M31 载波通信设备 标准查询与下载

ITU-T G.441-1989 频分多路复用无线接力系统上允许的电路噪声 国际模拟载波系统(研究15组)1

Permissible Circuit Noise on Frequency-Division Multiplex Radio-Relay Systems - International Analogue Carrier Systems (Study Group XV) 1 pp

Permissible Circuit Noise on Frequency-Division Multiplex Radio-Relay Systems - International Analogue Carrier Systems (Study Group XV) 1 pp

ITU-T G.431-1989 频分多路复用无线接力系统的假设参考电路 国际模拟载波系统(研究15组)2pp

The meaning of the symbols used in this Figure is given in the Preliminary notes to this fascicle.

Hypothetical Reference Circuits for Frequency-Division Multiplex Radio-Relay Systems - International Analogue Carrier Systems (Study Group XV) 2 pp

ITU-T G.423-1989 在频分多路复用无线接力系统的基带频率上互连 国际模拟载波系统 研究15组. 7pp

The CCIR issued Recommendations 380 [i] and 381 [2] so that, as far as possible, radio-relay links using frequency-division multiplex should have characteristics which allow direct interconnection at baseband frequencies with systems of the same capacity

Interconnection at the Baseband Frequencies of Frequency-Division Multiplex Radio-Relay Systems - International Analogue Carrier Systems Study Group XV; 7 pp

ITU-T G.352-1989 不同设计的同轴载波的互连 国际模拟载波系统(研究15组)4pp

Interconnection should be in conformity with Recommendation G.352.

Interconnection of Coaxial Carrier Systems of Different Designs - International Analogue Carrier Systems (Study Group XV) 4 pp

ITU-T G.243-1989 透明连接点导频和附加测试频率的保护 国际模拟载波系统(研究15组)5pp

In making this recommendation, it has been assumed that the addition of the various frequency components within pilot-operated line regulators will follow a square or average law of addition.

Protection of Pilots and Additional Measuring Frequencies at Points Where There is a Through-Connection - International Analogue Carrier Systems (Study Group XV) 5 pp

ITU-T G.242-1989 基群、超群等的透明连接 国际模拟载波系统(研究15组)7pp

It may be found desirable from both the technical and the economical points of view to provide facilities at the end of certain sections such that the channels routed over one section do not all have to be extended to the next section, this being done wit

Through-Connection of Groups, Supergroups, Etc. - International Analogue Carrier Systems (Study Group XV) 7 pp

ITU-T G.241-1989 基群、超群等的导频 国际模拟载波系统(研究15组)6pp

Where pilots of 300 kHz or 308 kHz are used on line systems it is recommended that the level of any harmonic shouId not exceed -73 dBmO, except that the second harmonic of 300 kHz should not exceed -75 dBmO.

Pilots on Groups, Supergroups, Etc. - International Analogue Carrier Systems (Study Group XV) 6 pp

ITU-T G.231-1989 载波设备的安装 国际模拟载波系统 研究15组

that countries not having a national industry for the construction of carrier systems must obtain them from different factories, and that the variations of the dimensions of the racks between different sources of supply do not allow of a simple and econom

Arrangement of Carrier Equipment - International Analogue Carrier Systems Study Group 15

ITU-T G.230-1989 由调制设备和透明连接滤波器产生的噪声的测量方法 研究15组

The above requirement is derived from a consideration of data signals on a telephone-type circuit over a 2500-km hypothetical reference circuit. Conforming to this requirement will ensure a high probability that the overall phase jitter from this source

Measuring Methods for Noise Produced by Modulating Equipment and Through-Connection Filters - International Analogue Carrier Systems Study Group 15

ITU-T G.229-1989 无用调制和相位抖动国际模拟载波系统(研究15组)2pp

The above requirements are derived from the hypothetical reference circuits for the 4 MHz, 12 MHz and 60 MHz systems. The same figures may be applied to other systems provided that their hypothetical reference circuit does not differ significantly from t

Unwanted Modulation and Phase Jitter - International Analogue Carrier Systems (Study Group XV) 2 pp

ITU-T G.227-1989 常规电话信号 国际模拟载波系统(研究15组)3pp

CCIR Recommendation Noise in the radio portion of circuits fo be established over real radio-relay links for FDM telephony, Vol. IX, Rec. 395, Dubrovnik, 1986.

Conventional Telephone Signal - International Analogue Carrier Systems (Study Group XV) 3 pp

ITU-T G.226-1989 实际链路上的噪声 国际模拟载波系统(研究15组)2pp

The case may arise, either of a country that has a national frequency standard with no facilities for distributing it throughout the country (particularly in an area in which a coaxial carrier system is to be set up), or of a country that has no national

Noise on a Real Link - International Analogue Carrier Systems (Study Group XV) 2 pp

ITU-T G.225-1989 关于载频准确度的建议 国际模拟载波系统(研究15组)3pp

The routine comparison of the frequencies generated by the master oscillators is made by means of a “frequency check pilot” transmitted to line for this purpose. It is not necessary to compare phases.

Recommendations Relating to the Accuracy of Carrier Frequencies - International Analogue Carrier Systems (Study Group XV) 3 pp

ITU-T G.224-1989 信令脉冲的绝对功率电平(相对于1mW的功率)最大允许值 国际模拟载波系统(研究15组)1pp

Maximum Permissible Value for the Absolute Power Level (Power Referred to One Milliwatt) of a Signalling Pulse - International Analogue Carrier Systems (Study Group XV) 1 pp

Maximum Permissible Value for the Absolute Power Level (Power Referred to One Milliwatt) of a Signalling Pulse - International Analogue Carrier Systems (Study Group XV) 1 pp

ITU-T G.222-1989 设计2500km载波传输系统的噪声声指标 国际模拟载波系统(研究15组)4pp

In Recommendation (3.230 methods for measuring the noise produced by modulating equipments are described.

Noise Objectives for Design of Carrier- Transmission Systems of 2500 km - International Analogue Carrier Systems (Study Group XV) 4 pp

ITU-T G.221-1989 关于载波传输系统的总建议 国际模拟载波系统(研究15组)2pp

The subdivision of the total noise between the various sources of noise is left entirely to the designer of the system, within the limits of 2500 pWOp for the terminal equipment and 7500 pWOp for the line. This allocation is intended to permit the use of

Overall Recommendations Relating to Carrier-Transmission Systems - International Analogue Carrier Systems (Study Group XV) 2 pp

ITU-T G.215-1989 用于模拟系统的5000km假设参考电话 国际模拟载波系统(研究15组)2pp

This design objective is in line with Recommendation G.123, “Circuit noise in national networks”, which in 0 2.1.1 recommends that the line noise in channels used to provide very long-distance circuits (over 2500 km) should not exceed 2 pWOp/km.

Hypothetical Reference Circuit of 5000 km for Analogue Systems - International Analogue Carrier Systems (Study Group XV) 2 pp

ITU-T G.213-1989 主转发器台系统的互连 国际模拟载波系统(研究15组)4pp

Figure 1/G.213 gives an example only.

Interconnection of Systems in a Main Repeater Station - International Analogue Carrier Systems (Study Group XV) 4 pp

ITU-T O.111 FRENCH-1988 载波信道频移的测量设备

The equipment described below is compatible with the measuring method described in Annex A to this Recommendation.

FREQUENCY SHIFT MEASURING EQUIPMENT FOR USE ON CARRIER CHANNELS

ITU-T R.49 FRENCH-1988 明线3路载波系统上的带际电报

The CCITT, considering it is considered necessary to introduce, for international traffic, an open-wire carrier system that uses common line repeaters for telephone and interband telegraph channels. This is important for some Administrations that desire to have a small number of telegraph channels (up to six) without having to use a standard voice-frequency telegraph system on one of the telephone circuits, thereby effecting an economy, as all the telephone circuits are retained entirely for telephone traffic.

INTERBAND TELEGRAPHY OVER OPEN - WIRE 3-CHANNEL CARRIER SYSTEMS