Abstract: A terminal device is provided. The terminal device includes an input unit configured to receive an input of a user command inviting a non-subscriber of a messaging service to join a messaging group, and a communication unit configured to transmit a request for invitation information to a server, when the invitation information is received from the server, to transmit an invitation message including the invitation information and an application installation Uniform Resource Locator (URL) to a non-subscriber terminal, and when a join result of the non-subscriber joining the messaging service is received, to transmit a request for an invitation of the non-subscriber to the messaging group.

Abstract: A mobile terminal and system scan method thereof is provided for effectively acquiring system information. The system scanning method includes performing a first scanning process on entire channels registered to a Preferred Roaming List (PRL) for acquiring system information, calculating, when the system information is not acquired in the first scanning process, a power saving time and a second scan time on the basis of a first scan time taken for the first scanning process, the second scan time being equal to the first scan time, and performing a second scanning process and a power saving process, on the basis of the power saving time and the second scan time, alternately until the system information is acquired.

Abstract: A mobile terminal and system scan method thereof is provided for effectively acquiring system information even in a weak electrical field area using Received Signal Strength Indicator (RSSI). A system scan method for a mobile terminal includes evaluating, when the mobile terminal is turned on, received signal strengths of all channels registered to a preferred roaming list, creating a candidate channel list listing channels, each having a received signal strength greater than a threshold value, performing a full-scan process on the channels listed in the candidate channel list, and performing, when the full-scan process fails to find a system, a power saving process, wherein the full-scan process and power saving process are performed alternately until the system is found.

Abstract: A mobile terminal and system scan method thereof is provided for effectively acquiring system information. The system scanning method includes performing a first scanning process on entire channels registered to a Preferred Roaming List (PRL) for acquiring system information, calculating, when the system information is not acquired in the first scanning process, a power saving time and a second scan time on the basis of a first scan time taken for the first scanning process, the second scan time being equal to the first scan time, and performing a second scanning process and a power saving process, on the basis of the power saving time and the second scan time, alternately until the system information is acquired.