Abstract: The present invention relates to a method of down-sampling data values. A first set of data values comprise a central data value and peripheral values of original data spatially surrounding the central data value. The central and peripheral values are compared to determine whether any differences exceed a threshold. Whenever a difference does exceed a threshold, a clipped value based upon the central data value replaces the corresponding peripheral value, thereby producing a second set of data values.

Abstract: A communication session between a first terminal and a second terminal is switched from a first network with no fixed infrastructure to a second network with a fixed infrastructure upon degradation on a first transmission channel between the terminals in the first network. In each terminal, a controller detects a degradation on the first transmission channel and stores the latest data received from the other terminal. An interface transmits an invitation message including connection parameters relative to a second transmission channel to the other terminal via one of the networks if the degradation is estimated as permanent. The second transmission channel from the other terminal is established through the second network so that the terminals are connected via the second network to thereby continue the communication session depending on the stored latest received data.