1. Telecommunications
Telecommunications refers to the electronic transmission and reception of signals for voice and data communications.
In this chapter:
Infrastructure
Cellular Network
Wireless Data Communications
Computer Network
Concepts > Telecommunications

2. Telecommunications Infrastructure
In telecommunications, infrastructure refers to the hardware, software, and protocols that support telecommunications.
In this section:
Telecommunications Signals
Telecommunications Media
Radio Spectrum
Telecommunications Devices
Telecommunications Software
Concepts > Telecommunications > Telecommunications Infrastructure

3. Telecommunications Signals
Telecommunications signals are analog or digital electronic transmissions for the purpose of communication.
Data transmission rate is also referred to as the bandwidth and is measured in bits per second (bps). Bandwidth options fall into two categories: narrowband or broadband.
The terms broadband and high-speed Internet refer to a connection that is always on or active, such as cable and DSL.
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Concepts > Telecommunications > Telecommunications Infrastructure > Telecommunications Signals

4. Telecommunications Media
Telecommunications media include anything that carries a signal and creates an interface between a sending device and a receiving device.
Twisted pair copper cable consists of pairs of twisted wires covered with an insulating layer.
A coaxial cable consists of an inner conductor wire surrounded by insulation, a conductive shield, and a cover.
In contrast, fiber-optic cable, which consists of thousands of extremely thin strands of glass or plastic bound together in a sheathing (a jacket), transmits signals with light beams.
Concepts > Telecommunications >Telecommunications Infrastructure > Telecommunications Media

5. Radio Spectrum
Radio spectrum, part of the electromagnetic spectrum, refers to all of the frequencies available for radio waves from about 10 KHz to 300 GHz and their assigned uses.
All wireless telecommunications—cell phones, wireless Internet, AM and FM radio—make use of radio waves designated to certain frequencies.
Concepts > Telecommunications > Telecommunications Infrastructure > Radio Spectrum

6. Telecommunications Devices
Telecommunications devices such as routers, network adapters, Wi-Fi access points, cellular towers, and satellites send and receive the signals employing telecommunications software that governs their operations.
Network devices
Hub
Switch
Repeater
Bridge
Gateway
Modem (various)
Router
Wireless access point
Firewall
Point/router/switch Satellite Cell Tower
A modem is a device that modulates and demodulates signals from one form to another.
Concepts > Telecommunications > Telecommunications Infrastructure > Telecommunications Devices

7. Telecommunications Software
Telecommunications software is software based on telecommunications protocols used to
control
monitor load (amount of traffic)
troubleshoot data
provide security
traveling over a telecommunications network.
Concepts > Telecommunications > Telecommunications Infrastructure > Telecommunications Software

8. Telecommunications Software
Network operating systems (NOS)
Network management software
monitor the use of individual computers and shared hardware, scan for viruses, and ensure compliance with software licenses.
Telecommunications devices software interfaces
Firewall software
Standards
Ethernet is the most widely used network standard for private networks. This standard defines the types of network interface cards, control devices, cables, and software required to create an Ethernet network.

9. Cellular Network
A cellular network is a radio network in which a geographic area is divided into cells with a transceiver antenna (tower) and station at the center of each cell, to support wireless mobile communications.
In this section:
Cellular Carrier
Cellular Plans
Cellular Services
Cellular Handset
Pager
Concepts > Telecommunications > Cellular Network

10. Cellular Carrier
A cellular carrier is a company that builds and maintains a cellular network and provides cell phone service to the public.
Global System for Mobile Communications (GSM) is the most popular international standard for mobile phones.
The Code Division Multiple Access (CDMA) networking standard is predominantly used in the United States, where it is in equal competition with GSM.
Concepts > Telecommunications > Cellular Network > Cellular Carrier

11. Cellular Plans
If two plans from different carriers seem roughly comparable in terms of features, you should view the coverage map of both carriers and examine their handsets and services.
A cellular plan defines the terms of service provided by a cellular carrier to which a cellular user subscribes.
Concepts > Telecommunications > Cellular Network > Cellular Plans

12. Cellular Services
Cellular services include specific features of a cell phone plan other than voice communication, which is assumed, such as text messaging, high-speed Internet, and streamed media.
Examples of Cell Phone Add-on Services:
Data plan
Text messaging
Internet communications
Push to talk
Games
Media
Concepts > Telecommunications > Cellular Network > Cellular Services

13. Cellular Handset Cell Phone Form Factors Bar Clamshell Flip Slide
Swivel
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Cellular handset, or cell phone, refers to the phone used by the subscriber to communicate on the cellular network.
Concepts > Telecommunications > Cellular Network > Cellular Handset

14. Wireless Data Communications
Wireless data communications refers to telecommunications that take place over the air for data and Internet access.
In this section:
Wi-Fi
WiMAX
Long Term Evolution (LTE)
Bluetooth
RFID
GPS
Concepts > Telecommunications > Wireless Data Communications

15. Wi-Fi
Wi-Fi (wireless fidelity) is networking technology that uses access points to wirelessly connect users to networks within a range of 250–1000 feet (75–300 meters).
Areas around access points where users can connect to the Internet are called hotspots.
Positioning access points at strategic locations throughout a building, campus, or city, Wi-Fi users can be continuously connected to the local area network (LAN) and Internet, no matter where they roam on the premises.
Concepts > Telecommunications > Wireless Data Communications > Wi-Fi

16. WiMAX
WiMAX is being proposed as a solution to the “last mile” problem. The last mile refers to the part of a telecommunications network that connects to residences and businesses—the part of the network other than the backbone.
WiMAX, which stands for Worldwide Interoperability for Microwave Access (aka IEEE ) is a so-called fourth-generation wireless broadband technology that evolved from Wi-Fi to provide faster Internet access at a longer range.
Concepts Telecommunications > Wireless Data Communications > WiMAX

17. Long Term Evolution (LTE)
Long Term Evolution (LTE) is a fourth-generation wireless broadband technology that was developed to allow GSM cellular technology to evolve to provide very high-speed Internet access.
Concepts > Telecommunications > Wireless Data Communications > Long Term Evolution (LTE)

18. Bluetooth
Bluetooth enables a wide assortment of digital devices to communicate directly with each other (in pairs) wirelessly over short distances.
Some Bluetooth-Enabled Devices:
PCs
Printers
Keyboards and mice
Headphones and headsets
Speakers
Mobile phones
Digital cameras
MP3 players
Automobiles
Microwave ovens
Refrigerators
Washers and dryers
A number of cell phone viruses have spread through Bluetooth. An open Bluetooth connection on a computer can be used by a hacker to access files on the computer. KEEP IT OFF, WHEN NOT IN USE.
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Concepts > Telecommunications > Wireless Data Communications > Bluetooth

19. RFID
RFID, or radio frequency identification, uses tiny transponders in tags that can be attached to merchandise or other objects and read wirelessly using an RFID reader, typically for inventory management to facilitate commercial transactions.
Privacy advocates concerned that RFID could be used by governments and law enforcement agencies in ways that infringe on people’s privacy and civil liberties.
Concepts > Telecommunications > Wireless Data Communications > RFID

20. GPS
GPS receivers provide navigation assistance and are also playing a part in social networking. Geotagging is the process of adding geographic identification metadata to digital media and messages.
A GPS, or global positioning system, uses satellites to pinpoint the location of objects on earth.
Concepts > Telecommunications > Wireless Data Communications > GPS

21. Pager
A pager is a small, lightweight device that receives signals from transmitters for the purpose of communications and messaging.
On-site paging systems are finding a variety of uses in businesses and organizations, including restaurants and emergency rooms.
National and regional systems set up transmission towers, much like cell phone networks, to cover large geographic areas.
Concepts > Telecommunications > Cellular Network > Pager

22. Computer Networks
A computer network is a collection of computing devices connected together to share resources such as files, software, processors, storage, printers, and Internet connections.
In this section:
Personal Area Network (PAN)
Home Network
Local Area Network (LAN)
Wide Area Network (WAN)
Concepts > Telecommunications > Computer Network

23. Computer Networks
Devices attached to a network are called nodes. Personal computers attached to a network are often called workstations.
Local resources are files, drives, printers or other peripheral devices connected directly to the workstation. Remote resources are resources that the workstation accesses over the network.
A system administrator is a person responsible for setting up and maintaining the network, implementing network policies, and assigning user access permissions.
Networks are classified by size in terms of the number of users they serve and the geographic area they cover.

24. Personal Area network (PAN)
A personal area network (PAN) typically covers a range of around 33 feet or 10 meters.
Bluetooth technology allows personal devices to communicate without wires, sharing data, media streams, phone conversations, and all types of information.
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A personal area network (PAN) is the interconnection of personal information technology devices, typically wirelessly, within the range of an individual.
Concepts > Telecommunications > Computer Network > Personal Area Network (PAN)

25. Home Network
A home network is a local area network designed for personal or business use in the home.
Home networks allow users to:
Share a single Internet connection
Share a single printer
Share files
Back up important files to another PC
Participate in multiplayer games
Stream music and movies from a computer to devices around the house
Concepts > Telecommunications > Computer Network > Home Network

26. Local Area Network (LAN)
A local area network (LAN) is a privately owned computer network that connects computers and devices within the same building or local geographic area.
In an intranet, a Web server provides confidential data to LAN users, while keeping the data safe from those outside the organization through the use of a firewall.
Concepts > Telecommunications > Computer Network > Local Area Network (LAN)

27. Virtual Private Network (VPN)
A virtual private network (VPN) is a network that uses primarily public telecommunication infrastructure, such as the Internet, to connect an organization’s networks dispersed around the world into one large intranet.
Content can be extended to specific individuals outside the network, such as customers, partners, or suppliers, in an arrangement called an extranet.
VPNs typically require remote users of the network to be authenticated, and often secure data with encryption technologies.
Concepts > Telecommunications > Computer Network > Wide Area Network

28. Wide Area Network (WAN)
A wide area network (WAN) connects LANs and MANs between cities, across a country, and around the world using microwave and satellite transmission or telephone lines.
A WAN that crosses an international border is considered a global or international network.
A LAN becomes a WAN when it extends beyond one geographic location to another geographic location.
Concepts > Telecommunications > Computer Network > Wide Area Network