| 主权项 |
1. A communication system comprising a user equipment, a base station and at least one intermediate apparatus, the user equipment being operable to transmit a communication signal, via the or each intermediate apparatus, to the base station, wherein the base station and the/each intermediate apparatus comprise an indicator derivator operable to derive one or more indicators of the received signal strength of a communication signal received at the base station, or at the intermediate apparatus respectively, the base station comprising:
i) an indicator deviation detector, operable to detect a deviation in the, or one of the, indicators of the received signal strength derived by the base station, from a desired value at which the indicators of the received signal strength of the communication signal received at the base station and at the intermediate apparatus are substantially in balance; ii) a receiving unit operable to receive from the intermediate apparatus an indicator of the received signal strength derived at the intermediate apparatus; iii) an imbalance detector periodically operable to detect an imbalance between one said indicator of the received signal strength derived by the base station and one said indicator of the received signal strength derived by the intermediate apparatus and received by the receiving unit, wherein the imbalance detector comprises a pathloss updater operable, following receipt of said indicators from both said base station and said intermediate apparatus, or following a change in one or both of said indicators received by a controller, to determine a measure of the pathloss experienced by a communication signal being transmitted between the user equipment and the intermediate apparatus, and between the intermediate apparatus and the base station; and iv) a controller, provided in the base station, the controller comprising a first calculator operable, following detection of a deviation by the indicator deviation detector caused by a change in a target value of the desired value, to calculate a new transmit power for the intermediate apparatus, or a new transmit power for the intermediate apparatus and the user equipment, that will: a) restore balance between one said indicator subsequently derived by the intermediate apparatus and one said indicator subsequently derived by the base station; orb) prevent said imbalance from arising, and a second calculator operable, following detection of an imbalance by the imbalance detector caused by a change in a pathloss between the intermediate apparatus and the base station determined by the pathloss updater, to calculate a new transmit power for the user equipment which will restore balance between one said indicator subsequently derived by said base station and one said indicator subsequently derived by said intermediate apparatus, wherein the controller is operable, following the calculation of a new transmit power for the user equipment, to transmit a command to the user equipment commanding a change in the transmit power of the user equipment and, following the calculation of a new transmit power for the intermediate apparatus, to transmit a command to the intermediate apparatus commanding a change in the transmit power of the intermediate apparatus, and wherein if said command transmitted to said user equipment is for an increase in transmit power, the controller is further operable to monitor said indicator derived by the intermediate apparatus in order to determine if said transmit power of said source apparatus has been changed in accordance with said command, wherein if it is determined that a change in transmit power of the source apparatus has not been carried out in accordance with said command, said controller is operable to prohibit any subsequent increases in transmit power of said intermediate apparatus, and wherein if an increase in transmit power of said intermediate apparatus is prohibited, and if no subsequent imbalance is detected by said imbalance detector, said controller is operable to allow a subsequent increase in transmit power of said intermediate apparatus. |
