Page:United States Statutes at Large Volume 49 Part 2.djvu/503

 TELECOMMUNICATIOX CONVEXTIOX. DECEMBER 9, 1932. [346] (b) The coast station shall transmit all its traffic on the wave or on the waves which are specifically assigned to it. [347] (c) A coast station to which one or more waves within the band 125 to 150 kc (2,400 to 2,000 m) have been allocated, shall have a prior right to this or these waves. [348] (d) Any other mobile service station transmitting public traffic on this or these waves and thereby causing interference with the said coast station must discontinue its work at the request of the latter. [349] B. (a) \Vhen a mobile station wishes to establish com- munication on one of these waves with another station of the mobile service, it must use the wave of 143 kc (2,100 m), unless otherwise indicated in the nomenclature. [360] (b) This wave, designated as a general calling-wave, must be used exclusively in the North Atlantic: 1. for making individual calls and answering these calls; 2. for transmitting signals preliminary to the trans- missIOn of traffic. P~51] C. A mobile station, after having established communica- tion with another station of the mobile service on the general calling- wave of 143 kc (2,100 m) must, so far as possible, transmit its traffic on some other wave of the authorized bands, provided it does not interfere with the work in progress of another station. F52] D. As a general rule, any mobile station equipped for service on type-AI waves in the band 100 to 160 kc (3,000 to 1,875) and which is not engaged in a communication on another wave, must, in order to permit the exchange of traffic with other stations of the mobile service, return each hour to the wave of 143 kc (2,100 m) for 5 minutes beginning at x:35 o'clock Greenwich mean time, during the specified hours, according to the category to which the station in question belongs. (363] E. (a) Land stations must, so far as possible, transmit calls in the form of call lists; in this case, the stations shall transmit their call lists at specified hours published in the nomenclature, on the wave or waves allocated to them, in the band 100 to 160 kc (3,000 to 1,875 m), but not on the wave of 143 kc (2,100 m). [364) (b) Land stations may, however, call mobile stations individually at any other time, outside the hours fixed for the trans- mission of call lists, according to circumstances or according to the work which they have to perform. [356] (c) The wave of 143 kc (2,100 m) may be used for individual calls and shall preferably be used for this purpose during the period indicated in § 4, D. [366] § 5. Radio communications from aeronautical and aircraft stations shall, in principle, be exchanged in the following manner: (361] 1. For aircraft stations: (a) In radiotelephony (calling and working) for aircraft of which the crew does not include a radiotelegraph operator. 2519