Telecommunications & Networks Flashcards
Telecommunications
Electronic transmission of signals for communications
Telecommunications medium
Any material substance that carries an electronic signal to support communications between a sending and receiving device
Networking protocol
Set of rules, algorithms, messages, and other mechanisms that enable software and hardware in networked devices to communicate effectively
Synchronous communications
Receiver gets message instantaneously (Phone call, Instant message like WhatsApp, Facebook)
Asynchronous communications
Receiver gets message after some delay (walkie-talkie, email, sms)
Simplex channel
Transmits data in only one direction (Example TV stations transmit signals to viewers, who receive the content but can’t send information back through the same channel.)
Half-duplex channel
Transmits data in either direction, but not simultaneously (Example Walkie Talkie, can’t talk together, have to wait until one person finishes talking)
Full-duplex channel
Permits data transmission in both directions at the same time (Mobile phones during a regular phone call operate in full-duplex mode. You can speak and listen at the same time, allowing for a natural conversation. )
Channel bandwidth
Rate at which data is exchanged
Circuit switching network
(For Sending Voice Only)
Sets up a circuit between the sender and receiver before any communications can occur (initially developed for voice communications)
This Is Known As Connection oriented
Packet switching network
(For Sending Data Only)
-No fixed path is created between the communicating devices (initially developed for data communications)
-Connectionless
-Will Be Faster & Cheaper
-Routes data packets from source to destination
Packet switching network have no guarantee that all data sent will be received everything, 1or 2 might lose
Guided transmission media types:
-Twisted Wire Pair
-Coaxial cable
-Fiber-optic Cable
Twisted-pair wire:
Classified by category: category 2, 3, 5, 5E, and 6
Coaxial cable:
Offers cleaner and crisper data transmission (less noise) than twisted-pair wire
Fiber-optic cable:
Transmits signals with light beams
Check at powerpoint 3 slide 13 for more info
Short Range Wireless Options
1.Near field communication (NFC) –
2.Bluetooth
3.Ultra wideband (UWB)
4.Infrared transmission
5.Zigbee
Medium-Range Wireless Options
1.Wi-Fi:
Wireless telecommunications technology brand owned by the Wi-Fi Alliance
2.Wireless access point:
-Consists of a transmitter with an antenna
-Receives the signal and decodes it
3.Wi-Fi access points(a form of wireless access point):
Have maximum range of about 300 feet outdoors and 100 feet within a dry-walled building
Wide Area Wireless Network Types
2.Wireless mesh:
Uses multiple Wi-Fi access points to link a series of interconnected local area networks
Computer Network
-Consists of communications media, devices, and software needed to connect two or more computer systems or devices
-Can transmit and receive information to improve organizational effectiveness and efficiency
Network Types
1.Personal area networks:
-Support interconnection of information technology within a range of about 33 feet
2.Local area networks:
-Connect computer systems and devices within a small area (e.g., office or home)
3.Metropolitan area networks:
-Connect users and their devices in a geographical area that spans a city
4.Wide area networks:
-Connect large geographic regions
- Personal area networks: Example Hotspot (It Doesn’t Support Far Range Or Many Devices) Because It Only Connects Short Range
- Local area networks: WIFI Network At Home (Networks Can Only Communicate Within the home/ within the office (one to one))
- Metropolitan area networks: Will Cover A City Size
- Wide area networks: Wider area
Basic Processing Alternatives
Centralized processing (Maintain Absolute Control):
All processing occurs in a single location or facility
Decentralized processing:
Processing devices are placed at various remote locations (independent)
Distributed processing:
Processing devices are placed at remote locations but are connected to each other via a network (a decision maker decides where to process)
File server systems(like shared folders on a network):
Users can share data through file server computing
Telecommunications Hardware
2.Modems:
Modulation(from digital to analog) /demodulation(from analog to digital) devices
3.Multiplexers:
Combine data from multiple data sources into a single output signal that carries multiple channels
4.Private branch exchange (PBX): (Almost Same As Intercomm)
-Telephone switching exchange that serves a single organization
-Must Have Lines
This is not only stops here but continues next
Telecommunications Hardware
1. Switch(Hub)
-They are the key building blocks for any network.
-They connect multiple devices, such as computers,wireless access points, printers, and servers; on the same network within a building.
-A switch enables connected devices to share information and talk to each other.
-Switches facilitate the sharing of resources by connecting all the devices, including computers, printers, and servers.
-with the switch, these connected devices can share information and talk to each other, regardless of where they are in a building.
-Building a business network is not possible without switches to tie devices together.
Short Key Point:
- Connecting devices
2.Sharing Information
3.Efficient Communication
4.Resource sharing
5.Network Expansion
This is not only stops here but continues next
Telecommunications Hardware
2.Router(Bridge):
-Routers connect computers & other devices to the internet
-Has the ability to forward IP packets(a package of data with an IP address) from one network to another
-Acts as a dispatcher, choosing the best route for the information to travel
-It connects user’s network to the world
-Protects information from security threats
-Decides which computers get priority over others
-Routers guide & direct network data
-Routers chooses the best route to use for each transmission
-Just as a switch connects multiple devices to create a network, a router connects multiple switches, and their respective networks, to form an even larger network.
-These networks may be in a single location or across multiple locations.
-When building a business network, you will need one or more routers.
-In addition to connecting multiple networks together, the router also allows networked devices and multiple users to access the Internet.
-A router works as a dispatcher, directing traffic and choosing the most efficient route for information, in the form of data packets, to travel across a network.
-A router connects your network to the world, protects information from security threats, and even decides which devices have priority over others.
Telecommunications Software
-Network operating system (NOS):
Systems software that controls the computer systems and devices on a network
-Network management software:
Locates telecommunications errors and potential network problems
1.Network Operating System
2.Network management software
- Systems software that controls the computer systems and devices on a network
2.Locates telecommunications errors and potential network problems
- Encryption
- Encryption Key
1.Converting an original message into a form that can only be understood by the intended receiver
2.Variable value that is applied (using an algorithm) to a set of unencrypted text to produce encrypted text or to decrypt encrypted text
Virtual Private Network (VPN)
Private network that uses a public network (usually the Internet) to connect multiple remote locations
Provides network connectivity over a potentially long physical distance
Supports secure, encrypted connections between a company’s private network and remote users
Global Positioning System
Global navigation satellite system that uses two dozen satellites roughly 11,000 miles above the earth
GPS receivers:
Have become as small as a cell phone and are relatively inexpensive
Are commonly found in automobiles, boats, planes, laptop computers, and cell phones
GPS tracking technology:
Has become the standard by which fleet managers monitor the movement of their cars
