Manado, Indonesia

Time filter

Source Type

Nikoukar A.,Yasouj University | Hwang I.-S.,Yuan Ze University | Liem A.T.,Klabat University | Lee J.-Y.,Chung Shan Institute of Science and Technology
Journal of Optical Communications and Networking | Year: 2016

Zap time (channel switching time) is a critical quality of experience (QoE) metric for IPTV systems where synchronization, signaling, and propagation delays are the components under consideration. An Ethernet passive optical network (EPON) is one of the main infrastructures in broadband access networks that provides high bandwidth with low propagation delay. The functionality of the EPON hardware architecture can be extended by adding programmable networking engine (PNE) and programmable sub-system (PSS) components in the optical line terminal (OLT) and optical network unit (ONU) as described in this paper to improve IPTV delivery performance for synchronization and signaling delays in terms of traffic localization. Furthermore, a new IPTV delivery mechanism is proposed to eliminate synchronization delay by buffering the current I-frames of broadcasted channels in the OLT for possible new coming requests and dropping additional streams along with the main stream. The OLTand ONUs implement a multicasting mechanism to handle part of the IPTV request as intra-domain traffic. Simulation results show that the proposed mechanism significantly improves the QoE and quality of service (QoS). IPTV bandwidth usage and system throughput have improved mean packet delays and packet loss in enhanced EPON architecture. © 2016 Optical Society of America.


Nikoukar A.A.,Yuan Ze University | Nikoukar A.A.,Yasouj University | Hwang I.-S.,Yuan Ze University | Liem A.T.,Klabat University | Wang C.-J.,Yuan Ze University
Photonic Network Communications | Year: 2015

Ethernet passive optical network (EPON) is a broadband access time-division multiplexing passive optical network technology which can be referred to as green network, as it has less power consumption compared with other networks. The optical network unit (ONU) is the best candidate to implement energy-saving adjustments in EPON. Turning off the ONU transmitter (Tx)/receiver (Rx) for substantial time is a common method to achieve the energy saving. However, setting overlong sleep duration decreases the QoS, while short sleep duration increases the ONU power consumption. The challenging issue is how to balance the trade-off between achieving energy saving and guaranteeing QoS. In this paper, we introduce an enhanced EPON architecture and a QoS-aware energy-saving mechanism to reduce ONU energy consumption and guarantee an overall QoS metric based on the ITU-T standards requirements. To achieve the energy saving in the upstream/downstream direction, two sleep durations are defined for the ONU’s Tx/Rx to generate four ONU modes including active, transmission, doze, and sleep. Simulation results show that the proposed scheme improves the energy efficiency 44 % in average to fulfill the QoS metrics in terms of packet loss, delay and jitter, and the buffer requirement. © 2015, Springer Science+Business Media New York.


Liem A.T.,Klabat University | Hwang I.-S.,Yuan Ze University | Nikoukar A.,Yuan Ze University
Proceedings - 5th International Conference on Electrical Engineering and Informatics: Bridging the Knowledge between Academic, Industry, and Community, ICEEI 2015 | Year: 2015

Today, the popularity of peer-To-peer (P2P) applications have increased significantly globally. It starts previously on music file sharing system and progressively develops in many application domains. Currently, P2P applications are able to offer various emerging applications ranging from music, video, IPTV and so on. P2P applications are an attractive service because it allows users for accessing different P2P services over Internet, permitting anybody to become a content provider so that anyone can share content (i.e., file, music, video, etc.) with other users. In P2P network, the mapping between the overlay network topology and underlying physical network topology has a significant impact on users Quality-of-Services as well as Internet Service Providers (ISPs). In particular, the major challenge that has received significant attention is that many network oblivious P2P applications without awareness of ISP boundaries that lead to inefficient Internet resource utilization and immense costs for ISPs due to the Inter-ISP traffic cost. Therefore, in this paper we propose an application-Aware mechanism in EPON that can reduce Inter-ISP traffic by optimizing peering locality, and at the same time enhancing the users QoS. Simulation results show that our proposed application-Aware mechanism can reduce the costly Inter-ISP traffic and improving overall system performances such as delay. © 2015 IEEE.


Wielgoss A.,University of Gottingen | Wielgoss A.,University of Würzburg | Clough Y.,University of Gottingen | Fiala B.,University of Würzburg | And 2 more authors.
Journal of Applied Ecology | Year: 2012

1.Herbivores inducing host-plant trait changes can indirectly affect the performance, distribution, abundance and behaviour of other herbivores, even when they are temporally or spatially separated. However, it is unclear whether this occurs at scales relevant for applied purposes such as pest control in agricultural crops. 2.We studied the indirect effects of a minor pest, the mirid bug Helopeltis sulawesi, on the major pest of cacao Theobroma cacao in Southeast Asia, the pod-boring moth Conopomorpha cramerella. For 2years, we surveyed herbivore damage and yield in 10 focal trees in each of the 43 cacao plantations and analysed patterns of co-occurrence of the two herbivores. In a two-choice experiment, we tested whether gravid females of C. cramerella searching for oviposition sites discriminate against pods damaged by H. sulawesi. 3.The proportion of pods affected by both pest species was significantly lower than expected. This pattern could not be ascribed to differential responses to environmental or management variables, but was because of avoidance of H. sulawesi damage by ovipositing C. cramerella females as shown in a two-choice experiment. The reduction in co-occurrence of damage by the two herbivores was found at tree and at plot scale and held across three harvest seasons. 4.The differential yield impacts by the two herbivores and the avoidance by C. cramerella of pods damaged by H. sulawesi lead to a yield optimum at a H. sulawesi incidence of 51%. 5.Synthesis and application. Plant-mediated indirect interactions between minor and major pest insects can be important drivers of yield loss at agriculturally relevant spatial and temporal scales. In cacao, the mirid bug H. sulawesi, a minor pest, generates conspicuous damage which often triggers pest control with insecticides. This practice may be counterproductive, because decreasing H. sulawesi damage benefits the main pest, the cacao pod borer C. cramerella resulting in a marketable yield optimum at intermediate densities of the minor pest. Pest control recommendations should take into account the relative effect of control measures on interacting herbivores to avoid replacing one pest problem with another, potentially more serious one, during the course of a fruiting season. © 2012 The Authors. Journal of Applied Ecology © 2012 British Ecological Society.


Hwang I.-S.,Yuan Ze University | Nikoukar A.,Yuan Ze University | Chen K.-C.,Yuan Ze University | Liem A.T.,Klabat University | Lu C.-H.,Yuan Ze University
Journal of Optical Communications and Networking | Year: 2014

Internet protocol TV (IPTV) is one of the most important multimedia applications for next-generation networks. IPTV provides triple-play services that require high-speed access networks with the functions of multicasting and quality of service (QoS) guarantees. Among access networks, Ethernet passive optical networks (EPONs) are regarded as among the best solutions to meet higher bandwidth demands. In this paper, we propose a new architecture for multicasting live IPTV traffic in EPONs. The proposed mechanism involves assigning a unique logical link identifier to each IPTV channel. To manage multicasting, a table in the optical line terminal (OLT) and in each optical network unit (ONU) is constructed. These tables are maintained in the reconciliation sublayer to deliver the IPTV traffic. We extend the message passing of the original real-time streaming protocol (RTSP), called the extended RTSP (ERTSP), to handle the IPTV requests. A mechanism is proposed to handle the IPTV requests as intra traffic in the ONU without sending the request to the OLT. Handling the live IPTV channel as intra traffic can save bandwidth in the feeder fiber and increase the system throughput. Simulation results show that our proposed architecture can improve the system performance and QoS metrics in terms of packet delay, jitter, system throughput, and packet loss. © 2014 OSA.


Wielgoss A.,University of Gottingen | Wielgoss A.,University of Würzburg | Tscharntke T.,University of Gottingen | Rumede A.,Klabat University | And 6 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2014

Owing to complex direct and indirect effects, impacts of higher trophic levels on plants is poorly understood. In tropical agroecosystems, ants interactwith crop mutualists and antagonists, but little is known about how this integrates into the final ecosystem service, crop yield. We combined ant exclusion and introduction of invasive and native-dominant species in cacao agroecosystems to test whether (i) ant exclusion reduces yield, (ii) dominant species maximize certain intermediate ecosystem services (e.g. control of specific pests) rather than yield, which depends on several, cascading intermediate services and (iii) even, species-rich ant communities result in highest yields. Ants provided services, including reduced leaf herbivory and fruit pest damage and indirect pollination facilitation, but also disservices, such as increased mealybug density, phytopathogen dissemination and indirect pest damage enhancement. Yields were highest with unmanipulated, species-rich, even communities, whereas ant exclusion decreased yield by 27%. Introduction of an invasivedominant ant decreased species density and evenness and resulted in 34% lower yields,whereas introduction of a non-invasive-dominant species resulted in similar species density and yields as in the unmanipulated control. Species traits and ant community structure affect services and disservices for agriculture in surprisingly complex ways, with species-rich and even communities promoting highest yield. © 2013 The Author(s) Published by the Royal Society. All rights reserved.


Liem A.T.,Klabat University | Hwang I.-S.,Yuan Ze University | Nikoukar A.,Yuan Ze University
Optical Fiber Technology | Year: 2014

Ethernet Passive Optical Network (EPON) is chosen for servicing diverse applications with higher bandwidth and Quality-of-Service (QoS), starting from Fiber-To-The-Home (FTTH), FTTB (business/building) and FTTO (office). Typically, a single OLT can provide services to both residential and business customers on the same Optical Line Terminal (OLT) port; thus, any failures in the system will cause a great loss for both network operators and customers. Network operators are looking for low-cost and high service availability mechanisms that focus on the failures that occur within the drop fiber section because the majority of faults are in this particular section. Therefore, in this paper, we propose an autonomous recovery mechanism that provides protection and recovery against Drop Distribution Fiber (DDF) link faults or transceiver failure at the ONU(s) in EPON systems. In the proposed mechanism, the ONU can automatically detect any signal anomalies in the physical layer or transceiver failure, switching the working line to the protection line and sending the critical event alarm to OLT via its neighbor. Each ONU has a protection line, which is connected to the nearest neighbor ONU, and therefore, when failure occurs, the ONU can still transmit and receive data via the neighbor ONU. Lastly, the Fault Dynamic Bandwidth Allocation for recovery mechanism is presented. Simulation results show that our proposed autonomous recovery mechanism is able to maintain the overall QoS performance in terms of mean packet delay, system throughput, packet loss and EF jitter. © 2014 Elsevier Inc. All rights reserved.


Wielgoss A.,University of Gottingen | Wielgoss A.,University of Würzburg | Wielgoss A.,Klabat University | Wielgoss A.,Tadulako University | Wielgoss A.,Lund University
Proceedings. Biological sciences / The Royal Society | Year: 2014

Owing to complex direct and indirect effects, impacts of higher trophic levels on plants is poorly understood. In tropical agroecosystems, ants interact with crop mutualists and antagonists, but little is known about how this integrates into the final ecosystem service, crop yield. We combined ant exclusion and introduction of invasive and native-dominant species in cacao agroecosystems to test whether (i) ant exclusion reduces yield, (ii) dominant species maximize certain intermediate ecosystem services (e.g. control of specific pests) rather than yield, which depends on several, cascading intermediate services and (iii) even, species-rich ant communities result in highest yields. Ants provided services, including reduced leaf herbivory and fruit pest damage and indirect pollination facilitation, but also disservices, such as increased mealybug density, phytopathogen dissemination and indirect pest damage enhancement. Yields were highest with unmanipulated, species-rich, even communities, whereas ant exclusion decreased yield by 27%. Introduction of an invasive-dominant ant decreased species density and evenness and resulted in 34% lower yields, whereas introduction of a non-invasive-dominant species resulted in similar species density and yields as in the unmanipulated control. Species traits and ant community structure affect services and disservices for agriculture in surprisingly complex ways, with species-rich and even communities promoting highest yield.


Liem A.T.,Klabat University
2013 International Conference on Quality in Research, QiR 2013 - In Conjunction with ICCS 2013: The 2nd International Conference on Civic Space | Year: 2013

The P2P lives streaming nowadays becomes more popular and begins to take a larger share of bandwidth together with the Internet video calling. Furthermore, a large scale peer-to-peer (P2P) live streaming has recently been successfully and commercially deployed to provide either live streaming or on-demand video streaming. Cisco predicts that 60% of video traffic worldwide will be consumed by these P2P applications in 2015, which is enough to make any Internet Service Provider (ISP) straitened. In particular, the major challenge that has received significant attention is that many network oblivious P2P applications without locality awareness of ISP boundaries that lead to inefficient Internet resource utilization due to the Inter-ISP traffic cost. Consequently, we propose P2P locality awareness architecture in Ethernet Passive Optical Network (EPON) that mitigates Inter-ISP traffic by optimizing peering locality for P2P live streaming. We design mechanisms in ONU. These mechanisms can reduce inefficient Internet resource utilization at the server sides and improve each peer QoS. © 2013 IEEE.


Infantano A.,Indonesian Air Force Academy | Wahyudi A.K.,Klabat University
Proceedings of 2014 International Conference on Electrical Engineering and Computer Science, ICEECS 2014 | Year: 2014

The firing exercise of air-to-ground rocket should be run safely. The result and evaluation were to be reported quickly. Generally, the Weapon Impact Scoring Systems (WISS) displayed the rocket impact point by using PC monitor at a fixed location. This may produce the gap of real time information which expected by all safety components of exercise. In this paper, we proposed a novel system to visualize results of the rocket firing exercise anytime, anywhere, and realtime. The system called ARoket was developed based on the markerless Augmented Reality and run on Android-based smartphone. ARoket was integrated with current method of the rocket detection, Image Subtraction and 3D-View geometry. It displayed process of how the rocket hit the target which informed some important data such as the position of the rocket explosion and its angle when hitting the target area, which were extracted from the cloud database and visualized in 3D. This proposed system succeded to display the rocket trajectory on the firing range based on the output of WISS which were sent to the internet cloud database. The interchangeable maps installed in the Military Strategic Desk represented the firing range and its environment. By using smartphones in any different places, all officers who related to the firing exercise kept watching the screen of devices to observe the process of the rocket hitting the firing range, and evaluated the results quickly. This proposed system could be contributed to improve the quality and safety level of the exercise thoroughly, even in military or other aspects. © 2014 IEEE.

Loading Klabat University collaborators
Loading Klabat University collaborators