• The KIPS Transactions:PartC
• /
• v.18C no.4
• /
• pp.265-278
• /
• 2011

The objective of this paper is to analyze and characterize end-to-end packet statistics after modeling and simulation of WiFi (IEEE 802.11g) and WiMAX (IEEE 802.16e) of a virtual wireless network using OPNET Modeler Wireless Suite. Wireless internal and external network simulators such as Remcom's Wireless InSite Real Time (RT) module, WinProp: W-LAN/Fixed WiMAX/Mobile WiMAX, and SMI system, are designed to consider data transfer rate based on wireless propagation signal strength. However, we approached our research in a different perspective without support for characteristic of these wireless network simulators. That is, we will discuss the purpose of a visual analysis for these packets, how to receive each point packets (e.g., wireless user, base station or access point, and http server) through end-to-end virtual network modeling based on integrated wired and wireless network without wireless propagation signal strength. Measuring packet statistics is important in QoS metric analysis among wireless network performance metrics. Clear packet statistics is an especially essential metric in guaranteeing QoS for WiMAX users. We have found some interesting results through modeling and simulation for virtual wireless network using OPNET Modeler Wireless Suite. We are also able to analyze multi-view efficiency through experiment/observation result.

• Journal of the Korea Society for Simulation
• /
• v.17 no.4
• /
• pp.21-27
• /
• 2008

In this paper, we design and implement the upstream packet bandwidth allocation algorithm on OPNET-based DOCSIS 3.0 simulator including channel-bonding CM (Cable Modem)s. Previous DOCSIS CM could not support channel bonding, it has problem in upstream bandwidth allocation and determine the contention area. The proposed upstream bandwidth allocation algorithm has been improved the queuing time and success rate. For the simulation, we design the MAC frame structure with channel bonding supported CM and not. And then, this paper design and implement the CMTS node model, CM node model, CMTS process model, and CM process model.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.103-110
• /
• 2010

This paper addressed the implementation of the systematic performance analysis of Quality of Service (QoS) by using OPNET simulator in the interworking architecture of IEEE 802.16e (mobile WiMAX) and IEEE 802.11e (WLAN) wireless network. Four simulation cases were provided in OPNET simulator and a voice traffic was simulated with various performance metrics, such as Mean Opinion Score (MOS), end-to-end delay and packet transmission ratio. Based on the simulation results, the MOS value presented better in WiMAX to WiMAX case compared to others in both static and mobility case. Meanwhile, end-to-end delay was not greatly affected by mobility in four cases. However, mobility was affected much in MOS value and packet transmission ratio in WLAN to WLAN case than in others.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.10A
• /
• pp.1189-1199
• /
• 2004

In this paper, we explain the development procedure for a WLAN (IEEE 802.l1b Wireless Lan) handoff simulator using OPNET Modeler 9.0 and analyze the handoff performance when TCP and UDP traffic is applied. Because the BSS (Basic Service Set) is set only once at the beginning of a simulation in WLAN model supported by OPNET Modeler 9.0, the discontinuation of the communication between MS (Mobile Station) and AP (Access Point) is occurred by the migration of the MS from one BSS to another. We implement a handoff simulator based on this WLAN model and analyze handoff performance in various scenarios Also, we propose a new handoff algorithm which prevents TCP timeout by analyzing the problems of the handoff using the simulator.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.3B
• /
• pp.274-287
• /
• 2009

In the Internet environment in which best-effort services are provided, we need to guarantee end-to-end performance rather than hop performance to provide services with a variety of QoS(Quality of Service) requirements. The end-to-end performance is affected by many factors along the path of traffic flow. Most existing simulation studies are concentrated on a single node or a few nodes. We need much different approach considering the simulation execution time to simulate a large-scale network. In this paper, we derive requirements and present methodologies for the implementation of the simulator to simulate it. Then, we design and implement our simulator using OPNET. Performance evaluation is carried out using the simulator for large-scale KII (National Information Infrastructure in Korea). We use a self-similar traffic model and present some results on the end-to-end performance metric for the networks.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.9
• /
• pp.917-922
• /
• 2016

There are many researches related on the brain wave signals to monitor the state of human health. Especially, some patients in the medical hospital need to be monitored in case of emergencies such as a seizure, an epilepsy and so on. To support QoS of the brain wave network in the hospital is a vital issue and the Opnet simulator is used for this experiment. So the efficient network topology is required for the stability of the brain wave network service. The brain waves of the patients are collected from the sensor devices in the network. Two different sensor network topologies are suggested and simulated for the comparison of the network performance. One topology is localized and the other is non-localized network. The simulation is operated with the Opnet simulator.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.49-50
• /
• 2015

최근 지능형전력망 산업에 이어 최근 IoT, 마이크로그리드 등 전력시스템의 고도화 및 활성화를 위해 다양한 분야의 접목이 시도되고 있다. 하지만 이러한 전력시스템의 진화가 생각보다 느리게 진행되는 이유는 시스템 자체의 신뢰성이 부족한 부분이 있지만, 수용가, 즉 소비자들의 신뢰를 확보하지 못한 부분 역시 간과하기 힘들다. 본 논문에서는 수용가 측 지능형 전기설비에 대한 신뢰성을 확보하기 위한 방안 중 하나로 적합성평가를 위해 OPNET을 활용한 저압 전기설비의 적합성평가 방법을 모의하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.5B
• /
• pp.466-474
• /
• 2003

In this paper, we develope the simulation model for Ethernet passive optical networks (Ethernet-PON) by using OPNET. Ethernet-PON is an emerging access network technology that provides a low-cost method of deploying optical access lines. The simulator uses a Request/Grant TDMA MAC protocol based on IEEE 802.3ah EFM. It also executes registration, ranging and dynamic bandwidth allocation algorithm by exchanging control packets between OLT and ONUs. We have evaluated for success ratio of initial registration process and delay of late registration process. We also have simulated for dynamic TDMA protocol and static TDMA protocol in terms of channel utilization and queueing delay. We expect that this simulator can help to determine various parameters which are considered for designing Ethernet-PON system.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.4
• /
• pp.87-97
• /
• 2009

A Mobile Ad hoc Network (MANET) is characterized by multi-hop wireless connectivity, frequently changing network topology with mobile nodes and the efficiency of the dynamic routing protocol plays an important role in the performance of the network. In this paper, the performance of five routing protocols for MANET is compared by using OPNET modeler: AODV, DSR, GRP, OLSR and TORA. The various performance metrics are examined, such as packet delivery ratio, end-to-end delay and routing overhead with varying data traffic, number of nodes and mobility. In our simulation results, OLSR shows the best performance in terms of data delivery ratio in static networks, while AODV has the best performance in mobile networks with moderate data traffic. When comparing proactive protocols (OLSR, GRP) and reactive protocols (AODV, DSR) with varying data traffic in the static networks, proactive protocols consistently presents almost constant overhead while the reactive protocols show a sharp increase to some extent. When comparing each of proactive protocols in static and mobile networks, OLSR is better than GRP in the delivery ratio while overhead is more. As for reactive protocols, DSR outperforms AODV under the moderate data traffic in static networks because it exploits caching aggressively and maintains multiple routes per destination. However, this advantage turns into disadvantage in high mobility networks since the chance of the cached routes becoming stale increases.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.7B
• /
• pp.780-788
• /
• 2011

The lack of QoS (Quality of Service) support functionalities in IEEE 802.11 DCF mode makes it difficult to provide real-time multimedia services in WLANs. In this paper, we propose an effective available bandwidth measurement method in IEEE 802.11b DCF environments. The proposed method measures the total channel idle time and the collision probability during each measurement period. Then, the available bandwidth is calculated by considering those measured information and the transmission overheads at MAC and PRY layers. The performances of the proposed method are evaluated using OPNET simulator. The simulation results show that the proposed method provides more exact results than existing comparable schemes.