Kyung Pyo Jun

An approximate analysis of open tandem queueing networks with blocking and general service times

Abstract An approximation algorithm is presented for open tandem queueing networks with finite buffers and with general service times. The algorithm decomposes the system into individual queues with revised arrival and service processes and revised queue capacity. Then, each queue is analyzed in isolation. The service process is revised to reflect the additional delay a unit might undergo due to blocking. Unlike previous algorithms, the arrival process to each decomposed queue is described by a C2 distribution. The parameters of the service and the arrival processes are computed approximately using an iterative scheme. The approximation procedure yields the steady-state queue-length distribution of each queue. From this, other more commonly sought performance measures, such as mean queue-length, probability that a queue is empty, throughput, etc., can be easily computed. Comparisons of the approximate results with simulation results showed that the proposed algorithm has a good error-level.

Open Service Platform: A Service Creation and Provisioning Environment for BcN Infrastructure

Open service platform makes the functions of telecommunication network open to external service applications through well-defined API. Under this scheme the service layer is independent from lower layers of network such as control and transport layers. So this architecture is well-suited as BcN service platform, because BcN seeks the convergence of existing diverse networks and one of its convergence areas is the service convergence. In this paper we describe our open service platform such as open service gateway and open service development tools. We also mention our approach and experience to find out new APIs and create new converged services.

Next-generation converged networking in Korea: The concept and its R&D activities

In Korea, we witness vivid evidences of changing trend in communication that insist the emergence of new networking architecture. To accommodate the changing trend and to hold current strong position in global IT industry, Korea have launched broadband convergence network (BcN) initiative. BcN vision for Korea is to be the first in the world to realize converged network infrastructure and ubiquitous service environment. In this paper, we have introduced the concept and the vision of BcN with a viewpoint of a new paradigm to prepare future-proof communication environment. And then, we have disclosed BcN research and development (R&D) activities including R&D philosophy, R&D phases, and key technologies required. Also, we have discussed current development issues in three technology branches including service and control technology, unified transport technology, and next-generation access technology.

Open Software Architecture for Multiservice Switching System

To meet the rigorous demands of todays fast-moving telecommunication environment, every carriers want to deploy new services smoothly with minimal impact on the underlying infrastructure. Also it is necessary to create an open environment that enables the deployment of multivendor switching systems with optimum functionality and performance. The MSF(Multiservice Switching Forum) is an industrial forum to develop the network infrastructure that meets the above requirements. The MSF has been focusing on reaching and promoting consensus on the implementation of MSS(Multiservice Switching System) that realizes the vision of multiservice switching and defines a set of open intra-switching system interfaces. In this paper, we review the system architecture and characteristics of the MSS based on MSF architecture. We propose the open software architecture for the implementation of the MSS, the control scenarios for ATM SVC(Switched virtual Connection) service and management functions in the software architecture. The environment for software development is also considered.

Development of a host DBMS for testing switching system software

A switching system generally uses its own real-time operating system and DBMS. One of the important issues for providing a test environment on a host computer is to prepare a DBMS simulator which has the same functionality as the DBMS in the target switching system and can run on a general-purpose computer. It is difficult to guarantee that both the DBMS and the simulator will have the same functions and behaviors. Therefore, we propose a host DBMS, H-DREAMS (Distributed and Real-time DBMS for Host computer), which can be automatically generated from the source system of the target DBMS and can run on the host computer to test a program. The source programs of the target DBMS are fully reusable in making the host DBMS. H-DREAMS acts like the target DBMS and can support real-time characteristics using a relative timer mechanism in the run-time system. It makes switching software portable and part of the functional blocks of the switching software can be moved to other general-purpose computers.

The implementation of a billing data processing mechanism for open access to information services

The billing data processing mechanism in a communication processing system (CPS) provides an information provider (IP) access function and a billing data generating function. To perform this mechanism, the CPS uses an information billing protocol (IBP) which defines the communication procedure between the CPS and IPs and generates the billing information. Using this mechanism, information users can connect open IPs without a service account and the IPs reduce the billing management overload. This paper describes the concept of the IBP, the generation of billing data in the information service access point (ISAP) and management of billing data in mediation-operation, administration and management (M-OAM).