each frame or of a group of frames preparation of the different symbols i 1 i to be sent on the following frames k k 1 k n to the subscriber d channel frequency location in the channel information to be transmitted on the frequency location of each successive symbol considered sending of the set of the channels of the frequency locations of the symbols to the lmac part and so on for all the other sending nodes e g i k at the lmac level for all the nodes before the start of each frame application to the rf synthesizer of the channel number desired for the frame to come at the lmac level for all the sending nodes just before each symbol to be transmitted sending to the phy layer of the binary information to be transmitted on the respective frequency locations for fabrication by the phy layer of the symbol to be transmitted all the point to point communications represented in the preceding configurations can be generalized to u201c multicast u201d type communications fig1 represents an exemplary implementation in which the hopping law is integrated in the umac part and the rf control is integrated in the lmac.