Abstract: A method for selecting one or more resources for use from among a set of resources comprises obtaining (201) a first sub-set of the resources. The resources belonging to the first sub-set are the ones which have, according to occupancy information gathered over a long period of time, highest probabilities of matching requirements related to estimated usage time and/or needed capacity. The method further comprises selecting (202) a second sub-set from among the first sub-set of the resources on the basis of second occupancy information gathered over a short period of time. The resources belonging to the second sub-set are the ones from among the first sub-set which, according to the second information, have highest probabilities of matching requirements related to estimated usage time and/or needed capacity. The subsequent use of the long and short term occupancy information increases the probability of optimal selection.

Abstract: A method for selecting one or more resources for use from among a set of resources comprises obtaining (201) a first sub-set of the resources. The resources belonging to the first sub-set are the ones which have, according to occupancy information gathered over a long period of time, highest probabilities of matching requirements related to estimated usage time and/or needed capacity. The method further comprises selecting (202) a second sub-set from among the first sub-set of the resources on the basis of second occupancy information gathered over a short period of time. The resources belonging to the second sub-set are the ones from among the first sub-set which, according to the second information, have highest probabilities of matching requirements related to estimated usage time and/or needed capacity. The subsequent use of the long and short term occupancy information increases the probability of optimal selection.

Abstract: A transmitter of a cognitive radio comprises a selector for selecting from a memory a channel which is determined free, for a power measurement. A power meter measures the received power from the selected channel. Detection selector compares the measured power and a power of the same channel saved in the memory and selects the channel for detection if the power in the channel is within a predetermined range from the power saved in the memory. A detector performs detection of the channel as a response to the selection for detection. A channel selector selects the channel for communication if the channel is detected unoccupied on the basis of detection. The transmitter communicates in the channel as a response to the selection for communication.

Abstract: A transmitter of a cognitive radio comprises a selector for selecting from a memory a channel which is determined free, for a power measurement. A power meter measures the received power from the selected channel. Detection selector compares the measured power and a power of the same channel saved in the memory and selects the channel for detection if the power in the channel is within a predetermined range from the power saved in the memory. A detector performs detection of the channel as a response to the selection for detection. A channel selector selects the channel for communication if the channel is detected unoccupied on the basis of detection. The transmitter communicates in the channel as a response to the selection for communication.

Abstract: The invention relates to detecting a narrowband signals from received signals. According to the different aspects of the invention, a sample set is first formed from received signals, whereby elements of the sample set represent their absolute values, and a lower reference value and an upper reference value are determined. Then adjacent samples exceeding the lower reference value are grouped in the same cluster. The purpose of the clustering is to group signals possibly originating from the same source together. Then, if at least one of these clustered samples exceeds also the upper reference value, it is most probable that the cluster is caused by a narrowband signal. The order of the determination steps can be varied according to the different aspects of the invention.

Abstract: The invention relates to detecting a narrowband signals from received signals. According to the different aspects of the invention, a sample set is first formed from received signals, whereby elements of the sample set represent their absolute values, and a lower reference value and an upper reference value are determined. Then adjacent samples exceeding the lower reference value are grouped in the same cluster. The purpose of the clustering is to group signals possibly originating from the same source together. Then, if at least one of these clustered samples exceeds also the upper reference value, it is most probable that the cluster is caused by a narrowband signal. The order of the determination steps can be varied according to the different aspects of the invention.