1、8 E FEDERAL STANDARD 1061 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FED-STD-1061 TE 7777777 0002753 4 FED-STD 1061 March 24, 1981 FEDERAL STANDARD TELECOMMUNICATIONS: GROUP 2 FACSIMILE APPARATUS FOR DOCUMENT TRANSMISSION This standard is issu
2、ed by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. 1. SCOPE 1.1 voiceband analog circuits. 1.2 Purpose. This standard is to facilitate interoperability between and among facsimile terminals within telecommunication faciliti
3、es and systems of the Federal Government. 1.3 and procurement of facsimile equipment/systems. Description. This standard establishes the machine specifications for Group 2 facsimile apparatus for use over Application. All Federal departments and agencies shall comply with this standard in the design
4、, development, 2. RELATED DOCUMENTS 2. I 2.2 Type Circuits. 2.3 CCITT Recommendation T.3, “Standardization of Group 2 Facsimile Apparatus for Document Transmission. 2.4 CCITT Recommendation T.30, “Procedures for Document Facsimile Transmission in the General Switched Telephone Network. 2.5 Network.“
5、 3. DEFINITIONS 3.1 Group 2 Facsimile Apparatus - Apparatus which exploits bandwidth compression techniques to achieve a transmission time of about three minutes for the transmission of a 216 mm X 297 mm size document at a nominal resolution of 4 lines per mm via a telephone-type circuit. Bandwidth
6、compression in this context includes encoding and/or vestigial sideband transmission but excludes processing of the document signal to reduce redundancy. 3.2 3.3 a drum apparatus, the index of cooperation is also equal to the product of the drum diameter and the scanning density. 3.4 Note: In the ca
7、se of drum apparatus, this is the same as the Dead Sector scanning time. 3.5 picture signal transmission. 4. REQUIREMENTS 4.1 Scanning Track The message area shall be scanned in the same direction in the transmitter and receiver. Viewing the message area in the vertical plane the scanning direction
8、shall be from left to right, and subsequent scans shall be adjacent and below the previous scan. In order to minimize loss of information, users should insert documents so that the scanning direction is from the wider to the narrower margin. 4.2 Dimensions of Apparatus The following dimensions are r
9、ecommended but apparatus with other dimensions may be used provided that the factor of cooperation is respected and that the total scanning line length lies between 213 and 222 mm. Federal Standard-1037, “Glossary of Telecommunication Terms.“ CCITT Recommendation T.0, “Classification of Facsimile Ap
10、paratus for Document Transmission Over Telephone- EIA Standard RS-466, “Procedures for Document Facsimile Transmission in the General Switched Telephone Factor of Cooperation - The product of the total scanning line length and the scanning density. Index of Cooperation - Quotient of the factor of co
11、operation divided by the quantity Pi (3.14159 . ). In the case of Lost Time-The portion of the scanning line period which cannot be used for picture signal transmission. Dead Sector-In drum apparatus, that portion of the drum surface the scanning time of which cannot be used for FSC TELE Provided by
12、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_ FED-STD-1061 TE W 7777777 0002754 b U FED-STD-I 061 Factor of cooperation Total scanning line-length Usable scanning line-length Input document size 8292 I% 215mm 200 mm 216 mm x 297 mm (Larger is optional.) All
13、 designs must accept input documents smaller than the chosen dimensions. The foregoing dimensions result in the following approximate secondary dimensions. Index of cooperation Scanning density 264 3.85 lines/mm Number of scanning lines in a document 297mm long I145 4.3 Scanning Line Frequency 4.3.1
14、 4.3.2 nominal value. The scanning line frequency shall be 360 lines per minute. The scanning line frequency during the transmission shall be maintained within 210 parts in IO6 of the 4.4 Phasing For phasing prior to transmission of document information the transmitter sends a signal as shown in Fig
15、ure 1. The start of the carrier indicates the end of the lost time. Both transmitter and receiver should phase the end of lost time with an accuracy of 2% of the total scanning line length. Note 1 - In the case of the multiple page transmission the phasing procedure may need to be repeated between N
16、ote 2-Receivers shall comply with the phasing accuracy whether the carrier phase of the phasing signal is pages. reversed or not. Line conditioning signal : 1.5 * 0.5 s Phasing signal : 6 f 0.5 s (equivalent to 36 f 3 lines) r &IA I -I - ACBC AC BC - 1 LCS - LCS = line conditioning signal : 1100 f 5
17、0 Hz. Transmission of this signal is optional A B C = carrier in O“ phase for 94-96% of total scanning line length = as A but may be in 180“ phase = no signal (at least 26 dB below the carrier) for the remaining 64% of scanning line length FIGUR1 1 Structure of line conditioning and phasing signal 4
18、.5 Document Transmission 4.5.1 During transmission of document information the transmitter shall transmit full amplitude carrier during lost time. The phase of the carrier may be reversed at the end of this signal. Both transmitter and receiver should align the end of lost time to this phase reversa
19、l with an accuracy of 2% in this case. 4.5.2 The phase reversal signal may be used at the receiver as an amplitude reference independent of the document signal, and also to indicate to the receiver that document transmission is still in progress. 4.6 Modulation and Demodulation 4.6.1 Equivalent modu
20、lated waveforms with vestigial sideband amplitude modulation-phase modulation characteris- tics shall be used for Group 2 apparatus operated on the general switched telephone network. The carrier frequency shall be 2100 210 Hz . A white signal shall be represented by maximum carrier, and a black sig
21、nal by minimum (at least 26 dB below white) or no carrier. The phase of the carrier representing white may be reversed after each transition through black. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FED-STD-1061 TE m 7979977 O002955 m FED-STD-
22、1061 4.6.2 than that sent during the lost time. 4.6.3 A vestigial sideband filter symmetrical about the 2100 Hz carrier frequency shall be provided at the transmitter. The response of this filter shall conform to Figure 2. The relative transmittance at the carrier frequency shall be 0.5 with a toler
23、ance of 20.05 and the characteristic shall be sensibly symmetrical about the carrier The facsimile transmission may contain a limited range of half-tones represented by a carrier amplitude less frequency. 1.c 0.f E B E 0.6 E P C .- C .- C - E 0.4 0.2 O 0.2 0.6 1 .o 1.4 9 *a 2.2 2 ,S 3.0 kHz Frequenc
24、y I-IGURI 2 Frequency response of the vestigial sideband filter 4.6.4 exceed its nominal value by more than 216 Hz. 4.6.5 4.7 The receiving apparatus must be capable of operating correctly when the drift of carrier frequency does not A fixed compromise equalizer, an automatic equalizer or an adaptiv
25、e equalizer is optional in the receiver. Power at the Transmitter Output The power of the white signal shall be such as to meet the network requirements. If the power level is adjustable, the equipment shall be so designed that this adjustment is not readily accessible to the operator. (The black le
26、vel shall be at least 26 dB below the white level.) 4.8 Power at the Receiver Input The receiving apparatus shall be capable of functioning correctly when the received signal level for white is within the range O dBm to -40 dBm. No control of receiver sensitivity shall be provided for operator use.
27、3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FED-STD-1061 TE m 7799977 0002956 T m FED-STD-106 1 5. CHANGES When a Federal department or agency considers that this standard does not provide for its essential needs, a statement citing inadequacie
28、s shall be sent in duplicate to the General Services Administration (CI, Washington, D.C. 20405, in accordance with provisions of Federal Property Management Regulations 4 1 CFR 10 1-29.3. The General Services Administration will determine the appropriate action to be taken, and will notify the agen
29、cy. 6. CONFLICT WITH REFERENCED DOCUMENTS Where the requirements stated in this standard conflict with any requirements in a referenced document, the requirements of this standard shall apply. The nature of the conflict between this standard and a referenced document shall be submitted in duplicate
30、to the General Services Administration (C), Washington, D.C. 20405. PREPARING ACTIVITY National Communications System Office of Technology and Standards (NCS-TS) Washington, D.C. 20305 MILITAR Y INTERESTS: Military Coordinating Activity DCA - DC Custodians Army - CR Review Activities Army - CR, SC N
31、avy - EC, NOSC Air Force - 90, XOKC Navy - EC Air Force - 90 This document is available from the General Services Administration (GSA), acting as agent for the Superintendent of Documents. A copy for bidding and contracting purposes is available from GSA Business Centers. Copies are for sale at the GSA, Specification and Consumer Information Branch (WFSIS), Building 197 (Washington Navy Yard), Washington, D.C. 20407. 4 -_ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
