Patent ID: 8064396

Claim:
A communication method of an orthogonal frequency division multiple access radio system, the method comprising: measuring, in a network system, a quality of a received signal transmitted by a user terminal, the measured quality is a transmission power of the received signal; performing at least two comparison operations, thereby comparing at least one property of the received signal with a predetermined threshold, the at least two comparison operations including a comparison operation between the measured quality and the predetermined threshold; comparing protection against interference of the received signal with a maximum protection, the protection against interference comprising at least one of robustness of encoding and modulation of the received signal performed by the user terminal; decreasing the number of sub-channels for a transmission of the user terminal if each comparison operation indicates that a compared property is at the predetermined threshold or within a predetermined range of the threshold and if the protection against interference is at the maximum protection or within a predetermined range of the maximum protection; and increasing the number of sub-channels for a transmission of a user terminal in response to the number of sub-channels for a transmission of a user terminal having been decreased and the transmission power of the signal being outside a predetermined range of the maximum, thereby canceling at least partly the limitation concerning the number of sub-channels.