Modem and Signal Conversion

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Questions and Answers

What is the primary function of connection devices in a communication system?

To establish physical connections

To convert outgoing messages into packets (correct)

To define data transmission specifications

To send and receive messages

What is the main purpose of a modem?

To convert digital signals to analog signals and vice versa (correct)

To provide high-speed internet connection

To increase the speed of data transmission

To connect multiple computers in a network

What type of connection uses a solid medium to connect sending and receiving devices?

Fiber-optic connection

Wireless connection

Satellite connection

Physical connection (correct)

What is the unit of measurement for the speed of data transmission?

Millions of bits Signup and view all the answers

What is the purpose of data transmission specifications in a communication system?

To define rules and procedures for sending and receiving devices Signup and view all the answers

What type of modem uses the same coaxial cable as the television?

Cable modem Signup and view all the answers

Which type of cable is used in telephone lines and Ethernet cables?

Twisted-pair cable Signup and view all the answers

What is the term for converting digital signals to analog signals?

Modulation Signup and view all the answers

What is the term used for sending data to a satellite?

Uplink Signup and view all the answers

What is the term for a computer network that connects multiple computers to exchange information and share resources?

Computer Network Signup and view all the answers

Which wireless connection technology is used for high-speed internet access?

WiMax Signup and view all the answers

What type of modem is also known as a WWAN modem?

Wireless modem Signup and view all the answers

What is the primary difference between physical and wireless connections?

Physical connections use a solid medium Signup and view all the answers

What is the term for the speed of transmitting data?

Transfer rate Signup and view all the answers

Which of the following is an application of satellite communication?

GPS (Global Positioning System) Signup and view all the answers

What type of connection service uses standard phone lines to provide high-speed connection?

DSL service Signup and view all the answers

What is the primary function of a switch in a network?

To coordinate the flow of data by sending messages directly between sender and receiver nodes Signup and view all the answers

What type of network topology is characterized by a central node connected to two or more nodes that are in turn connected to other nodes?

Tree Signup and view all the answers

What is the term for a device that requests and uses resources available from other nodes?

Client Signup and view all the answers

In a bus network, how do communications travel?

Along a common cable called a bus or backbone Signup and view all the answers

What is the term for a node that shares resources with other nodes?

Server Signup and view all the answers

What type of network topology is characterized by a central node connected to multiple nodes that in turn are connected to other nodes?

Star Signup and view all the answers

What is the term for a device that can be accessed over a network?

Host Signup and view all the answers

In a ring network, how are messages sent?

Passed around the ring until it reaches the intended destination Signup and view all the answers

Study Notes

Connection Devices

Telephones send and receive analogue signals, while computers use digital signals.
A modem is required to convert digital signals to analog signals and vice versa.
Modem stands for modulator-demodulator, which enables digital microcomputers to communicate across different media including telephone wires, cable lines, and radio waves.
The speed of transmitting data is called the transfer rate, which is measured in millions of bits.

Types of Modems

There are three types of modems: DSL, Cable, and Wireless.
DSL modem provides high-speed connection using standard phone lines.
Cable modem uses the same coaxial cable as the television.
Wireless modem is also known as a WWAN (wireless wide area network) modem.

Connection Services

Old dial-up services have been replaced by higher-speed connection services including:
- Digital Subscriber Line (DSL)
- Cable service
- Fiber-optic service
- Satellite connection services
- Cellular services (3G and 4G)

Networks

A computer network is a communication system that connects two or more computers to exchange information and share resources.
Networks can be set up in different arrangements to suit users' needs.
The four basic elements of a communication system are:
- Sending and receiving devices
- Communication channel
- Connection devices
- Data transmission specifications

Communication Channels

Computer channels carry data from one computer to another.
There are two categories of communication channels:
- Physical connection
- Wireless connection

Physical Connection

Physical connections use a solid medium (wire or cable) to connect sending and receiving devices.
Types of physical connections include:
- Twisted-pair cable
- Coaxial cable
- Fiber-optic cable

Wireless Connection

Wireless connection doesn't use solid substance to connect sending and receiving devices.
Types of wireless connections include:
- Bluetooth
- Wi-Fi (wireless fidelity)
- Microwave
- Infrared
- WiMax (Worldwide Interoperability for Microwave Access)
- Cellular
- Satellite

Network Terms

Node: any device connected to a network such as a computer, printer, or storage device.
Client: a node that requests and uses resources available from other nodes.
Server: a node that shares resources with other nodes.
Directory server: a specialized server that manages resources such as users' accounts.
Host: any computer system that can be accessed over a network.
Switch: a central node that coordinates the flow of data by sending messages directly between sender and receiver nodes.

Network Architecture: Topologies

Network architecture describes how a network is arranged and how resources are coordinated and shared.
Network topology describes the physical arrangement of the network.
Types of network topology include:
- Bus
- Ring
- Star
- Tree
- Mesh

Network Topologies

Bus Network: each device is connected to a common cable called a bus or backbone.
Ring Network: each device is connected to two other devices forming a ring.
Star Network: each device is connected directly to a central network switch.
Tree Network: each device is connected to a central node either directly or through one or more other devices.
Mesh Network: each device is connected to every other device in the network.

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Description

Learn about the role of modems in converting digital signals to analog signals and vice versa, enabling communication between devices. Understand the concepts of modulation and demodulation.