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7Chapter
Telecommunications, the
Internet, and Wireless
Technology
LEARNING OBJECTIVES
• Identify the principal components of telecommunications
networks and key networking technologies.
• Describe the main telecommunications transmission media
and types of networks.
• Explain how the Internet and Internet technology work and
how they support communication and e-business.
• Identify the principal technologies and standards for
wireless networking, communication, and Internet access.
• Assess the value to business of radio frequency
identification (RFID) and wireless sensor networks.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Virgin Megastores Keeps Spinning with Unified Communications
• Problem: 1400 employees in 11 retail locations; slow resolutions of business issues because of cost of conference calls
• Solutions: Implement unified communications to integrate voice mail, e-mail, conference calling, instant messaging
• Microsoft’s Office Communication Server, Office
Communicator, RoundTable conferencing and
collaboration tools
• Demonstrates IT’s role in hastening communication
and flow of information
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
• Networking and communication trends
• Convergence:
• Telephone networks and computer networks converging
into single digital network using Internet standards
• Cable companies providing voice service
• Broadband:
• More than 60% of U.S. Internet users have broadband
access
• Broadband wireless:
• Voice and data communication as well as Internet access
are increasingly taking place over broadband wireless
platforms
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Components of data communication
What is Data ?
• Data is a collection of facts, such as values or measurements.
• It can be numbers, words, measurements, observations or even
just descriptions of things.
• Data can exist in a variety of forms -- as numbers or text on
pieces of paper, as bits and bytes stored in electronic memory,
or as facts stored in a person's mind.
• Data is the plural of datum, a single piece of information.
DATA COMMUNICATION
Data communication is the transfer of information between two points, either
via an analogue (sine wave) electrical signal or digital (binary ) signal via
electrical pulses or optically via light pulses.
High speed data exchange between computers and/or other
electronic devices via cable or wireless.
Data Transmission Modes
There are three modes of transmitting data fromone point to another. These are :
• Simplex
• Half-duplex OR
• Full-duplex
AND
SenderReceiv
er
Sender(or
Receiver)
Receiver(or
Sender)
Sender(and
Receiver)
Receiver(and
Sender)
COMPONENTS
The main components of data communication system are:
• Message
• Sender
• Receiver
• Medium
MESSAGE
• Message may exist in several different forms. It could be sound, light, picture, text, video etc.
• A message is information which is sent from a source to a receiver.
Transmitter
A transmitter is the agent, which could be a
human or a machine, that actually wishes to
transmit the data/ information to a recipient is
called the transmitter or sender.
Receiver
Receiver is the component that collects the coded message
from the communication channel. This piece of data is still not
in the form of the original message.
Medium
Once signal corresponding to the message is obtained, an end-
to-end medium is required through which the signal may travel
from the sender to the other end.
Transmission Medium
• Provides the path for data communication.
• Allows a bit stream to be transported from one machine to another.
Twisted Pair Cable
Coaxial Cable
Optical Fiber Cable
MEDIA ADVANTAGES DISADVANTAGES
Twisted Pair Cables
Coaxial Cable
Optical Fiber Cable
Inexpensive, wellestablished.
High bandwidth, long distances.
Very high bandwidth, long distances, high security,
small size.
Sensitive to noise, short distances, security hazard because of easy
interception.
Security is better in comparison to twisted
pair cable.
Connections Cost.
• What is a computer network?
• Two or more connected computers
• Major components in simple network
• Client computer
• Server computer
• Network interfaces (NICs)
• Connection medium
• Network operating system
• Hub or switch
• Router
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
Components of a Simple Computer Network
Figure 7-1
Illustrated here is a very simple computer network, consisting of
computers, a network operating system residing on a dedicated
server computer, cabling (wiring) connecting the devices, network
interface cards (NIC), switches, and a router.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
What is a Computer Network?
A network is a collection of computers, printers, routers, switches, and other
devices that are able to communicate with each other over some
transmission media.
Types of Networks
There are two basic types of networks currently in existence:
A Local Area Network (LAN)
A Wide Area Network (WAN)
Local Area
Networks
(LAN)A Local Area Network (LAN) is a group of computers and
network communication devices within a limited geographic area,
such as an office building. No third party involvement here.
They are characterized by the following:
• High data transfer speeds
• Generally less expensive technologies
• Limited geographic area
Wide Area
Networks
(WAN) A Wide Area Network (WAN) interconnects LANs. It is not
restricted to a particular geographic area and may be
interconnected around the world. Third party network is involved.
They are characterized by the following:
• Multiple interconnected LANs
• Generally more expensive technology
• More sophisticated to implement than LANs
• Exist in an unlimited geographic area
• Less error resistance due to transmission travel distances
Common LAN Topologies
Bus Architecture In a bus topology:
• a single cable connects each
workstation in a linear, daisy-chained
fashion.
•signals are broadcasted to all
stations, but stations only act on the
frames addressed to them.
Ring Architecture•In a ring topology:
•Unidirectional links connect the
transmit side of one device to the
receive side of another device.
•Devices transmit frames to the next
device (downstream member) in the
ring.
Star Topology
In a star topology, each station is connected to a central
hub or concentrator that functions as a multi-port
repeater. Each station broadcasts to all of the devices
connected to the hub. Physical LAN topologies are
usually characterized as either bus or ring.
LAN Transmission Methods
LAN transmission methods fall into 3 main categories:
• Unicast transmission
• Multicast transmission
• Broadcast transmission
Unicast Transmission
Unicast Process
• The source addresses
the packet with the
destination address.
• The packet is sent into
the network.
• The network delivers the
packet to the destination.
In unicast transmissions, a single data packet is sent from a source to a
single destination on the network.
Multicast Transmission
Multicast Process
• The source addresses the packet
using a multicast address.
• The packet is sent into the
network.
• The network copies the packet.
• A copy is delivered to each
destination that is included in the
multicast address.
In multicast transmissions, a single data packet is copied and sent to
specific destinations on the network
Broadcast Tranmission
In Broadcast transmissions, a single data packet is copied and sent to all
destinations on the network
Broadcast Process
• The source addresses the packet with the broadcast address.
• The packet is sent into the network.
• The network copies the packet.
• The packet copies are delivered to all destinations on the
network.
Uses of Computer Networks
• Resource Sharing: Many organizations have large number ofsubstantial computers in operation often located far apart. Letus consider an example, a company having many factoriessituated at different locations. A computer at each location(that is in each factory) keeps the track of inventories, monitorproductivity and do the local pay roll. Initially each of thesecomputers may have worked in isolation from each other, butat some point, the management may have decided to connectthese computers to be able to extract and correlate theinformation of the entire company.
The issue here is resource sharing. Its goal is to make all theprograms, equipments, especially data available to anyone onthe network irrespective of the location of the resource andthe user.
• High Reliability: The second goal or use ofnetworking in companies is to high reliability byhaving alternative sources of supply. For example allthe files can be replicated on two or more machines,so that in case one of them is not available (due tohardware failure), other copies can be used. Thisfeature is used in financial institutions.
• Scalability: Another goal is scalability. Scalability isthe ability to increase the system performancegradually as the workload grows, by just adding moreprocessors.
• Saving Money: The third goal is to save money. Smallcomputers often have better price/performance ratiothan the larger ones. Mainframe (room-size) computersare roughly ten times faster than the personalcomputers, but are a thousand times costly. Thisimbalance caused the system designers to design asystem consisting of personal computers, one per user,with data kept on one or more shared file servermachines. In this model the user are called the clientsand this whole arrangement is known as the client-servermodel.
In client-server model, the communication generallytakes the form of a request message from a client to thereceiver asking for some work to be done. Server doesthe work and sends back the reply.
• Access to Remote Information: Access to remoteinformation occurs in many forms. One of the areaswhere it is happening is access to the financialinstitutions. Many people pay their bills, managebank accounts and handle investments electronically.Home shopping is also becoming popular these days.
Another application that falls under this category isthe access to information systems like World WideWeb which contains information about art, business,history, government, geography, economics andseveral other topics.
All the above applications involve the interactionbetween the user and a remote database.
• Person to Person Communication: Electronic Mailpopularly known as email is widely used by millionsof people to send text messages, photographs audioas well as video to other people or group of people.This application belongs to person to personcommunication category.
Videoconferencing is also becoming popular thesedays. This technology makes it possible to havevirtual meetings among far flung people. It is also atype of person to person communication.
• Interactive Entertainment: These days we cansee many live programmes and shows. Thebest thing is that we can interact with them byparticipating in the quizzes and the contestsorganized by them.
• File sharing: Have you ever needed to access afile stored on another computer? A networkmakes it easy for everyone to access the samefile and prevents people from accidentallycreating different versions.
• Printer sharing: If you use a computer, chances areyou also use a printer. With a network, severalcomputers can share the same printer. Although youmight need a more expensive printer to handle theadded workload, it's still cheaper to use a networkprinter than to connect a separate printer to everycomputer in your office.
• Communication and collaboration: It's hard forpeople to work together if no one knows whatanyone else is doing. A network allows employees toshare files, view other people's work, and exchangeideas more efficiently. In a larger office, you can usee-mail and instant messaging tools to communicatequickly and to store messages for future reference.
• Organization: A variety of scheduling softwareis available that makes it possible to arrangemeetings without constantly checkingeveryone's schedules. This software usuallyincludes other helpful features, such as sharedaddress books and to-do lists.
Networking Hardware
• NICs
• Repeaters and Hubs
• Switches
• Routers
• Bridges
• Brouter
• Gateway
• Modems
• ISDN Adaptors
• CSU/DSU
• Network Example
NICs
• Network interface cards (also called NICs, network adapters,LAN Card or network cards) are connectivity devices thatenable a workstation, server, printer, or other node toreceive and transmit data over the network media.
• Nearly all NICs contain a data transceiver, the device thattransmits and receives data signals.
• NICs belong to both the Physical layer and Data Link layer ofthe OSI Model, because they apply data signals to the wireand assemble or disassemble data frames.
• In addition, they perform the routines that determine whichnode has the right to transmit data over a network at anygiven instant
Repeaters and Hubs
• Repeaters operate in the Physical layer of the OSI Modeland, therefore, have no means to interpret the data theyretransmit.
• They simply regenerate a signal over an entire segment.
• A repeater contains one input port and one output port,so it is capable only of receiving and repeating a datastream
• Repeaters are suited only to bus topology networks
• The advantage to using a repeater is that it allows you toextend a network inexpensively
Repeaters and Hubs
• A hub is a repeater with more than one output port.
• A hub typically contains multiple data ports intowhich the patch cables for network nodes areconnected.
• A hub accepts signals from a transmitting node andrepeats those signals to all other connected nodes ina broadcast fashion
Switches
• Switches are connectivity devices thatsubdivide a network into smaller logicalpieces, or segments.
• Switches operate at the Data Link layer of theOSI Model, while more modern switches canoperate at Layer 3 or even Layer 4.
• Switches interpret MAC address information
• Because they have multiple ports, switches canmake better use of limited bandwidth.
• Each device connected to a switch effectivelyreceives its own dedicated channel to the switch.
• From the Ethernet perspective, each dedicatedchannel represents a collision domain.
• Because a switch limits the number of devices in acollision domain, it limits the potential for collisions.
• By their nature switches provide better security thanmany other devices because they isolate onedevice's traffic from other device’s traffic
• Connecting a workstation to a switch
• A switch on a small network
Switches Contd….
• Switches differ in the method of switching they use:1. Cut-through mode2. Store and forward mode
Cut-Through Mode
• A switch running in cut-through mode reads a frame's headerand decides where to forward the data before it receives theentire packet.
• What if the frame becomes corrupt? Because the cut-through mode does not allow the switch to read the framecheck sequence (FCS) before it begins transmitting, it can'tverify data integrity in that way.
Store and Forward Mode
• In store and forward mode, a switch reads the entiredata frame into its memory and checks it foraccuracy before transmitting the information.
• Although this method is more time-consuming thanthe cut- through method, it allows store and forwardswitches to transmit data more accurately.
• Store and forward mode switches are moreappropriate for larger LAN environments, becausethey do not propagate data errors.
Routers
• A router is a multiport connectivity device thatdirects data between nodes on a network.
• Routers can integrate LANs and WANs running atdifferent transmission speeds and using a variety ofprotocols.
• When a router receives an incoming packet, it readsthe packet's logical addressing information.– Based on this, it determines to which network the packet
must be delivered.– Then it determines the shortest path to that network.– Finally it forwards the packet to the next hop in that path.
• A router's strength lies in its intelligence.
• Not only can routers keep track of thelocations of certain nodes on the network, asswitches can, but they can also determine theshortest, fastest path between two nodes.
• For this reason, and because they can connectdissimilar network types, routers arepowerful, indispensable devices on largeLANs and WANs.
• The Internet, for example, relies on amultitude of routers across the world
• A typical router has an internal processor, an operatingsystem, memory, input and output jacks for different types ofnetwork connectors (depending on the network type), and,usually, a management console interface.
Hub versus Switch
• Hub provide connection to all ports (i.e. in oneport and out all other ports).– Passive hub – no signal regeneration
– Active hub – provide signal regeneration
• Switch direct the message from appropriateport (directs a message from the input port tothe desired output port).– More expensive but better bandwidth utilization
Hub versus Switch
Bridge
• Connects two LAN segments to make one largercontinuous LAN
• Filters LAN traffic to keep local traffic.
• Allows connectivity to other parts of the LAN
• Simple to install and manage—costs less than router
• Checks MAC address to make forwarding decisions
• Considered layer 2 device
Bridge – Access Point (WLAN)
Brouter
• Network bridge and router combinedtogether to form a device known asbrouter.
Gateway• A gateway is a network point that acts as an entrance to
another network. On the Internet, a node or stopping pointcan be either a gateway node or a host (end-point) node. Boththe computers of Internet users and the computers that servepages to users are host nodes, while the nodes that connectthe networks in between are gateways. For example, thecomputers that control traffic between company networks orthe computers used by internet service providers (ISPs) toconnect users to the internet are gateway nodes.
• In the network for an enterprise, a computer server acting asa gateway node is often also acting as a proxy server and afirewall server. A gateway is often associated with both arouter, which knows where to direct a given packet of datathat arrives at the gateway, and a switch, which furnishes theactual path in and out of the gateway for a given packet.
Modem
• Allows modems of different vendors tooperate together
• Define How modems operate:
– Modulation techniques
– Data compression technique
– Error detection strategy
– Parallel to Serial and vice versa
• Analog
– Infinite number of levels
– Conform to voice pattern
– Times from highest to lowest and back to the highest point in one second is the frequency
– Can be transmitted over long distance
• Digital
– Only two levels (high and low)
– Conforms to how computers operate
– Cannot transmitted over long distance
Modem - Connection
Modem – Internal/External
ISDN Adaptors
• ISDN (Integrated Services Digital Network) is a datacommunication method and it is used over theregular telephone lines. To use the ISDN lines, youneed to install add-on adapters known as ISDNterminal adapters. ISDN Terminal Adapter works likea digital modem i.e. it converts the signals fromdigital to analog and vice versa. ISDN Terminaladapter is plugged into the serial port of thesystem. Some ISDN adapters have the feature ofswitching between digital and analog modes.
CSU/DSU
• CSU/DSU stands for channel service unit and dataservice unit. CSU is used to connect a terminal to adigital line. DSU is used to perform the protectiveand diagnostic functions of the telecommunicationline. CSU/DSU is a network device of the size of anexternal modem. The Channel service unit receivesand transmits the signals from the wide areanetwork line. CSU/DSU are two separate devices andthey are sometimes used in conjunction with the T1LAN cards.
Network Example
Network Software• Network Software is a set of primitives that define the protocol
between two machines. The network software resolves an ambiguityamong different types of network making it possible for all themachines in the network to connect and communicate with oneanother and share information.
• Network software is the information, data or programming used tomake it possible for computers to communicate or connect to oneanother.
• Network software is used to efficiently share information amongcomputers. It encloses the information to be sent in a “package” thatcontains a “header” and a “trailer”. The header and trailer containinformation for the receiving computer, such as the address of thatcomputer and how the information package is coded. Information istransferred between computers as either electrical signals in electricwires, as light signals in fiber-optic cables, or as electromagnetic wavesthrough space.
Networks provide computer users aconvenient way to transfer files acrossdata connections. Secured networksrequire a user name and password inorder to connect your computer to thenetwork. Unsecured networks do notneed any authentication. All types ofnetworks need software to interface withthe network and begin communicationand data transfer.
• Home Software : Setting up a network using the Ciscosoftware Network Magic Pro is easy; the software wasprogrammed with novice computer users in mind. Tasks suchas creating secured Internet connections, sharing digitaldevices such as cameras and printers and monitoring Webaccess are all controlled through the software's maininterface. This software is ideal for entry-level computerusers.
• Free Software : Spiceworks provides a budget-friendly optionfor individuals who want a network management softwarepackage. The software is free and offers many of the samefeatures as other software packages available for sale. Thissoftware package was intended to be used within small tomedium sized businesses. The few of the key features are theability to inventory everything on your network, run an ITHelpdesk and Map the Network.
• Monitoring Tools : Networks are often damaged from burntpower supplies, servers crashing, low bandwidth and evenattacks from computer hackers. Computer hackers are expertsin network administration, but the appropriate software willstop hackers dead in their tracks. The software Monitor Toolsprovides a central location to monitor and maintain all thesepotential trouble spots. The software will tell you of possiblesystem issues and provide quick suggestions for the resolutionof each problem as it arises.
• Application Performance : Network administrators aresometimes charged with the sole task of monitoringapplication performance, for example, making sure that filesare sent immediately and are successfully delivered on thereceiving end. Orion APM is a software package that focusesexclusively on application monitoring, ensuring all networksystems are running as quickly as possible.
• Warning : Choosing to set up a security system foryour wireless network is a decision to be takenseriously. A wireless network places your computerfiles at the fingertips of anyone within the broadcastrange of your wireless router. Personal informationsuch as Social Security numbers and credit cardsshould always be stored behind the protection ofcertified network security software. Once yournetwork is set up, and your files are secured, routinebackups of any important files should be createdonto hard drives, DVDs or other external storagemedium. The only way to be absolutely certain yourfiles are safe is to have a hard copy stored outsidethe network; if the network fails and data is lost, youwill be certain your important files are still safe.
Network Model Overview
In order for a computer to send information to another computer, and for that
computer to receive and understand the information, there has to exist a set
of rules or standards for this communication process. These standards
ensure that varying devices and products can communicate with each other
over any network. This set of standards is called a model.
Network Model Advantages
This division provides advantages for the network design, architecture and
implementation. These include:
Reduces complexity - by dividing the processes into groups, or layers,
implementation of network architecture is less complex
•Provides compatibility - standardized interfaces allow for "plug-and-play"
compatibility and multi-vendor integration
•Facilitates modularization - developers "swap" out new technologies at
each layer keeping the integrity of the network architecture
•Accelerates evolution of technology - developers focus on technology at
one layer while preventing the changes from affecting another layer
•Simplifies learning - processes broken up into groups divides the
complexities into smaller, manageable chunks
• Networks in large companies
• Components can include:
• Hundreds of local area networks (LANs) linked to firmwide
corporate network
• Various powerful servers
• Web site
• Corporate intranet, extranet
• Backend systems
• Mobile wireless LANs (Wi-Fi networks)
• Videoconferencing system
• Telephone network
• Wireless cell phones
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
Corporate Network Infrastructure
Figure 7-2Today’s corporate network
infrastructure is a collection of
many different networks from the
public switched telephone
network, to the Internet, to
corporate local area networks
linking workgroups, departments,
or office floors.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
• Key digital networking technologies
• Client/server computing
• Distributed computing model
• Clients linked through network controlled by network
server computer
• Server sets rules of communication for network and
provides every client with an address so others can find it
on the network
• Has largely replaced centralized mainframe computing
• The Internet: Largest implementation of client/server
computing
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
• Packet switching
• Method of slicing digital messages into parcels (packets),
sending packets along different communication paths as
they become available, and then reassembling packets at
destination
• Previous circuit-switched networks required assembly of
complete point-to-point circuit
• Packet switching more efficient use of network’s
communications capacity
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
Packet-Switched Networks and Packet Communications
Figure 7-3Data are grouped into small packets,
which are transmitted independently over
various Communications channels and
reassembled at their final destination.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
• TCP/IP and connectivity
• Connectivity between computers enabled by protocols
• Protocols: Rules that govern transmission of information
between two points
• Transmission Control Protocol/Internet Protocol
(TCP/IP)
• Common worldwide standard that is basis for Internet
• Department of Defense reference model for TCP/IP
• Four layers
• Application layer
• Transport layer
• Internet layer
• Network interface layer
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
The Transmission Control Protocol/Internet
Protocol (TCP/IP) Reference Model
Figure 7-4This figure illustrates the four layers of the
TCP/IP reference model for communications.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Telecommunications and Networking in Today’s Business World
OSI Network Model
There are 7 layers in the OSI
model. Each layer is
responsible for a particular
aspect of data communication.
For example, one layer may be
responsible for establishing
connections between devices,
while another layer may be
responsible for error checking
during transfer.
The layers of the OSI model are divided into two groups: the upper layer
and lower layer. The upper layers focus on user applications and how files
are represented on the computers prior to transport. For the most part,
network engineers are more concerned with the lower layers. It's the lower
layers that concentrate on how the communication across a network
actually occurs.
ALL People Seem to Need Data Processing (Layer 7 to 1)
Please Do Not Take Sausage Pizzas Away (Layer 1 to 7)
The Application Layer
The Application Layer is the highest layer in the
protocol stack and the layer responsible for
introducing data into the OSI stack. In it resides the
protocols for user applications that incorporate the
components of network applications.
Classification of ApplicationsComputer applications
Network applications
Internetwork applications
Examples: Telnet, FTP, HTTP, WWW Browsers, NFS,
SMTP, POP, TFTP .
Presentation Layer
The Presentation Layer manipulates the
representation of data for transfer to applications on
different devices.
The Presentation Layer is responsible for the
following services:
• Data representation
• Data security
• Data compression
Data Representation
Session Layer
The Session Layer establishes, manages, and
terminates sessions (different from connections) between
applications as they interact on different hosts on a
network.
Its main job is to coordinate the service requests and
responses between different hosts for applications.
Examples: NFS, SQL, RPC, ASP
Three different communication modes exists for data
transfer within a session connection:
• Single-duplex
• Half-duplex
• Full-duplex.
2.80
Figure 2.1 Tasks involved in sending a letter
What do the 7 layers really do?
• Signals: digital vs. analog
• Modem: Translates digital signals into analog form
• Types of networks
• Local-area networks (LANs)
• Client/server or peer-to-peer
• Ethernet – physical network standard
• Topologies: star, bus, ring
• Campus-area networks (CANs)
• Wide-area networks (WANs)
• Metropolitan-area networks (MANs)
Communications Networks
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Functions of the Modem
Figure 7-5
A modem is a device that translates digital signals from a computer into analog form so that they can be transmitted over
analog telephone lines. The modem also translates analog signals back into digital form for the receiving computer.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
Network Topologies
Figure 7-6The three basic network
topologies are the bus,
star, and ring.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
• Physical transmission media
• Twisted wire (modems)
• Coaxial cable
• Fiber optics and optical networks
• Wireless transmission media and devices
• Microwave
• Satellites
• Cellular telephones
• Transmission speed
• Hertz
• Bandwidth
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
BP Amoco’s Satellite Transmission System
Figure 7-7Communication satellites
help BP Amoco transfer
seismic data between oil
exploration ships and
research centers in the
United States.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
• What is the Internet?
• Connecting to the Internet
• Internet service providers (ISPs)
• Services
• DSL, cable, satellite, T lines (T1, T3)
• Internet addressing and architecture
• IP addresses
• The domain name system
• Hierarchical structure
• Top-level domains
The Global Internet
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Domain Name System
Figure 7-8The Domain Name System is a
hierarchical system with a root
domain, top-level domains,
second-level domains, and host
computers at the third level.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Internet Architecture
• Trunk lines (backbone networks)
• Regional networks
• ISPs
• Internet Governance
• No formal management
• Policies established by professional, government organizations
• IAB, ICANN, W3C
• The Future Internet
• IPv6
• Internet2, NGI
The Global Internet
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
Internet Network Architecture
Figure 7-9The Internet backbone connects
to regional networks, which in
turn provide access to Internet
service providers, large firms,
and government institutions.
Network access points (NAPs)
and metropolitan area
exchanges (MAEs) are hubs
where the backbone intersects
regional and local networks and
where backbone owners connect
with one another.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Read the Interactive Session: Organization and then
discuss the following questions:
• What is network neutrality? Why has the Internet operated
under net neutrality up to this point in time?
• Who’s in favor of network neutrality? Who’s opposed?
Why?
• What would be the impact on individual users, businesses,
and government if Internet providers switched to a tiered
service model?
• Are you in favor of legislation enforcing network
neutrality? Why or why not?
Should Network Neutrality Continue?
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
• Internet services
• Chatting and instant messaging
• Newsgroups
• Telnet
• File Transfer Protocol (FTP)
• World Wide Web
• Voice over IP (VoIP)
• Unified communications
• Virtual private networks (VPNs)
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
Client/Server Computing on the Internet
Figure 7-10Client computers running Web
browser and other software can
access an array of services on servers
over the Internet. These services may
all run on a single server or on
multiple specialized servers.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Read the Interactive Session: Management and
then discuss the following questions:
• Should managers monitor employee e-mail and Internet
usage? Why or why not?
• Describe an effective e-mail and Web use policy for a
company.
Monitoring Employees on Networks: Unethical or Good Business?
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
How Voice over IP Works
Figure 7-11
An VoIP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before
being reassembled at the final destination. A processor nearest the call’s destination, called a gateway, arranges the packets
in the proper order and directs them to the telephone number of the receiver or the IP address of the receiving computer.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
A Virtual Private Network Using the Internet
Figure 7-12
This VPN is a private network of computers linked using a secure “tunnel” connection over the Internet. It protects data transmitted
over the public Internet by encoding the data and “wrapping” them within the Internet Protocol (IP). By adding a wrapper around a
network message to hide its content, organizations can create a private connection that travels through the public Internet.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• The World Wide Web
• HTML (Hypertext Markup Language):
• Formats documents for display on Web
• Hypertext Transfer Protocol (HTTP):
• Communications standard used for transferring Web
pages
• Uniform resource locators (URLs):
• Addresses of Web pages
• E.g.,
http://www.megacorp.com/content/features/082602.html
• Web servers
• Software for locating and managing Web pages
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Search engines
• Started in early 1990s as relatively simple software programs
using keyword indexes
• Today, major source of Internet advertising revenue via
search engine marketing, using complex algorithms and
page ranking techniques to locate results
• Sponsored links vs. organic search results
• Shopping bots
• Use intelligent agent software for searching Internet for
shopping information
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
How Google Works
Figure 7-13The Google search engine is
continuously crawling the
Web, indexing the content of
each page, calculating its
popularity, and storing the
pages so that it can respond
quickly to user requests to
see a page. The entire
process takes about one-half
second.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
Major Web Search Engines
Figure 7-14Google is the most popular search
engine on the Web, handling 56 percent
of all Web searches.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Web 2.0
• Second-generation interactive Internet-based services enabling
people to collaborate, share information, and create new
services online
• Cloud computing
• Software mashups and widgets
• Blogs: Chronological, informal Web sites created by
individuals using easy-to-use weblog publishing tools
• RSS (Really Simple Syndication): Syndicates Web content
so aggregator software can pull content for use in another
setting or viewing later
• Wikis: Collaborative Web sites where visitors can add, delete,
or modify content on the site
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Web 3.0
• Current efforts to make using Web more productive
• Inefficiency of current search engines: Of 330 million
search engine queries daily, how many are fruitful?
• Semantic Web
• Collaborative effort to add layer of meaning on top of
Web, to reduce the amount of human involvement in
searching for and processing Web information
• Other, more modest views of future Web
• Increase in cloud computing, SaaS
• Ubiquitous connectivity between mobile and other
access devices
• Make Web a more seamless experience
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Intranets
• Use existing network infrastructure with Internet connectivity
standards software developed for the Web
• Create networked applications that can run on many types of
computers
• Protected by firewalls
• Extranets
• Allow authorized vendors and customers access to an internal
intranet
• Used for collaboration
• Also subject to firewall protection
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Global Internet
• Wireless devices
• PDAs, BlackBerry, smart phones
• Cellular systems
• Competing standards for cellular service
• United States: CDMA
• Most of rest of world: GSM
• Third-generation (3G) networks
• Higher transmission speeds suitable for broadband Internet
access
The Wireless Revolution
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
• Wireless computer networks and Internet access
• Bluetooth (802.15)
• Links up to 8 devices in 10-m area using low-power, radio-
based communication
• Useful for personal networking (PANs)
• Wi-Fi (802.11)
• Set of standards: 802.11a, 802.11b, 802.11g, 802.11n
• Used for wireless LAN and wireless Internet access
• Use access points: Device with radio receiver/transmitter
for connecting wireless devices to a wired LAN
The Wireless Revolution
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
A Bluetooth Network (PAN)
Figure 7-15Bluetooth enables a variety
of devices, including cell
phones, PDAs, wireless
keyboards and mice, PCs,
and printers, to interact
wirelessly with each other
within a small 30-foot (10-
meter) area. In addition to
the links shown, Bluetooth
can be used to network
similar devices to send data
from one PC to another, for
example.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
An 802.11 Wireless LAN
Figure 7-16Mobile laptop computers equipped with
wireless network interface cards link to
the wired LAN by communicating with
the access point. The access point uses
radio waves to transmit network signals
from the wired network to the client
adapters, which convert them into data
that the mobile device can understand.
The client adapter then transmits the
data from the mobile device back to the
access point, which forwards the data
to the wired network.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
• Wireless computer networks and Internet access
• Wi-Fi (cont.)
• Hotspots: One or more access points in public place to
provide maximum wireless coverage for a specific area
• Weak security features
• WiMax (802.16)
• Wireless access range of 31 miles
• Require WiMax antennas
• Sprint Nextel building WiMax network
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
• Radio frequency identification (RFID)
• Use tiny tags with embedded microchips containing data
about an item and location, and antenna
• Tags transmit radio signals over short distances to special
RFID readers, which send data over network to computer for
processing
• Active RFID: Tags have batteries, data can be rewritten,
range is hundreds of feet, more expensive
• Passive RFID: Range is shorter, also smaller, less
expensive, powered by radio frequency energy
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
• Radio frequency identification (RFID)
• Common uses:
• Automated toll-collection
• Tracking goods in a supply chain
• Requires companies to have special hardware and software
• Reduction in cost of tags making RFID viable for many firms
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
How RFID Works
Figure 7-17
RFID uses low-powered radio transmitters to
read data stored in a tag at distances ranging
from 1 inch to 100 feet. The reader captures the
data from the tag and sends them over a
network to a host computer for processing.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
• Wireless sensor networks
• Networks of hundreds or thousands of interconnected wireless
devices embedded into physical environment to provide
measurements of many points over large spaces
• Used to monitor building security, detect hazardous substances
in air, monitor environmental changes, traffic, or military activity
• Devices have built-in processing, storage, and radio frequency
sensors and antennas
• Require low-power, long-lasting batteries and ability to endure in
the field without maintenance
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution
A Wireless Sensor Network
Figure 7-18The small circles represent
lower-level nodes and the larger
circles represent high-end
nodes. Lower-level nodes
forward data to each other or to
higher-level nodes, which
transmit data more rapidly and
speed up network performance.
Management Information SystemsChapter 7 Telecommunications, the Internet, and Wireless Technology
The Wireless Revolution