Abstract: A method, apparatus and computer program product are provided for generating Reference Signals utilized in downlink tracking of an unlicensed band. A method and apparatus may determine whether carriers of an unlicensed band secondary component carrier are available for usage to provide a signal(s), enabling timing and frequency tracking of downlink carriers responsive to discontinuous transmission via a medium(s) of the unlicensed band utilized to provide content to devices. The method and apparatus may also select the signal based on a band of the carriers and a detection indicating whether communication terminals of a coexisting system are using a carrier of the band. The method and apparatus may provide the signal to a device(s) via a carrier responsive to determining that the carrier is available or via an occupied carrier utilized by the coexisting system enabling the device to continue tracking of timing and frequency information of the downlink carriers.

Abstract: There is provided a mechanism for controlling communications conducted via different frequency bands or communication spectrums. When a communication via a first communication path, for example an unlicensed or white space communication spectrum, is to be established, e.g. for offloading traffic from a second communication path, for example a licensed cellular communication spectrum, a preamble transmission command is generated and transmitted from a communication network control element, such as an eNB, via the second communication path to a communication element, such as a UE. By means of the preamble transmission command, the transmission of a preamble signal by the receiving communication element on the first communication path with predetermined communication resources is triggered.

Abstract: There are provided measures for enabling a semi-full-duplex single-carrier transmission technique. Such measures may exemplarily comprise classifying each one of served terminals into one of two transmission groups, assigning an uplink-downlink configuration of a frame structure for time division duplex communication for each one of the two transmission groups such that uplink subframes for one transmission group and downlink subframes of the other transmission group coincide with each other, and scheduling uplink and downlink transmissions for the served terminals on a single carrier according to the assigned uplink-downlink configurations for the two transmission groups.

Abstract: A method, apparatus and computer program product are provided for generating a downlink synchronization group utilized during a discontinuous transmission in an unlicensed band. A method and apparatus may determine a carrier(s) providing a signal(s) enabling timing and frequency tracking a downlink carrier(s) within a downlink synchronization group to devices responsive to discontinuous transmission via a medium(s) of an unlicensed band on a secondary component carrier. The medium(s) previously utilized to provide content to a device(s). The method and apparatus may also provide an indication of the carrier(s) to the device notifying the device that information of the signal is receivable via the carrier on the unlicensed band. The method and apparatus may also send the signal(s) to the device via the carrier enabling the device to obtain timing and frequency information.

Abstract: A method and a network side device for trunking communication are provided, and the method includes: in the frequency hopping synchronization of the trunking communication, sending a frequency hopping synchronization information frame to a mobile terminal intended to communication, wherein the frequency hopping synchronization information frame includes the frequency hopping synchronization information. The amount of the transmitted synchronization information is large, the time for establishing synchronization is short, and the confidentiality is strong; and the technical difficulty of the implementation is not high.