State the reason for keeping uplink and downlink frequency different in satellite communication.

State the reason for keeping uplink and downlink frequency different in satellite communication.
by

1 Answer

Answer :

Uplink frequency is used for transmission of signals from earth station transmitter to satellite. Downlink frequency is used for transmission of signals from satellite to earth station receiver. Satellite takes uplink signal coming from sender, processes it and converts to downlink frequency and transmit it towards earth. Both the frequencies are different because: 1. The satellite transmitter generates a signal that would jam its own receiver if both uplink and downlink shared same frequency. 2. Trying to receive and transmit an amplified version of the same uplink waveform at same satellite will cause unwanted feedback or ring around from downlink antenna back to the receiver. 3. Frequency band separation allows the same antenna to be used for both receiving and transmitting simplifying satellite hardware.
by

Related questions

The Ku frequency band used in satellite communication (for uplink and downlink) is:

Description : The Ku frequency band used in satellite communication (for uplink and downlink) is: (1) 14 GHz and 11 GHz (2) 30 GHz and 20 GHz (3) 70 GHz and 50 GHz (4) 60 GHz and 45 GHz 

Last Answer : The Ku frequency band used in satellite communication (for uplink and downlink) is: 14 GHz and 11 GHz 

The signal path from satellite to earth-based receiver. A. Downlink signal B. Uplink signal C. Incident signal D. Reflected signal

Description : The signal path from satellite to earth-based receiver. A. Downlink signal B. Uplink signal C. Incident signal D. Reflected signal

Last Answer : A. Downlink signal

The signal path from earth station satellite A. Uplink signal B. Reflected signal C. Incident signal D. Downlink signal

Description : The signal path from earth station satellite A. Uplink signal B. Reflected signal C. Incident signal D. Downlink signal

Last Answer : A. Uplink signal

A satellite signal transmitted from a satellite transponder to earth’s station. A. Uplink B. Downlink C. Terrestrial D. Earthbound

Description : A satellite signal transmitted from a satellite transponder to earth’s station. A. Uplink B. Downlink C. Terrestrial D. Earthbound

Last Answer : B. Downlink

Satellite signal transmitted from a satellite transponder to earth’s station. A. Vertically polarized B. Uplink C. Downlink D. RHCP

Description : Satellite signal transmitted from a satellite transponder to earth’s station. A. Vertically polarized B. Uplink C. Downlink D. RHCP

Last Answer : C. Downlink

First communication satellites used frequencies of A. 6 GHz for uplink B. 3 GHz for uplink C. 6 GHz for downlink D. 5 GHz for downlink

Description : First communication satellites used frequencies of A. 6 GHz for uplink B. 3 GHz for uplink C. 6 GHz for downlink D. 5 GHz for downlink

Last Answer : 6 GHz for uplink

The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Last Answer : A. 403 dB

What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz

Description : What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz

Last Answer : A. 6.065 GHz

Explain Satellite communication with neat diagram

Description : Explain Satellite communication with neat diagram

Last Answer : SATELLITE COMMUNICATION: In satellite communication, signal transferring between the sender and receiver is done with the help of satellite. In this process, the signal which is basically a beam ... of satellite: Satellite television digital cinema satellite radio satellite internet access

A microwave link between the earth station and the down-town terminal. A. STL B. Uplink C. Downlink D. Terrestrial link

Description : A microwave link between the earth station and the down-town terminal. A. STL B. Uplink C. Downlink D. Terrestrial link

Last Answer : D. Terrestrial link

A communication device that combines transmissions from several I/O devices into one line is a A) Concentrator B) Modifier C) Multiplexer D) Full duplex file

Description : A communication device that combines transmissions from several I/O devices into one line is a A) Concentrator B) Modifier C) Multiplexer D) Full duplex file

Last Answer : C) Multiplexer

Which of the communication modes support two way traffic but in only once direction of a time? A) Simplex B) Half-duplex C) Three - quarter's duplex D) Full duplex

Description : Which of the communication modes support two way traffic but in only once direction of a time? A) Simplex B) Half-duplex C) Three - quarter's duplex D) Full duplex

Last Answer : B) Half-duplex

Explain handoff procedure in mobile communication.

Description : Explain handoff procedure in mobile communication.

Last Answer : Assume that there is a call going on between two parties over a voice channel. When the mobile unit moves out of coverage area of a particular cell site the reception becomes weak. Then the cell ... arranges the handoff requests in a queue instead of rejecting them, if the new cell sites are busy.

Explain horizontal and vertical communication.

Description : Explain horizontal and vertical communication.

Last Answer : Horizontal communication Fig: Horizontal Communication in OSI Model. 1) The horizontal communication is the logical connection between the layers, there is no direct communication ... communication, it becomes protocol at each layer simultaneously. Fig:Vertical communication

Explain infrared communication. List any two disadvantages of infrared communication.

Description : Explain infrared communication. List any two disadvantages of infrared communication.

Last Answer : Infrared communication (IR) is an example of wireless communication. However, it is limited to very simple applications & suffers from several disadvantages, mainly very small bandwidth & distances ... areas require multiple emitter panels, which will increase the cost of the system.

What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz

Description : What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz

Last Answer : C. 2225 MHz

A satellite receives an uplink frequency of _______ MHz from a ground station of 3700 MHz. A. 8150 MHz B. 1475 MHz C. 2225 MHz D. 5925 MHz

Description : A satellite receives an uplink frequency of _______ MHz from a ground station of 3700 MHz. A. 8150 MHz B. 1475 MHz C. 2225 MHz D. 5925 MHz

Last Answer : D. 5925 MHz

Enlist different types of servers.

Description : Enlist different types of servers.

Last Answer : Different types of servers are: Definition of server: The central computer which is more powerful than the clients which allows the clients to access its software, database is called as the server. Types of server: 1. File server 2. Print server 3. Application server 4. Mail server

Enlist different types of computer networks on the basis of their geography.

Description : Enlist different types of computer networks on the basis of their geography. 

Last Answer : Classification of networks based on geography LAN - Local Area Network MAN - Metropolitan Area Network WAN - Wide Area Network CAN - Campus Area Network PAN - Personal Area Network

Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.

Description : Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.

Last Answer : TCP/IP Model contains following layer. 1) Host-to-Network Layer - It defines characteristics of transmission media. It also concern with delivery of data when two systems are attached to same network ... such broadcasts are not forwarded by routers, so a RARP server is needed on each network. 

Explain different modes of fibre optic cable.

Description : Explain different modes of fibre optic cable.

Last Answer : Current technology supports two modes for propagating light along optical channels. 1. Multimode. 2. Single mode.  Multimode can be implemented in two form:  1. Step ... All the beams arrive at the destination together and can be recombined with little distortion to the signal.

List different classes of IP Address.

Description : List different classes of IP Address.

Last Answer : Different classes of IP address. Class A Class B Class C Class D Class E

An a.c series circuit has resistance of 10ohm, inductance of 0.1H and capacitance of 10µf, voltage applied to circuit is 200V. find (i) Resonant frequency (ii) Current at resonance (iii) Power at resonance

Description : An a.c series circuit has resistance of 10ohm, inductance of 0.1H and capacitance of 10µf, voltage applied to circuit is 200V. find (i) Resonant frequency (ii) Current at resonance (iii) Power at resonance 

Last Answer : Solution: For RLC series circuit

Derive an expression for resonant frequency of series RLC circuit.

Description : Derive an expression for resonant frequency of series RLC circuit.

Last Answer : At resonance frequency in RLC series circuit, we have inductive reactance is equal to capacitive reactance i.e.  Where fr is the resonant frequency in RLC series circuit. 

Compare series and parallel resonance on the basis of (i) Resonating frequency (ii) Impedance (iii) Current (iv) Magnification

Description : Compare series and parallel resonance on the basis of (i) Resonating frequency (ii) Impedance (iii) Current (iv) Magnification

Last Answer : S. No . Parameter Series Circuit Parallel Circuit 1 Resonating frequency 2 Impedance Minimum, Z = R Maximum, Z = L/CR 3 Current Maximum, I ... , I = V/(L/CR)  4 Magnification Voltage magnification takes place Current magnification takes place

State whether the following statement are true. i) An application-level gateway is often referred to as a proxy. ii) In proxy, a direct connection is established between the client and destination server. A) True, False B) False, True C) True, True D) False, False

Description : State whether the following statement are true. i) An application-level gateway is often referred to as a proxy. ii) In proxy, a direct connection is established between the client and destination server. A) True, False B) False, True C) True, True D) False, False

Last Answer : A) True, False

State true or false. i) Socks are a standard for circuit level gateways. ii) The NAT is used for small number of the hosts in a private network. A) True, False B) False, True C) True, True D) False, False

Description : State true or false. i) Socks are a standard for circuit level gateways. ii) The NAT is used for small number of the hosts in a private network. A) True, False B) False, True C) True, True D) False, False

Last Answer : C) True, True

State whether true or false. i) A connection oriented protocol can only use unicast addresses. ii) The any cast service is included in IPV6. A) True, False B) True, True C) False, True D) False, False

Description : State whether true or false. i) A connection oriented protocol can only use unicast addresses. ii) The any cast service is included in IPV6. A) True, False B) True, True C) False, True D) False, False

Last Answer : B) True, True

State the following statement is true or false. i) In class B addresses a total of more than 1 billion addresses can be formed. ii) Class E addresses are reserved for future or experimental use. A) True, False B) True, True C) False, True D) False, False

Description : State the following statement is true or false. i) In class B addresses a total of more than 1 billion addresses can be formed. ii) Class E addresses are reserved for future or experimental use. A) True, False B) True, True C) False, True D) False, False

Last Answer : B) True, True

State whether the following is True or False. i) In bus topology, heavy Network traffic slows down the busspeed. ii) It is multipoint configuration. A) True, True B) True, False C) False, True D) False, False

Description : State whether the following is True or False. i) In bus topology, heavy Network traffic slows down the busspeed. ii) It is multipoint configuration. A) True, True B) True, False C) False, True D) False, False

Last Answer : A) True, True

State four features of Wi-Fi.

Description : State four features of Wi-Fi.

Last Answer : Wi-Fi 1. Wi-Fi stands for wireless fidelity. 2. Wi-Fi typically provides local network access for around a few hundred feet with speeds of up to 54 Mbps. 3. Wi-Fi based on IEEE 802.11 standards. 4. High Capacity Load Balancing 5. Scalability 6. Network Management System

State the need for computer networks.

Description : State the need for computer networks. 

Last Answer : Need for computer network: File/Folder Sharing Hardware Sharing (Resource sharing) Application sharing User Communication (Email, Remote Access)

It is desired to connect five computers that are joined at a single point called central node. i) Draw the setup. ii) Name the topology. iii) State two advantages and disadvantages of this topology.

Description : It is desired to connect five computers that are joined at a single point called central node. i) Draw the setup. ii) Name the topology. iii) State two advantages and disadvantages of this topology.

Last Answer : i. Setup:  ii. Name of topology: Star topology iii. Advantages of Star Topology 1) As compared to Bus topology it gives far much better performance, signals don't necessarily get ... as well number of nodes which can be added in such topology is depended on capacity of central device.

State the functions of i. Repeater ii. Switch iii. Gateway iv. Bridges

Description : State the functions of i. Repeater ii. Switch iii. Gateway iv. Bridges

Last Answer : i) Repeater: Repeaters are used to take the distorted, weak and corrupt input signal and regenerate this signal at its output. It ensures that the signals are not distorted or weak before it ... and decides whether to forward or discard it. It sends packets between two networks of same type.

State two advantages of Mesh topology.

Description : State two advantages of Mesh topology.

Last Answer : Network Topology refers to layout of a network. Network topology specifically refers to the physical layout of the network especially the locations of the computers & how the cable is run ... to Point Connection: Point-to-point links make fault identification and fault isolation easy.

State features of any one network control devices.

Description : State features of any one network control devices. 

Last Answer : A hardware device that are used to connect computers, printers, fax machine and other electronic devices to a network are called network devices. These devices transfer data in a fast, ... transforms incoming analog signals into their digital equivalents. A two way communication is established.

State the situations under which gateways are necessary in the network.

Description : State the situations under which gateways are necessary in the network.

Last Answer : Gateway operates at all 7 layers of the OSI model. It is a device, which connects two different dissimilar n/w which have same function of communication. Situation where gateways are necessary ... case of different frame sizes, data rates, format, acknowledgement schemes, and priority schemes tec.

State the factors to be considered for selecting transmission media.

Description : State the factors to be considered for selecting transmission media.

Last Answer : Eight factors to be considered:  1. Type of medium.  2. No of conductors/connectors.  3. Flexibility.  4. Durability.  5. Bandwidth.  6. Reliability of connection  7. Required ... parallel wires  12. Resistance to external EMI outside the cable.  13. Attenuation characteristics  14. Cost

Is a loss of power of a satellite downlink signal due to earth’s atmosphere. A. Atmospheric loss B. Path loss C. Radiation loss D. RFI

Description : Is a loss of power of a satellite downlink signal due to earth’s atmosphere. A. Atmospheric loss B. Path loss C. Radiation loss D. RFI

Last Answer : B. Path loss

..................mode is used whenever either end of a security association is gateway. A) Tunnel B) Encapsulating C) Transport D) Gateway

Description : ..................mode is used whenever either end of a security association is gateway. A) Tunnel B) Encapsulating C) Transport D) Gateway

Last Answer : A) Tunnel

In packet-filtering router, the following information can be external from the packet header. i) Source IP address ii) Destination IP address iii) TCP/UDP source port iv) ICMP message type v) TCP/UDP destination port A) i, ii, iii and iv only B) i, iii, iv and v only C) ii, iii, iv and v only D) All i, ii, iii, iv and v

Description : In packet-filtering router, the following information can be external from the packet header. i) Source IP address ii) Destination IP address iii) TCP/UDP source port iv) ICMP message type v) TCP/UDP destination port A) i, ii, ... iv and v only C) ii, iii, iv and v only D) All i, ii, iii, iv and v

Last Answer : D) All i, ii, iii, iv and v

On the upper layer of SSL, a protocol for initial authentication and transfer of encryption keys, called the ………………… A) SSL handshake protocol B) SSL authentication protocol

Description : On the upper layer of SSL, a protocol for initial authentication and transfer of encryption keys, called the ………………… A) SSL handshake protocol B) SSL authentication protocol

Last Answer : A) SSL handshake protocol

While initiating SSL session, the client code recognizes the SSL request and establishes a connection through TCP Part.................to the SSL code on the server. A) 420 B) 1032 C) 443 D) 322

Description : While initiating SSL session, the client code recognizes the SSL request and establishes a connection through TCP Part.................to the SSL code on the server. A) 420 B) 1032 C) 443 D) 322

Last Answer : C) 443

At the lower layer of SSL, a protocol for transferring data using a variety of predefined cipher and authentication combinations called the ………………. A) SSL handshake protocol B) SSL authentication protocol C) SSL record protocol D) SSL cipher protocol

Description : At the lower layer of SSL, a protocol for transferring data using a variety of predefined cipher and authentication combinations called the ………………. A) SSL handshake protocol B) SSL authentication protocol C) SSL record protocol D) SSL cipher protocol

Last Answer : C) SSL record protocol

The............................. Is a collection of protocols designed by Internet Engineering TaskForce(IETF) to provide security for a packet at the Network level. A) IPsec B) Netsec C) Packetsec D) Protocolsec

Description : The............................. Is a collection of protocols designed by Internet Engineering TaskForce(IETF) to provide security for a packet at the Network level. A) IPsec B) Netsec C) Packetsec D) Protocolsec

Last Answer : A) IPsec

In........................mode, a common technique in packet-switched networks consists of wrapping a packet in a new one. A) Tunneling B) Encapsulation C) Both A and B D) None of the above

Description : In........................mode, a common technique in packet-switched networks consists of wrapping a packet in a new one. A) Tunneling B) Encapsulation C) Both A and B D) None of the above

Last Answer : C) Both A and B

The................is used to provide integrity check, authentication and encryption to IPdatagram. A) SSL B) ESP C) TSL D) PSL

Description : The................is used to provide integrity check, authentication and encryption to IPdatagram. A) SSL B) ESP C) TSL D) PSL

Last Answer : B) ESP

The primary goal of the......................protocol is to provide a private channel between communicating application, which ensures privacy of data authentication of the partners, and integrity. A) SSL B) ESP C) TSL D) PSL

Description : The primary goal of the......................protocol is to provide a private channel between communicating application, which ensures privacy of data authentication of the partners, and integrity. A) SSL B) ESP C) TSL D) PSL

Last Answer : A) SSL

A ..................is an extension of an enterprise’s private intranet across a public Network such as the Internet across a public Network such as the Internet, creating a secure private connection. A) VNP B) VPN C) VSN D) VSPN

Description : A ..................is an extension of an enterprise’s private intranet across a public Network such as the Internet across a public Network such as the Internet, creating a secure private connection. A) VNP B) VPN C) VSN D) VSPN

Last Answer : B) VPN

In.................. Mode, the authentication header is inserted immediately after the IP header. A) Tunnel B) Transport C) Authentication D) Both A and B

Description : In.................. Mode, the authentication header is inserted immediately after the IP header. A) Tunnel B) Transport C) Authentication D) Both A and B

Last Answer : A) Tunnel