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Engineering Construction Standard Full Text Information System
National Standard of the People's Republic of China
GB7283—87
Communication system for urban public transport
Communication system for urban public transportConstruction Standard
Published on January 26, 1987
Implemented on November 1, 1987
Published by the Ministry of Urban and Rural Construction and Environmental Protection of the People's Republic of ChinaW.bzsoso.coI Engineering Construction Standard Full Text Information System
National Standard of the People's Republic of China
Communication system for urban public transport
Communication system for urban public transportGB7283—87
This standard applies to public transportation systems such as urban buses, trolleybuses, taxis, rail transit, passenger ferries, rail cable cars, and cable cars.
1 Terms and Terminology
1.1 Rail transit
A general term for public transportation that uses electric energy as power and adopts wheel-rail operation. For example, trams, express trams, subways, etc. 1.2 Passenger ferries
Ships that transport passengers in urban waters. 1.3 Rail cable cars
Passenger-carrying vehicles that are pulled by steel cables and run on tracks laid along the slope. 1.4 Cableway cable cars
Passenger-carrying vehicles that are pulled by steel cables and run along aerial ropeways. 1.5 Dispatching stations
Stations or docks with dispatching business functions. 1.6 Dispatching room (dispatching sub-center)
A control center that conducts comprehensive dispatching of multiple lines. 1.7 Central dispatching room (general dispatching room, dispatching center) A control center that conducts comprehensive dispatching of the city's lines (or multiple lines). 1.8 Passenger capacity
The number of passengers loaded on public transportation. 1.9 Full load rate
The ratio of the actual passenger capacity of public transportation to the rated passenger capacity. 1.10 Maximum passenger flow section
The section with the largest passenger flow on the line.
1.11 Passenger gathering and dispersing point
The place where passengers gather and evacuate.
1.12 Station distance
The distance between two adjacent stations on the same line. 1.13 Communication network
The overall communication organization formed by many user equipment, transmission equipment, and switching equipment connected to each other, in which any two users can communicate with each other.
1.14 Rope
In the switch or dispatching equipment, the circuit that feeds power to the user's telephone, connects the call bridge, monitors the user's usage status, and controls the key recovery.
The Ministry of Urban and Rural Construction and Environmental Protection of the People's Republic of China approved on January 26, 1987 and implemented on November 1, 1987
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1.15 Single Call
The switchboard sends a predetermined selective call signal, which can only call a predetermined extension. 1.16 Group Call
The switchboard sends a predetermined selective call signal, which can call a predetermined group of extensions. 1.17 All Call
The switchboard sends a predetermined selective call signal, which can call all extensions. 1.18 Coverage
In an area (region) centered on the base station, communication between the base station and its affiliated extensions can be carried out according to certain technical conditions.
1.19 Radio Frequency
The radiation frequency used for transmitting or receiving in radio communication. 1.20 Closed-circuit transmission
Use cables or optical cables to transmit signals.
1.21 Analog display
Use analog line diagrams (charts) to display the dynamic position of operating vehicles (ships). 1.22 Positioning beacon
A device for receiving (transmitting) marking signals set up on the operating line to determine the position of the vehicle. 1.23 Electronic odometer
An electronic device for measuring the distance traveled by the vehicle. 2 Wired telecommunication system
2.1 Functions of the system
2.1.1 The urban public transportation wired telecommunication system is a dedicated automatic telephone exchange network for public transportation operation and dispatching. 2.1.2 This system should be able to ensure the dispatching communication between the following duty units: a. between dispatching rooms (stations) at all levels; b. between the power supply dispatching room and each rectifier station (substation); b. between the dispatching room and the emergency repair unit; c. between the central dispatching room and the urban traffic control center; d. between the power supply dispatching room and the dispatching room of the urban power supply bureau. 2.1.3 Business contacts between other duty units of public transportation, as well as non-dispatching business communications in the dispatching room (station), should use local telephones, and generally do not occupy dispatching communication equipment. 2.2 System transmission quality
The main quality indicators of system transmission should comply with the relevant provisions on transmission quality in the "Technical System of Automatic Telephone Exchange Network" of the Ministry of Posts and Telecommunications (see Appendix A).
2.3 System composition and basic characteristics
This system consists of dispatching equipment, telephone exchanges, telephone extensions, line networks and other equipment. 2.3.1 Dispatching equipment
The dispatching equipment is a special equipment used by dispatching rooms at all levels to dispatch and command the public transportation system using communication facilities. The dispatching equipment should have the following functions:
Directly call each dispatching extension in the system for single, group and full calls; a.
b. Host a telephone conference,
Equipped with a dispatching rope with a two-way amplification function, dispatching or talking between two users on the tandem network; c.
d. Remote control broadcasting equipment;
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Remind to hang up,
f. Monitor;
Record the content of the call or telephone conference; g.
Send a time calibration signal to each dispatching room and station.
2.3.2 Telephone exchange
The conditions that need to be met are as follows:
a. The telephone exchange of this system should be an automatic telephone exchange; b. The capacity of the telephone exchange in the dispatching center should be determined according to the scale and dispatching mode of the public transportation enterprise. Generally, it can be calculated as 4 doors for each dispatching room and 1 door for each dispatching station, and a certain amount of expansion capacity should be reserved; c. The number of trunk lines of the telephone exchange for local telephones should be determined according to the upper limit value specified in the "Local Telephone Business Regulations" of the Ministry of Posts and Telecommunications: d. The technical requirements should comply with the relevant provisions of the "Technical System of Automatic Telephone Exchange Network" of the Ministry of Posts and Telecommunications on the requirements for the access of local automatic exchange equipment.
2.3.3 Telephone extensions
Each telephone extension in the system should be an automatic telephone. The technical requirements should comply with the provisions of GB1493-79 "Technical Conditions for Public Power and Automatic Telephones".
2.3.4 Line networkbzxZ.net
According to the conditions of the local area, local telephone lines can be rented or set up separately. The technical requirements should comply with the "Technical System of Automatic Telephone Exchange Network" of the Ministry of Posts and Telecommunications on the types, series and access requirements of the local transmission system. 3 Radio communication system
3.1 Functions of the system
3.1.1 The urban public transportation radio communication system is a dedicated mobile communication network for public transportation operation dispatch and business liaison. 3.1.2 This system should be able to ensure dispatch communication between the following units: a. between dispatch rooms (stations) at all levels; b. between the dispatch room (station) and the operating vehicles (ferries) under its jurisdiction; c. between the dispatch room (station) and the on-site command vehicle and engineering emergency repair vehicle; d. between the central dispatch room and the urban traffic control center. 3.2 System format
3.2.1 Networking mode
The dispatch center (sub-center) radio station covers a large area of all the sub-stations under its jurisdiction. 3.2.2 Working mode
Generally, duplex or half-duplex is adopted.
3.2.3 Modulation mode
Frequency modulation, phase modulation.
3.3 System transmission quality
The quality index of system transmission shall comply with the relevant provisions of the "Mobile Communication Network Technical System" of the Ministry of Posts and Telecommunications (see Appendix B). 3.4 System composition and basic characteristics
3.4.1 This system consists of a general dispatching station, sub-dispatching stations, vehicle (ship)-mounted stations and other dispatching equipment. 3.4.2 The dispatching station can make single calls, group calls and full calls to each sub-station. 3.4.3 The general dispatching station should be able to monitor the communication between the sub-stations under its jurisdiction. 3.4.4 The dispatching station has the functions of recording and playing. 3.4.5 The whole system should be able to calibrate the time uniformly. 3.4.6 It can realize the connection between wired and wireless users in this system. Engineering Construction Standard Full Text Information System
3.4.7 The technical requirements of the main equipment of this system shall comply with the main technical index requirements for radio equipment in the "Mobile Communication Network Technical System" of the Ministry of Posts and Telecommunications.
3.5 Radio frequency band
The frequency band allocated by the state for mobile communications shall be used (see Appendix B). 4 Television monitoring system
4.1 Functions of the system
4.1.1 The urban public transportation television monitoring system is used to conduct on-site monitoring of the operation status of public transportation. 4.1.2 The system monitors the following places: a. The largest passenger flow section of key routes;
b. The main passenger gathering and distribution points;
c. Key public transportation intersections.
4.2 System format
The format and basic technical requirements of this system shall comply with the relevant provisions of GB3174-82 "Color TV Broadcasting" or GB1385-78 "Black and White TV Broadcasting".
The transmission mode is closed circuit or open circuit.
4.3 System transmission quality
The system transmission quality shall comply with the relevant provisions of GB1583-79 "Color TV Image Transmission Standard". 4.4 System composition and basic characteristics
4.4.1 This system consists of the following four parts: a. Camera and sending equipment,
Receiving equipment centered on monitors;
Transmission equipment;
Control equipment.
4.4.2 This system should be able to transmit images, audio and data information. 4.4.3
The opening, closing and adjustment of the transmitting equipment should be program-controlled and remotely controlled. 4.4.4 According to needs, the dispatching center (sub-center) shall be equipped with several monitors and be able to select and receive information sent by each monitoring point. 4.4.5 The dispatching center (sub-center) shall be able to record or replay the live situation at each monitoring point. 4.4.6 After transfer, this system shall be able to exchange information with the urban traffic control center. 5 Automatic monitoring system
5.1 Functions of the system
5.1.1 The urban public transportation automatic monitoring system is a dispatching system that automatically monitors and processes the operating conditions of public transportation vehicles in real time.
5.1.2 This system should be able to perform the following tasks: a.
Monitor the dynamic position of operating vehicles;
Detect the passenger capacity or full load rate of vehicles;
According to relevant information and operation plans, propose control commands and send them to vehicles or stations; d.
Simulate and display the operation status;
Print operation reports;
Vehicle alarm;
Processing of vehicles entering or exiting this system; g.
h. Accumulate data to provide a basis for predicting passenger flow, compiling operation plans and optimizing line networks. W.bzsoso.cO Engineering Construction Standard Full Text Information System
5.2 System Standard
5.2.1 Information Collection Method
The electronic equipment of the dispatching center (sub-center) periodically and automatically queries the operation data of each vehicle. 5.2.2 Control method
The electronic equipment of the dispatch center (sub-center) periodically and automatically controls the dispatch signal device or station display device in the vehicle, and manual intervention can be performed when necessary.
5.2.3 Vehicle positioning method
Use beacons or a combination of beacons and electronic odometers. 5.2.4 Networking method
The dispatch center (sub-center) radio station covers a large area of all sub-stations under its jurisdiction, or uses wired transmission. 5.3 System performance indicators
5.3.1 The vehicle is queried at least twice during the time it travels between any two stations (excluding stop time). 5.3.2 The vehicle position error is not greater than 1/2 station distance. 5.3.3 The system clock error is not greater than 1s.
5.3.4 The measurement error of the vehicle arrival time is less than 30s. 5.3.5 The measurement error of the vehicle passenger capacity (full load rate) is not greater than 10%. 5.4 System composition and basic characteristics
5.4.1 This system is generally composed of a central computer, a front-end computer, an on-board computer, a central radio, an on-board radio, a vehicle position detection device, a passenger capacity (or full load rate) detection device, a simulation display device, a departure display device, etc. 5.4.2 The function of the central computer is to control the operation of the entire system, process and store operating data, exchange information with dispatchers, compile and print operating reports, and exchange information with the urban traffic control center. 5.4.3 The function of the front-end computer is to exchange information with each vehicle or station through the central radio, control the simulation display device of the dispatch center, etc.
5.4.4 The function of the on-board computer is to collect operating data from the detection equipment and pre-process it, and exchange information with the dispatch center or station through the on-board radio.
5.4.5 The central radio is a heterodyne duplex radio. 5.4.6 The on-board radio is a heterodyne duplex or heterodyne simplex radio. 5.4.7 The vehicle orientation detection equipment detects the direction and position of the vehicle, and the measurement unit is "station"**. 5.4.8 The passenger capacity (full load rate) detection equipment is vehicle-mounted. 5.4.9 The analog display device of the dispatching center displays the dynamic position of the operating vehicles of the entire system. 5.4.10 The analog display device of the main station displays the dynamic position of the vehicle that is about to arrive at the station. 5.4.11 The station announcement device in the car predicts the name of the arrival station. 5.4.12 The departure display device at the departure station displays the vehicle number and departure time of the vehicle to be departed. When the departure time arrives, the departure signal is issued. 5.5 Radio frequency band
The frequency band allocated to mobile communications by the state (see Appendix B)* The passenger capacity measurement error is the full load error, which is calculated as follows: Full load error = upper scene cycle value x 100%. The nominal full load value
** refers to the interval of 1/2 station distance with the bus stop as the midpoint. Engineering Construction Standard Full Text Information System
5*Local Telephone Network
5.3 Transmission Loss Standard and Distribution
Appendix A
"Technical System of Automatic Telephone Exchange Network" (Excerpt) (Reference)
5.3.1 The maximum reference equivalent of the entire distance between users in the city should not exceed 30.0dB. The maximum transmission loss of the entire distance should not exceed 29.0dB. Note: ① The reference equivalent of the inter-office trunk line refers to the non-inductive cable with a wire diameter of 0.7mm. According to the CCITT Recommendation G121 Appendix C4.3, when d=0.7mm, k=1.06, A800=13.0dB, Y. =KA800~14.0dB. ② The user line transmission loss of 7.0dB refers to the non-inductive cable with d=0.5mm. 5.3.2 The maximum reference equivalent and transmission loss for the entire route between urban users and suburban users and between suburban users are the same as those in Section 5.3.1. 5.3.3 Allocation of transmission loss
5.3.3.1 User circuit
The user circuit refers to the distance from the transmitter of the user's telephone to the distribution frame of the exchange (end or tandem) where it is located or from the distribution frame of the exchange where the receiving user is located to the receiver of the user's telephone. a. Reference equivalent (when the user cable diameter d=0.5mm standard telephone): the sending reference equivalent is less than or equal to 12dB; the receiving reference equivalent is less than or equal to 3dB.
b. Transmission loss:
When f is 800Hz, the transmission loss of the non-inductive cable with a diameter of 0.5mm should not exceed 7.0dB. c In the case of user switches, the transmission loss from the user switch to the city telephone terminal should not exceed 4.5dB, and the transmission loss from the user switch to other users should not exceed 1.5dB. 5.3.3.2 City inter-office trunk lines
City inter-office trunk lines refer to the lines (or circuits) between the main distribution frame of the sending branch office (including the suburban county bureau and satellite town bureau of a large city) and the main distribution frame of the receiving branch office (including the suburban county bureau and satellite town bureau of a large city). The maximum reference equivalent between the two ends should not exceed 14.0dB, and the maximum transmission loss between them should not exceed 13.OdB; the transmission loss from the terminal office to the tandem office should not exceed 3.5dB, and the transmission loss between tandem offices should not exceed 4.0dB. 5.3.3.3 Switch transmission loss
The transmission loss within the second-line switch office should be less than 1.0dB. 5.3.4 Switch Noise
The busy-hour noise of a long-distance four-wire switch should be no more than 200pWp (-67dBm0p) when converted to the zero relative level of the four-wire circuit. The busy-hour noise of a local telephone switch and a two-wire long-distance switch should be no more than 200pWp. The step-by-step switch can be relaxed to 500pWp (-63dBmp).
5.3.5 Inter-office trunk line noise
When the trunk line uses frequency division multiplexing short-distance carrier, the busy-hour noise of the telephone should be no more than 1000pWp (-60dBm0p) when converted to the zero relative level of the circuit. When the trunk line uses audio cable, the noise caused by thermal noise and crosstalk between pairs should be no more than 500pWp (-63dBmp) when measured at the end of the trunk line.
5.3.6 User Line Noise
The noise caused by thermal noise and crosstalk between pairs on the user line should be no more than 100pWp (-70dBmp) when measured at the telephone end. *The serial numbers in the appendix are original serial numbers.
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5.3.7 User Line Crosstalk Attenuation (f=800Hz) The crosstalk attenuation between two pairs of user lines at the same distribution point should be no less than 80dB (for individual cases of existing cables, it is allowed to be above 70dB).
11.8 Requirements for the access of automatic switching equipment in the city 11.8.1 It can be used as the terminal office of the single-office system, multi-office direct system and tandem system of the intranet with equal-position dialing, and can also be used as a tandem office. If necessary, after installing additional equipment, it can meet the requirement that the length difference of the number in the intranet should not exceed one. 11.8.2 It can work with the vertical and horizontal system or step-by-step direct dial small exchange included in the intranet, and can also work with the user small exchange not included in the intranet.
11.8.3 It can work with the vertical and horizontal system branch offices that occupy several tens and hundreds of numbers. 11.8.4 It can work with various types of long-distance automatic, semi-automatic and manual switching equipment produced in my country. 11.8.5 It has special service relay equipment (including directory inquiry station, time announcement station, etc.). The arrangement of special service numbers is shown in Chapter 7. 11.8.6 It has the performance of realizing the tandem of incoming and outgoing calls. When selecting the relay circuit, the direct route should be preferred, and the relocation route should be the second choice. The number of outgoing routes (except special service routes) for six-digit and seven-digit tandem and terminal exchanges shall be no less than 35, for five-digit tandem exchanges or terminal exchanges with 5,000 to 10,000 ports, shall be no less than 20, and for terminal exchanges with 1,000 to 5,000 ports, shall be no less than 15.
11.8.7 Voice channel restoration control mode:
a. In local connections, connections between ordinary users are in a non-mutual control mode. If the called party is a special service "112", "113", "116", "119" or "110", it is also in a called party control mode. Automatic answering special services such as "117" are in a non-mutual control mode. For other special service calls, all are in a caller control mode. b. In long-distance connections, long-distance fully automatic outgoing call connections and long-distance fully automatic incoming call connections are caller control. Long-distance semi-automatic and manual incoming call connections are both caller control modes. Long-distance semi-automatic outgoing call connection is in called control mode after the operator answers. 11.8.8 It should have the performance of international semi-automatic exchange and the performance of checking the calling user number. 11.8.9 The following user terminal equipment is allowed to be connected: dial telephones, coin-operated telephones, key telephones and user single-channel fax machines, writing telephones, and low-medium speed data transmission terminals. It has the performance of counting or duplex counting for local connections, and calls to certain special services may not be counted. In an emergency, the outgoing calls of general users can be temporarily cut off to ensure smooth communication for important users. Public control equipment (markers) have the performance of reconnection and verification. Important public equipment (such as markers, ring current generators, etc.) should adopt mutual assistance, standby or multi-working working modes to ensure reliable communication. The switching equipment should include a weight measuring table and control test equipment. For basic performance details, please refer to the "Compilation of Ministry-determined Technical Documents (Long and Municipal Automatic Switching Part)".
11.8.10 Traffic load capacity of switching equipment: At present, most cities in my country have a low telephone penetration rate (average number of telephones per 100 people), and the traffic volume is generally high. Therefore, it is recommended that the traffic load capacity of switching equipment be taken as follows in the near future: for cities with large traffic volume, the maximum sum of outgoing and incoming calls is 0.22~0.23 hours of calls/line. For cities with small traffic volume, the maximum sum of outgoing and incoming calls is 0.19~0.21 hours of calls/line. As the telephone penetration rate in my country increases, the long-term traffic load capacity will decrease, and adjustments will be made at that time. 11.8.11 Call loss index of switching equipment:
For vertical and horizontal switching equipment and quasi-electronic switching equipment under design load conditions: a. The obvious loss rate from the user picking up the phone to hearing the dial tone is not more than 0.3%~0.5%. b. The apparent loss rate from the time the user dials the last digit to the time the ringback tone is heard (excluding the busy rate of the called user) for local calls shall not exceed 1.5% to 2%, for incoming calls shall not exceed 1.5% to 2%, and for outgoing calls shall not exceed 1%. The call loss rate allowed to increase after each tandem shall not exceed 1%, and it is required that when the traffic volume of a route is 25 hours of calls, the utilization rate of each trunk line shall not be less than 0.6 hours of calls.
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c. When the overload is 10%, all call loss rates shall not exceed 300% of the rated call loss rate. 11.8.12 Connection speed:
For vertical and horizontal switching equipment or quasi-electronic switching equipment: a. Without waiting for public equipment, the time from the user picking up the phone to hearing the dial tone (or busy tone) shall not exceed 0.6s. b. The probability that the time from when a user picks up the phone to when he hears a dial tone or busy tone (including waiting for public equipment) exceeds 6 seconds shall not exceed 0.5% under the design load.
c. Under normal circumstances without waiting for public equipment and a successful connection, the time from when a user finishes dialing the last digit or when an incoming call receives the last digit to when he hears a ringback tone (or busy tone) shall not exceed 0.&s for calls to single-machine users in this office, and shall not exceed 1.0s for calls to trunk lines of small exchange in this office. For outgoing calls, the connection time shall be increased by 1.0s for each office they pass through (tentative). d. The probability that the time from when a user finishes dialing the last digit or when an incoming call receives the last digit to when he hears a ringback tone (or busy tone) (including waiting for public equipment) exceeds 6 seconds (calculated by a unified method) shall not exceed 1% for both local and incoming calls under the design load.
11.9 Transmission indicators of local automatic switching equipment 11.9.1 Intra-office loss
The intra-office loss of the automatic telephone exchange from user to user at 800Hz should not be greater than 0.87dB, and the loss caused by the intra-office cable should not be greater than 0.35dB.
11.9.2 Attenuation frequency characteristics
The difference between the attenuation measured at other frequencies and the attenuation measured at 800Hz for an intra-office connection should be within the following range (where "+" means greater attenuation than 800Hz, and "_" means less attenuation than 800Hz). 300~400Hz
400~2400Hz
2400~3400Hz
11. 9.3 Nonlinear distortion
-0.2~+0.5dB
-0.2~+0.3dB
-0.2~+0.5dB
When the test signal level changes from -40dB (relative to the absolute power level at the zero level point) to +3.5dB in an intra-office connection, the transmission loss change should not exceed 0.20dB.
11.9.4 Crosstalk loss|| tt||11.9.4.1 Crosstalk loss between two connections The intra-office crosstalk loss is tested using a single frequency of 1100Hz. Under the most unfavorable conditions, that is, when two connection scales may be adjacent, the crosstalk loss between the two call loops should not be less than 78dB. 11.9.4.2 Crosstalk loss between the sending branch and the receiving branch on each side of the same connection The crosstalk loss between the sending and receiving branches of the same voice channel of a four-wire switching device should be greater than 60dB. 11.9.5 Noise
The noise meter power level of the switching office during busy hours should be less than or equal to -67dB (relative to the absolute power level at the zero level point), which is equivalent to the noise meter power measured at the zero relative level point being less than 200pW, and the non-noise meter power level during busy hours (the measurement bandwidth is 30~20000Hz) should be less than or equal to -40dB (relative to the absolute power level at the zero level point), Equivalent to a power of 0.1uW. The average number of pulse noises at the exchange during busy hours, the number of pulse noises exceeding -35dB (relative to the absolute power level at the zero level point) within 5 minutes should be less than five times.
The maximum number of pulse noises with a level of -35 to -25dB allowed within a 5-minute period is 5 to 20 times. 11.9.6 Intermodulation distortion
When using multi-frequency signals at the end and the sub-end and transmitting data, the interference of intermodulation distortion should be considered. During the test, 900Hz and 1020Hz are sent simultaneously. The transmission level of each signal frequency is -6dB (relative to the absolute power level at the zero level point), and the difference between the signal frequency level and the level measured at the (2fr-f2) or (2f2-f1) frequency should be no less than 40dB. 11.9.7 Group delay distortion
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The group delay distortion of the intra-office connection in the frequency band of 600～3000Hz shall not exceed 100us. 11.9.8 Unbalance to ground
The unbalance of the call loop shall meet the following indicators: 300～600H, the unbalance loss in the frequency band shall not be less than 40dB. 600～3400H, the unbalance loss in the frequency band shall not be less than 46dB. 12 Types, series and access to the network of transmission systems Requirements 12.1 Intra-city transmission system
12.1.1 User cable
Lead-sheathed cable: Wire diameter 0.4, 0.5, 0.6, 0.7mm Network access requirements:
12.1.2 Inter-office relay cable
Different line DC resistance
(Q/km)(20℃)
≤148
Lead-sheathed twisted pair cable: Wire diameter 0.7, 0.9mm. 12.1.2.2 Lead-sheathed star-twisted low-frequency symmetrical cable: a.
Wire diameter 0.8, 0.9, 1.0, 1.2mm;
Network access requirements:
DC resistance of different lines
(2/km)(20℃)
Insulation resistance between different lines
≥2000
Nominal value 50
Insulation resistance between different lines
(MQ·km)
≥10000g
Shielded 38
Copper core polyethylene hydrocarbon insulation aluminum-plastic composite sheath urban communication cable: a.
Wire diameter 0.32, 0.4, 0.5, 0.6, 0.8mm; Network access requirements:
DC resistance of conductor (2/km)(20℃）
Wire diameter (mm）
②Insulation resistance between conductors (MQ·km）| |tt||Filled petroleum jelly: ≥3000
Working capacitance
(nF/km)
Working capacitance
(nF/km)
Unshielded 36
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Non-filled petroleum jelly: ≥10000
(DC voltage 100~500V, charging 1min)Working capacitance (nF/km)
Average value
Maximum value
More than 10 pairs
More than 10 pairs
Inherent attenuation (dB/km) (20℃)
Wire diameter (mm)
Far-end crosstalk protection;
③Near-end crosstalk attenuation.
150kHz
High capacitance
Low capacitance
Not more than 42
The ratio to the average working capacitance of the cable in the reel is not more than 1.091024kHz
Intra-city communication relay multiplexing system (12, 24, 30/60 carrier systems) 12.1.3
Series: 12-channel carrier system
24-channel carrier system
30/60-channel carrier system
12.1.3.2 Network access requirements:||t t||Voice channel transmission frequency band: 300~3400Hz;
Circuit noise: each carrier telephone circuit does not exceed 1000pW0ps at the zero relative level pointCircuit attenuation distortion: should reach the limit given in the following table (tentative);Frequency (Hz)
300~3400
400~3000
6002400
Intelligible crosstalk defense: not less than 65dB;Non-linear distortion: not more than 2%;
Time delay: to be determined.
Network access requirements for urban communication balanced amplification transmission systema.
Voice channel transmission frequency band: 300~3400Hz;
Circuit noise: not more than 1000pW0p;
Maximum allowable deviation relative to 800Hz (dB) -0.9~~+3.0
-0. 9~+1. 7
-0. 9~+0. 9
Circuit attenuation distortion: Maximum allowable deviation relative to 800Hz -0.2dB
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dIntelligible crosstalk defense: not less than 65dB;e.
Non-linear distortion: not more than 2%;
Time delay: to be determined.
Appendix B
"Technical System of Mobile Communication Network" (excerpt) (reference)
Frequency configuration of land public mobile communication network 4*
4.1 Working frequency band
160MHz band, 450MHz band, 900MHz band. 160MHz frequency band:
138.000MHz～149.900MHz
150.050MHz~167.000MHz
450MHz frequency band:
403.000MHz～420.000MHz
450.000MHz～470.000MHz
900MHz frequency band:
870.000MHz~898.975MHz
915.000MHz～943.975M Hz
Among them, the national public mobile service frequency bands approved by the State Radio and Television Commission are as follows:450MHz frequency band:
450.500MHz～453.500MHz (mobile station transmission)460.500MHz～463.500MHz (base station transmission)900MHz frequency band:
879.000MHz～898.975MHz (mobile station transmission)924.000MHz943.975MHz (base station transmission)4.2 Channel spacing
The adjacent channel spacing of each frequency band is 25kHz. The last two significant digits of the nominal frequency should be 00, 25, 50, 75k. For the public mobile communication network with large and medium capacity in the 450MHz frequency band, in order to reduce intermodulation and co-frequency interference within the network, the carrier frequency is allowed to be offset by 1.25kHz. 4.3 Duplex Transceiver Interval
The duplex transceiver interval for each frequency band is shown in Table B1. The base station frequency transmits high and receives low, and the mobile station frequency receives high and transmits low. Table B1
Duplex Transceiver Interval
4.4 Frequency Tolerance
Duplex Transceiver Interval for Each Frequency Band
Within the specified power supply voltage range and the temperature range of the mobile environment, the frequency error of any carrier frequency transmission shall not exceed the frequency error given in Table B2*The serial numbers in the appendix are original serial numbers.
W.
Non-linear distortion: no more than 2%;
Time delay: to be determined.
Appendix B
"Mobile Communication Network Technical System" (Excerpt) (Reference)
Frequency configuration of land public mobile communication network 4*
4.1 Working frequency band
160MHz band, 450MHz band, 900MHz band. 160MHz frequency band:
138.000MHz～149.900MHz
150.050MHz~167.000MHz
450MHz frequency band:
403.000MHz～420.000MHz
450.000MHz～470.000MHz
900MHz frequency band:
870.000MHz~898.975MHz
915.000MHz～943.975M Hz
Among them, the national public mobile service frequency bands approved by the State Radio and Television Commission are as follows:450MHz frequency band:
450.500MHz～453.500MHz (mobile station transmission)460.500MHz～463.500MHz (base station transmission)900MHz frequency band:
879.000MHz～898.975MHz (mobile station transmission)924.000MHz943.975MHz (base station transmission)4.2 Channel spacing
The adjacent channel spacing of each frequency band is 25kHz. The last two significant digits of the nominal frequency should be 00, 25, 50, 75k. For the public mobile communication network with large and medium capacity in the 450MHz frequency band, in order to reduce intermodulation and co-frequency interference within the network, the carrier frequency is allowed to be offset by 1.25kHz. 4.3 Duplex Transceiver Interval
The duplex transceiver interval for each frequency band is shown in Table B1. The base station frequency transmits high and receives low, and the mobile station frequency receives high and transmits low. Table B1
Duplex Transceiver Interval
4.4 Frequency Tolerance
Duplex Transceiver Interval for Each Frequency Band
Within the specified power supply voltage range and the temperature range of the mobile environment, the frequency error of any carrier frequency transmission shall not exceed the frequency error given in Table B2*The serial numbers in the appendix are original serial numbers.
W.
Non-linear distortion: no more than 2%;
Time delay: to be determined.
Appendix B
"Mobile Communication Network Technical System" (Excerpt) (Reference)
Frequency configuration of land public mobile communication network 4*
4.1 Working frequency band
160MHz band, 450MHz band, 900MHz band. 160MHz frequency band:
138.000MHz～149.900MHz
150.050MHz~167.000MHz
450MHz frequency band:
403.000MHz～420.000MHz
450.000MHz～470.000MHz
900MHz frequency band:
870.000MHz~898.975MHz
915.000MHz～943.975M Hz
Among them, the national public mobile service frequency bands approved by the State Radio and Television Commission are as follows:450MHz frequency band:
450.500MHz～453.500MHz (mobile station transmission)460.500MHz～463.500MHz (base station transmission)900MHz frequency band:
879.000MHz～898.975MHz (mobile station transmission)924.000MHz943.975MHz (base station transmission)4.2 Channel spacing
The adjacent channel spacing of each frequency band is 25kHz. The last two significant digits of the nominal frequency should be 00, 25, 50, 75k. For the public mobile communication network with large and medium capacity in the 450MHz frequency band, in order to reduce intermodulation and co-frequency interference within the network, the carrier frequency is allowed to be offset by 1.25kHz. 4.3 Duplex Transceiver Interval
The duplex transceiver interval for each frequency band is shown in Table B1. The base station frequency transmits high and receives low, and the mobile station frequency receives high and transmits low. Table B1
Duplex Transceiver Interval
4.4 Frequency Tolerance
Duplex Transceiver Interval for Each Frequency Band
Within the specified power supply voltage range and the temperature range of the mobile environment, the frequency error of any carrier frequency transmission shall not exceed the frequency error given in Table B2*The serial numbers in the appendix are original serial numbers.
W.
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