This Recommendation presents an objective picture quality measurement method by use of in-service test signals in a digital television network. This method is separated into three procedures: a) test signal generation at the transmission side using the invisible marker method, b) test signal detection at measurement points, and c) picture quality measurement using the result of test signal detection. A practical implementation is described in Appendix I, whilst the parameters for generating in-service test signals and the performance of this method are described in Appendices II and III, respectively.