The communication terminal apparatus measures reception quality and reports the measurement result to the base station apparatus, and the base station apparatus switches the transmission rate based on the reported result of the reception quality. In this way, the transmission rate is switched starting at the point in time at which the reception quality of the communication terminal apparatus deteriorates. Furthermore, the transmission rate is switched so that the amount of interference with others is within the allowable range according to the channel condition between the communication terminal apparatus and base station apparatus.
A mobile station decreases its transmit bit rate in response to a determination that its transmit power has exceeded an alarm-power threshold. The mobile station increases its bit rate in response to a determination that its transmit power is below a lower-power threshold. Lower-power threshold and alarm-power threshold delays can be employed to prevent ping-pong effects and avoid unnecessary throughput degradation. A dynamic lower-power threshold can be employed in which the mobile station estimates or predicts its transmit power if it were to increase its transmit bit rate and increases its transmit bit rate only if this can be performed without exceeding the alarm-power threshold.
A communications network including first and second stations, the first station comprising a transmitter and the second station comprising a receiver. The network further including a transition control portion which is operable, prior to a change in a transmission rate of a preselected signal from the first station to the second station, to cause transitional signals to be transmitted from the first station to the second station over the course of a transitional period expiring before the change is effected. The power levels of the transitional signals are varied over the course of the period in such a way as to reduce a level of instability in the network. In another embodiment probing signals are transmitted prior to making such a rate change to probe a likely relationship between the transmission rate and transmission power after the change is effected.
The object of the present invention is provide a mobile communication system which can reduce power consumption of a mobile station without increasing the number of times the data signals which are to be received by the mobile station are retransmitted. The base station 10 comprises a signal transmitter 11 configured to transmit the data signal a to the mobile station 30 within a predetermined period, and transmit each of retransmission signals a1 to a3 of the data signal a, in a form different from that of the data signal a, from the base station 10 to the mobile station 30 within the predetermined period A. The mobile station 30 comprises a receiving processor 31 configured to carry out receiving processing of the data signal a or the retransmission signal a1 within the predetermined period A; a communication quality detector 32 configured to detect a communication quality of the data signal a or the retransmission signal a1; and a reception processing method decider 33 configured to decide a reception processing method for the data signal a or the retransmission signal a1 in the predetermined period A, in accordance with the communication quality detection result.
A base station comprises: an interference quantity measurement unit configured to measure an interference quantity toward a frequency band used in a communication system in which the base station is provided; an allowable interference quantity calculation unit configured to calculate an allowable interference quantity toward the frequency band, which is allowed to maintain a determined number of terminal equipments connecting lines with the base station, based on the measured interference quantity and the determined number of the terminal equipments; a reception unit configured to receive a request of connecting the line transmitted by the terminal equipment; and an acceptance control unit configured to control an acceptance of the request for connecting the line by comparing the measured interference quantity with the allowable interference quantity.
The invention relates to a method of channel-adaptive power control. According to the invention, the method makes it possible to control the transmission power in a channel-adapting way, employing an arbitrary large set of different TPC algorithms (TPCAs) for use. Each TPCA should be well adapted to a special kind of channel characteristics. The set of TPCAs is all the better performing when it covers the largest scale possible of channel characteristics. At any time, the transmission power is controlled by that algorithm chosen among the set of algorithms that appears to be optimal for the actual channel characteristics.