• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.2864-2870
• /
• 2014

We suggest various supporting methods for seamless services to support the stable service of system and network. As a representative, the redundancy is the duplication for supporting the stable service of the system and networks. The various redundancy systems have been proposed, these may have a variety forms depending on the number of the service supporting systems. We analyze a availability of a various redundancy model about a redundancy systems. We use a SRN based SPNP as an analysis tool. In this paper, we explain a various redundancy models, then compare and analyze the availability of redundancy models according to a number of service units.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.11
• /
• pp.2634-2639
• /
• 2014

The idea of redundancy is used in order to improve the availability of networks and systems and there are various methods for implementing redundancy. To perform the availability analysis various stochastic models have been used. In this paper, 2N redundancy with one active service unit and one standby service unit is considered. To evaluate the expected availability, we model 2N redundancy using Stochastic Reward Nets. This model can be solved using the SPNP package.

• Electronics and Telecommunications Trends
• /
• v.28 no.5
• /
• pp.221-231
• /
• 2013

인터넷 접속료 정산방식은 그동안 피어링과 트랜짓 모델이 주로 활용되어 왔으나 인터넷 트래픽의 폭발적 증가, OTT 서비스 확산 등으로 망 이용대가의 적정 분담을 위해 발신자지불방식(SPNP: Send Party network Pay) 등 새로운 정산모델 도입이 필요하다는 주장도 제기되고 있다. 본고에서는 인터넷 접속료 정산방식으로 활용되어 온 피어링과 트랜짓 정산모델의 특징과 도입배경, 다양한 피어링/트랜짓 변형 모델을 살펴보고, 최근 유렵 통신사업자 협회가 제안한 발신자지불방식 정산모델의 제안 배경 및 ITU, OECD 등 국제기구에서의 논의 동향을 검토해보고자 한다.

• ETRI Journal
• /
• v.26 no.4
• /
• pp.360-366
• /
• 2004

Synchronization Markup Language (SyncML) is a specification of a common data synchronization framework for synchronizing data on networked devices. SyncML is designed for use between mobile devices that are intermittently connected to a network and network services that are continuously available on the network. We have designed and developed a data synchronization system based on the SyncML protocol and evaluated the throughput of the system using the stochastic Petri nets package (SPNP) and analyzed the relationship between the arrival rate and the system resources. Using this model, we evaluate various performance measures in different situations, and we estimate the relationship between the arrival rate and the system resources. From the results, we can estimate the optimal amount of resources due to the arrival rate before deploying the developed system.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.4
• /
• pp.1-14
• /
• 1995

A new stochastic Petri nets model, called Stochastic Petri Nets Reward Model(SPNRM) is used for modeling and evaluating the performance of telecommunication protocols. We have developed a SPNRM of the TDX-10 Internal protocol, which has a packet data exchange facility between DCEs, Especially a timer and retransmission handling model is presented for error control of the data transmission phase. The stochastic Petri nets package(SPNP), a software package for SPNRM used in this paper, has been used to generate numerical results by analytical-numerical method rather than simulation. From the steady state solution of the net, it is possible to calculate automatically the performance measure of the protocol medeled with both end-to-end and link-by-link method, which are the mean response times and the throughputs.

• IE interfaces
• /
• v.8 no.2
• /
• pp.161-169
• /
• 1995

In this paper, a threshold policy is considered for the Markovian queueing system with server vacations. The threshold policy considered in this paper has the following form: "when the number of customers present in the system increases to N, the server is turned on and serves customers until the system becomes empty". In this paper, we show how the finite capacity or finite population queueing system under a threshold policy can be modeled by the stochastic Petri net. The performance evaluation of the model is carried out using the software called "SPNP". Some examples are also presented in which it is shown that how the optimal threshold policies can be obtained under a linear cost structure.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.12
• /
• pp.2828-2835
• /
• 2015

In this paper, we analyse the effect of redundancy types and non-stop forwarding scheme on network service availability. We use stochastic reward net models as enabling modeling approach for the analytical evaluation. We first design stochastic reward nets for redundancy models with or without non-stop forwarding and then evaluate their availability using Stochastic Petri Net Package.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.9
• /
• pp.1717-1722
• /
• 2016

Availability, one of the important metrics used to assess the performance of network system, is defined as the probability that a system is operational at a given point in time under a given set of environmental conditions. To improve the availability of the network service, the redundancy models and the rejuvenation schemes are the effective schemes to be typically used. In this paper, we analyse the effect of 2N redundancy model and/or rejuvenation scheme on the availability of network service. The 2N redundancy model consists of one active and one standby component and the performance of time-based rejuvenation scheme mainly depends on its rejuvenation period. We design stochastic reward net model for the 2N redundancy model with time-based rejuvenation scheme and analyse the service availability of the model using stochastic Petri net package. We provide some numerical examples of the service availability, which shows that the system with rejuvenation has higher availability than the system without rejuvenation.