Abstract: In the present invention, as a mobile communication terminal, which is using service in the area of an asynchronous mobile communication system, detects signals from a synchronous mobile communication system, the mobile communication terminal repeatedly performs a process of examining whether, in a predetermined time, signals from the asynchronous mobile communication system have been detected a designated number of times, and measuring the intensity of the signals. When the number of times that the intensity of signals from the asynchronous mobile communication system is smaller than a designated number of times, or no signals from the asynchronous mobile communication system are detected, within the predetermined time, it is determined whether to perform handover of the mobile communication terminal.

Abstract: The present invention relates to a handover method for a dual band/dual mode mobile communication terminal between a synchronous mobile communication network and an asynchronous mobile communication network.

Abstract: The present invention implements a chatting the chatting service interworking with a video phone service which can transmit and receive a text during a video phone conversation without terminating the video phone conversation, and furthermore, it improves service quality of a video phone by transmitting and receiving a text during a video phone conversation if a video phone conversation is made in poor an unsuitable environment.

Abstract: Disclosed herein is a mobile communication terminal and handover method therefor, which enable handover of a mobile communication terminal that is using a packet data service or is in a dormant state in a mobile communication network in which asynchronous and synchronous networks coexist. In the handover method, if a channel is assigned between a mobile communication terminal and a synchronous mobile communication system in response to a request from an asynchronous mobile communication system as a mobile communication terminal using packet data service in the asynchronous mobile communication system moves into an area of the synchronous mobile communication system, call setup is performed. A node B of the asynchronous communication releases a connection to the mobile communication system and assigns a new mobile IP to the mobile communication terminal, thus providing continuous packet data service to the mobile communication terminal.

Abstract: A method of etching a carbon-containing layer, a method of forming a contact hole using the same, and a method of manufacturing a semiconductor device using the same, the method of etching a carbon-containing layer including forming a capping layer pattern on a carbon-containing layer to expose a portion of the carbon-containing layer, and plasma etching the exposed portion of the carbon-containing layer using an etching gas, wherein the etching gas includes oxygen gas and an inert gas, the inert gas being xenon gas or a gas mixture of xenon gas and argon gas.

Abstract: Disclosed herein is a mobile communication terminal and handover method therefor. In the mobile communication system, a Gateway GPRS Support Node (GGSN) of the asynchronous network is connected to a Packet Data Service Node (PDSN) of the synchronous network. Accordingly, as a mobile communication terminal, using packet data service in the asynchronous mobile communication system, moves into an area of a synchronous mobile communication system, the synchronous mobile communication system sets control signals and traffic to transmit packet data in response to a request from the asynchronous mobile communication system. Further, if forward and reverse channels are assigned between the mobile communication terminal and the synchronous mobile communication system, call setup is performed to provide the packet data service, and then a node B of the asynchronous mobile communication system releases the connection to the mobile communication terminal.

Abstract: Disclosed herein is a mobile communication terminal and handover method therefor. In the mobile communication system, a Gateway GPRS Support Node (GGSN) of the asynchronous network is connected to a Packet Data Service Node (PDSN) of the synchronous network. Accordingly, as a mobile communication terminal, using packet data service in the asynchronous mobile communication system, moves into an area of a synchronous mobile communication system, the synchronous mobile communication system sets control signals and traffic to transmit packet data in response to a request from the asynchronous mobile communication system. Further, if forward and reverse channels are assigned between the mobile communication terminal and the synchronous mobile communication system, call setup is performed to provide the packet data service, and then a node B of the asynchronous mobile communication system releases the connection to the mobile communication terminal.

Abstract: The video telephony service method includes the step of the mobile communication system, which stores profile information, setting up a call between culling and called mobile communication terminals; the step of the mobile communication system transmitting the profile information of the calling mobile communication terminal to the called mobile communication terminal, as the calling mobile communication terminal transmits the profile information thereof to the mobile communication system; the step of the called mobile communication terminal consulting the profile information, and transmitting a response signal to the mobile communication system after establishing conditions for video telephony if it is determined that video telephony is possible for a received profile, and the mobile communication system transmitting the response signal to the calling mobile communication terminal; and the step of the mobile communication system establishing a communication path between the calling and called mobile communica

Abstract: Disclosed herein is a handover method for a mobile communication terminal in a mobile communication network in which an asynchronous network and a synchronous network coexist. In the present invention, as a mobile communication terminal, which is making a call through an asynchronous mobile communication system, moves into the area of a synchronous mobile communication system, and thus a handover event occurs, the establishment of a call with a synchronous mobile communication system is performed by the automatic call termination or origination of the mobile communication terminal while a connection between the asynchronous modem unit of the mobile communication terminal and the asynchronous mobile communication system is maintained, and then the connection with the asynchronous mobile communication system is released. Accordingly, a call interruption can be prevented at the time of handover between heterogeneous networks.

Abstract: The present invention relates to a handover method for a dual band/dual mode mobile communication terminal between a synchronous mobile communication network and an asynchronous mobile communication network.

Abstract: In the present invention, as a mobile communication terminal, which is using service in the area of an asynchronous mobile communication system, detects signals from a synchronous mobile communication system, the mobile communication terminal repeatedly performs a process of examining whether, in a predetermined time, signals from the asynchronous mobile communication system have been detected a designated number of times, and measuring the intensity of the signals. When the number of times that the intensity of signals from the asynchronous mobile communication system is smaller than a designated number of times, or no signals from the asynchronous mobile communication system are detected, within the predetermined time, it is determined whether to perform handover of the mobile communication terminal.

Abstract: The present invention relates to a dual band/dual mode mobile communication terminal, which can perform stable roaming between synchronous and asynchronous mobile communication networks. The mobile communication terminal of the present invention includes an antenna (410), an asynchronous RF device (420), a synchronous RF device (430), and a common module (440). The antenna (410) transmits/receives radio waves to/from an asynchronous mobile communication network (100) and a synchronous mobile communication network (200). The asynchronous RF device (420) performs asynchronous communication with the asynchronous mobile communication network (100) through the antenna (410). The synchronous RF device (430) performs synchronous communication with the synchronous mobile communication network (200) through the antenna (410).

Abstract: Disclosed is a multi-mode multi-band mobile communication terminal and a mode switching method thereof wherein a mode switching can be performed between an asynchronous network and a synchronous network by minimizing interruption in communication. According to the switching method of a multi-mode multi-band mobile communication terminal, the power of a signal received from an asynchronous network or a synchronous network is measured and the measured power of the received signal drives a modem portion, thereby switching the mode of the mobile communication terminal.

Abstract: Disclosed herein is a mobile communication terminal and handover method therefor, which enable handover of a mobile communication terminal that is using a packet data service or is in a dormant state in a mobile communication network in which asynchronous and synchronous networks coexist. In the handover method, if a channel is assigned between a mobile communication terminal and a synchronous mobile communication system in response to a request from an asynchronous mobile communication system as a mobile communication terminal using packet data service in the asynchronous mobile communication system moves into an area of the synchronous mobile communication system, call setup is performed. A node B of the asynchronous mobile communication releases a connection to the mobile communication system and assigns a new mobile IP to the mobile communication terminal, thus providing continuous packet data service to the mobile communication terminal.