џWPCL ћџ2BJ|xа АH аа АА X агга ХА6p&А6p&Х аеЄ† а Hр аааУ Уб cмˆ4 PŽТ б Fascicle VII.2 Р-Р Rec. U.60 PAGE1 Єее† а HH аааУ Уб cмˆ4 PŽТ бPAGE2 Fascicle VII.2 Р-Р Rec. U.60 еа HH ааЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаа X  аУ Уб cмˆ4 PŽТ бRecommendation U.60 Ср83Сб cмˆ4 PŽТ бGENERAL REQUIREMENTS TO BE MET IN INTERFACING THE INTERNATIONAL Ср8<СTELEX NETWORK WITH MARITIME SATELLITE SYSTEMSФ Ф Ср88СУУб cмˆ4 PŽТ б(Geneva, 1980; amended at MalagaР-РTorremolinos, 1984)ФФ аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHјP Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаТа ТThe CCITT,ЦЦ аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаУУconsidering а Hx аФФС С(a)СpСthat, with fully automatic working between subscribers in the international telex service, it is desirable that the interface between the international telex network and maritime satellite systems be defined; а H аС С(b)СpСthat the CCIR is charged with the task of making Recommendations relating to the radio path of maritime satellite systems; С С(c)СpСthat explanation of the detail of the interface between the international telex network and maritime satellite systems would be of assistance to the CCIR; а H аС С(d)СpСthat Recommendation U.61 specifies the detailed interface requirements, УУunanimously recommends а H аФФС С(1)СpСthat maritime satellite systems should be capable of interfacing the international telex network with one or more signalling systems in accordance with: а Hh аТа ТР-РТ№ ТRecommendation U.1: Signalling conditions to be applied in the international telex service (type A and type B signalling);ЦЦ а H аТа ТР-РТ№ ТRecommendation U.11: Telex and gentex signalling on intercontinental circuits used for intercontinental automatic transit traffic (type C signalling);ЦЦ а H аТа ТР-РТ№ ТRecommendation U.12: Terminal and transit control signalling system for telex and similar services on international circuits (type D signalling);ЦЦ а H аС С(2)СpСthat type D signalling (Recommendation U.12) and, as a second choice, type C signalling (Recommendation U.11) are the preferred signalling systems, when they are available within the national boundaries, for the reasons given in Annex A; С С(3)СpСthat as the maritime signalling from the ship to the coast earth station is in the same relationship as the connection from the subscriber to the originating exchange in the international network, it is necessary that the transit delays inherent in the maritime system should be considered in conjunction with the standards recommended for the international network. а H аС С(4)СpСthat the access of ship earth stations to storeР-РandР-Рforward units, if provided, should be in accordance with the relevant Series F and U Recommendations on international storeР-РandР-Рforward units. ‚Ср VСб cмˆ4 PŽТ бANNEX A Ср MСб cмˆ4 PŽТ б(to Recommendation U.60) аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџH јP Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаСр IСб cмˆ4 PŽТ бУ УSignalling systems types C and D аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаб cмˆ4 PŽТ бФ ФA.1С  СThese signalling systems have been developed in CCITT to permit the maximum utilization of the international telex network as well as to simplify the interface problems that exist between Administrations using different signalling systems within their national boundaries. In particular, types C and D signalling systems, which use telex destination codes in accordance with Recommendation F.69 [1], are of assistance in solving the problems of routing to and from maritime satellite systems where multiple access techniques are employed. а H аA.2С  СType C signalling (Recommendation U.11) facilitates the use of improved techniques for switching traffic in the international network. In particular: а H аТа ТТ№ ТС€ Сa)СpСit permits any telegraph circuit capable of carrying International Telegraph Alphabet No. 2 (ITA 2) to be used without the need to convert supervisory signals to a form capable of being carried by the circuit;ЦЦ а H аТа ТТ№ ТС€ Сb)СpСit permits the automatic testing of the ability of the international circuit to transmit teleprinter characters before the call is established to the distant subscriber;ЦЦ а H аТа ТТ№ ТС€ Сc)СpСit permits the detection of headР-Рon collision of calls and thus permits service protocols to be established in handling such collisions. It may be noted that headР-Рon collisions may occur on telegraph circuits that are operated in the bothway mode due to the fact that the calling signal takes a finite time, depending upon the nature of the transmission path, before the receiving end of the circuit detects the seizure from the outgoing end;ЦЦ а H аТа ТТ№ ТС€ Сd)СpСit permits the efficient use of the international network with particular reference to the most economical use of automatic alternative routing and, by providing transit centre identification, permits full flexibility in routing as well as international accounting and subscriber billing.ЦЦ а H аA.3С  СType D signalling (Recommendation U.12) facilitates the introduction into the international network of the following facilities (in addition to the advantages mentioned in РSР A.2 above): Та ТТ№ ТС€ Сa)СpСuser groups;ЦЦ Та ТТ№ ТС€ Сb)СpСnetwork identification signals;ЦЦ а H аТа ТТ№ ТС€ Сc)СpСidentification of the calling station without the necessity of using the WRU signal;ЦЦ а H аТа ТТ№ ТС€ Сd)СpСidentification of a call relating to service matters, which the international network carries as a nonР-Рchargeable call.ЦЦ аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџH јP Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаС  СС  С‚У УReferenceФ ФЦЦ а Hh ааЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬа[1]Тh  ТCCITT RecommendationУУ Plan for telex destination codesФФ, Rec. F.69.ЦЦ ‚У У