Chapter 6: Data Communication Flashcards
Data Communication
Electronic transfer of data from one location to another
Bandwidth
The amount of data that can be transferred from one point to another in a certain time period, usually one second
Attenuation
Loss of power in a signal as it travels from the sending device to the receiving device
Broadband (data transmission)
Multiple pieces of data are sent simultaneously to increase the transmission rate
Narrowband
Voice-grade transmission channel capable of transmitting a maximum of 56,000 bps, so only a limited amount of information can be transferred
3 Major components of a data communication systems
1) Sender and receiver devices
2) Modems (devices that connect a user to the Internet) or routers (connects network systems and controls their traffic flow)
3) Communication media (connect sender and receiver devices)
Digital subscriber line (DSL)
A type of modem that uses ordinary phone lines
Communication Media/Channels
Connect sender and receiver devices
- Either conducted: Physical path that signals are transmitted or
- Radiated: Uses antenna
3 types of processing configurations
1) Centralized: One computer
2) Decentralized: Many computers
3) Distributed: Processing power is distributed among several locations
Network Interface Card (NIC)
- Hardware component that enables computers to communicate over a network
- Also called adapter card
3 Types of Networks
1) Local area network (LAN): Connects devices that are in close proximity
2) Wide area network (WAN): Spans serval cities, states, or countries and is owned by different parties
3) Metropolitan area network (MAN): Data communications for multiple organizations in a city or nearby cities
Network Topologies
Represent a network’s physical layout, including the arrangement of computers and cables
- Types: Star, ring, bus, hierarchical, mesh
Star Topology
Consists of a central computer (host computer or serve) and a series of nodes (workstations or peripheral devices)
Ring Topology
- No host computer is required as each computer manages its own connectivity
- Each node is connected to two other nodes
- Transmission in one direction
- Needs less cable than star topology
Bus Topology (linear bus)
Connects nodes along a network segment, but the ends of the cable are not connected, as they are in ring topology
Hierarchical Topology (tree)
Combines computers with different processing strengths in different organizational levels
- Consists of the controller: Hardware and software device that controls data transfer from a computer to a peripheral device
- And the multiplexer: Hardware device that allows several nodes to share one communication channel
Mesh Topology (plex/interconnected)
Every node is connected to every other node
- Known as plex or interconnected
Protocols
Rules that govern data communication/information exchange
- Ex: Error detection, message length, and transmission speed
Routing
The process of deciding which path data takes on a network.
- Usually determined by the type of network and the software used to transmit the data
- Routing table: Generated automatically by software and is used to determine the best possible route for a packet
Packet
A collection of binary digits (including message data and control characters for formatting and transmitting) sent from computer to computer over a network
2 types of routing
1) Centralized routing: One node is in charge of selecting the path for all packets. Stores routing table, does changes to a route
2) Distributed routing: Relies on each node to calculate its own best possible route. Each node contains its own routing tables
Router
A network connection device containing software that connects network systems and controls their traffic flow
- Chooses the best path for packets
2 Types of routers
1) Static: Require the network routing manager to give it information about which addresses are on which network
2) Dynamic: Build tables that identify addresses on each network
Client/Server Model
Software runs on the local computer and communicates with the remote server to request information or services
- A server is a remote computer on the network that provides information or services in response to client requests
Wireless network
A network that uses wireless instead of wired technology
Mobile network (cellular network)
A network operating on a radio frequency (RF)
- Consists of radio cells, each served by a fixed transmitter, known as a cell site or base station
Throughput
Similar to bandwidth, the amount of data transferred or processed in a specific time, usually one second
Convergence
In data communication, refers to integrating voice, video, and data so that multimedia information can be used for decision making
