Telecommunication

1
Telecommunication

• The exchange of information in any form (voice,
  data, text, images, audio, video) over networks

2
Trends in Telecommunications
3
Telecom Network Components

• Terminals any input/output device that uses
  telecommunications networks to transmit or
  receive data
• Telecommunications Processors devices that
  perform control and support functions
• Telecommunications Channels media over which
  data are transmitted and received
• Computers all sizes and types
• Telecommunications Control Software programs
  that control telecommunications activities

4
Telecom Network Components
5
Telecommunications Processors

• Modems convert digital signals from a computer
  into analog frequencies that can be transmitted
  over ordinary telephone lines
• Multiplexers allows a single communications
  channel to carry simultaneous data transmissions
  from many terminals

6
Bandwidth

• Information carrying capacity
• Measured in cycles per second/Hz.
• Indicates the difference between lowest and
  highest frequencies.
• Higher the bandwidth, greater the volume of data
  that can be transmitted per unit time.
• Narrow-band very low BW e.g. telegraph links.
• Voice Band- telephone line with a frequency range
  of 300-3400 Hz.
• Broadband high-speed high capacity. e.g.
  microwave, cable, fibre optics

7
Data Transfer Rate

• Amount of data that can be transmitted through
  the channel.
• Expressed in number of bits per second or bit
  rate (Bps).
• Baud rate - signal change from positive to
  negative or vice versa.
• - may not be always same as bit rate.

8
Types of Signals Analog and Digital

• Analog signal
• Continuous waveform
• Passes through communications medium
• Used for voice communications
• Digital signal
• Discrete waveform
• Transmits data coded into two discrete states as
  1-bits and 0-bits
• Used for data communications

9
Telecommunications Media

• Twisted-Pair Wire copper wire twisted into
  pairs. e.g. telephone system (300bps-10Mbps)
• Coaxial Cable sturdy copper or aluminum wire
  wrapped with spacers to insulate and protect it.
  e.g. Cable TV.
• - faster data rate (56 Kbps-200 Mbps), larger
  BW.
• Fiber Optics one or more hair-thin filaments of
  glass fiber wrapped in a protective jacket
• - Data transmitted using light beams.
• - Very high BW high data transmission rate (500
  Kbps- 25Tbps)

10
Telecommunications Media
11
Wireless Technologies

• Terrestrial Microwave data transmitted with the
  help of microwaves. Microwaves are
  electromagnetic waves with frequency in the range
  of 300,00 MHz to 3000MHz.
• Radio Waves also electromagnetic waves with
  low frequency range of 3KHz to 30MHz.
• Communications Satellites - high-earth orbit
  communications satellites placed in stationary
  geosynchronous orbits

12
Wireless Technologies

• Cellular and PCS Systems a geographic area
  divided into cells with one low-power transmitter
  device per cell used to relay calls from one cell
  to another
• Wireless LANs high- or low-frequency radio
  technology installed in an office or building
• Wireless Web wireless, Web-enabled information
  appliances accessing the Internet, intranets and
  extranets

13
Wireless Application Protocol (WAP)
14
Communication Subnet

• Switching devices- used for switching data
  signals from source to destination point.
• Telephone exchange- signals on incoming lines are
  transmitted to appropriate outgoing lines.
• Transmission lines- that carry data signals from
  one host to another .
• - also known as circuits or trunks.
• - speed as well as efficiency depend on the
  speed at which the transmission lines can
  transmit the data.
• - e.g. optical fibres, twisted pair, cable etc.

15
Switching Alternatives

• Circuit Switching a switch opens a circuit to
  establish a link between a sender and receiver
  it remains open until the communication session
  is completed.
• Packet Switching messages are divided into
  fixed or variable length packets, and packets are
  sent across networks.

16
Computer Networks

• Comprises of communication media, devices,
  software to connect two or more computer system.
• enable the companies to share H/W, computer
  applications, and databases across the
  organization.
• geographically dispersed employees and
  workgroups can share documents

17
Client and ServerNetworking

• Client- Machine that initiates the session with
  another computer and request for information.
• Server- computer that stores information and
  delivers the requested information

18
Network Topologies

• Bus all the networked devices share the same
  communications channel and connected to backbone
  by transceiver.
• Ring Ties local computer processors together in
  a ring.
• Star Ties end user computers to a central
  computer.

19
Network Topologies
20
Types of Telecom Networks

• Point-to-point Communication
• - point to point communication between two
  computers for data transmission.
• - e.g. computer networks in banks
• Broadcast Communication
• - All the machines on the network share a single
  communication channel.
• - message broadcasted for all receivers.
• Peer-to-Peer file-sharing software connects
  each PC to a central server or to another online
  users PC

21
Types of Telecom Networks

• Peer-to-Peer Networks
• Type of client/server distributed processing
  that allows two or more computers to share their
  resources.
• In a standard client/server networks,
  information stored in centralized file server
  Information stored across peer to peer networks
  is decentralized.

22
Peer to Peer Networks
23
Types of Telecom Networks

• Local Area Network (LAN)
• Network that connect devices sharing a common
  communication link and share resources within a
  limited geographical area.
• Serves a local area like floor of a building,
  college or university campus.
• Typical transmission speed is 100Mbps.
• Within the organization, provides fast and
  efficient access to common bank of information.

24
Local Area Networks
25
Local Area Networks

• Wireless LANs
• Wi-Fi (802.11b) standard Up to 11 Mbps, low
  cost, high-speed mobile Internet access, links
  work groups
• Bluetooth standard Up to 720 Kbps, small
  personal area networks

26
Types of Telecom Networks

• Wide Area Network (WAN)
• covers a large geographical area such as a state
  or a country.
• May include large corporate networks, military
  networks, banking networks, airline reservation
  networks etc.
• Typical transmission rates are 2Mbps, 34Mbps,
  45Mbps, 625Mbps etc.
• Often implemented in the form of VPN.

27
Types of Telecom Networks

• Virtual Private Network (VPN)
• Secure network that uses the Internet as its
  main backbone network
• Relies on network firewalls, encryption, and
  other security features.
• Effective for extranets and important for
  international businesses.

28
Types of Telecom Networks

• Metropolitan Area Network (MAN)
• Network that interconnects users with computer
  resources in a geographical area larger than that
  covered by LAN but smaller than a WAN.
• Covers an area between 5-50 Km diameter. (an
  area the size of a city).
• Generally owned by either group of users or a
  single network provider

29
Types of Telecom Networks

• Value Added Network (VAN)
• A private network that can be hired by
  organization.
• Enable the users to more closely tailor
  communication capabilities to their specific
  business needs.

30
Network Architectures Protocols

• Protocol standard set of rules and procedures
  for the control of communications in a network
• Network Architecture the use of standard
  protocols, standard communications hardware and
  software interfaces standard interface between
  end users and computer systems
• - the goal of promoting an open, simple,
  flexible, and efficient telecommunications
  environment

31
OSI TCP/IP Models

• Open Systems Interconnection (OSI) - model is a
  seven-layer model that serves as a standard model
  for network architectures
• Transmission Control Protocol / Internet Protocol
  (TCP/IP) is a five layer telecommunications
  protocol used by the Internet

32
OSI TCP/IP Models
33
Internet

• A network made up of millions of smaller private
  networks, each operate independent of, or in
  harmony with, all the other millions of networks
• Surf
• E-mail
• Buy and sell
• Download
• Publish

34
Business Value of Telecommunications
35
E- Commerce and E-Business Technologies

• Teleconferencing Ability to confer with a group
  of people simultaneously
• Data conferencing Two or more users can edit and
  modify data files simultaneously
• Videoconferencing Participants are able to see
  each other over video screens

36
Electronic Commerce and Electronic Business
Technologies

• Distance learning Education or training
  delivered over a distance to individuals in one
  or more locations
• E-learning Instruction delivered online using
  the Internet or private networks

37
Summary

• Organizations are becoming networked enterprises
  using the Internet, intranets, and other
  telecommunications networks to support business
  operations and collaboration.
• Telecom technology is moving toward open,
  inter-networked digital networks for voice, data,
  video and multimedia

38
Summary

• Open systems with unrestricted connectivity
  using Internet technologies are the primary
  telecommunications technology drivers in
  e-business systems.
• Companies are deriving strategic business value
  from the Internet, intranets etc. which enables
  them to disseminate information globally

39
Summary

• Businesses are installing and extending intranets
  throughout their organizations to
• Improve communications and collaboration among
  individuals and teams within the enterprise
• Publish and share valuable business information
  easily, inexpensively, and effectively via
  enterprise information portals
• Develop and deploy critical applications to
  support business operations and decision making

40
Summary

• The major generic components of any
  telecommunications network are
• Terminals
• Telecommunications processors
• Communications channels
• Computers
• Telecommunications software