Patent GB-1277678-A (GB)
Title: Traffic measuring system for an automatic telecommunications switching system
IPC: H04M3/36
Filed: 1970-07-14
Abstract: 1277678 Automatic exchange systems INTERNATIONAL STANDARD ELECTRIC CORP 14 July 1970 [24 July 1969] 34044/70 Heading H4K In a programme controlled exchange, traffic path data is serially accumulated in a store, each data item concerning a path through the network including the time of occurrence of the data together with a tag which is later used to collate all the data relating to a same path. The data is collected during the busy hour and is processed on-, or, off-line by the exchange computer. Restrictions may be made on the particular junctors that are to be monitored. Statistical counters are operated by the processed data e.g. in respect of junctor occupation time. Particular description.-The computer (control CU, arithmetic AU) periodically institutes programmes for testing the states of peripherals TSN. Of these, the incoming junctors IJ are scanned for calling conditions during a programme PR1 and present state conditions are passed via interface IOA to a buffer IJMI in memory M. If, during programme PR4 there is a mismatch with "last-look" data in IJM2, a subprogramme Sp41-Sp43 is started for the registration of the calling incoming junctor's identity IJA in a hopper H1 and for the replacement of the "free" marking by a "register" marking in the IJ's storage register IJR in an incoming junctor memory IJM. A traffic measurement programme PR10 is instituted by Sp41 to cause a tag to be read out of tag counter TC and inserted in IJR. The tag, the address IJA of the calling junctor and the time (clock C) are loaded into buffer BT for subsequent transfer to a magnetic tape unit TU. When hopper H1 is polled the presence of data therein starts a translation programme PR8 (SP81, 82) which results in the class CR of a suitable digit receiver being recovered from a table CRT and inserted in hopper H2 together with IJA. During PR9, (SP91-SP96), IJA and CR are used to select a free receiver R (together with its associated storage RR). The address RA of the receiver is stored in IJR and IJA is stored in RR. A junctor-receiver path IJR1 is sought in memory map IRRIM and its identity is stored in RR and in hopper H3. With programme PR7, (SP71), the path is set up through network RS1N with the aid of a marker driver MD in the interface. The calling exchange transmits the three digit exchange code of the wanted party using multi-frequency compelled techniques. Programmes PR3, PR6 (SP61-SP67) are utilized for supervizing digit reception and acknowledgement signalling in conjunction with hopper H4. With the latter loaded programmes PR8, 9, 7 (SP83-85, 97-910) are executed. These involve translating the exchange digits into appropriate outgoing junctor equipment numbers, (hopper H5), free junctor selection, incoming junctor to outgoing junctor route selection (hopper H6) and connecting the selected path. The obvious details of this process are stored in IJR and OJR (outgoing junctor register). In the event of a direct route the originating exchange is instructed to send the called subscribers number (4th and subsequent digits) whereas if the route is indirect or an alternative the first three digits must be transmitted to the subsequent exchange. Another traffic measuring programme PR12 (Sp 103- 106) now takes place in order to transfer the identity of the outgoing junctor OJA, the tag, the time t2 and the wanted exchange digits in the buffer BT. The "register" phases in IJR, OJR are changed to "ringing". The incoming junctor-receiver path is released (programme PR9, SP 911-915) using hopper H8. The outgoing junctor is monitored (programmes PR2, PR3) for the reply of the called party whereupon programme 10 is started to record the time t3, tag and OJA in BT. At the end of the call (either party release, although specifically described in terms of calling party release) the programmes necessary to release the connection are started after allowing 300 msec. to ensure a genuine hang-up. The release times of IJ and later OJ are entered in BT together with their addresses and tags. Detailed flow sheets of the operations summarized above are given.