• Journal of the Korea Society for Simulation
• /
• v.15 no.3
• /
• pp.79-86
• /
• 2006

This paper proposes a new protocol to enhance the routing performance and applies our proposal to AODV (Ad hoc On-demand Distance Vector routing) protocol, which is a typical on-demand routing protocol in MANET. In general, when a route repair procedure is performed due to the transfer or failure of a node, the source node re-initiate a route discovery procedure in most routing protocols of MANET. This causes to increase the control traffic overhead largely and degrade the routing performance. The main idea of our study is to provide a methodology that can minimize the control traffic overhead and enhance the performance by initiating a route repair procedure at destination node and utilizing the previous routing information maximumly. To evaluate the performance of the our mechanism, we have performed a series of simulations. The simulations include comparisons with AODV and AODV with local repair. The simulations have been executed under simulation environments taking into account mobility speed and network site. The simulation results show that our proposal overall outperforms the existing protocols.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.9 s.339
• /
• pp.11-18
• /
• 2005

In ad hoc networks, many applications use the broadcast service that is elementary operation to support various important functions such as route discovery procedure. This paper presents several adaptive probabilistic broadcast schemes base on local information to alleviate the broadcast storm problem for wireless ad hoc network. Our schemes dynamically determine the rebroadcast probability at each node based on the neighbor information within two-hop span. Simulation results are presented, which show our schemes have a better performance over the deterministic flooding approach.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.11
• /
• pp.730-742
• /
• 2014

In the case of On-demand routing protocol in cognitive radio ad-hoc networks, broadcasting of control packets may occur common control channel overload and packet collisions during the routing procedure. This situation is to increase the overhead of path finding and also limited to find the accurate and reliable path. Since reliable channel and path finding is restricted, path life time is shorten and path reliability is reduced. In this paper, we propose a new routing algorithm that reduces control channel overhead and increases path life time by considering the probability of appearance of primary user and channel status of neighbor nodes. Each node performs periodic local sensing to detect primary user signal and to derive primary user activity patterns. The probability of primary appearance on the current channel and the channel status can be obtained based on the periodic sensing. In addition, each node identifies the quality of the channel by message exchange through a common channel with neighbor nodes, then determines Link_Levels with neighbor nodes. In the proposed method, the Link Level condition reduces the number of control messages that are generated during the route discovery process. The proposed method can improve path life time by choosing a path through Path_Reliability in which stability and quality are weighted depending on the location. Through simulation, we show that our proposed algorithm reduces packet collisions and increases path life time in comparison with the traditional algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.1
• /
• pp.143-153
• /
• 2008

Recently has there been a great increase of the interests in the excavation of governing institutions and their restoration. There also arise discussions on whether the municipal governments should appoint old governing institutions as the historical spots. In the course of the excavation and restoration of old governing institutions, their practical use becomes a matter of concern. So the reproduction of the past ritual ceremonies and events in the governing institutions attracts considerable attention. But the discovery and the analysis of historical materials are very insufficient to meet the recent increase of such demand. In that point of view, this study aims to analyze the ceremony of Kwanchalsa's(觀察使; a provincial governor) arrival at one's post and the use of governing institutions for it and to examine the Kwanchalsa's route of sulryeok(巡歷) and the ritual ceremonies held in the cities he visited. The Chungcheong-Gamsa(忠淸監司; the governor of Chungcheong-Do) in the 18th century is the subject of this analysis and three local officials' diaries - Chungcheong Gamyeong Ilgi ($\ulcorner$忠淸監營日記$\lrcorner$), Hoseo Gamyeong Ilgi ($\ulcorner$湖西監營日記$\lrcorner$), Geumyeong Ilgi($\ulcorner$錦營日記$\lrcorner$) - are closely investigated for that purpose.