1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 (b) that this drawback results in part from the inadequacy of existing rules on the setting up, supervision andclearing of phototelegraph calls over circuits normally used for telephone traffic, even if these circuits have beendesignated in advance as cap
2、able of carrying phototelegraph calls;(c) that phototelegraph communications between public stations on the one hand and public and private stationson the other, require close collaboration between the telegraph and telephone services of the various Administrations;(d) that, on the other hand, photo
3、telegraph communications between private stations do not concern thetelegraph services, although it is desirable for all phototelegraph calls between public stations, between public andprivate stations, and between private stations to be established in the same way,unanimously declaresthat the follo
4、wing rules should be applied to the provision of international phototelegraph connections.1 Field of application1.1 The rules below define the operating procedure to be followed in the international phototelegraph service whenphototelegraph calls are set up on circuits normally used for telephone tr
5、affic. They do not apply to phototelegraphtransmissions on circuits in permanent use for that purpose or on leased circuits.1.2 These rules define the procedure applicable to the setting up, supervision and clearing of internationalphototelegraph calls: between public stations; between a public and
6、a private station; between private stations.2 General provisions2.1 In relations where telephone circuits are used for both the phototelegraph service and the telephone service, theAdministrations concerned shall assign by mutual agreement a certain number of circuits for phototelegraphtransmissions
7、, taking into account the usual requirements of both phototelegraphy and the telephone service.2.2 These circuits shall be specially marked at terminal exchanges and repeater stations with a view to the protectionof the phototelegraph transmissions.2.3 The telephone circuits used for international p
8、hototelegraph transmissions shall, as far as practicable, be four-wire circuits. For phototelegraph transmission, they shall normally be disconnected from the switching equipment usedfor telephone calls. Interconnection of circuits for setting up phototelegraph calls should be four-wire-four-wire, a
9、s far aspossible, both on the international and the national side.2.4 Administrations shall designate in each international phototelegraph terminal centre an authority responsible forthe international phototelegraph calls. This authority is in a position to carry out, or cause to be carried out, all
10、 theoperations necessary for the establishment of international phototelegraph calls. This authority shall henceforth be calledthe international phototelegraph position (IPP).2.5 Administrations are recommended to centralize, as far as possible, in one place all the technical, operational andchargin
11、g procedures necessary in an international centre when telephone circuits are used for phototelegraph calls.2.6 A booking for a phototelegraph call emanating from a public or private phototelegraph station is routed to (orarrives directly at) the IPP of the origin country responsible for setting up
12、the international phototelegraph call that hasbeen booked. This IPP then becomes the control IPP for establishing the call.2 Fascicle II.4 - Rec. F.1073 Setting up, supervision and clearing of international phototelegraph calls3.1 If the telephone service on the international circuit needed for sett
13、ing up a phototelegraph call is operated withadvance preparation, requests for phototelegraph calls rank in the order in which they are accepted among requests fortelephone calls of the same category.3.2 In this case the control IPP advises the telephone office responsible for these circuits that a
14、phototelegraphtransmission is to take place. The control IPP agrees with the telephone service on the probable time at which thephototelegraph transmission will be taking place.3.3 The IPPs shall proceed as follows when setting up an international call.3.3.1 The control IPP transmits the following i
15、nformation as quickly as possible to the destination IPP: designation of the transmitting station; designation of the destination station; probable time at which the phototelegraph call will take place; where necessary, indication of the subscriber responsible for the charges; and, in addition:a) fo
16、r calls requested by public stations: category of phototelegram to be transmitted; date and time of handing-in of the phototelegram.b) for calls requested by private stations: category of call requested; date and time of the request.3.3.2 The destination IPP shall take the necessary steps to advise
17、immediately the destination phototelegraph station bytelephone that a phototelegraph transmission is about to take place.3.3.3 If the called phototelegraph station is in a position to receive the phototelegraph call at the time fixed, thedestination IPP informs the control IPP. At the said time, the
18、 two IPPs take the necessary steps, in agreement with thetelephone service, to establish the call. Care must be taken to avoid interrupting telephone calls in progress.3.3.4 If the called phototelegraph station is not in a position to receive the call at the time fixed, the destination IPPfixes the
19、time when the transmission is to take place, taking into account the information received from the receivingphototelegraph station. It then communicates the time fixed to the control IPP, which informs the calling station.3.3.5 The control IPP then takes the necessary measures, in agreement with the
20、 telephone service, to establish thephototelegraph call between the stations concerned at the agreed time.3.4 If the telephone service involved is demand service, the outgoing IPP shall take an available circuit for thephototelegraph call, after ensuring that telephone calls in progress are not inte
21、rrupted; it shall use this circuit to call theincoming IPP.3.4.1 To establish a phototelegraph call, it shall transmit the data mentioned under 3.3.1 above to the incoming IPP,except for the probable time of the phototelegraph call.3.4.2 The incoming IPP shall take the necessary steps to advise imme
22、diately the called phototelegraph station bytelephone that a phototelegraph transmission is about to take place.3.4.3 If the called phototelegraph station is in a position to receive the phototelegraph call immediately, the two IPPsshall straight away establish the necessary connection.3.4.4 If the
23、called phototelegraph station is not in a position to receive the call immediately, the destination IPP fixesthe time when the transmission is to take place, taking into account the information received from the receivingphototelegraph station. It then communicates the time fixed to the control IPP,
24、 which informs the calling station. The twoimmediately clear the international telephone circuit.3.4.5 At the time agreed upon, the outgoing IPP shall take the necessary steps to establish the phototelegraph call.3.5 The control IPP shall note the time when the phototelegraph call starts. The beginn
25、ing of the call is the momentwhen the connection with the called station is offered to the caller. When the international circuit is extended towards anational PP at the callers end, the latter shall determine the beginning of the call and indicate it to the IPP in its countrywhen the call is cleare
26、d (see 3.7 below).Fascicle II.4 - Rec. F.107 33.6 The control IPP supervises the transmission in progress:a) on the transmitting (go) path by means of a device enabling it to check, without risk of interference, thattransmission is taking place;b) on the return path by means of a device enabling it
27、to listen to service conversation from the phototelegraphreceiving station.Intervention in the circuits should be avoided after the call has been established, unless such intervention has beenrequested by one of the IPPs or one of the phototelegraph stations connected.3.7 After consulting the receiv
28、ing phototelegraph station, the calling phototelegraph station announces the end of thecall either direct to its IPP, or, in the case of extension of an international circuit, to the national PP on which it depends.3.7.1 The latter must inform its IPP as quickly as possible, giving the time at which
29、 it received notice of the end of thecall. The control IPP notes the end-of-transmission time and immediately communicates the notice announcing the end tothe incoming IPP and, if necessary, to the transit IPP.3.7.2 The outgoing and incoming IPPs and any transit IPPs then take the necessary measures
30、 to restore theinternational circuit to the telephone service without delay.3.7.3 It is recommended that the called station should likewise announce the end of transmission so that the calledstation may be cleared more quickly.3.8 Unless the Administrations concerned decide to the contrary, the term
31、inal IPPs do not come to an agreement onthe chargeable duration, since this is determined by the control IPP.4 Special procedures for phototelegraph stations4.1 For each phototelegram to be transmitted, the outgoing public station shall prepare a narrow tape comprising thepreamble and address (and,
32、if necessary, the signature and special service indications), unless these indications have beenwritten on the phototelegram by the sender. This tape is transmitted with the phototelegram.4.2 As soon as the call is established, the interconnected phototelegraph stations proceed to adjust the equipme
33、nt andto transmit, in accordance with the instructions of the receiving station, adopting the following order of operations:a) if necessary, agreement on the index of cooperation and speed of transmission, then synchronizationadjustment by means of the synchronization frequency;b) adjustment of the
34、white level;c) adjustment of the black level;d) phasing;e) start;f) transmission.4.3 If the phototelegram is passed to a public station by a private station, the public station shall ask the privatestation, if necessary, for information regarding establishment of the preamble and conditions of deliv
35、ery to the addressee.5 Faulty transmissions5.1 In the case of fault conditions, the control IPP shall immediately make arrangements to clear the fault or makeanother circuit available.5.2 When, after completion of the call, it is seen that the transmission was faulty, the receiving phototelegraph st
36、ationshall inform its IPP. If it so desires, the receiving phototelegraph station can make a new booking with its IPP for aphototelegraph call, in the manner defined in 2.6, with the sending station.5.3 If the phototelegraph station that receives the faulty picture and books a new call is a private station, its attentionshould be drawn to the fact that both calls will be chargeable if the faults in the picture are not due to the telephone ortelegraph services.
