Communication system, communication apparatus, and transmission controlling method

A communication apparatus comprising:

• data rate selecting means for selecting one data rate from among a plurality of data rates;
• communication signal transmitting means for transmitting a communication signal at the selected one data rate to a counter communication apparatus;
• transmission power remaining data transmitting means for transmitting transmission power remaining data representing a difference between a maximum transmittable power of said communication signal transmitting means and a transmission power, when said communication signal transmitting means transmits a communication signal, to said counter communication apparatus;
• and
• data rate information receiving means for receiving data rate information transmitted from said counter communication apparatus,
• wherein said data rate selecting means selects a data rate in correspondence to the data rate represented by the data rate information.

A communication apparatus comprising:

• data rate selecting means for selecting one data rate from among a plurality of data rates;
• communication signal transmitting means for transmitting a communication signal at the selected one data rate to a counter communication apparatus;
• maximum transmittable power transmitting means for transmitting data on a maximum transmittable power of said communication signal transmitting means to said counter communication apparatus;
• transmission power transmitting means for transmitting data on a transmission power, when said communication signal transmitting means transmits a communication signal, to said counter communication apparatus;
• and
• data rate information receiving means for receiving data rate information transmitted thereto from said counter communication apparatus,
• wherein said data rate selecting means selects a data rate in correspondence to the data rate represented by the data rate information.

A communication apparatus comprising:

• necessary received power data storing means for storing therein necessary received power data in correspondence to each of the plurality of data rates, the necessary received power data being received power data representing a received power;
• receiving means for receiving a communication signal transmitted thereto from a counter communication apparatus;
• received power data acquiring means for acquiring received power data representing a received power of the communication signal received by said receiving means;
• transmission power remaining data acquiring means for acquiring transmission power remaining data representing a difference between a maximum transmittable power of said counter communication apparatus and a transmission power when said counter communication apparatus transmits the communication signal;
• data rate determining means for determining a data rate to be selected by said data rate selecting means based on a maximum received power data estimated based on the transmission power remaining data acquired by said transmission power remaining data acquiring means and the received power data, and the necessary received power data acquired by said received power data acquiring means;
• and
• data rate information transmitting means for transmitting data rate information representing the data rate determined by said data rate determining means to said counter communication apparatus.

A transmission controlling method of performing transmission method control in a communication system including a first communication apparatus and a second communication apparatus adapted to communicate with each other,

• said transmission controlling method comprising:
• a data rate selecting step of selecting one data rate from among a plurality of data rates;
• a communication signal transmitting step of transmitting a communication signal at the one data rate selected at said data rate selection step;
• a receiving step of receiving the communication signal transmitted at said communication signal transmitting step in said second communication apparatus;
• a received power data acquisition step of acquiring received power data representing a received power of the communication signal received at said receiving step in said second communication apparatus;
• a transmission power remaining data acquisition step of acquiring transmission power remaining data representing a difference between a maximum transmittable power in said communication signal transmission step and a transmission power when the communication signal is transmitted in said communication signal transmission step in said second communication apparatus;
• a data rate determining step of determining a data rate to be selected in said data rate selecting step based on a maximum received power data estimated based on the acquired transmission power remaining data and the acquired received power data, and necessary received power data stored by necessary received power data storing means for storing therein necessary received power data in correspondence to each of the plurality of data rates, the necessary received power data being received power data representing a received power, in said second communication apparatus;
• a data rate information transmitting step of transmitting data rate information representing the data rate determined at said data rate determining step from said second communication apparatus to said first communication apparatus;
• and
• a data rate information receiving step of receiving the data rate information transmitted at said data rate information transmitting step in said first communication apparatus,
• wherein a data rate is selected in correspondence to the data rate represented by said data rate information in the data rate selection step.