An in-service measurement system for the quality analysis of facsimile transmissions

The paper presents a measurement technique for the assessment of the degree of quality of facsimile transmissions over a telephone-type network that can be performed while the communication lines are in use. The main impairments introduced by the telecommunication channel are continuously measured by using a blind equalization technique and a timing recovery system, thus assuring a high accuracy with a reasonable measurement time, even under poor signal-to-noise ratio (SNR) conditions. Experimental results, that confirm the good performance of the proposed method, are reported and discussed.