Patent ID: 7865146
Filing Date: 2011-01-04
Classification: H04B,H04W

Abstract:
1. A communication system comprising a source apparatus, a destination apparatus and at least one intermediate apparatus, the source apparatus being operable to transmit a communication signal via the or each intermediate apparatus, to the destination apparatus, wherein the destination apparatus and the intermediate apparatus are each operable to derive one or more indicators of the quality of a communication signal respectively received at the destination apparatus or the intermediate apparatus, the communication system further comprising: i) a controller provided in the intermediate apparatus; ii) an indicator deviation detector operable to detect a change in one said indicator derived by the destination apparatus from a desired value, wherein said desired value is the value of the indicator of the quality of the communication signal derived by the destination apparatus when the value is at, or close to, a target value set by the destination apparatus, and when a measure of a quality of a communication signal received at the destination apparatus is in balance with a measure of a quality of a communication signal received at the intermediate apparatus; iii) an imbalance detector operable to detect an imbalance between one said indicator derived by the destination apparatus and one said indicator derived by the intermediate apparatus; iv) a first determination unit operable, following the detection of such a change, to determine a required change in the transmit power of the intermediate apparatus that will tend to bring said indicator derived by the destination apparatus to said desired value, said required change being determined relative to the degree of change detected by said indicator deviation detector, wherein the determination unit further comprises a request transmitter operable to transmit a request for a change in the transmit power of the intermediate apparatus to the controller; and v) a second determination unit operable, following detection of such an imbalance by said imbalance detector, to determine a required change in the transmit power of the source apparatus that will tend to reduce such an imbalance, wherein said required change in the transmit power of the source apparatus is determined relative to the degree of imbalance detected by said imbalance detector.