TELEMETRY MONITORING SYSTEM FOR TRANSMITTING INFORMATION BY MEANS OF ASYNCHRONOUS TRANSFER MODE TECHNIQUE IN BROADBAND ISDN

摘要

A telemetry supervisory system for transmittinginformation by means of an asynchronous transfer mode techniquein a broadband integrated services digital network (B-ISDN),is disclosed. The system comprises a monitoring means formonitoring a state of an object and for generating monitoringinformation related to the state of the object; andencoding/transmission means for encoding the generatedmonitoring information into a number of cells of fixed lengthusing a variation coding technique, such that 1) when no changein the state of the object occurs and less monitoringinformation is generated, the cells are generated at a givenrate defined as number of cells per unit time, and 2) when achange of the state of the object occurs and more monitoringinformation is generated, the cells are generated at a newrate, wherein a variation of the given rate to the new ratecorresponds to a magnitude of change of the state of theobject. The encoding/transmission means transmits the cellsof fixed length to a monitor station in an asynchronoustransmission mode through a communication network. The monitorstation includes 1) a cell number counter for counting a numberof cells per unit time received from the communication network;and 2) a cell number increase detection means connected to thecell number counter and outputting an alarm signal whichidentifies a monitored object, when a change of the number ofcells counted by the cell number counter is larger than apredetermined value.