Hee-Seon Jang

Business Models for SongTan Ubiquitous City

This paper presents the main business models in ubiquitous city (u-City), the future city strategically integrated with the ubiquitous computing technology. Based on the concept of u-City, the chief services related to the u-City that has been actively developed are analysed, and then the best main four business models (u-Tour, u-ITS, u-SCM and B2B) for SongTan city are presented. The four business models are selected from making an analysis for the present situation of the tour industries, industrial complex, traditional market in SongTan. With the business models, the strategies to realize the active business transactions, high revenues, high value-adding industries, self-sufficient business through the construction of u-City are also presented. Finally, the promoting plans for local autonomy party, citizen party and consortium of industries/universities/researches to give an comfortable u-Life to citizen in SongTan are described.

Call/mobility processing capacity of the personal communication exchange

We analyze the call processing capacity of a personal communication exchange (PCX) for various call types (local, outgoing, incoming and transit calls). We also analyze the mobility processing capacity of the PCX for mobility functions (handover and location registration). The call/mobility processing capacities are calculated by simulation on a queueing network model. The delay times in the processing of call and mobility functions are also calculated by simulation and queueing network analyzer (QNA) for comparison between the two methods. We focus our analysis on the PCX system with distributed call/mobility processing structure, which has been under development in Korea. The numerical computations show that the results from the simulation and QNA are in closer agreement when the utilization rate (the faction of time a processor is busy) of processor handling the mobility functions becomes lower. It is estimated that the call processing capacity of the PCX is 421,280 busy hour complete call (BHC) which is equivalent to 150,700 subscribers of 1.6 BHC. The handover and location registration processing capacities are calculated to be 26,000 transactions/hour and 406,000 transactions/hour, respectively.

Center-based Shared Route Decision Algorithms for Multicasting Services

Recently, with the IPTV services, e-learning, real-time broadcasting and e-contents, many application services need the multicasting routing protocol. In this paper, the performance of the algorithm to assign the rendezvous router (RP: rendezvous point) in the center-based multicasting mesh network is analyzed. The estimated distance to select RP in the candidate nodes is calculated, and the node minimizing the distance is selected as the optimal RP. We estimate the distance by using the maximum distance, average distance, and mean of the maximum and average distance between the RP and members. The performance of the algorithm is compared with the optimal algorithm of all enumeration. With the assumptions of mesh network and randomly positioned for sources and members, the simulations for different parameters are studied. From the simulation results, the performance deviation between the algorithm with minimum cost and optimal method is evaluated as 6.2% average.

Performance Analysis of Distance-based Location Registration Scheme Considering Terminating Call

In this paper, we propose and evaluate the performance distance-based registration considering call arrival. We propose the mobility model, which can be used to analyze the performance of proposed registration schemes. Numerical results show that zone-based registration needs less number of registration than distance-based registration. On the other hand, the registration load of the distance-based registration is equally distributed to all cells in a location area. However, the registration load of the distance-based registration considering cail arrival is similar to that of zone-based registration and equally distributed to all cells in a location area. Therefore, the proposed scheme can be effectively used restricted radio resources.