于光子信号处理的宽带混合信号分离

Telecom Pub Date : 2021-11-02 DOI: 10.3390/telecom2040024

Yang Qi, Taichu Shi, Ben Wu

{"title":"Wideband Mixed Signal Separation Based on Photonic Signal Processing","authors":"Yang Qi, Taichu Shi, Ben Wu","doi":"10.3390/telecom2040024","DOIUrl":"https://doi.org/10.3390/telecom2040024","url":null,"abstract":"The growing needs for high-speed and secure communications create an increasing challenge to the contemporary framework of signal processing. The coexistence of multiple high-speed wireless communication systems generates wideband interference. To protect the security and especially the privacy of users’ communications requires stealth communication that hides and recovers private information against eavesdropping attacks. The major problem in interference management and stealth information recovery is to separate the signal of interest from wideband interference/noise. However, the increasing signal bandwidth presents a real challenge to existing capabilities in separating the mixed signal and results in unacceptable latency. The photonic circuit processes a signal in an analog way with a unanimous frequency response over GHz bandwidth. The digital processor measures the statistical patterns of the signals with sampling rate orders of magnitude smaller than the Nyquist frequency. Under-sampling the signals significantly reduces the workload of the digital processor while providing accurate control of the photonic circuit to perform the real-time signal separations. The wideband mixed signal separation, based on photonic signal processing is scalable to multiple stages with the performance of each stage accrued.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125319357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Comprehensive Comparison of VNE Solutions Based on Different Coordination Approaches 基于不同协调方法的VNE解决方案的综合比较

Telecom Pub Date : 2021-10-25 DOI: 10.3390/telecom2040023

Stelios Prekas, P. Karkazis, Vasileios Nikolakakis, P. Trakadas

{"title":"Comprehensive Comparison of VNE Solutions Based on Different Coordination Approaches","authors":"Stelios Prekas, P. Karkazis, Vasileios Nikolakakis, P. Trakadas","doi":"10.3390/telecom2040023","DOIUrl":"https://doi.org/10.3390/telecom2040023","url":null,"abstract":"Virtualization is commonly accepted as the catalyst that would grant the internet the ability to shed the shackles of legacy technologies and evolve to its future self. In order to make this transformation feasible, unavoidable concurrent radical remodeling of all the involved counterparts is required, particularly in the context of automatically and optimally serving application requests by taking advantage of new virtualized environments and their latent capabilities. A considerable number of embedding strategies that efficiently map virtual computational and networking demands over physical resources have already been proposed in the literature, following different strategies. Among these suggested strategies, different coordination proposals have been adopted, in order to solve the node and link mapping functions. In this paper, we study the capabilities of the most popular embedding strategies, based on their coordination categorization. Our study confirms that by invoking a coordination strategy, especially the single stage one, added benefits on multiple performance layers can be achieved. Moreover, we propose a new mixed coordination algorithm, essentially creating a new category in the field of VNE coordination strategies.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130273847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

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