ALACA: A platform for dynamic alarm collection and alert notification in network management systems

Mobile network operators run Operations Support Systems that produce vast amounts of alarm events. These events can have different significance levels and domains and also can trigger other ones. Network operators face the challenge to identify the significance and root causes of these system problems in real time and to keep the number of remedial actions at an optimal level, so that customer satisfaction rates can be guaranteed at a reasonable cost. In this paper, we propose a scalable streaming alarm management system, referred to as Alarm Collector and Analyzer, that includes complex event processing and root cause analysis. We describe a rule mining and root cause analysis solution for alarm event correlation and analyses. The solution includes a dynamic index for matching active alarms, an algorithm for generating candidate alarm rules, a sliding window–based approach to save system resources, and a graph-based solution to identify root causes. Alarm Collector and Analyzer is used in the network operation center of a major mobile telecom provider. It helps operators to enhance the design of their alarm management systems by allowing continuous analysis of data and event streams and predict network behavior with respect to potential failures by using the results of root cause analysis. We present experimental results that provide insights on performance of real-time alarm data analytics systems. Copyright © 2017 John Wiley & Sons, Ltd

Demo: AIML-as-a-service for SLA management of a digital twin virtual network service

Proceedings of: IEEE INFOCOM 2021 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS).This demonstration presents an AI/ML platform that is offered as a service (AIMLaaS) and integrated in the management and orchestration (MANO) workflow defined in the project 5Growth following the recommendations of various standardization organizations. In such a system, SLA management decisions (scaling, in this demo) are taken at runtime by AI/ML models that are requested and downloaded by the MANO stack from the AI/ML platform at instantiation time, according to the service definition. Relevant metrics to be injected into the model are also automatically configured so that they are collected, ingested, and consumed along the deployed data engineering pipeline. The use case to which it is applied is a digital twin service, whose control and motion planning function has stringent latency constraints (directly linked to its CPU consumption), eventually determining the need for scaling out/in to fulfill the SLA.Work supported in part by EU Commission H2020 5Growth project (Grant No. 856709) and H2020 Europe/Taiwan 5G-Dive project (Grant No. 859881)

Performance evaluation of schedulers in MIMO-OFDMA based cellular networks

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Bu bildiride çok-girdili çok-çıktılı (multiple-input multiple-output, MIMO) ve ortogonal frekans bölmeli çoklu erişim (orthogonal frequency division multiple access, OFDMA) tabanlı hücresel kablosuz ağlarda farklı algoritmalara dayalı olarak birçok kullanıcıya, kaynakları tahsis eden zamanlayıcıların performansları incelenmektedir. OFDMA’in alışılmış zaman ve frekans kaynaklarına ek olarak, MIMO yapısı ile oluşan anten kaynakları, algoritmalara dahil edilmiştir. MIMO ve OFDM teknolojileri hakkında temel bilgiler verildikten sonra, Long Term Evolution (LTE) aglarında Round Robin (RR), Proportional Fair (PF) ve Maximum Throughput (MT) zamanlayıcılarının performsları değerlendirilmiştir. Makro hücre kentsel alan kanal modeli kullanılarak, çoklu anten yapısı içeren LTE sistem mimarisi dikkate alınmıştır. Performans değerlendirmeleri için Shannon Kapasitesi (Shannon Capacity) ve Jain’in adillik endeksi (Jain’s fairness index) kullanılmıştır. Buna ek olarak, kapasiteyi en üst düzeye çıkarma ile adilliğe ulaşma arasında bulunan ödünleşmeler Monte Carlo simülasyonlarıyla gösterilmiştir.In this paper, we investigate the performances of schedulers, which basically allocate the resources to multiple users based on different algorithms, in multiple-input multiple-output (MIMO) and orthogonal frequency division multiple access (OFDMA) based cellular wireless networks. In addition to conventional OFDMA resources which are time and frequency, antennas are also considered as resource during scheduling process. After explaining the basic concepts of MIMO and OFDMA technologies, the performances of Round Robin (RR), Proportional Fair (PF) and Maximum Throughput (MT) scheduling algorithms are evaluated in Long Term Evolution (LTE) networks. LTE system architecture including multiple antenna structure with the use of macro cell urban area channel model is considered. Shannon capacity and Jain's fairness index are utilized for performance evaluations. Additionally, the common trade-offs between maximizing capacity and achieving fairness are presented through Monte Carlo simulations

Towards QoS-aware scheduling in software-defined storage networks

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Yazılım-Tanımlı Veri Depolama (Software-Defined Storage, SDS) konsepti son zamanlarda veri merkezlerinde yeni bir teknoloji olarak ortaya çıkmıştır. Bu teknoloji, hem veri merkezi sahiplerine, hem uygulama geliştiricilerine hem de Mobil Ağ Operatörleri (Mobile Network Operator, MNO), Mobil Sanal Ağ Operatörleri (Mobile Virtual Network Operator, MVNO) vb. dahil olmak üzere abonelere yüksek kullanılabilirlik, yönetilebilirlik, performans ve maliyet avantajları sağlayabilir. Bu çalışmada MNO’ların veri merkezindeki depolama birimlerine erişimini düzenleyen Max-Min Fairness programcı algoritmasının performansı, veri merkezindeki talepler ve mevcut depolama kaynakları temel alınarak incelenmektedir. Kaynakların tahsisi, garanti edilen ve anlık depolama miktarı göz önünde bulundurularak yapılmaktadır. Performans göstergesi (key performance indicator, KPI) olarak doymuş-MNO-oranı (satisfied-MNO-ratio) ve en basit tahsis algoritması olan, Round Robin, karşılaştırmalarda kıstas olarak kullanılmaktadır.Software-Defined Storage (SDS) concept has recently emerged as a new technology inside data centers. It can provide high availability, manageability, performance and cost benefits to both data center owners, application developers and subscribers including Mobile Network Operators (MNO) or Mobile Virtual Network Operators (MVNO). In this paper, based on the assumption that MNOs are competing to access the storage units inside data centers, performance of Max-Min Fairness scheduler algorithms is investigated based on MNO's demands and available storage resources inside data center. The allocation of resources are performed under the consideration of both guaranteed and instantaneous storage amount. Satisfied-MNO-ratios are used as key performance indicator (KPI) and simplest allocation algorithm, Round Robin, is considered as benchmark in comparison.http://ieeexplore.ieee.org/document/7960313

On the performance of max-min fairness scheduler in software-defined networks

Due to copyright restrictions, the access to the full text of this article is only available via subscription.In this paper, we investigate the performance of max-min fairness scheduler in software-defined networks (SDNs) which basically centralizes the controller after separating the control plane from the data plane of network devices. Like traditional networks, traffic control mechanism (i.e., resource allocation) plays a fundamental role to satisfy the quality of service (QoS) in SDN. Scheduler allocates the available resources to users under the consideration of some metrics such as fairness, data rate, service requirements etc. In respect to this, we provide a performance improvement of user-satisfied-ratio and quality of a real-time video service with the use of max-min fairness scheduling algorithm, which is a QoS-aware scheduler, on a network structure generated in a laptop. Additionally, the fairness issue is also considered and round robin scheduler which is the simplest resource allocation algorithm is used as benchmark in comparison.TÜBİTA

Optimization and analysis of WLAN RF energy harvesting system architecture

This paper presents the design, analysis and optimization of RF energy harvesting system for WLAN source operating at 2.4 GHz and 5.8 GHz. The system architecture comprises of RF WLAN source, wireless channel, an efficient dual band microstrip patch antenna, an impedance matching network, 4-stage voltage rectifier and a storing circuit. Matching network ensures the maximum power transfer from source to load. HSMS-2850 Schottky diodes are used in rectifier design, which provide low forward voltage and low substrate leakage. The proposed system design is used to analyze the effect of distance on RF power obtained at receiving side. The size of storage capacitor is chosen carefully such that it can store sufficient amount of charge and takes reasonable charging time. Moreover, the circuit parameters are varied to optimize the designed circuit that provides the maximum efficiency of 45% and 22% at 2.4 GHz and 5.8 GHz respectively, at a distance of 1 meter from source. Simulated results show that for received RF power of 5 dBm the system can provide 1.3 mW power across 10 kΩ load, which can be enough to energize the low power devices. The voltage supplied by the harvesting system can be increased further by increasing the number of stages in voltage rectifier according to the application but at the cost of parasitic loss.TUBITA

Visually evoked startle response in a patient with epilepsy: a case report and review of the literature

Both symptomatic and genetic, cases with hyperekplexia or startle seizures induced by acoustic stimuli, are previously reported. By contrast, startle response induced by visual stimuli is rare. While visual stimuli are more commonly associated with startle seizures, here we present an 11-year-old girl with epilepsy, motor-mental retardation, and spastic tetraparesis, who had repetitive startle responses by photic stimulation during the electroencephalogram recording, without any spike-and-wave discharges associated with the startles. We report this unique case with startle responses induced both by acoustic and photic stimuli and review the literature related to this exceptionally rare combination of symptoms

Electrophysiological Investigations in Orthostatic Myoclonus: Preliminary Findings

We report the clinical and electrophysiological findings in seven patients with orthostatic myoclonus (OM) associated with gait initiation failure and falls. OM is one of the causes of unsteadiness of stance and gait, and it may develop as a symptom of neurodegenerative disorders. Both positive myoclonic bursts and negative myoclonus may be seen in electrophysiological recordings, and electrophysiological analysis suggests a subcortical origin for OM