Abstract: Disclosed is a method and apparatus for transmitting/receiving image data in a mobile communication system, in which image data are classified into two types of image data, a first type of image data corresponding to entire-image data in a current time period, a second type of image data being image data representing a difference between previous time-period image data and current time-period image data. A transmission side transmits image data to a reception side, and the reception side notifies the reception side of error occurrence of received image data when detecting the error occurrence on the received image data. When receiving the notification of the error occurrence, the transmission side generates the first type of image data and transmits the first type of image data to the reception side. The reception side receives generated the first type of image data from the transmission side and decodes the first type of image data.

Abstract: Improving the audio QoS of a video call service in a weak signal environment is accomplished. To do this, even if data is damaged in a weak signal environment during a video call using a mobile station in the weak signal environment, an audio call is preferentially processed such that a minimum audio QoS can be secured. If a transmitting mobile station enters into a weak signal environment while transmitting audio data and video data together during a video call, the transmitting mobile station transmits only audio data, and in response to this, a receiving mobile station processes the audio data transmitted during a set time interval and continuously reproduces the audio data. Audio interruption can be reduced, thereby securing a minimum audio QoS.

Abstract: Improving the audio QoS of a video call service in a weak signal environment is accomplished. To do this, even if data is damaged in a weak signal environment during a video call using a mobile station in the weak signal environment, an audio call is preferentially processed such that a minimum audio QoS can be secured. If a transmitting mobile station enters into a weak signal environment while transmitting audio data and video data together during a video call, the transmitting mobile station transmits only audio data, and in response to this, a receiving mobile station processes the audio data transmitted during a set time interval and continuously reproduces the audio data. Audio interruption can be reduced, thereby securing a minimum audio QoS.

Abstract: Disclosed is a method and apparatus for transmitting/receiving image data in a mobile communication system, in which image data are classified into two types of image data, a first type of image data corresponding to entire-image data in a current time period, a second type of image data being image data representing a difference between previous time-period image data and current time-period image data. A transmission side transmits image data to a reception side, and the reception side notifies the reception side of error occurrence of received image data when detecting the error occurrence on the received image data. When receiving the notification of the error occurrence, the transmission side generates the first type of image data and transmits the first type of image data to the reception side. The reception side receives generated the first type of image data from the transmission side and decodes the first type of image data.

Abstract: A method for synchronizing data frames in a communication system, and in particular an apparatus and method for preventing flag emulation in a system for synchronizing data frames using flags, in which a start and an end of each data frame having a data sequence to be transmitted are indicated using a flag. The method comprises classifying the data sequence into a plurality of unit data sequences, the step of inputting the unit data sequences into a predetermined table as indices, the step of outputting output data sequences having dummy bits which are alternatively inserted from the table in correspondence to the indices, and the step of attaching the flags to front and rear ends of the each data frame, respectively.