Abstract: According to an example aspect of the present invention, there is provided an apparatus configured to determine a first channel definition describing a first wireless communication channel between the apparatus and a second apparatus, the first wireless communication channel being on a first frequency band, determine a second channel definition describing a second wireless communication channel between the apparatus and the second apparatus, the second wireless communication channel being on a second frequency band which has a lower bound at a higher frequency than an upper bound of the first frequency band, and derive an encryption key at least partly based on the second channel definition, and use the encryption key to encrypt information before it is transmitted to the second apparatus over the first wireless communication channel.

Abstract: Certain examples relate to an apparatus for receiving configuration information to receive a first Reference Signal (RS), and a second RS, wherein the configuration information comprises information indicative of: a first and second time-frequency resource allocated to the first and second RS respectively; wherein the allocation of at least one of the resources is based, at least in part, on: an estimate of a coherence time and a coherence bandwidth of a channel between the apparatus and a node; receiving, based at least in part on the configuration information, the first and second RSs; determining a phase offset between the received first and RSs; adjusting the first or second received RS based, at least in part, on the phase offset; and generating, based, at least in part, on the adjusted RS and the other of the first and second RS, a third RS for use in position estimation.

Abstract: A method for allocating downlink transmission power of coordinated transmission devices in coordinated multi-point transmission system includes the coordinated transmission devices receiving feedback of channel state information of sub-channels occupied by a terminal from the terminal. The channel state information includes channel phase information and channel amplitude information. Each of the coordinated transmission devices adjusts phases of their sending signals over its sub-channels respectively so as to make phase difference of the sending signals, which are received by the terminal from the coordinated transmission devices via a same sub-channel, to be minimal. Each of the coordinated transmission devices determines its power allocation proportions for the sub-channels on the basis of feedback of channel amplitude information from the terminal and the adjusted phases of the sending signals.

Abstract: A method for allocating downlink transmission power of coordinated transmission devices in coordinated multi-point transmission system includes the coordinated transmission devices receiving feedback of channel state information of sub-channels occupied by a terminal from the terminal. The channel state information includes channel phase information and channel amplitude information. Each of the coordinated transmission devices adjusts phases of their sending signals over its sub-channels respectively so as to make phase difference of the sending signals, which are received by the terminal from the coordinated transmission devices via a same sub-channel, to be minimal. Each of the coordinated transmission devices determines its power allocation proportions for the sub-channels on the basis of feedback of channel amplitude information from the terminal and the adjusted phases of the sending signals.