Description : Discuss different Routing plan adopted in a Telephone network.
Last Answer : Hierarchical networks are capable of handing heavy traffic where required, and at the same time use minimal number of trunk groups. Three methods are used for deciding on the route for a ... selection methods can be implemented. Computer based routing is a standard feature in data networks.
Description : Explain simple telephone communication system with circuit and equation of current flow in microphone?
Last Answer : Simple Telephone Communication: In the simplest form of a telephone circuit, there is one way communication involving two entities, one receiving (listening) and the other transmitting (talking). ... carrier wave in AM system. The quantity m is equivalent to the modulation index in AM.
Description : Write short notes (i)Telephone hand set and it’s working. (ii) CPU based exchange
Last Answer : (i) A standard telephone set is comprised of a transmitter, a receiver, and electrical network for equalization, associated circuitry to control side tone levels and to regulate signal power, ... commands are designed to be of variable length necessitating the use of an end-of-command symbol
Description : What is the need of a hybrid in telephone networks? How does it work?
Last Answer : Digital exchanges require receive and transmit signals on separate two-wire circuits. This calls for two-wire to four-wire conversion. Such a conversion is normally required for trunk transmissions in ... from the subscriber end is completely nullified from coupling into the winding A.
Description : What is store program control (SPC)? Give the organization of centralized SPC. Discuss the advantages of SPC automation in telephone switching.
Last Answer : In stored program control systems, a program or set of instructions to the computer is stored in its memory and the instructions are executed automatically one by one by the processor. Carrying out ... of services can be provided to customers. (v) Increase level of automotive in switching
Description : A certain amount of side tone is essential in telephone communication (A) TRUE (B) FALSE
Last Answer : Ans: (A)
Description : Engaged tone is generated in the: (A) Telephone instrument of calling subscriber (B) Telephone instrument of called subscriber (C) Exchange (D) Repeater
Last Answer : (C) Exchange
Description : Telephone Traffic is measured in (A) Seconds. (B) Hours. (C) Erlang (D) Pulses per minute.
Last Answer : (C) Erlang
Description : Example of circuit switching and S&F (Stored and Forward) switching is (A) Telephone and Post of Telegraph (B) Video Signal Post or Telegraph (C) Digital Signal Post or Telegraph (D) None of above
Last Answer : (A) Telephone and Post of Telegraph
Description : Distortion caused on telephone line by an adjacent one is called (A) Cross Fire (B) Inductive Disturbance (C) Cross Talk (D) None of these
Last Answer : (C) Cross Talk
Description : The bandwidth requirement of a telephone channel is (A) 3 KHz (B) 15 KHz (C) 5 KHz (D) 25 KHz
Last Answer : (A) 3 KHz
Description : Telex is a (A) Telephone Service between various subscribers (B) Tele printer Service between various subscribers (C) Television Service between various subscribers (D) Telegraph Service between various subscribers
Last Answer : (B) Tele printer Service between various subscribers
Description : The ________is a circuit-switched network, while the ______is a packet-switched network. (A) Telephone, ATM (B) SONET and FDDI (C) Satellite, Telephone (D) FDDI and SONET
Last Answer : (A) Telephone, ATM
Description : A sample rate of ________is required for a good quality representation of telephone conversation. (A) 4500 times per second. (B) 700 integer sample points per minute. (C) 50 times per second per mile of distance travelled. (D) 8000 times per second.
Last Answer : (C) 50 times per second per mile of distance travelled.
Description : Which transmission mode is used for data communication along telephone lines? (A) Parallel (B) Serial (C) Synchronous (D) Asynchronous
Last Answer : (B) Serial
Description : In the illustration, A, B, C, and D are 12 volts in the circuit. What is the voltage of the lead connected to C and D with respect to the lead connected to A and B? EL-0039 A. (-) 48 volts B. (+) 48 volts C. (-) 24 volts D. (+) 24 volts
Last Answer : Answer: D
Description : In the illustration circuit, A, B, C, and D are each 12 volts. What is the voltage of the lead connected to C and D with respect to the lead connected to A and B? EL-0039 A. (+) 48 volts B. (-) 24 volts C. (-) 48 volts D. (+) 24 volts
Description : In the illustration circuit, A, B, C, and D are each 12 volts. What is the voltage at the output lead connected to 'A' and 'B' with respect to the output lead connected to 'C' and 'D'? EL-0039 A. (+) 48 volts B. (-) 24 volts C. (-) 48 volts D. (+) 24 volts
Last Answer : Answer: B
Description : In a hundred-line exchange 24 two-motion selectors are used. Draw the schematic you suggest for this exchange and explain its working. How many simultaneous calls can be made during peak hour in this exchange?
Last Answer : The desired schematic for 100 lines exchange with 24 two motion selectors is shown in Fig. In the case, 24 simultaneous calls can be put through the switch . Typically, a 24- ... selector. At the next step, the two-motion selector responds to the dial pulses for appropriate connection.
Description : One Erlang is equal to (A) 3600 CCS (B) 36 CCS (C) 60 CCS (D) 24 CCS
Last Answer : (A) 3600 CCS
Description : A Master group consists of (A) 12 voice channels. (B) 24 voice channels (C) 60 voice channels. (D) 300 voice channels
Last Answer : (D) 300 voice channels
Description : In the illustration, 24 volts is applied to the circut where the resistance for R1 is 3 ohms, R2 is 4 ohms, and R3 is 5 ohms. What is the power consumed in R3? EL-0020 A. 12 watts B. 20 watts C. 24 watts D. 48 watts
Description : What is the power consumed by 'R3' in the circuit illustrated if the supply is 24 volts and resistance of R1 is 3 ohms, R2 is 4 ohms, and R3 is 5 ohms? EL-0020 A. 12 watts B. 20 watts C. 24 watts D. 48 watts
Description : What is the total power consumed by the illustrated circuit if the supply is 24 volts and the resistances of R1 is 3 ohms, R2 is 4 ohms, and R3 is 5 ohms? EL-0020 A. 2 watts B. 12 watts C. 48 watts D. 288 watts
Last Answer : Answer: C
Description : Trunks are the lines that run between (A) Subscribers and exchange (B) Switching system and power plant (C) Local area network (D) Switching stations
Last Answer : (D) Switching stations
Description : Trunks are the lines that run between (A) subscribers and exchange (B) switching system and power plant (C) Local Area Network (D) switching systems
Last Answer : (B) switching system and power plant
Description : Trunks are the lines that run between (A) Subscribers and exchange (B) switching system and power plant (C) Local area network. (D) Switching stations.
Last Answer : (D) Switching stations.
Description : Are telephone directories(books) becoming obsolete, just like home telephones?
Last Answer : I got a phone book delivered to me, and it went straight to the recycling bin lol. I have internet on my phone, I’ll use one in case the internet completely shuts down.
Description : What is ‘Teletext’ ? (1) Flashing of telephone conversation on TV screen. (2) Printing the text of the message on the telex machine. (3) Connecting the local telephone with outstation telephones without STD codes. (4) Flashing of the text of news and information on the TV screen.
Last Answer : Flashing of the text of news and information on the TV screen.
Description : The electrical energy necessary to power a sound-powered telephone's small vibrating bell is obtained from _________. A. the emergency batteries for the general alarm B. each station's hand-cranked generator C. the emergency switchboard D. normal 115 volt DC supplies
Description : Three 12 volt, lead-acid, batteries connected in series will develop __________. A. 12 volts B. 24 volts C. 36 volts D. 48 volts
Description : In the illustration, A, B, C and D are 12 volt batteries. a voltmeter across the output of the circuit will indicate _____________. EL-0039 A. 6 volts B. 12 volts C. 24 volts D. 48 volts
Description : In the illustration, the component VR2 on the A1 AMPLIFIER MODULE is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply from common B. a variable resistor diode to control the output to terminal ... 2 at 9.1 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Description : In the illustration, the component VR1 on the A1 AMPLIFIER MODULE is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply from common B. a variable resistor diode to control the output to ... terminal 9 at 6.6 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Last Answer : Answer: A
Description : In the illustration, the component VR1 on the A1A1 PCB is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply B. a variable resistor diode to control the output to terminal 9 that controls ... terminal 9 at 6.6 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Description : What is the purpose of the 'annunciator module' (6000F35) shown in the illustration? EL-0094 A. Provide an input to the setpoint module. B. Drive the alarm lamp and, through the controller, the horn. ... and +24 volts to their respective power supplies. D. Connect 24 volts to both sides of the horn.
Description : What do you mean by numbering and addressing? Draw the ISDN address structure and explain how the addressing works?
Last Answer : Numbering and Addressing: In telephone and data networks, the end equipments are more often single units than multiple devices units like PABX or LAN. Historically, a telephone, a computer, or a ... as reference point may also be addressed by using direct inward dialing (DID) feature.
Description : Explain the process of inter-register signalling.
Last Answer : Registers are used in common control exchanges to store and analyze routing data. They are provided on a common basis is a single register provides routing data for a number of speech circuits. Once a call ... it is released and the originating register signals to the next register.
Description : Draw a centralized SPC organization and explain how it works under load sharing operation.
Last Answer : In centralized control, all the control equipment is replaced by a single processor which must be quite powerful. It must be capable of processing 10 to 100 calls per second, depending on the ... both the processors are active simultaneously and share the load and the resources dynamically.
Description : Explain FDM and show how CCITT standards help in building the base band?
Last Answer : Frequency Division Multiplexing: It is the process of combining several information channels by shifting their signals to different frequency groups within the spectrum so that they can be transmitted simultaneously ... of 24 channels were assembled together in one stage of modulation.
Description : What are transmission bridges? How do they help in satisfying the connectivity?
Last Answer : A typical transmission bridge is shown in Fig. The series capacitance and the shunt inductances of the two relays provide a high-pass filter to transmit the AC speech signals, while the relays respond independently to the DC loop/disconnect signals from the calling and called customer.
Description : What are the different ways of designing 100 line exchange using uni selector and two motion selectors? Show at least three variations. Which is the best option?
Last Answer : Here three different designing methods for 100 line exchange are discussed: Design 1: Here, Strowger switching system is designed using one two-motion selector for each subscriber. A ... only under certain specific traffic conditions and generally lead to higher blocking probabilities.
Description : How numbering plan is achieved in modern telephony? Give the structure with example.
Last Answer : The objective of numbering plan is to uniquely identify every subscriber connected to a telecommunication network. A numbering plan may be open, semiopen or closed. An open-numbering plan permits wide ... known as the subscriber number which is the number listed in the telephone directory.
Description : How does a touch tone receiver differs from pulsed dial receiver? Explain with schematic.
Last Answer : Pulse dialing: 1. Generated through make and break contact. 2. DC Current pulse is generated. 3. Each number is separated by a short pause to prevent overlapping. 4. Codes ... dialing pulse is not misinterpreted as the phone being returned to its on-hook (idle) condition.
Description : Discuss briefly subscriber loop system. Give some technical specification for subscriber lines.
Last Answer : Subscriber Loop System: Every subscriber in a telephone network is connected generally to the nearest switching office by means of a dedicated pair of wires. Subscriber loop refers to this pair of wires. It is un ... 1. Diameter of wire 2. D.C. resistance per Km 3. Attenuation per Km
Description : What is Traffic Engineering? Define the term busy hour, traffic intensity and grade of service.
Last Answer : Traffic engineering provides the basis for analysis and design of telecommunication network to carry a given traffic at a particular loss probability. It provides a means to determine the quantum of common equipments ... A0 Where A= offered traffic A0 = carried traffic A-A0= lost traffic
Description : Explain topology method used in LAN technology in detail.
Last Answer : LAN Topologies: Network topology is a physical schematic which shows interconnection of the many users. There are four basic topologies as under: (i) Direct Connection or one to all topology ( ... temporarily, inserting the new node and then reestablishing the complete ring path.
Description : List all seven layer of OSI model and describe function of application layer.
Last Answer : The layers of OSI model are as follows: (1) The Physical Layer: This defines an interface in terms of the connections, voltage levels and data rate, in order for signals to ... with the applications programs needed. Examples include electronic mail, word processing, banking transactions, etc.
Description : Find the total number of link L having five entities? Explain differences between folded and non-folded network.
Last Answer : Folded network: When all the inlets/outlets are connected to the subscriber lines, the logical connection appears as shown in Fig. In this case, the output lines are folded back to the input ... non-folded network to be non-blocking, the network should support N simultaneous switching paths.