Yngve Rapp - The history of Ericsson

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36 Fig. 6 The hardware in a function block corresponds in mechanical construction to a building module called a magazine, composed of a PC board frame and a wiring unit groups, closed user groups, etc., a number of new facilities have been introduced in system AXB 20 which give subscribers even better means for exchange of messages. There follows a brief account of some of the most common of these new facilities. Abbreviated address The abbreviated address facility enables a subscriber to store in the AXB 20 exchange a number of telex numbers which he often calls, e.g. of branch offices, agents, suppliers, etc. An abbreviated telex number is called by the subscriber keying a code consisting of 1 —3 letter or numerals at his own choice. Hot line When a subscriber presses his call button, he is automatically connected to a predetermined number. This is usually a more advantageous facility than the present method of leased circuits. The use of this facility can also be assigned to specific periodically recurring intervals (scheduled calling). Store and forward facility The store and forward facility enables a subscriber, when he encounters busy condition, congestion or the like, to store his message(s) in the AXB 20 exchange, which forwards them automatically at a later time. A subscriber knows that, towards the end of office hours for example, there will be little possibility of reaching certains destinations and can then instead send his messages to the AXB exchange for later forwarding. This has a trafficequalizing effect in telex networks. Broadcast and conference calls The broadcast and conference call facility permits the transmission of messages to several subscribers simultaneously. This facility can be combined with the abbreviated address facility, so enabling a call to be made to several subscribers on one abbreviated number. Operation and maintenance The costs for operation and maintenance of a telex/data switching exchange today consist predominantly of salaries and wages. The constant rise of these costs is another reason for automating the operation and maintenance functions as far as possible. This applies, of course, not only to the switching
Fig. 7 Great attention has been paid in system AXB 20 to the selection of components in order to ensure the use of reliable units. Here is a PC board for the equipment but also to other parts of the telex network such as subscriber equipment, trunk and local lines, etc. As already noted, the operation and maintenance functions in AXB 20 are to a high degree automatic and integrated in the normal mode of functioning of the system. Preventive exchange maintenance in system AXB 20 is required only in the form of a minor inspection of certain input and output devices I/O. Anotherdifference compared with older systems is that alterations, extensions, traffic rerouting, etc., are effected by commands from an I/O device, which involves very much less work and allows simpler and better documentation. Operational functions The administration of such functions as subscriber facilities, tariffs, charging routines, etc., is greatly simplified in system AXB 20. These operational functions are initiated and supervised from input and output devices I/O placed either in the AXB 20 exchange building or, fora large area, in a common operation and maintenance centre linked to the AXB 20 exchange by a data channel. 37 The operational functions consist of the administration of - subscriber terminations - routes - charging, international accounting, tariffs - traffic routing - traffic statistics Great pains have been taken to simplify the control and supervision of these functions. By way of example for alteration of a route analysis table the modified table is prepared and tested separately down to the last detail before being put into service. Charging is based on the multimetering ortoll ticketing principle. The necessary data are collected in the exchange and stored in an external store, usually magnetic tape. These data later go on to the administrative routines for processing of billing data. In this form the material is also suited for production of various statistical data. Maintenance functions System AXB 20 contains a large number of functions which simplify the maintenance of the switching equipment, and to a large extent too the maintenance of the subscriber and transmission equipments.
Page 1: ERICSSON REVIEW 1 SODERTALJE-THE FI
Page 4 and 5: Transmission Technique Transmission
Page 6 and 7: Södertälje— the First AXE Excha
Page 8 and 9: Fig. 5 The switchroom. Space for 12
Page 10 and 11: 6 Fig. 9 One of the two central pro
Page 12 and 13: 8 Yngve Rapp at his doctoral disser
Page 14 and 15: Design of ERICOFON 700 Carl-Arne Br
Page 16 and 17: 12 Fig. 4 The base with keyset and
Page 18 and 19: Computerized Operation ana Maintena
Page 20 and 21: 16 Fig. 3 Principle of disturbance
Page 22 and 23: 18 Fig. 5 TV monitor showing alarm
Page 24 and 25: 20 Fig. 7 Operation and maintenance
Page 26 and 27: The Stored Program Controlled Group
Page 28 and 29: 24 Fig 4 Grouping plan for an incom
Page 30 and 31: 26 Fig 8 Local and tandem exchanges
Page 32 and 33: Transmission Properties of Paper-in
Page 34 and 35: 30 Fig. 4 Attenuation for paper-ins
Page 36 and 37: AXB 20-All Electronic, Stored- Prog
Page 38 and 39: 34 Fig. 4 In system AXB 20 separate
Page 42 and 43: 38 Fig. 8 Computerized functional t
Page 44 and 45: 40 Simplified maintenance of switch
Page 46 and 47: 42 Fig. 2 Schematic presentation ot
Page 48 and 49: 44 Fig. 5 Hardware structure of the
Page 50 and 51: 46 Fig. 7 Line adapter equipment fo
Page 52 and 53: 48 Fig. 9 The central processor is
Page 54 and 55: 50 Fig. 11 Block diagram of the inp
Page 57 and 58: The Ericsson Group With associated

Yngve Rapp - The history of Ericsson

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