This document discusses communications and networks. It introduces connectivity and how the wireless revolution has increased connectivity through mobile devices. It describes the basic elements of communication systems including sending/receiving devices, communication channels, connection devices, and data transmission specifications. The document outlines both physical wired connections like Ethernet cables and wireless connections like Wi-Fi, Bluetooth, and cellular networks. It also discusses connection devices, services, bandwidth, protocols, computer networks, network types, organizational networks, and security measures.

1. COMMUNICATIONS
AND NETWORKS
Texas A&M University Commerce

2. Introduction
 We live in a truly connected society.
 Increased connectivity potentially means increased productivity, especially in business.
 You will learn more about the concept of connectivity and the impact of the wireless
revolution in this chapter.

3. Communications
 Computer communications is the process of sharing data, programs, and
information between two or more computers
 Numerous applications depend on communication systems, including
 E-mail
 Instant messaging
 Internet telephone
 Electronic commerce
 Global positioning systems (GPS)

4. Communications Today
 Connectivity uses computer networks to link people and resources
 The Wireless Revolution
 Single most dramatic change in connectivity and communications has been widespread use of
mobile telephones with wireless Internet connectivity

5. Communication Systems
 Four basic elements
 Sending and receiving devices
 Communication channel
 Connection devices
 Data transmission specifications

6. Communication Channels
 Communication channels carry the data from one computer to another
 Two categories of communication channels
 Physical connection
 Wireless connection

7. Physical Connections
 Ethernet cable
(Twisted pair cable)
 Coaxial cable
 Fiber-optic cable

8. Wireless Connections
 Radio frequency (RF)
 Wi-Fi (wireless fidelity)
 Bluetooth (short-range)
 WiMax (extends Wi-Fi)
 Microwave
 Satellite
 Global positioning system (GPS)
 Infrared
 Cellular
 2G, 4G, 5G
 CDMA

9. Connection Devices
 Types of modems
 Telephone modem
 DSL (digital subscriber line)
 Cable modem
 Wireless modem (WWAN)

10. Connection Services
 Dial-Up services
 Uses phone lines
 Leased lines – T1
 Faster T3 and DS3
 Replaced by optical carrier (OC) lines
 Digital subscriber line (DSL)
 Uses phone lines
 ADSL is most widely used type of DSL
 Cable
 Uses existing TV cable
 Speeds as fast as DSL
 Satellite connection services
 Use almost anywhere
 Slower than DSL and cable modem
 Cellular Services
 Use 3G , 4G and 5G cellular network to
provide wireless connectivity

11. Bandwidth
 Measurement of the width or capacity of the communication channel
 Categories
 Voice band (or low bandwidth)
 Medium band
 Broadband
 Baseband

12. Protocols
 Communication rules for exchanging data between computers
 Internet standard: TCP/IP (Transmission control protocol/Internet protocol)
 Identification – unique IP address
 Packetization – broken down and reassembled

13. Networks
 A computer network is a communication system that connects two or more
computers
 Allows exchange of information and resources

14. Computer Networks
 Node
 Client
 Server
 Directory server
 Host
 Switch
 Network interface
cards (NIC)
 Network operating
systems (NOS)
 Network administrator

15. Network Types
 Local area network (LAN)
 Home network
 Wireless LAN (WLAN)
 Personal area network (PAN)
 Metropolitan area network (MAN)
 Wide area network (WAN)

16. Organizational Networks
 Intranets
 Private network within an organization Works like the Internet, where employees use browsers to
access Web sites and Web pages
 Extranets
 Private network that connects organizations Works like the Internet, but provides suppliers and other
trusted partners with limited access to the organization’s networks

17. Network Security
 Firewalls
 Combination of hardware and software
 Proxy server provides pass-through access
 Protects against external threats
 Intrusion detection systems (NIDS)
 Virtual private networks (VPN)
 Creates a secure private network connection between your computer and the organization

18. Questions
 Define and discuss connectivity, the wireless revolution, and communications.
 Identify and describe the various physical and wireless communication channels.
 Identify the standard Internet protocol and discuss its essential features.