Transmission of wire less telegrams. Signals. Stations on shipboard shall to that end have the necessary tariffs. They shall be at liberty, however, to obtain information from coastal stations on the subject of rates for wireless telegrams for which they do not possess all the necessary data. 6. TRANSMISSION OF WIRELESS TELEGRAMS. a. SIGNALS OF TRANSMISSION. XV. Morse Inter- The signals to be employed are those of the Morse Innational Code. ternational Code. Distress call. Immediate attention, etc. Call letters. Use of International Signal Code. Order of transmission. Alternate or in series. XVI. Ships in distress shall use the following signal: repeated at brief intervals. As soon as a station perceives the signal of distress it shall cease all correspondence and not resume it until after it has made sure that the correspondence to which the call for assistance has given rise is terminated. In case the ship in distress adds at the end of the series of her calls the call letters of a particular station the answer to the call shall be incumbent upon that station alone. If the call for assistance does not specify any particular station, every station perceiving such call shall be bound to answer it. XVII. 1. The call letters following the letters "PR B" signify that the vessel or station making the call desires to communicate with the station called by means of the International Signal Code. The combination of the letters PR B as a service signal for any other purpose than that specified above is prohibited. 2. Wireless telegrams may be framed with the aid of the International Signal Code. Those addressed to a wireless telegraph station with a view to being forwarded by it are not to be translated by such station. b. ORDER OF TRANSMISSION. XVIII. Between two stations wireless telegrams of the same order shall be transmitted one by one, by the two stations alternately, or in series of several telegrams, as the coastal station may indicate, provided the duration of the transmission of each series does not exceed twenty minutes. C. METHOD OF CALLING WIRELESS STATIONS AND TRANSMIS- XIX. 1. As a general rule, it shall be the shipboard station that calls the coastal station. Method of calling and transmission. General rule. Distance of vessel. of apparatus. 2. The call should be made, as a general rule, only when the distance of the vessel from the coastal station is less than 75 per cent of the normal range of the latter. 3. Before proceeding to a call, the station on shipboard Adjustment shall adjust its receiving apparatus to its maximum sensibility and make sure that the coastal station which it wishes to call up is not in correspondence with any other station. If it finds that any transmission is in progress, it shall wait for the first pause. 4. The shipboard station shall use for calling the normal wave of the coastal station. Wave to be used. tions. 5. If in spite of these precautions the public exchange Interrupof wireless telegrams is impeded at any place, the call shall cease upon the first request from a coastal station open to public correspondence. The latter station shall in such case indicate the approximate length of time it will be necessary to wait. XX. 1. The call shall comprise the signal the call letters of the station called repeated three times, the word" from " (" de ") followed by the call letters of the sending station repeated three times. Call signal. Answer 2. The called station shall answer by making the signal signal. followed by the call letters of the corresponding station repeated three times, the word "from," its own call letters, and the signal XXI. If a station called does not answer the call (Article XX) repeated three times at intervals of two minutes, the call shall not be resumed until after an interval of Calls not answered. Statement from ship board station. From coastal stations. Delayed service. Order of receiving at coastal stations. Preliminary signals. Transmission signals. half an hour, the station issuing the call having first made sure that no wireless telegraph correspondence is in progress. XXII. 1. As soon as the coastal station has answered, the shipboard station shall make known to it: (a) The distance of the vessel from the coastal station in nautical miles; (b) Her true bearing in degrees counted from 0 to 360; (c) Her true course in degrees counted from 0 to 360; (d) Her speed in nautical miles; (e) The number of words she has to transmit. 2. The coastal station shall answer, stating the number of words to be transmitted to the vessel. 3. If the transmission can not take place immediately, the coastal station shall inform the station on shipboard of the approximate length of time that it will be necessary to wait. XXIII. When a coastal station receives calls from several shipboard stations, the coastal station shall decide the order in which the shipboard stations shall be admitted to exchange their messages. In fixing this order the coastal station shall be guided exclusively by the necessity of permitting each station concerned to exchange the greatest possible number of wireless telegrams. XXIV. Before beginning the exchange of correspondence the coastal station shall advise the shipboard station whether the transmission is to be effected in the alternate order or by series (Article XVIII); it shall then begin the transmission or follow up the preliminaries with the signal (invitation to transmit). XXV. The transmission of the wireless telegram shall be preceded by the signal and terminated by the signal followed by the name of the sending station. XXVI. sages. When a wireless telegram to be transmitted contains Long mesmore than 40 words, the sending station shall interrupt the transmission after each series of about 20 words by an interrogation point and shall not resume it until after it has obtained from the receiving station a repetition of the last word duly received, followed by an interrogation point. Series mes In the case of transmission by series, acknowledgment sages. of receipt shall be made after each wireless telegram. XXVII. signals. 1. When the signals becomes doubtul every possible Doubtful means shall be resorted to to finish the transmission. To this end the wireless telegram shall be repeated at the request of the receiving station, but not to exceed three times. If in spite of such triple repetition the signals are still unreadable the wireless telegram shall be canceled. If no acknowledgment of receipt is received the transmitting station shall again call up the receiving station. If no reply is made after three calls the transmission shall not be followed up any further. 2. If in the opinion of the receiving station the wireless telegram, although imperfectly received, is nevertheless capable of transmission, said station shall enter the words "reception doubtful" at the end of the preamble and let the wireless telegram follow. XXVIII. Minimum energy to be All stations are bound to carry on the service with as little expense of energy as may be necessary to insure used. safe communication. d. ACKNOWLEDGMENT OF RECEIPT AND CONCLUSION OF work. XXIX. 1. Receipt shall be acknowledged in the form prescribed by the International Telegraph Regulations, preceded by the call letters of the transmitting station and followed by those of the receiving station. Acknowledgment of receipt and conclusion of work. Form of re signal. 2. The conclusion of a correspondence between two sta- Conclusion tions shall be indicated by each station by means of the signal followed by its, call letters. Directions for sending. e. DIRECTION TO BE FOLLOWED IN SENDING WIRELESS TELEGRAMS. XXX. From shipboard stations. 1. In general, the shipboard stations shall transmit their wireless telegrams to the nearest coastal station. 2. A sender on board a vessel shall, however, have the right to designate the coastal station through which he desires to have his wireless telegram transmitted. 3. The station on shipboard shall then wait until such coastal station shall be the nearest. If this can not be done, the wishes of the sender are to be complied with only if the transmission can be effected without interfering with the service of other stations. Delivery of 7. DELIVERY OF WIRELESS TELEGRAMS AT THEIR DESTINA messages. Notice of nondelivery. Messages for ships not signalling. TION. XXXI. When for any cause whatever a wireless telegram proceeding from a vessel at sea can not be delivered to the addressee, a notice of non-delivery shall be issued. Such notice shall be transmitted to the vessel if possible. When a wireless telegram received by a shipboard station can not be delivered, the station shall notify the office of origin by official notice. Such notice shall be transmitted, whenever practicable, to the coastal station through which the wireless telegram has passed in transit; otherwise, to the nearest coastal station. XXXII. If the ship for which a wireless telegram is intended has not signalled her presence to the coastal station. within the period designated by the sender, or, in the absence of such designation, by the morning of the 29th day following, the coastal station shall notify the sender. The latter shall have the right to ask, by a paid official notice, sent by either telegraph or mail and addressed to the coastal station, that his wireless telegram be held for a further period of 30 days for transmission to the vessel, and so on. In the absence of such request the wireless telegram shall be put aside as not transmissible at the end of the 30th day (exclusive of the day of posting). If, however, the coastal station has positive informa tion that the vessel has left its radius of action before it has been able to transmit to her the wireless message, such station shall so notify the sender. |