Abstract: A two-hop link transmission method and apparatus are provided. The method includes establishing a two-hop link and scheduling transmission on the two-hop link in a Device-To-Device (D2D) communication network. The two-hop link transmission method includes identifying neighbor terminals available for communication with the transmission terminal, selecting one of the neighboring terminals as a recipient terminal, determining a type of a link to be established with the selected neighboring terminal between a single-hop link and two-hop link types, selecting, when the two-hop link type is determined, a relay terminal among the neighboring terminals, establishing the two-hop link with the recipient terminal via the relay terminal, allocating a Multi-Hop Connection Identifier (MCID) for the two-hop link, and transmitting data to the recipient terminal through the two hop link.

Abstract: A link scheduling method in a system for performing Device-to-Device (D2D) communication includes periodically collecting information indicating whether to perform a medium access from at least one neighboring link determining at least one link expected to perform a medium access in a corresponding traffic slot among links with a higher priority than the terminal based on the collected information, and determining whether to perform the medium access of the terminal by considering only the at least one link expected to perform the medium access.

Abstract: In a method for deciding an unregistered macrocell user equipment (MUE) adjacent to a femtocell base station (home evolved node B; HeNB), a macrocell base station (macro evolved node B; MeNB) decides occurrence of an unregistered MUE influenced by interference from a HeNB among MUEs. The MeNB requests an adjacent HeNB to transmit system information (SI) of the adjacent HeNB of which interference has influence on the unregistered MUE, and the unregistered MUE searches for the SI of the adjacent HeNB and transmits the searched SI to the MeNB, when it is decided that the unregistered MUE has occurred. The MeNB informs the adjacent HeNB of existence of the unregistered MUE using a closed subscriber group identifier (CSG ID) of the SI of the adjacent HeNB, transmitted from the unregistered MUE.

Abstract: A link scheduling method in a system for performing Device-to-Device (D2D) communication includes periodically collecting information indicating whether to perform a medium access from at least one neighboring link determining at least one link expected to perform a medium access in a corresponding traffic slot among links with a higher priority than the terminal based on the collected information, and determining whether to perform the medium access of the terminal by considering only the at least one link expected to perform the medium access.

Abstract: Provided is a handover apparatus and method for a terminal based on a received signal strength (RSS) and a radial velocity. The handover method may measure an RSS from a currently accessed base station and RSSs from candidate base stations for handover, may measure a radial velocity with respect to the currently accessed base station and radial velocities with respect to the candidate base stations for handover, and may perform a handover by determining a base station for handover based on the measured RSSs and the measured radial velocities when the RSS from the currently accessed base station is less than or equal to a reference RSS.

Abstract: Provided are a scheduling apparatus and method, an user equipment, and a relay-based mobile communication system. The scheduling apparatus receives information on a channel state of the access zone from the eNB UE separately from the information on the channel state of the relay zone, performs scheduling for the eNB UE in a subsequent relay zone temporally following the relay zone on the basis of the information on the channel state of the relay zone, and performs scheduling for the eNB UE in a subsequent access zone temporally following the access zone on the basis of the information on the channel state of the access zone.

Abstract: Provided is a handover apparatus and method for a terminal based on a received signal strength (RSS) and a radial velocity. The handover method may measure an RSS from a currently accessed base station and RSSs from candidate base stations for handover, may measure a radial velocity with respect to the currently accessed base station and radial velocities with respect to the candidate base stations for handover, and may perform a handover by determining a base station for handover based on the measured RSSs and the measured radial velocities when the RSS from the currently accessed base station is less than or equal to a reference RSS.

Abstract: In a method for deciding an unregistered macrocell user equipment (MUE) adjacent to a femtocell base station (home evolved node B; HeNB), a macrocell base station (macro evolved node B; MeNB) decides occurrence of an unregistered MUE influenced by interference from a HeNB among MUEs. The MeNB requests an adjacent HeNB to transmit system information (SI) of the adjacent HeNB of which interference has influence on the unregistered MUE, and the unregistered MUE searches for the SI of the adjacent HeNB and transmits the searched SI to the MeNB, when it is decided that the unregistered MUE has occurred. The MeNB informs the adjacent HeNB of existence of the unregistered MUE using a closed subscriber group identifier (CSG ID) of the SI of the adjacent HeNB, transmitted from the unregistered MUE.

Abstract: Disclosed is a method of recognizing an available channel in order to prevent channel occupation requirements from colliding with each other when one wireless channel is shared by plural terminals in a CSMA/CA mechanism using an IEEE 802.15.4 protocol slot, the method including: a first step of initializing a counter, CW, as 2, the CW being used for CCA which an attempt to perform is made before frame transmission; a second step of determining if a required channel is occupied; a third step of decreasing the CW by 1 when the channel is idle in the second step; a fourth step of re-determining if the channel is occupied; and a fifth step of, based on a determination result in the fourth step, determining if the CW is 1 when the channel is occupied.

Abstract: Disclosed is a method of recognizing an available channel in order to prevent channel occupation requirements from colliding with each other when one wireless channel is shared by plural terminals in a CSMA/CA mechanism using an IEEE 802.15.4 protocol slot, the method including: a first step of initializing a counter, CW, as 2, the CW being used for CCA which an attempt to perform is made before frame transmission; a second step of determining if a required channel is occupied; a third step of decreasing the CW by 1 when the channel is idle in the second step; a fourth step of re-determining if the channel is occupied; and a fifth step of, based on a determination result in the fourth step, determining if the CW is 1 when the channel is occupied.