Abstract: A method of an aerial vehicle for urban air mobility may include: reporting, to a first base station, a measurement result for neighboring base stations including a second base station; receiving, from the first base station and as a processing result based on the measurement result, an indication of a failure of a handover to the second base station; requesting, to a control station, first location information indicating a first location to move according to the failure of the handover; receiving the first location information from the control station; and moving according to the received first location information.

Abstract: A method and apparatus for handover is provided. In a network environment in which a plurality of beams are provided within a base station, a terminal measures signal strength of a serving beam and signal strength of a target beam and transmits a measurement report message when a first condition or a second condition is satisfied. The base station determines inter-beam coordinated scheduling when the signal strength of the serving beam and target beam satisfy the first condition, and determines handover between beams when the signal strength of the serving beam and target beam satisfy the second condition. The base station transmits a message for commanding handover to the terminal when the handover between beams is determined. The terminal then stops communicating with the serving beam and performs handover to the target beam.

Abstract: A UE does not immediately perform handover after receiving a handover command from a serving base station, but instead backups that message and continuously compares the signal strength of a serving base station and the signal strength of a target base station and performs a handover to the target base station at the best timing when handover is required. Once the timing of handover is determined, the UE transmits a handover indication message to the serving base station, and thereafter the UE performs a handover to the target base station.

Abstract: A method and apparatus for handover is provided. In a network environment in which a plurality of beams are provided within a base station, a terminal measures signal strength of a serving beam and signal strength of a target beam and transmits a measurement report message when a first condition or a second condition is satisfied. The base station determines inter-beam coordinated scheduling when the signal strength of the serving beam and target beam satisfy the first condition, and determines handover between beams when the signal strength of the serving beam and target beam satisfy the second condition. The base station transmits a message for commanding handover to the terminal when the handover between beams is determined. The terminal then stops communicating with the serving beam and performs handover to the target beam.

Abstract: A UE does not immediately perform handover after receiving a handover command from a serving base station, but instead backups that message and continuously compares the signal strength of a serving base station and the signal strength of a target base station and performs a handover to the target base station at the best timing when handover is required. Once the timing of handover is determined, the UE transmits a handover indication message to the serving base station, and thereafter the UE performs a handover to the target base station.

Abstract: A mobile personal base station having a caching function and a method for providing service by the same are disclosed. The mobile personal base station is connected to a service provision server, downloads and stores content, and then broadcasts the availability of the service corresponding to the content to a neighboring terminal. Upon receiving a service request from the neighboring terminal, the mobile personal base station provides the downloaded and stored content to the neighboring terminal.

Abstract: A method for handover of a terminal using a multi-connection in a cellular communication system is disclosed. The method for handover according to the present invention includes a multi-connection setting procedure of setting a connection to a second base station in addition to a connection to a first base station according to movement of a terminal in a direction from the first base station to the second base station, and a connection release procedure of releasing the connection to the first base station. Specifically, the present invention may be applied in a multi-beam management environment of super high frequency (SHF) and extremely high frequency (EHF) bandwidths, and may obtain an effect of decreasing signaling overhead and process latency of a conventional handover method.

Abstract: Provided is an operation method of a cellular telecommunication system for operating multiple beams. In an operation method of a base station, a beam identifier (ID) is allocated to each of the multiple beams, and a terminal reports a beam ID of a selected beam to the base station. When the operation method of the cellular telecommunication system is used, the base station can rapidly sense the entry of the terminal into a specific beam area. Even when the terminal moves between beam areas, it is possible to rapidly make a beam area change with a minimum overhead without performing random access again or performing a complex procedure such as a handover procedure.

Abstract: Provided are a wireless relaying method, a method of controlling a relay mode, and a wireless relay apparatus using the wireless relaying method. The wireless relaying method of a relay node (RN) includes operating in an amplify-and-forward (AF) mode of amplifying and forwarding a received signal upon setup, broadcasting identifier (ID) information on the RN, and, when a mode change message is received from an evolved node-B (eNB), changing an operating mode to a decode-and-forward (DF) mode. Accordingly, it is possible to improve resource efficiency while having an advantage of minimum delay time for relay.

Abstract: The present invention relates to a method for establishing a connection between heterogeneous user-networks and a domain name system proxy server for controlling the same. The present invention has features of providing a method for supporting communication between user-computers included in Internet-compatible heterogeneous networks through a gateway based on an Internet public network and a domain name system proxy server for controlling the method. According to the present invention, supporting mutual communication between various networks based on one network can be expected.

Abstract: Provided are a method of controlling a machine type communication (MTC) device in a radio communication network providing an MTC service, and a wireless communication system providing an MTC service. The method includes registering an MTC device in an MTC server, performing, at the MTC server, authentication of an MTC user to be connected with the MTC device, requesting, at the MTC server, a state report on the MTC device requested by the MTC user from the MTC device and transmitting state information received from the MTC device to the MTC user, and performing, at the MTC server, service control for the MTC device according to a request of the MTC user.

Abstract: A method of assigning a resource of a united system in which a plurality of single systems are complexly operated includes: determining a cost function using standard network state information commonly used within the united system; and assigning a resource based on the cost function. Therefore, a state of each system and user requirements can be fully reflected and a resource can be efficiently managed within a united system in which several systems are complexly operated.

Abstract: The present invention relates to a method for establishing a connection between heterogeneous user-networks and a domain name system proxy server for controlling the same. The present invention has features of providing a method for supporting communication between user-computers included in Internet-compatible heterogeneous networks through a gateway based on an Internet public network and a domain name system proxy server for controlling the method. According to the present invention, supporting mutual communication between various networks based on one network can be expected.

Abstract: A method for supporting session mobility, more particularly, a method for supporting session mobility that can move various sessions between two or more devices by using session initiation protocol (SIP). Various sessions can be simultaneously moved by utilizing a SIP PUBLISH message. Accordingly, a user can utilize various services as they are regardless of changing of service receiving device while the user utilizes various services. Also, the session mobility can be effectively supported whether the target of the session movement is known or not.

Abstract: The SIP-based multimedia communication system for providing mobility using lifelong numbers provides mobility through SIP network service domains and a global domain. The SIP network service domain comprises a user agent and an SIP network server. The user agent transmits request/response messages between users to set up, correct, and cancel calls, and when contact information of the user agent is registered and registration of the contact information is cancelled, requests to be informed of state changes in registration information. The SIP network server performs message routing between user agents and informs the contact information of the user agents during message routing. The global domain manages the SIP network service domains and allocates global SIP identifiers, that is, lifelong numbers to users to provide user-centered mobility.

Abstract: A method and an apparatus for performing handover in a mobile communication network and a mobile communication terminal using the same are provided. The method of performing handover in a mobile communication network includes: receiving information about signal intensity of mobile networks to which a user terminal can be connected; selecting at least one of connectable mobile networks as a network for handover using user information including information about user requirement and information about the received signal intensity; requesting approval of handover of the user terminal to the selected network for handover and receiving result information about the approval request from the network for handover; and transmitting information about a network in which handover is approved among the networks for handover to the user terminal.

Abstract: A method of assigning a resource of a united system in which a plurality of single systems are complexly operated includes: determining a multi-user diversity order based on the quantity of users existing within the system; determining a cost function using the determined multi-user diversity order; and assigning a resource based on the determined cost function. Therefore, a state of each system and user requirements can be fully reflected and a resource can be efficiently managed within a united system in which several systems are complexly operated.

Abstract: A user and service mobility support system and method of in a ubiquitous environment is provided. When a user moves to a domain area capable of using various service equipment by pursuing a location of a user using a mobile communication service outdoors, the user may continuously use a service by determining service equipment based on the user's preference information, available equipment information, and service characteristic information. The user may continuously use a service through various equipments although the user moves into the domain area while the user has used a mobile communication service through the terminal outdoors. In order to select service equipment from among various media equipment, the optimum service equipment is determined based on the user and service characteristic information, and accordingly, it is possible to provide service movement convenience and satisfaction to the user.

Abstract: Provided is a polarization division multiplexed optical transmission system including a transmitter and a receiver. The transmitter includes a first light source generating an optical signal having a linear polarization state; a second light source generating an optical signal having a horizontal polarization state; a first signal generator receiving a first data stream to modulate the optical signal output from the first light source using an M method; a second signal generator receiving a second data stream to modulate the optical signal output from the second light source using an N method; and a polarization beam combiner (PBC) multiplexing the optical signals that were modulated using the M and N methods while maintaining the linear and horizontal polarization states.

Abstract: A method for supporting session mobility, more particularly, a method for supporting session mobility that can move various sessions between two or more devices by using session initiation protocol (SIP). Various sessions can be simultaneously moved by utilizing a SIP PUBLISH message. Accordingly, a user can utilize various services as they are regardless of changing of service receiving device while the user utilizes various services. Also, the session mobility can be effectively supported whether the target of the session movement is known or not.