Abstract: The invention relates to a device for direct communication in simplex mode between mobile devices, in particular mobile phones, using carrier frequencies of a cellular mobile phone system, wherein each carrier frequency transmits a TDMA frame with a TDMA frame duration of 4.615 ms and each TDMA frame comprises 8 time slots with a duration of 577 microseconds, wherein the device comprises a hardware module which controls direct communication, wherein the device is designed to combine TDMA frames into a multi-frame which comprises 13 TDMA frames with the positions 0 to 12 and is configured in such a manner that in simplex mode the mobile devices involved constantly transmit and receive in time slots which are separate from one another and within each multi-frame in each TDMA frame only the first time slot TS0 is assigned to transmitting or receiving, while the other time slots TS1 to TS7 of the TDMA frame are left free.

Abstract: The invention pertains to a method for direct communication between mobile terminals by using GSM carrier frequencies, wherein each carrier frequency transmits TDMA frames with a TDMA frame duration of 4.615 ms and each TDMA frame comprises 8 time slots with a duration of 577 microseconds, with the invention being characterized in that a multiframe is agreed upon by combining multiple TDMA frames, preferably 26 TDMA frames, wherein the involved terminals operate in the simplex mode and always transmit and receive in separate time slots within an agreed TDMA frame of the multiframe.

Abstract: The invention relates to a device for direct communication in simplex mode between mobile devices, in particular mobile phones, using carrier frequencies of a cellular mobile phone system, wherein each carrier frequency transmits a TDMA frame with a TDMA frame duration of 4.615 ms and each TDMA frame comprises 8 time slots with a duration of 577 microseconds, wherein the device comprises a hardware module which controls direct communication, wherein the device is designed to combine TDMA frames into a multi-frame which comprises 13 TDMA frames with the positions 0 to 12 and is configured in such a manner that in simplex mode the mobile devices involved constantly transmit and receive in time slots which are separate from one another and within each multi-frame in each TDMA frame only the first time slot TS0 is assigned to transmitting or receiving, while the other time slots TS1 to TS7 of the TDMA frame are left free.

Abstract: The invention pertains to a method for direct communication between mobile terminals by using GSM carrier frequencies, wherein each carrier frequency transmits TDMA frames with a TDMA frame duration of 4.615 ms and each TDMA frame comprises 8 time slots with a duration of 577 microseconds, with the invention being characterized in that a multiframe is agreed upon by combining multiple TDMA frames, preferably 26 TDMA frames, wherein the involved terminals operate in the simplex mode and always transmit and receive in separate time slots within an agreed TDMA frame of the multiframe.