1. Telecommunications and Networking
Chapter 4
Telecommunications and Networking

2. Chapter Objectives
To understand the basic performance characteristics of telecommunications and networking technologies.
To have an appreciation for the trends in telecommunications technologies and how they influence technology options and decisions.
To understand how it is possible to view telecommunications as an enabler of organizational communications.
To appreciate the potential for distortion in organizational communications, and how information and telecommunication technologies may help to reduce distortion.

3. Organizational Communication
Communication is the sharing of information between two or more entities.
Organizational Communication is the sharing of information related to an organization activity between two or more individuals or organizational units.
Sharing of information implies, collection, analysis, and transmission of information.
Formal and Informal Communication

4. Communication Dyads
A communication network is made of a series of communication dyads.
A dyad consists of
Sender
Receiver
Message
Channel
Medium

5. Distortion in Communication
Communication Distortion is the transformation of the meaning of a message by intentionally or unintentionally altering its content.
Lost
Destroyed
Modified or Altered
Noise consists of disturbances in the communication process that interferes with the intended effect of the message.

6. Types of Distortion Distortion Intentional Unintentional
Routing – the message gets routed to the wrong receiver or not at all.
Delaying the message
Modifying it the content of the message
Summarizing
Intentional
Unintentional

7. Distortion Type Intentional Unintentional Routing
Sending a message to wrong person; news leaks
Not knowing where to send message; sending to wrong address
Delaying
Purposely waiting for a deadline to go by
Not being able to send message due to overload
Modifying
Changing the message; destroying data
Forgetting to include some material in message
Summarizing
Leaving negative data out
Not having time to integrate all available material

8. Analog and Digital Data
Analog signals are transmitted as sound waves along a channel such as a copper telephone wire
Digital signals are transmitted as a series of bits or on/off signals
A modem converts digital signals into analog signals and another modem can be used to convert analog signals back to digital signals.
See Figure 4.6

9. Telecommunications Voice communications require:
A source device
A switching system
A data channel
A destination device
Data communications is used to refer to telecommunications involving computerized data.
Data traffic on the Internet doubles every 100 days.

10. Data Channels
Bandwidth is used to describe the capacity of a communications medium
bps, bits per second
kHz, kilohertz and MHz, megahertz
Narrowband (transmission speeds of 64 kbps or less)
Wideband (transmission speeds between 64 kbps and Mbps)
Broadband (transmission rates of Mbps or higher)

11. Data Channels Wireline Wireless Twisted pair copper
Coaxial cable (cable television)
Fiber-optic cable
Wireless
Infrared light
Cellular telephone (analog or digital)
Microwave
Satellite (geostationary or low-earth)

12. Communication Protocol
A communication protocol is essentially a set of codes or conventions used for facilitating communications between hardware and software.
IP or Internet Protocol directs packets on the Internet.
TCP or Transmission control protocol puts the packets in their correct sequence.
HTTP or hyper text transfer protocol is used to transmit web pages over the Internet.
Mobile IP provides IP routing for mobile devices.

13. Telecommunications
ISDN or Integrated Services Digital Network is a set of standards that provide additional capabilities for copper wire.
DSL or digital subscriber line technology refers to a a group of methods for transmitting at speeds up to 8 Mbps over copper wire.
Cable Modems allow transmission of Internet traffic through the cable TV network.

14. Telecommunications
T-carrier systems are digital transmission systems that take analog voice circuits and converts them to digital form for transmission. Companies typically lease T lines.
Frame relay carries data packets over the system that vary in length and are referred to as frames.
Fast Ethernet is a protocol that was designed originally local area networks.

15. Networks
A computer network is used to connect multiple uses and computing devices together, using telecommunications technologies.
Three classes of networks
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Two types of networks
Server-based networks
Peer-to-peer networks

16. LAN Components LANs employ both wireline and wireless communications
Twisted pair cable, Coaxial cable, & Fiber optical cable
Wireless
Infrared light, & Radio waves
A bridge connects two networks of the same type
A router connects several networks
A gateway is used to connect different types of networks.

17. Music Industry Napster and Gnutella Morpheus and KaZaA
Allow users to swap files using file sharing software.
Napster allowed a users machine to become a client in a server-based network.
Gnutella allows users to share files via a peer-to-peer network.
Morpheus and KaZaA
Tried peer-to-peer but still needed a central web server to provide service.

18. LAN Protocols
Network communications are facilitated by some type of protocol.
Ethernet
Data are moved at 10 Mbps
Fast Ethernet
Data are moved at 100 Mbps
Giga Ethernet
Data are moved at 1 Gbps

19. LAN Protocols Other Network Protocols Token ring protocol
Used in wired LANs
IEEE (WI-FI)
Several variations designed for used in medium range, higher data rate applications.
Range less than 150 yards and 22 Mbps are possible.
Bluetooth is a radio frequency technology designed to provide wireless connectivity to a broad range of devices.
Uses less power than most wireless LAN technologies
Named for Danish King

20. LAN Topologies
Topology is the configuration of the LAN (See Figure 4.15)
Star, Ring, Bus
Performance can be measured by the mode of the connection.
Simplex transmission, messages can be carried in only one direction.
Half-duplex, messages can be carried in both directions just not simultaneously.
Full-duplex, messages can be carried in both directions simultaneously.

21. Intranets and Extranets
An Intranet is a controlled, self contained grouping of information resources that can be accessed using Web browsers.
An Extranet is similar to an Intranet but is designed to facilitate communications between two or more business partners.