Public telephone station traffic analyzing arrangement

Claim 1

A traffic analyzing arrangement for public telephone stations which are served from a telephone exchange equipped to transmit charging pulses to said telephone stations through telephone subscriber's lines, said arrangement comprising: means connected in parallel to each telephone line or telephone line input means of said telephone exchange for detecting charging pulses during telephone calls requested by the telephone station connected to said telephone line; means connected to said charging pulse detecting means for periodically counting the number of detected charging pulses during a predetermined observation period allocated to said telephone station; first means for storing the address of each telephone station, two predetermined charging pulse number values specific to said telephone station, and a predetermined observation period duration allocated to said telephone station; second means for storing predetermined average charging pulse numbers of each of said telephone stations during a long observation period; time recording means connected to said first storing means for determining the end of each observation period and in response thereto, reading-out the charging pulse number in said counting means for resetting said counting means; means responsive to the reading-out of said charging pulse number for comparing said charging pulse number to said two stored predetermined charging pulse number values specific to said telephone station; coding means connected to said comparing means for producing a coded signal indicating an operation failure of said telephone station when said charging pulse number is greater than one or less than the other of said predetermined charging pulse number values and for producing another coded signal indicating the normal operation state of said telephone when the charging pulse number lies between said two predetermined charging pulse number values; changing means connected to said first storing means for changing said predetermined charging pulse number values and said observation period of any telephone station when the average number of charges over a predetermined time of said telephone station has undergone a significant change; means for displaying the result of the number comparisons in response to a further coded signal transmitted by said coding means; third means for storing data groups each of said data groups being assigned to telephone stations which have their average charging pulse numbers lying between two predetermined average values and the data of each group being two predetermined average values, two predetermined charging pulse number values specific to said telephone stations of said group and an observation period value; distributing means connected to said first, second and third storing means for successively comparing said average charging pulse number of each telephone station to two average values of each of said groups thereby distributing in each data group the addresses of the telephone stations which have average charging pulse numbers between said two average value of said group; and said two predetermined charging pulse number values and said predetermined observation period of each telephone station being those of the data group in which said telephone station is distributed.