Abstract: To improve the capacity of global system for mobile communications(GSM) network, a multi-user reusing one slot(MUROS) solution is given based on the proposed MSK-based orthogonal pair(MSK-OP) scheme and low correlated training sequence codes(TSC) design principles. One user occupies a time slot to transmit its burst in current GSM network, while MUROS allows two or more user to coexist in the same slot simultaneously. Theoretical analysis and simulation results showed that MUROS can improve the capacity significantly without degrading the speech quality very much or changing the hardware structures of transmitter or receiver.