• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.797-801
• /
• 2008

This paper describes technical method about remote control and monitoring of local system by use personal mobile device in anytime and anywhere. Therefore, the user don't need to stay in operation room of local system. The PC server environment for the mobile connection are constructed with Apache web server, PHP and MySQL ODBC. The mobile internet homepage for the remote mobile connection is designed by Anybuilder software and mobile simulator, Openwave SDK 6.2 is used for the development. The mobile internet program can be applicate to all of domestic communication companies LGT, SKT and KTF. We use KTF mobile contains WAP browser for the test. We used NI Labview software to control and monitoring of local system. The local system, which will be controlled remotely have constructed with analog/digital signal acquisition device, signal control board and their software. By experiments, we confirmed remote control by mobile device are possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.05a
• /
• pp.187-190
• /
• 2008

Owing to rapid advancements of the mobile computing technologies and the performance of mobile device recently, the data synchronization techniques between severs and mobile clients are getting more and more important. OMA also proposes and recommends standard synchronization methods to use SyncML. However, the feasible data in the method are limited to normal document data, scheduler data, etc. This paper a standard framework based on SyncML. We call it SCGFG. The SCGFG is able to synchronize not only the above data but also GIS data which is very useful in mobile applications. It applies GML, international GIS standard, to the synchronization. By means of using XML, it is also able to resolve the serious problem that is the increase of data volume occurred by SyncML and GML. efficiently. It is highly expected to be useful in the smart synchronization of GIS data among several servers and mobile clients.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.6
• /
• pp.1039-1044
• /
• 2008

Owing to rapid advancements of the mobile computing technologies and the performance of mobile device recently, the data synchronization techniques between severs and mobile clients are getting more and more important. OMA also proposes and recommends standard synchronization methods to use SyncML. However, the feasible data in the method are limited to normal document data, scheduler data, etc. This paper a standard framework based on SyncML. We call it SCGFG. The SCGFG is able to synchronize not only the above data but also GIS data which is very useful in mobile applications. It applies GML, international GIS standard, to the synchronization. By means of using XML, it is also able to resolve the serious problem that is the increase of data volume occurred by SyncML and GML. efficiently. It is highly expected to be useful in the smart synchronization of GIS data among several servers and mobile clients.

• Journal of KIISE:Information Networking
• /
• v.33 no.5
• /
• pp.369-379
• /
• 2006

In recent years, there have been many researches about Ad-hoc Networks which is available to communicate freely between mobile devices by using multi-hop without any support of relay base or access point. TCP that used the most widely transport protocol in the Internet repeats packet loss and retransmission because it increases congestion window size by using reactive congestion control until packet loss occurs. As a result of this, energy of mobile device is wasted unnecessarily. In this paper, we propose TCP-New Veno in order to improve the energy efficiency of mobile device. According to the state of network, the scheme adjusts appropriate size of congestion window. Therefore, the energy efficiency of mobile device and utilization of bandwidth are improved by the scheme. From the simulation by using ns-2, we could see more improved energy efficiency with TCP-New Veno than those with TCP in Ad-hoc Networks.

• Journal of KIISE:Databases
• /
• v.33 no.1
• /
• pp.1-11
• /
• 2006

It is possible to track the moving vehicle as well as to develop the location based services actively according to the progress of wireless telecommunication and GPS, to the spread of network, and to the miniaturization of cellular phone. To provide these location based services, it is necessary for an index technique to store and search too much moving object data rapidly. However the existing indices require a lot of costs to insert the data because they store every position data into the index directly. To solve this problem in this paper, we propose a buffer node operation and design a GU-tree(Group Update tree). The proposed buffer node method reduces the input cost effectively since the operation stores the moving object location data in a group, the buffer node as the unit of a non-leaf node. hnd then we confirm the effect of the buffer node operation which reduces the insert cost and increase the search performance in a time slice query from the experiment to compare the operation with some existing indices. The proposed tufter node operation would be useful in the environment to update locations frequently such as a transportation vehicle management and a tour-guide system.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.6
• /
• pp.111-117
• /
• 2009

In the wideband code division access (WCDMA) systems, a pilot channel is used to determine WCDMA network coverage, cell identification, synchronization, timing acquisition and tracking, user-set handoff, channel estimation, and so on. A wireless repeater, which is deployed in the urban area for the WCDMA system to meet the growing demand on wireless communication services, has the possibility to receive several pilot signals from a large number of base stations, however, cannot distinguish its service base station's signal among them. This pilot interference results in frequent handoffs in the user equipment, which degrades the radio reception, transmission efficiency, quality of service, and channel capacity and increases the unwanted power consumption. In this paper, thus, we propose a pilot pollution interference cancellation scheme using one of the adaptive estimation algorithms, normalized least mean square (NLMS), which is applicable to a wireless repeater. We carried out link-level and network-level computer simulations to evaluate the performance of the proposed scheme in a wireless repeater. The simulation results verify the bit error rate (BER) improvement in the link level and the call drop probability improvement in the network level.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.543-545
• /
• 2011

The concern which is abundant in MANET VoIP for comprising the mobility guarantee and mobile network is received without the infrastructure system between the mobile terminal node. However, because the access of system and border is easy, the issue which is big in the security problem becomes more than the wired network system with this convenience by the foreign network attacker differently. In this paper, we would like to the fundamental web network, NAT and concluding the security problem technology in which Firewall can inquire on MANET VoIP and whether it is appropriate or not which can solve this is proposed.

• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.1
• /
• pp.69-76
• /
• 2006

Telematics, which is a compound word of a telecommunication and informatics, provides drivers with useful driving information such as driving path guidance, accident or robbery detection, traffic conditions and other valuable data at real time. This paper proposes and implements how to build a telematics terminal equipped with CDMA and GPS running embedded Linux, to check a vehicle's state through communication between telematics server and vehicle terminals using a cellular phone and to control a vehicle using SMS as shown in Figure 1. In order to do this, we use the SK-VM platform which is mobile terminal platform based on JAVA to design, implement and evaluate it.

• Journal of Digital Contents Society
• /
• v.8 no.3
• /
• pp.371-376
• /
• 2007

Many modules such as controller, sensor, telematics terminal, navigation, audio and video are connected each other via vehicle network (CAN, MOST, etc). Futhermore, users can have ITS or internet services in moving by connecting to wireless mobile network. These network capabilities can cause a lots of security issues such as data hacking, privacy violation, location tracking and so on. Some possibilities which raise a breakdown or accident by hacking vehicle operation data (sensor, control data) are on the increase. In this paper, we propose a security module which has encryption functionalities and can be used for vehicle network system such as CAN, MOST, etc. This security module can provide conventional encryption algorithms and digital signature processing functionality such as DES, 3-DES, SEED, ECC, and RSA.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.4
• /
• pp.327-334
• /
• 2004

In this paper, a triplexer for Advanced Mobile Phone Service(AMPS), United States-Personal Communication Services(US-PCS), and Global Positioning System(CPS) is designed using L and C lumped elements. The triplexer shows the insertion loss of 0.6 ㏈, 1.1 ㏈, and 1.6 ㏈ for AMPS, US-PCS, and GPS bands, respectively. Also, it shows the attenuation characteristic of less than 18 ㏈, and the VSWR of less than 2.0 through the all pass-band.